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WATERSHED BASED PLAN FOR THE LAKE THUNDERBIRD WATERSHED Photo courtesy of OTRD Prepared By: Oklahoma Conservation Commission Water Quality Division 2800 N. Lincoln Blvd., Suite 160 Oklahoma City, OK 73105 (405) 5224500 Lake Thunderbird WBP June 2010 2 Table of Contents LIST OF TABLES 3 LIST OF FIGURES 3 PREFACE 4 INTRODUCTION 6 CAUSES and SOURCES 7 LOAD REDUCTIONS 17 NPS MANAGEMENT MEASURES 18 PUBLIC OUTREACH 24 CRITERIA 26 IMPLEMENTATION SCHEDULE and INTERIM MILESTONES 28 MONITORING PLAN 31 TECHNICAL and FINANCIAL ASSISTANCE NEEDED 37 REFERENCES 38 Lake Thunderbird WBP June 2010 3 LIST OF TABLES Table 1. Population growth in Cleveland and Oklahoma Counties 10 Table 2. Landuse in the Lake Thunderbird watershed 10 Table 3. Waterbodies in the Lake Thunderbird watershed 12 Table 4. Livestock in Oklahoma and Cleveland Counties 16 Table 5. Possible management practices for urban areas 20 Table 6. Impact of targeted BMPs on phosphorus and chlorophylla 23 Table 7. Schedule and load reduction goals 29 Table 8. Interim milestones for Trailwoods project 30 Table 9. Autosampler locations in the Lake Thunderbird Watershed 34 Table 10. OCC analytical parameters and sampling frequency 34 Table 11. Funding for specific projects/efforts 37 LIST OF FIGURES Figure 1. Lake Thunderbird watershed 7 Figure 2. Municipalities in the Lake Thunderbird watershed 9 Figure 3. Landuse in the Lake Thunderbird watershed 11 Figure 4. Location of highest total phosphorus yields 13 Figure 5. Location of highest sediment yields 14 Figure 6. Percent change in percent impervious area from baseline to buildout 14 Figure 7. Location of permitted total retention lagoons and oil/gas wells …..15 Figure 8. Street design of Trailwoods project and location in watershed 18 Figure 9. Potential wetland development sites 22 Figure 10. Timeline for Trailwoods LID Demonstration Project 31 Figure 11. Location of autosamplers in the Lake Thunderbird watershed 35 Lake Thunderbird WBP June 2010 4 PREFACE Lake Thunderbird, located in central Oklahoma, is a popular recreational lake as well as a water supply reservoir for the cities of Norman, Del City, and Midwest City, which have a combined population of approximately 178,000. Significant taste and odor problems, linked to eutrophication in the lake, have led to complaints from water users. According to the Oklahoma Department of Environmental Quality (ODEQ) 2008 Integrated Report, Lake Thunderbird is not supporting its Fish and Wildlife Propagation (Warm Water Aquatic Community) designated use due to turbidity and low dissolved oxygen (DO), its Aesthetics use due to color, or its Public Water Supply use due to chlorophylla. The chlorophylla concentration is approximately three times the water quality standard required for a sensitive water supply. Other impaired waterbodies in the watershed include 1) Hog Creek, impaired by turbidity and low DO, 2) West Branch of Hog Creek, impaired by low DO, 3) Moore Creek, impaired by total dissolved solids (TDS), 4) Elm Creek, impaired by E. coli, turbidity, and TDS, and 5) East Elm Creek, impaired by low DO. Excessive nutrient loading in the watershed, primarily from urban development, has caused the observed eutrophication in the lake. The Central Oklahoma Master Conservancy District (COMCD), in cooperation with the Oklahoma Water Resources Board (OWRB), has been monitoring chlorophylla and nutrient concentrations in the lake since 2000 and has implemented several management alternatives that have improved the lake’s algae and chlorophyll problems. However, further action is necessary to achieve full attainment of designated beneficial uses in the watershed. The Lake Thunderbird watershed covers 256 square miles (163,840 acres) in Oklahoma and Cleveland Counties, with the major tributary being the Little River. The watershed is approximately 60 percent agricultural (mostly pasture) and 40 percent residential development. Significant, consistent population growth has occurred over the past 30 years and is expected to continue in the area, with a great deal of pasture being converted to urban areas. Without a proactive plan to address the potential impact of this urban expansion, water quality in the area is expected to continue to decline rapidly. Based on SWAT model results by Vieux (2007), it is estimated that approximately 18,000 kg of phosphorus enters Lake Thunderbird each year. Nonpoint source (NPS) pollution associated primarily with increased impervious surfaces due to urban growth appears to be the primary source of the water quality problems in the Lake Thunderbird watershed. Modeling of the watershed has resulted in a recommendation of a 58% percent reduction (about 10,000 kg/yr) of total phosphorus to Lake Thunderbird in order to produce acceptable water quality conditions (chlorophylla concentration of 10 mg/L or less) (OWRB 2006). A TMDL is currently being developed by the ODEQ for the lake to address sediment and dissolved oxygen impairments. Load reduction estimates resulting from this effort will be added to the watershed plan when the TMDL is released. Lake Thunderbird WBP June 2010 5 It is projected that various low impact development (LID) practices could dramatically improve the nutrient and sediment loading in the watershed in a relatively short time frame. The Lake Thunderbird Watershed Based Plan (WBP) refers to the initial implementation of actions focused on LID, which are necessary to restore beneficial use support to Lake Thunderbird and its tributaries. Lake Thunderbird WBP June 2010 6 INTRODUCTION The Nonpoint Source Program and Grants Guidelines for States and Territories for FY 2004 and Beyond requires a Watershed Based Plan (WBP) to be completed prior to any implementation efforts using incremental funds. The guidance describes nine key components to be addressed in a watershedbased plan, much of which builds from the strategies outlined in the Watershed Restoration Action Strategy (WRAS). These components include: 1) identification of causes and sources that will need to be controlled to achieve load reductions, 2) estimate of load reductions expected from the management measures described, 3) a description of the management measures that will need to be implemented to achieve load reductions, 4) an estimate of the amounts of technical and financial assistance needed, associated costs, and/or the sources or authorities who will bear responsibility, 5) an information/education component that will be used to enhance public understanding of the project and encourage early participation in the overall program, 6) a schedule for implementing the NPS management measures identified in this plan that is reasonably expeditious, 7) a description of interim, measurable milestones for determining whether control actions are being implemented, 8) a set of criteria that can be used to determine whether loading reductions are being achieved over time and substantial progress is being made or whether the Watershed Plan or Total Maximum Daily Load (TMDL) needs to be revised, and 9) a monitoring component to evaluate the effectiveness of the implementation efforts over time. In order for the WBP to become an integral part of the entire watershed restoration program, it must be amenable to revision and update. The Lake Thunderbird WBP has been developed as a dynamic document that will be revised to incorporate the latest information, address new strategies, and define new partnerships between watershed stakeholders. It is anticipated that at least biannual revisions may be necessary and that the responsibility for such revisions will rest primarily with the Oklahoma Conservation Commission (OCC), with support from the Oklahoma Department of Environmental Quality (ODEQ), Office of the Secretary of the Environment (OSE) and the NPS Working Group. It is understood that the water quality goals and the technical approach set forth in this WBP may not be comprehensive, so they may be expanded in the future, especially as ODEQ’s work with the TMDL/WMP is completed. Federal and state funding allocations for future water quality projects designed to address the Lake Thunderbird Watershed problems should not be based solely upon their inclusion in this WBP; rather, the WBP should be considered a focal point for initial planning and strategy development. Lake Thunderbird WBP June 2010 7 CAUSES and SOURCES (element a) Watershed Characterization The Lake Thunderbird watershed (HUC 111090203010) covers a 163,840 acre area in Cleveland and Oklahoma Counties. The principal tributary to Lake Thunderbird is the Little River, which was impounded by the Bureau of Reclamation to form the lake in 1965. Other tributaries are shown in Figure 1. Designated uses of the dam and the impounded water are flood control, municipal water supply, recreation, and fish and wildlife propagation. Designated uses of streams in the watershed include aesthetics, agriculture, warm water aquatic community (WWAC), industrial and municipal process and cooling water (I & M), primary body contact recreation (PBCR), public and private water supply (PPWS), fish consumption, and sensitive water supply (SWS). Cleveland Co. Oklahoma Co. Hog Cr. Kitchen Cr. West Elm Cr Elm Cr. Little Riv er Nort h Fork Little Moore Cr. Rock Cr. Dav e Blue Cr. Clear Cr. Jim Blue Cr. West Hog C L. Stanley Draper Lake Thunderbird 0 5 10 15 Miles OSAG E TEXAS KAY ELLIS BEAV ER CADD O CMI AR RO N LE FLO RE WO ODS MCC URTAIN GRAD Y KOI WA ATOKA GRAN T CREEK BRYAN MAJ OR DEW EY BLANI E HARPE R CUST E R PTI T S BURG CRAIG IL NC OLN NOBLE WA S HTI A LO GAN GARV IN GARFI ELD TIL LM AN PAY NE PUSHM AT AH A ALFAL FA CARTE R LO VE MAYES WO ODW AR D COAL HUGH ES AD AI R COM ANCH E BECKH AM TUL SA GRE E R CA NAD IA N JA CKSO N LA TIM ER ROG ER MIL LS STEPHE NS ROG ERS CHOC TA W COTT O N KNI G FIS HER MUSK OGE E DELAW ARE HASKE L CHER OKEE PAW NEE MCI NTOS H JE FF ERSO N NO W ATA MCC LANI PONTO T OC OKLAH OMA SEQU OYAH SEMI NOLE OKM ULGEE HARM ON JO HNS TON OKFUS KEE OTT AW A WA G ON ER MUR RAY POTT AW ATO MIE CLEVEL AN D MARS HAL L W AS HNI GTO N Figure 1. Lake Thunderbird watershed. As a municipal water supply, Lake Thunderbird furnishes raw water for Del City, Midwest City, and the City of Norman under the authority of the Central Oklahoma Master Conservancy District (COMCD). Lake Thunderbird WBP June 2010 8 The morphologic features of Lake Thunderbird are (OWRB 2002): Area 5,439 acres Volume 105,838 acrefeet Shoreline 96 km Mean Depth 4.7 m (15.4 ft) Maximum Depth 17.7 m (58 ft) Water Supply Yield 21,700 acrefeet/ yr (19.4 mgd) Mean Monthly Discharge/Outflow 74.5 cfs All of these values represent a reduction since impoundment in 1966 due to sedimentation. The overall sedimentation rate was estimated as 393 acrefeet per year with a total loss of 13,762 acrefeet, about 12% higher than originally planned. Most of the sediment accumulation has occurred in the upper portion of the conservation pool. The decrease of surface area is mostly due to inflow of largegrained solids from tributaries (OWRB 2002). Although the Lake Thunderbird watershed contains Lake Stanley Draper and its watershed (Figure 1), this area was removed from modeling analyses since discharges are not allowed over the spillway. This means that seepage under the dam is the only way that water from the Lake Stanley Draper watershed could enter Lake Thunderbird. Since any seepage is minimal, Lake Stanley Draper is not considered a source of nutrient loading to Lake Thunderbird and will not be shown in any of the other figures. The Lake Thunderbird watershed is located in the Central Great Plains and Cross Timbers ecoregions (Woods et al. 2005). The Central Great Plains ecoregion is a transition area between mixed grass prairie in the west, now primarily a winter wheat growing region, and forested low mountains in eastern Oklahoma. “Gently sloping narrow ridgetops are separated by steep slopes bordering drainage ways. Some stream valleys with nearly level flood plains and large stream terraces exist. Dissected plains with broad rolling ridgetops and moderately steep valley sides occur. Valleys are usually narrow with broad flood plains and terraces and hilly dissected plains. There are rivers with wide flood plains and terraces and small streams with narrow bottomlands. Rolling plains have a deep mantle of windblown sand and sandy outwash. Elevation ranges from 1,310 to 2,950 ft (400 to 900 m). Soils include Mollisols and Alfisols” (McNab and Avers 1994). Predominant vegetation includes bluestemgrama prairie, sandsagebluestem prairie, northern flood plain forests, and buffalo grass. Precipitation ranges from 20 to 35 inches (500 to 900 mm), and temperature averages 50 to 61 degrees F (10 to 16 degrees C). “Groundwater is abundant in areas associated with sand and gravel deposits; however, it is scarce and may be mineralized in areas where shale, sandstone, clay, and limestone are near the surface” (McNab and Avers 1994). The Cross Timbers ecoregion “is a region of rolling hills and narrow valleys. The terrain generally is more complex than other parts of central Oklahoma. Elevation ranges from 330 to 1,300 ft (100 to 400 m). Soils in the Cross Timbers ecoregion are mainly Ustalfs. Lake Thunderbird WBP June 2010 9 Soils are deep, well drained, and fine to moderate textured; moisture is limited for use by vegetation during part of the growing season” (McNab and Avers 1994). Oakhickory and oakhickorypine forest and extensive areas of tall grassland with a tree layer comprise the ecoregion. Forest cover consists of post, live, and blackjack oaks, and pignut and mockernut hickories. Grasses consist of big and little bluestems, Indian grass, and sunflower. Precipitation averages 35 to 40 inches (900 to 1,050 mm), and temperature averages 55 to 63 degrees F (13 to 17 degrees C) (McNab and Avers 1994). Human Population: The population in Cleveland County, where the majority of the Lake Thunderbird watershed is located, is 224,898 (2005 Census). The city of Norman, which comprises about half of the watershed area (Figure 2), is the largest city in the county, with approximately 102,000 residents (86% urban). The city of Moore makes up about 8 percent of the watershed area and has a population of nearly 45,000. There has been a steady increase in Cleveland County’s population since 1960, especially in urban areas (Table 1). Figure 2. Municipalities in the Lake Thunderbird watershed (Vieux 2007). About 38% of the Lake Thunderbird watershed area is located within the Oklahoma City municipal boundary. In Oklahoma County, the population is 691,266, with 523,303 Lake Thunderbird WBP June 2010 10 located within Oklahoma City (2005 Census). The population in Oklahoma County has also shown consistent growth (Table 1). Table 1. Population growth in Cleveland and Oklahoma Counties. County Parameter 1960 1970 1980 1990 2000 Total population 47,600 81,839 133,173 Cleveland 174,253 208,016 Percent change 71.93% 62.73% 30.85% 19.38% Oklahoma Total population 439,506 527,717 568,933 599,611 660,448 Percent change 20.07% 7.81% 5.39% 10.15% Landuse: As shown in Table 2 and Figure 3, approximately 60 percent of the watershed is agricultural, with pasture comprising the majority of the agriculture land. Most of the remainder of the watershed is developed, primarily residential. Table 2. Landuse in the Lake Thunderbird watershed. Landuse Percent of Watershed Area Residential Medium Density 26.00 Residential High Density 0.07 Agricultural – Pasture 53.84 AgriculturalGeneric (parks and open spaces) 7.62 Commercial 0.68 Industrial 1.39 Transportation 4.18 Institutional 1.17 Open Water 5.05 Lake Thunderbird WBP June 2010 11 Figure 3. Landuse in the Lake Thunderbird watershed (Vieux 2007). Causes The designated beneficial uses for Lake Thunderbird and its tributaries include Aesthetics, Agriculture, Warm Water Aquatic Community, Primary Body Contact Recreation, Public and Private Water Supply, Fish Consumption, Industrial and Municipal Process and Cooling Water, and, for the lake itself, Sensitive Water Supply. The impaired designated uses and the causes of nonattainment of designated uses are shown in Table 3. Lake Thunderbird is listed in Oklahoma’s Integrated Report as a Category 5 waterbody with impairment of the fish and wildlife propagation beneficial use due to excess turbidity and low dissolved oxygen as well as nonattainment of the public and private water supply beneficial use due to high chlorophylla. The three streams in the Thunderbird watershed with enough monitoring data to assess designated beneficial uses (Hog Creek, Elm Creek, and Moore Creek) are listed as impaired for one or more assigned uses. It is likely that other streams in the watershed are impaired as well, but not enough data has existed to make an assessment; for the next reporting cycle, the OCC will have enough data to assess five additional streams in the watershed (Table 9). The WBP will be updated with the results of that assessment when it is performed. Lake Thunderbird WBP June 2010 12 Table 3. Waterbodies in the Lake Thunderbird watershed (ODEQ 2008). Waterbody ID Site Name Impaired Designated Uses Causes of Impairment OK520810000020_00 Thunderbird Lake Warm Water Aquatic Community Public and Private Water Supply turbidity, low DO chlorophylla OK520810000030_00 Hog Creek Warm Water Aquatic Community turbidity, low DO OK520810000040_00 West Hog Creek Warm Water Aquatic Community low DO OK520810000050_00 Clear Creek * OK520810000060_00 Dave Blue Creek * OK520810000070_00 Jim Blue Creek * OK520810000080_00 Little River * OK520810000090_00 Rock Creek * OK520810000100_00 Elm Creek Primary Body Contact Recreation Warm Water Aquatic Community Agriculture E. coli turbidity total dissolved solids OK520810000110_00 East Elm Creek Warm Water Aquatic Community low DO OK520810000120_00 East Elm Creek * OK520810000140_00 West Elm Creek * OK520810000150_00 Kitchen Creek * OK520810000160_00 Kitchen Lake * OK520810000170_00 North Fork Little River * OK520810000175_00 Moore Creek Agriculture total dissolved solids OK520810000180_00 Mussel Shoals Lake Creek * OK520810000190_00 Mussel Shoals Lake * *insufficient information or not assessed Oklahoma Water Resources Board (OWRB) studies on Lake Thunderbird have shown that chlorophylla levels are high, thus indicative of the excessive algae growth causing taste and odor problems for the City of Norman water supply. In 2000, over onehalf of the water samples collected by the OWRB had chlorophylla concentrations greater than 20 μg/L (OWRB 2003). The chlorophylla concentration was reduced in 2002, after aeration of the lake ceased, but the lake still had chlorophylla levels high enough to cause eutrophication. BUMP data collected from 20012003 showed an average chlorophylla concentration of 30.8 μg/L. Algae species which are known to cause taste and odor problems in drinking water are present in the lake, and two potentially toxic algae have been noted in Lake Thunderbird as well. The concentrations of these algae in the lake corresponded to a low to moderate risk from direct exposure or accidental ingestion in 2001 and low risk in 2002. This risk was for recreational exposure, with no evidence of risk noted for water supply (OWRB 2003). Reducing the amount of nutrients entering the lake is necessary to decrease the algal concentrations. Sources There are no point sources in the Lake Thunderbird watershed; hence, nonpoint sources are the primary contributors to the pollution problems in this watershed. Nonpoint sources are those which supply pollutants to surface water diffusely, rather than as a definite, measurable quantity at a single location. These sources typically Lake Thunderbird WBP June 2010 13 involve land activities that contribute bacteria, sediment, and/or nutrients to surface water as a result of runoff during and following rainfall. Urban Land Use: The primary sources of pollution in the Lake Thunderbird watershed are associated with urban expansion and the accompanying development. As urbanization progresses, runoff from impermeable surfaces and from construction areas (both housing developments and road construction) are increasingly contributing to nutrient and sediment loading from the watershed. Water quality is being severely impacted by increasing runoff volume and velocities, which cause increased erosion of streambanks, destruction of instream and riparian habitat, and siltation, as well as increased nutrient loads. Improper use of fertilizers or overfertilization may increase with the expected population growth in the watershed and contribute to the pollution of lakes and groundwater through loading of soluble and particulate phosphorus as well as nitrogen. Bacteria and nutrients from domestic pets will be expected to increase as well with the expected increase in population growth. According to Vieux (2007), urban runoff should be considered as an increasing, highly significant nonpoint source of pollution in this watershed. Vieux and associates performed a study in the Rock Creek watershed, a tributary to Lake Thunderbird (COMCD 2006). Based on monitoring and analysis of water quality data in Rock Creek, it was determined that a higher level of nutrients was found in runoff from developed versus undeveloped land. Vieux’s modeling efforts of the entire Lake Thunderbird watershed in 2007 supported this finding, indicating that the areas of the watershed contributing the greatest phosphorus (the limiting nutrient of the lake) load per unit area were the highly urbanized areas of Moore and Oklahoma City, as well as a small portion of Norman immediately north of the lake (Figure 4). Figure 4. Location of total phosphorus sources and yields (kg/hectare) in the Lake Thunderbird Watershed as determined from SWAT modeling (Vieux 2007). Lake Thunderbird WBP June 2010 14 Similarly, the greatest sediment load is coming from Moore and the west side of Norman, followed by the Oklahoma City area (Figure 5). Figure 5. Location of sediment sources and yields (kg/hectare) in the Lake Thunderbird Watershed as determined from SWAT modeling (Vieux 2007). The Rock Creek study (COMCD 2006) indicated that the greater loading of nutrients from developed areas was due to increased impervious surface and increased fertilization in urban areas. Vieux’s 2007 SWAT modeling also suggested that imperviousness was a key factor affecting loading rates in the watershed. It is expected that continued conversion of agricultural land to residential land will more than double the phosphorus load to the lake, increasing from an average of 25 kg/ha currently to 54 kg/ha in the future (assuming a buildout scenario with conversion of 50% of agricultural areas to residential). Figure 6 shows the areas which are expected to experience the greatest increases in impervious surface under a buildout scenario. Figure 6. Percent change in impervious area from baseline (current levels) to buildout (projected conversion of 50% of agricultural lands to residential) (Vieux 2007). Lake Thunderbird WBP June 2010 15 Based on Vieux’s SWAT model calculations, the total average phosphorus load to Lake Thunderbird is between 18,000 kg/yr and 23,000 kg/yr. According to Figure 4, the highest phosphorus loading is occurring in the watersheds of the North Fork of the Little River and Moore Creek on the west side of the lake, as well as Hog Creek on the east side of the Thunderbird watershed. The Moore and Norman areas on the west side of the watershed are contributing the highest sediment load, especially in the headwaters of Little River, the North Fork of the Little River, Moore Creek, and Rock Creek (Figure 5). While there are no point source discharges in the Lake Thunderbird watershed, “bypassdischarges” from municipalities may occur due to overflows or sewer main breaks. Several of these events have occurred within the watershed. For example, from June 2004 to August 2006, the sum of these discharges was: City of Moore 59,930 gallons discharged to Little River City of Norman 44,483 gallons discharged to Little River According to Vieux (2007), raw sewage contains approximately 415 mg/L of watersoluble phosphorus, equating to 25 kg of phosphorus over that two year period. This is not considered a significant amount relative to the overall phosphorus entering the watershed. The City of Norman completed a wastewater treatment plant (WWTP) upgrade in March 2010, which should reduce the number of failures in the future. The hydraulic capacity of the plant has increased from 45,000m³ a day to nearly 100,000m³ a day. Permitted Sources: Nonpoint source permitted activities within the watershed include 12 total retention lagoons (Figure 7). Total retention lagoons hold solid and liquid wastes prior to land application and may leak or overflow, thus affecting water quality. In addition, there are over 300 oil and gas permits in the watershed, located on approximately every section in the watershed. Not all of the permitted wells are active; however, oil and gas operations could be a potential source of high TDS values as well as turbidity sources. Figure 7. Location of permitted total retention lagoons and oil/gas wells. # # # # # # # # # # # # $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ # Total Retention Lagoons $ Oil and Gas Wells Lake Thunderbird WBP June 2010 16 Rural Land Use: Pasture/forage land is the prevalent rural land use in the watershed. Cattle are the dominant animal industry in Oklahoma and Cleveland Counties (Table 4). Livestock grazing in pastures deposit manure, making it possible for the nutrients and bacteria to enter surface water with runoff. In addition, livestock often have direct access to waterbodies providing a concentrated source of loading directly into streams. Animals loafing in the stream also contribute to turbidity problems by stirring up sediment, and their travels to and from the stream erode banks and carve trails which serve as direct conduits for NPS contribution during runoff events. Table 4. Livestock in Oklahoma and Cleveland Counties (USDA Census 2002). Livestock County Number of animals Cattle and calves OClkelavheolamnda 2216,,592825 Horses and ponies OClkelavheolamnda 34,,034800 Layers 20 weeks old and older OClkelavheolamnda 12,,472748 Hogs and pigs Cleveland 2,267 Goats Oklahoma 1,696 Sheep and lambs Oklahoma 1,402 Despite the large number of animals, particularly cattle, in these counties, agriculture in the Lake Thunderbird watershed is largely in the form of small, urban ranchettes, where landowners have 520 acres to keep a few horses or a small herd of cattle. Preliminary results from Vieux (2007) suggest that, although these areas contribute to overall loading, urban sources dominate. Septic Systems: Failing septic systems can contribute to pathogen and nutrient problems in both groundwater and surface waters if leakage or illicit discharge occurs. Any loading of bacteria into the groundwater can enter surface water through seeps or springs. Failing septic systems were not likely to be a significant factor in this watershed due to the low density of septic systems. Wildlife: Wild animals which produce fecal bacteria and have direct access to streams include deer, raccoons, other small mammals, and avian species. Wildlife is considered to be a minor contributor of pollution in this watershed. Shoreline / Streambank Erosion: Lake Thunderbird is experiencing considerable shoreline erosion with cut banks exceeding 20 feet in height in some locations (OWRB 2001a). Wave action and runoff on these bare areas are contributing significantly to the turbidity impairment of the lake. A shoreline erosion control demonstration project was intiated by the OWRB in order to reduce the amount of suspended sediment in Lake Thunderbird. During 2003, the OWRB staff installed hundreds of feet of breakwater structures and more than 1,000 aquatic plants along a 450foot area of the southern shoreline. It is expected that the Lake Thunderbird WBP June 2010 17 breakwaters will help settle out sediments and promote the establishment of beneficial shoreline vegetation. In addition, the OCC in partnership with the City of Norman is currently implementing a project to restore a riparian buffer along the North Fork of the Little River. Unstable streambanks could also contribute significantly to phosphorus loading in the watershed, especially since streambank soils are often high in phosphorus. Lake Thunderbird shoreline erosion control LOAD REDUCTIONS (element b) Because of Lake Thunderbird’s impaired status, Total Maximum Daily Load (TMDL) allocations are required for dissolved oxygen and turbidity. The Oklahoma Department of Environmental Quality Water Quality Division (ODEQ) is currently working on a detailed Hydrological Simulation Program Fortran (HSPF) model for the watershed and has contracted to have an EFDC inlake model developed. These two models will be used to develop a comprehensive TMDL for the lake. Until the release of the TMDL, the focus of this WBP will be on reducing phosphorus, since data collected and analyzed by the OWRB indicates that phosphorus is the limiting nutrient in Lake Thunderbird. The subwatersheds in red in Figure 4 will be the primary targets for implementation projects since these are the areas supplying the highest phosphorus loads and, thus, should provide the largest load reductions. Using a SWAT model, Vieux (2007) calculated that the total average phosphorus load to Lake Thunderbird is between 18,000 kg/yr and 23,000 kg/yr. This correlates with a measured average total phosphorus concentration of 0.057 mg/L and chlorophylla concentration of 30.8 mg/L. The primary source of phosphorus loading in the watershed is urbanization, as shown in Figure 4 and discussed in the previous section. Runoff from impervious surfaces in urban areas has the highest potential for contributing pollutants to waterbodies in these areas. The goal of this WBP is to reduce the nutrient loading to Lake Thunderbird so that the chlorophylla concentration is 10 mg/L, a 32% reduction. This corresponds to a reduction of approximately 10,000 kg/yr total phosphorus (58% overall) (Vieux 2007). This reduction in phosphorus should increase the dissolved oxygen concentration of the lake, decrease the turbidity, and allow restoration of the WWAC designated use. In addition, it is expected that measures implemented through this watershed project to address phosphorus will concomitantly reduce the bacteria loading in Elm Creek and sediment loading in Moore Creek. However, urbanization is expected to continue in this watershed, so it is vital to examine the required load reductions in light of future development plans. Lake Thunderbird WBP June 2010 18 Vieux (2007) modeled the loads expected if 50% of the agricultural or vacant land was converted to residential property over the next 30 years. The findings indicate that the total phosphorus load would be 24,907 kg/yr under these conditions, so a reduction of approximately 68% (approximately 16,937 kg/yr) would be necessary to achieve the chlorophylla goal of 10 mg/L in the future. This reduction will be the longterm goal for the project. The following section of the WBP addresses the management measures necessary to achieve these present (shortterm) and future (buildout) load reductions. After the release of the TMDL for Lake Thunderbird, most likely in 2011, management measures and load reduction goals described in this WBP will be updated based on the recommendations of the TMDL. NPS MANAGEMENT MEASURES (element c) SWAT modeling has allowed for estimation of nutrient load reductions expected from certain management measures (Vieux 2007). The results of this modeling effort show that Best Management Practices (BMPs) should focus on reduction of nutrient loading from urban nonpoint sources. Implementation of such practices is expected to achieve an initial NPS phosphorus load reduction goal of 58% and is likely to significantly improve the turbidity, bacteria, and dissolved oxygen issues in the lake and streams. It is recognized that not any one activity could realistically result in the required reduction; instead, numerous strategies will have to work together to achieve the desired result. With this in mind, this document is not intended as a final, static plan, but rather one that will be updated as needed to reflect new information, resources, and necessary adjustments in implementation strategy. The initial watershed implementation program will focus on facilitating Low Impact Development (LID) techniques in the watershed. A local developer has partnered with OCC to implement and assess LID practices in a new residential development, titled the Trailwoods Project. For this project, 18 houses will be built along a street with rain gardens to filter stormwater runoff from the street (dark green in Figure 8) while 18 houses will be built on an adjoining street with conventional curbs and street gutters to convey stormwater. The OCC will install autosamplers for continual monitoring and assessment of Figure 8. Street design (LID side) of Trailwoods project (left), and location of the neighborhood in the watershed (right). Lake Thunderbird WBP June 2010 19 the runoff of both streets. This project will be primarily a demonstration and research project. Results will be presented to City of Norman officials in the hope that more projects like this will be approved. Before more broadreaching projects can be tackled, a significant portion of the implementation strategy will be to work with cities in the watershed to revise their building codes as needed to allow for construction of LID systems. Special approval was granted for the Trailwoods project from the City of Norman. OCC will compile and review examples of existing codes from nearby communities that support LID and provide for water quality friendly construction techniques. These examples will be presented to the watershed cities for possible incorporation into their municipal codes. In addition, OCC will send city planners from the area to LID workshops and related training such as the one offered by the Water Conservation Resource Center in Fayetteville, Arkansas. OCC will also organize and facilitate tours of LID implementation in nearby areas to demonstrate possibilities for the city planners and relevant personnel. Since most of the project area is incorporated and zoned, the OCC will also work with municipalities to achieve pollution control through zoning and ordinance regulations. Vieux’s modeling results clearly indicate the subwatersheds contributing the greatest loads currently, as well as those where the greatest future load is expected (Figures 4, 5, and 6). These urban areas of the watershed will be targeted for the initial demonstration of lowimpact development (LID) so that the most efficient load reductions can be accomplished. Examples of urban practices that will be suggested are given in Table 5. The efficiency of each of these practices in removing phosphorus is included in the table, as well as the practical application and constraints associated with each practice. Combining certain types of practices and implementing them throughout the watershed could result in reductions in total phosphorus load beyond the required reduction to meet the chlorophylla goal of 10 mg/L (Vieux 2007). Initial implementation will be focused in the subwatersheds with the highest phosphorus loading (Figure 4). As mentioned previously, these areas are the most developed and actively developing areas in the watershed, so it will be vital to work with officials from Norman, Moore, and Oklahoma City to get approval for LID implementation. An additional strategy for inlake reduction in sediment and nutrient loads would be to work with management authorities to institute new/amended boat traffic limitations. Because of its proximity to the urban community, Lake Thunderbird experiences particularly heavy powered boat traffic, which is thought to contribute significantly to shoreline erosion and thus nonpoint delivery of sediment and nutrients. Lakewide limitations on engine size and/or speed restrictions could aid in reducing this problem. Urban raingarden Lake Thunderbird WBP June 2010 20 Table 5. Possible management practices for urban areas. Highlighted rows are practices recommended for this project by Vieux (2007). Best Management Practice Phosphorus Removal Efficiency Maintenance Required Other Benefits Problems Applicable Landuse Conditions Sediment Forbay Required to achieve Phosphorus removal efficiency for structural practices. Sediment should be removed every 35 years or when 612 inches have accumulated, whichever occurs first. To reduce maintenance costs, an onsite sediment disposal area should be included in the design. Improves phosphorus and sediment removal efficiency of primary MPs. Facilitates maintenance of MPs and extends the "life expectancy" of primary management practice. Phosphorous removal efficiencies are based on the inclusion of sediment forbays in the project design. Required to improve efficiency and life span of most other management practices. Also facilitates maintenance of other management practices. Vegetated Filter Strip 10% Requires regular maintenance. This management practice usually has short life span due to lack of maintenance, improper location, and poor vegetative cover. Maintenance includes inspections, fertilizing, watering, and replanting. Also repair from gully erosion, traffic, and concentrated flow. After established (several years), maintenance requires removal of accumulated sediment, reestablishing vegetations, weeding invasive weeds, pruning woody growth. May also result in reduction of nitrogen in storm water. For Overland Sheet Flow!!! Max contributing area 5 acres. From Center for Watershed Protection (1996), runoff changes from sheet flow to concentrated flow after traveling 75 feet on impervious surfaces and 150 on pervious surfaces. Requires soils with infiltration rate of 0.52 in/hr (sand and sandy loams). Residential (1621%) impervious or as a pretreatment component to structural management practices. Grassed Swale 15% Maintain thick vegetation at 36 inches. Remove debris, and sediment, and reestablish vegetation if needed. Excellent for residential areas. Requires matenance agreements included in land titles. Maintenance responsibility of each land owner. (Monograph 14, pg 400) Cost effective compared to concrete gutters and efficient sediment removal. Landowners are likely to mow the grass in the swale too short reducing pollutant removal efficiency. Requires soils with infiltration rates of 0.27 in/hr (silty loams) or better. Residential 1621% impervious cover. If water quality swales are incorporated, will work with higher density development up to 37% impervious area. 10% with voluntary reduction May be difficult to obtain "buyin" from the community. Requ Urban ires annual soil testing. Nutrient Management Up to 22% with statutory reduction Urban nutrient management involves the reduction of fertilizer (especially phosphorus) to grass lawns and other urban areas. Implementation of urban nutrient management is based on public education and awareness, with emphasis on reducing excessive fertilizer use. May also result in reduction of nitrogen in storm water. Requires implementing an ordinance such as the Minnesota Phosphorus Lawn Fertilizer Law. Percent impervious cover 1621%. Constructed Wetlands 30% Second season reinforcement plantings are often needed. Mow biannually to reduce woody growth on outer boundary. Maintain sediment forbay. Pretreatment management practices will reduce the cost of maintenance and the effective life expectancy of the constructed wetland. Remove sediment from forbay every 35 years or when 612 inches of sediment has accumulated. High removal rate of particulate and soluble pollutants (nutrients) and sediment. Wildlife preservation. Bird watching. Permeable soils are not suited for wetlands construction. Requires large land areas (2% of the size of the contributing watershed). Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and may not be located near (within 100 feet) of septic systems. Permeable soils are not suited for constructed wetlands. May not be suited for highly visible sites or adjacent to highly manicured sites. Extended Detention Basin (2xWQ Vol) 35% Mow 2x's per year; remove debris from spill way and trash rack at control structure; and maintain sediment forbay. Excellent option for watershed approach. Function as designed for long periods without routine maintenance. Not aesthetically pleasing. Requires 20 foot vegetative buffer. Drainage areas over 5075 acres require provisions for base flow. Not suitable for highly permeable soils. Percent impervious cover 2237%. Low visibility sites. Appropriate for regional or watershed approach. Extended DetentionEnhanced 50% Mow two times per year; remove debris from spill way and trash rack at control structure; and maintain sediment forbay. The enhanced extended detention basin has a shallow marsh which provides additional pollutant removal and reduces resuspension of settled pollutants. To increase the phosphorus removal of the extended detention basin one must increase the volume of the marsh. Wildlife habitat and associated recreation. Not aesthetically pleasing. Requires a 20 foot vegetative buffer. Drainage areas over 5075 acres require provisions for base flow. Not suitable for highly permeable soils. Percent impervious cover 3866%. Lake Thunderbird WBP June 2010 21 Best Management Practice Phosphorus Removal Efficiency Maintenance Required Other Benefits Problems Applicable Landuse Conditions Retention Basin I (3XWQ Vol) 40% Mow two times per year; remove debris from spill way and trash rack at control structure; maintain sediment forbay. Aeration may be needed in Oklahoma. High nutrient, sediment and phosphorous removal efficiencies. Can help with flood control and downstream channel erosion when coordinated within a Watershed Management Plan. Increase water table. Needs to be part of "watershed management plan" as too many detention/retention basins in a basin can severely alter the natural flow conditions with combined peak flows and increased flow durations, resulting in downstream flooding and stream channel degradation. Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and not located near (within 100 feet) of septic systems. Permeable soils are not suited for retention basins. Retention Basin II (4xWQ Vol) 50% Mow two times per year; remove debris from spill way and trash rack at control structure; maintain sediment forbay. Aeration may be needed in Oklahoma. High nutrient, sediment and phosphorous removal efficiencies. Can help with flood control and downstream channel erosion when coordinated within a Watershed Management Plan. Increase water table. Needs to be part of "watershed management plan" as too many detention/retention basins in a basin can severely alter the natural flow conditions with combined peak flows and increased flow durations, resulting in downstream flooding and stream channel degradation. Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and not located near (within 100 feet) of septic systems. Permeable soils are not suited for retention basins. Retention Basin III (4xWQ Vol with aquatic bench) 65% Mow two times per year; remove debris from spill way and trash rack at control structure; maintain sediment forbay. Aeration may be needed in Oklahoma. High nutrient, sediment and phosphorous removal efficiencies. Can help with flood control and downstream channel erosion when coordinated within a Watershed Management Plan. Increase water table. Needs to be part of "watershed management plan" as too many detention/retention basins in a basin can severely alter the natural flow conditions with combined peak flows and increased flow durations, resulting in downstream flooding and stream channel degradation. Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and not located near (within 100 feet) of septic systems. Permeable soils are not suited for retention basins. Bioretention basin or Rain Gardens 50% Annual soil pH testing and application of lime to adjust pH; routine mulching and maintenance of plant material. Removal of hazardous and toxic soil/plant material required when the system "dies". Degradation of oily pollutants, clay absorbs heavy metals, nutrients and hydrocarbons. Reduce peak discharge and provides groundwater recharge. Accumulation of toxins and heavy metals within 5 years. Requires permeable soil! Life expectancy as little as 5 years. May require removal of infiltration media and plant material. Percent impervious cover 3866%. Highly visible development. Residential to fairly high density commercial projects. Bioretention filter 50% Annual soil pH testing and application of lime to adjust pH; routine mulching and maintenance of plant material. Removal of hazardous and toxic soil/plant material required when the system "dies". Filter is connected to storm sewer which can lead to structural or other primary management practices. Requires permeable soil. Life expectancy as little as 5 years. May require removal of infiltration media and plant material when the system dies. This material may be classified as hazardous or toxic upon removal. Percent impervious cover 3866%. Infiltration (1 x WQ Vol) 50% Inspection monthly and after large storm events until operations are stable. After the system is stable, inspect semiannually and after large storm events. Control sediment and maintain vegetation. Reduce peak discharge and provide groundwater recharge Does not control large volumes of runoff, works for 2year design storm. Requires permeable soil and lower water table. Does not work for oily sites due to clogging from sediment, oil, and grease. Percent impervious cover 3866%. Not suitable for roadways, parking lots and car service facilities unless a settling basin or "cell" is used for pretreatment. Infiltration (2xWQ Vol) 65% Inspection monthly and after large storm events until operations are stable. After the system is stable, inspect semiannually and after large storm events. Control sediment and maintain vegetation. Reduce peak discharge and provide groundwater recharge Does not control large volumes of runoff, works for 2year design storm. Requires permeable soil and lower water table. Does not work for oily sites due to clogging from sediment, oil, and grease. Percent impervious cover 3866%. Not suitable for roadways, parking lots and car service facilities unless a settling basin or "cell" is used for pretreatment. Sand Filter 65% Properly sized filters have a life span of up to 20 years. However, the top few inches of sand needs to be replaced every 35 years. Requires accessibility (manholes) for vacuum trucks. Removal of heavy metals, BOD, nutrients, and hydrocarbons. Aerobic filters enriched with iron may attain nearly complete removal of phosphorus. Can be placed underground. Subject to failure by clogging by sediment and heavy hydrocarbon loads. Underground vaults are classified by OSHA confined spaces. Will not function properly if subjected to continuous or frequent flows. Essential to exclude flow containing chlorine (such as pool water). Ultraurban settings with percent impervious cover 67100%. Suited for high pollutant removal on medium to high density development. Not suitable for basins with high sediment loads due to clogging. Lake Thunderbird WBP June 2010 22 Vieux (2007) found that the Little River Arm of Lake Thunderbird reduced the phosphorus load to the main body of the lake by 36% by allowing sediment and the phosphorus bound to it to settle as the water velocity decreases upon entering this area. It is possible that increasing the residence time of sediment in shallow arms of the lake such as this may significantly improve water quality. One of the tasks in the current OCC project will be to create a wetland development plan for the Upper Little River (above the bridge) and Hog Creek arms to promote more extensive settling of sediment and associated nutrients before entering the lake Figure 9. Potential wetland development (Figure 8). sites. The City of Norman has recently completed a 682 page, comprehensive “Storm Water Master Plan” (SWMP) which considers issues such as water quality, creek corridor environmental features, creek erosion / stabilization, and greenbelt / open space expansion opportunities at a very detailed subwatershed level. One of the goals of the plan is “to protect natural creek riparian environments, as well as comprehensively managing floodplains to include recreational opportunities, trails and open spaces” (Cole 2007). This document describes 12 subwatersheds in great detail, including proposed BMPs to address problems causing flooding and stream erosion. The establishment and expansion of riparian buffers is one of the top recommendations for improving water quality and addressing flooding in the city. The City of Norman realizes that the restoration of the bottomland hardwood forest and riparian wetlands that once were widespread along the Little River and its tributaries could improve overall quality of the lake. In addition, streambank stabilization projects and LID are to be encouraged. The OCC is currently cooperating with the City in a streambank stabilization project and hopes to participate in the development of different aspects of the larger SWMP. The entire SWMP may be viewed at this link: http://www.ci.norman.ok.us/sites/default/files/WebFM/Norman/Public%20Works/Storm WaterMasterPlanFinalDraft.pdf Oversight of OCC project activities will be the responsibility of the Project Coordinator with assistance from the City of Norman, the Cleveland County Conservation District, and additional OCC staff. This WBP will be presented to cities, developers, and other appropriate groups in the watershed in an attempt to further the adoption of these practices. Activities in the watershed will be designed to complement projects that the Cleveland Co. Oklahoma Co. Hog Cr. Kitchen Cr . West Elm Cr Elm Cr. Little Riv e r North F ork Lit tle M oore Cr. Rock Cr. Dav e B lue Cr. Clear Cr. Jim Blue Cr. West Hog C L. Stanley Draper Lake Thunderbird 0 5 Proposed wetland development sites Little River in Norman Lake Thunderbird WBP June 2010 23 cities have planned, for example, those detailed in the City of Norman SWMP. Soil tests may be offered as part of this project in order to reduce nutrients in runoff from lawns, gardens, parks, and golf courses in the watershed. The average soil test phosphorus (STP) level of lawn and garden soils in Oklahoma is several times higher than that required by plants. This suggests that too much fertilizer and/or incorrect fertilizer formulas are being used for those areas. Studies have shown that dissolved reactive phosphorus (which is linked to algae blooms directly) in the runoff from lawn and golf courses increases as STP and fertilizer rates increase. Education efforts will be tied to soil test results so that proper fertilizer application is emphasized. Vieux modeled several combinations of BMPs that would result in the necessary reduction in total phosphorus (TP) loading to achieve a chlorophylla concentration below 10mg/L. As shown in Table 6, below, constructing wetlands and installing some structural controls would reduce TP loading by 66%, and if coupled with fertilizer reductions, these BMPs are expected to result in the appropriate decrease in TP and, subsequently, chlorophylla. Table 6. Impact of targeted BMPs on percent reduction of total phosphorus (TP), TP loads, TP concentration, and chlorophylla concentration. The small acreage size managed by the typical agricultural producer, coupled with the respectively large number of small landowners, adds to the difficulty of significantly reducing loads from agricultural areas in this watershed. In the future projects, agricultural BMPs may be funded, including: (1) riparian area establishment to include fencing, vegetative establishment, offsite watering, livestock shelters and incentive payments; (2) streambank stabilization to include fencing and vegetative plantings; (3) animal waste storage facilities / heavy use areas; and (4) pasture management / pasture establishment. Cooperation with NRCS in Cleveland and Oklahoma Counties may allow expansion of EQIP and CSP programs (CSP began in 2005 in this area as part of the Little River priority watershed) which include practices to reduce soil erosion and improve livestock watering facilities. The OWRB conducted a shoreline erosion control demonstration project at Lake Thunderbird through EPA’s §319 NPS program. Depending on the success of this project, other similar projects may be implemented in the lake to reduce lake margin Lake Thunderbird WBP June 2010 24 sediment contributions. Through this project, the OWRB seeks to educate lake managers on the benefits of establishing aquatic plants to improve the health of the aquatic community and reduce erosion. In addition, the OWRB and COMCD have partnered to install an aeration system in the lake to increase the dissolved oxygen and improve overall water quality. The project will withdraw water from the lake bottom, oxygenate it to 300% (310 mg/l), and return the supersaturated water back into the lower lake layer, restoring the dissolved oxygen to levels that will allow attainment of the designated uses and reduce summer chlorophylla levels. Funding ($692,773) for this effort was derived from the Oklahoma Water Resources Board’s Clean Water State Revolving Fund obtained through the American Recovery and Reinvestment Act of 2009. The aerator is scheduled to begin operating in the summer of 2010. BMPs, planned and implemented, will be tracked for future watershed modeling and for reporting project performance. Project staff will make regular site visits to assess progress in implementing planned BMPs. Details will be summarized in the project final report. PUBLIC OUTREACH (element e) Much of the initial focus of the WBP will involve educating personnel and changing city ordinances. This section identifies agencies, organizations, and services that are already active in the watershed or that will be collaborators in the Lake Thunderbird watershed. These groups will help develop the WBP and assist in other planning efforts in the watershed to varying degrees. Cooperation and implementation by cities in the watershed is imperative to achieve the water quality improvement goals. The specific roles of the groups and programs which are likely to contribute to the public outreach efforts in the Lake Thunderbird Watershed are summarized in no particular order below: 1. Local Conservation District Offices The Cleveland County Conservation District will provide substantial support for the implementation of this project. The Oklahoma County Conservation District will also provide support for the project, but to a lesser degree than Cleveland County due to difference in district area in the watershed. The Districts may participate in educational activities such as seminars, training sessions, and meetings to interact with local people and provide technical assistance and information. 2. Municipalities Cities in the watershed maintain active, welldeveloped education programs. However, education programs are rarely funded to a level that meets existing needs and can always use additional technical support and other resources. The Lake Thunderbird WBP June 2010 25 Lake Thunderbird education program will supplement rather than replace the existing education programs in the watershed in cooperation with local stakeholders. The City of Norman specifically plans to establish a program to educate residents about fertilizer usage. 3. OCC Education Programs The education component of the Lake Thunderbird Watershed Implementation Project will be developed around the following goals: (1) Work within the MS4 coordinators of Moore, Norman, and Oklahoma City to assist their programs with NPS pollution education. (2) Educate city staff about low impact development, nonpoint source pollution, water quality, and water conservation. (3) Involve cities and residents in the targeted areas in education programs designed to explain the water quality problems and what can be done to reduce potential impacts. (4) Write frequent articles for area newsletters and/or newspapers about project activities. (5) Work with Conservation Districts on a Blue Thumb program in the watershed. (6) Develop a display for the project that can be used to educate the public on the 319 Program. Display should include basic information on the program, its cooperators, and contact people of ongoing programs in the watershed. (7) Track how participation in the education program has changed people’s behaviors. Project coordinator will follow five to ten percent of people intercepted through different aspects of this and related project activities and will contact them on an annual basis throughout the project period to determine whether they have made any changes that would affect NPS pollution. (8) Plan and conduct educational meetings to include: tours, earth days, fairs, etc. These education programs will be designed to explain the water quality problems and what can be done to reduce potential impacts, both agricultural and urban. (9) Coordinate education of public on nutrient management and water quality through the Master Gardener Programs of Oklahoma and Cleveland Counties. Master Gardeners will be educated on water quality issues and technologies. They will participate in the bioretention cell program by helping to evaluate the performance of vegetation in the rain gardens and by explaining their performance to the public. The Master Gardeners will also conduct demonstrations for the public at visible locations and at public functions like the County Fair and other events. Initially, the OCC will organize and hold one regional LID workshop through the Institute for Quality Communities. This will allow for indepth education on stormwater BMPs and allow civic officials training in Oklahoma and the southcentral plains region. The OCC will provide educational programs as part of other projects in the watershed as well. For instance, as part of a 2003 Riparian Area Restoration project, three seminars, targeted at City planners, local officials, and students of various ages, will be held to Lake Thunderbird WBP June 2010 26 relate the importance of riparian wetland areas within urban and rural environments. Demonstration of riparian management practices will also be part of the education program for this project. In general, youth education is a significant effort that will be pursued in the Lake Thunderbird watershed. Most youth education activities focus on general water quality maintenance and improvement and include activities such as 4H group water quality monitoring and education, “EarthDayEveryDay” activities fair where hundreds of elementary school children and some of their parents are exposed to environmental education, and various other training sessions. Blue Thumb educators will play an important role in youth education in this watershed. The success of water quality protection programs in the watershed depends on the approval and cooperation of the local landowners and various government agencies. In summary, public outreach to assure support of this and future evolutions the Watershed Based Plan will come from: · Regular media coverage of activities/issues (both at local and State levels). · Education programs that involve segments of the community ranging from school children to agricultural producers to homeowners. · Programs that encourage local citizens to experience “ownership and understanding” of environmental issues such as volunteer monitoring, cleanup events, and other educational grassroots efforts to address the problem. The goal of the public outreach portion of this project is to develop a program that will help the citizens of the Lake Thunderbird Watershed reduce NPS pollution. CRITERIA to DETERMINE PROGRESS (element h) The ultimate goal of this WBP is to reduce the nutrient loading to Lake Thunderbird by approximately 10,000 kg total phosphorus per year, as well as reduce the pathogen and sediment loads in the tributaries to the lake, so that all designated uses of waterbodies in the watershed are fully attained. These goals are guided by the water quality criteria described in this section, all of which are based on Oklahoma’s Water Quality Standards (OWRB 2008). However, in 2000, the COMCD, OWRB, and the three municipalities receiving water from Lake Thunderbird (Norman, Midwest City, and Del City) set goals for an upper limit of 20 μg/L of chlorophylla for open water sites during the growing season (OWRB 2001b). This will be an interim target for improvement in the lake. Lake Thunderbird’s designated beneficial uses include Aesthetics, Agriculture, Warm Water Aquatic Community, Primary Body Contact Recreation, Public and Private Water Supply, Fish Consumption, and Sensitive Water Supply. The tributaries to Lake Thunderbird have these same designated uses, with the exception of Moore Creek, which does not have the Sensitive Water Supply designation. Only the criteria for the listed causes of impairment (from Table 3) are presented below, along with the criteria Lake Thunderbird WBP June 2010 27 for the Sensitive Water Supply (SWS) and Nutrient Limited Watershed (NLW) designation. To determine attainment of the Primary Body Contact Recreation use (for streams), samples must be collected during the recreation season, from May 1September 30, and at least ten samples are required to make an attainment assessment. To attain the PBCR use: · Escherichia coli (E. coli) a) No sample shall exceed 406 colonies/100 ml. b) Monthly geometric mean must be less than 126 colonies/100 ml. To attain Warm Water Aquatic Community use: · Turbidity (only applicable during baseflow) a) No more than 10% of samples will exceed 25 NTU (for lakes). b) No more than 10% of samples will exceed 50 NTU (for streams) · Dissolved oxygen (DO) a) No more than 50% of the water column at any given sample site in a lake or an arm of a lake will be below 2 mg/L due to other than naturally occurring conditions (for lakes). b) No more than 10% of samples will be below 5 mg/L, or 4 mg/L from June 16October 15, based on at least 10 samples (for streams). A minimum of ten samples is required to make an attainment determination for any agriculture parameter. To attain the Agriculture use (for streams): · Total dissolved solids (TDS) a) Samples shall not exceed 700 mg/L. If any sample exceeds 700 mg/L, then the yearly mean shall not exceed 265 mg/L, and no more than 10% of the samples shall exceed 294 mg/L (values specific to waterbody segment 520810). Sensitive Water Supply designation: The "sensitive water supply" (SWS) designation means that new point source discharges of any pollutant and increased load of any pollutant from any point source discharge shall be prohibited in these waterbodies or watersheds unless the discharger “demonstrates to the satisfaction of the permitting authority that a new point source discharge or increased load from an existing point source discharge will result in maintaining or improving the water quality of both the direct receiving water and any downstream waterbodies designated SWS.” In addition, a waterbody designated SWS shall not have longterm average concentrations of chlorophylla at 0.5 meters below the lake surface of greater than 10 mg/L. Nutrient Limited Watershed designation: A nutrient limited watershed is one in which a designated beneficial use is adversely affected by excess nutrients as determined by Carlson’s Trophic State Index using chlorophylla of 62 or greater. Lake Thunderbird WBP June 2010 28 All of the above criteria stem from Oklahoma’s Water Quality Standards (OAC 785:45, OWRB 2008). Attainment of these criteria will indicate full success of the WBP. The procedures by which the data must be collected and analyzed to verify whether or not these criteria have been met are identified in Oklahoma’s Use Support Assessment Protocols (OAC 785:46, OWRB 2008). Progress toward achieving these criteria will be gauged through monitoring by both the OWRB (inlake data) and the OCC (stream data). Any improvement in the parameters described above will be considered indicative of success in the watershed. It is expected that complete attainment of the water quality criteria will not occur for several years after implementation of BMPs, especially in the lake itself, since there is a lag time between BMP implementation and observable water quality changes, especially in large waterbodies. After release of the TMDL, more specific interim criteria can be set. For the initial LID project, the OCC will compare water quality from runoff events in the control side of the neighborhood (built with conventional curbs and storm drains) to the LID side of the neighborhood (built with rain gardens to filter runoff from the street and lots). The effect of this single project in the watershed is expected to be small; however, the results of this monitoring (details in a later section) will be used to guide future LID projects in the watershed. As future projects are implemented by the OCC or other entities, the WBP will be updated, and expected load reductions will be calculated. Data from ambient monitoring in the watershed will be assessed on a regular basis and compared with modeling results to determine whether revisions are necessary. IMPLEMENTATION SCHEDULE and INTERIM MILESTONES (elements f and g) Education, implementation, and demonstration of BMPs should reduce the overall load of nutrients, sediment, and bacteria entering the waterbodies of the Lake Thunderbird watershed and ultimately reaching the lake. Implementation of best management practices will focus on low impact development in urban areas as well as some riparian reestablishment and stream bank protection. The effects of implementation programs in the watershed on bacteria, nutrient, and sediment loading from the various sources will be evaluated at the end of the project as well as every five years to determine the future strategy to be followed. This Watershed Based Plan will be revised approximately every two years to reflect new information and address shortcomings identified with earlier plans. The initial goal is that at least a fiftyeight percent total phosphorus load reduction will be achieved through multiple activities in the watershed. Until this load reduction can be proven with water quality data, it will be demonstrated by modeling the expected load reductions from implemented practices. Goals for improvement in dissolved oxygen and turbidity will be added to the plan once these TMDLs have been completed. Table Lake Thunderbird WBP June 2010 29 7 details the schedule of the goals and actions of the WBP and longterm load reductions, as well as some interim activities. The “ultimate total load reduction” goal is based on the expected 2030 buildout scenario as described in Vieux (2007). Table 8 presents interim milestones planned for the current LID project (Trailwoods). Figure 10 shows the timeline of the Trailwoods project, which will be implemented in two phases, as denoted by the vertical dashed line in that figure. More specific timeframes are given in the workplans and QAPPs related to this project. There is ongoing longterm monitoring to assess water quality in the lake. The OWRB will continue to collect water quality data and source information, and the OCC will install autosamplers to insure that load reductions in the watershed can be measured throughout the project period. Trend analyses will be performed on the various data sets (bacteria, turbidity, lake chlorophylla concentrations, TSIs, and nutrient concentrations and loading) and will be evaluated at three year intervals with the revisions of the WBP to determine whether measurable changes have occurred in water quality. Table 7. Schedule and Load Reduction Goals Associated with Activities Planned. Goal Action Parameter to Address Initial Load Reduction Ultimate Total Load Reduction Year to Begin Year to Evaluate and Adjust Year to Complete SWAT modeling and targeting Nutrients, Sediment complete complete TMDL development Dissolved oxygen, Turbidity 2008 2011 Characterize NPS contributions and evaluate nutrient dynamics and impacts in watershed Treatment Wetlands study Nutrients, Sediment NA NA 2010 2013 Compile and review LID ordinances in nearby states complete complete Send city planners / staff to LID training workshop 2010 annually Implement LID tour for city planners / staff 2011 annually OCC Blue Thumb Program ongoing annually ongoing Education and outreach programs Municipal Stormwater Programs ongoing ongoing Trailwoods 319 project 2008 2011 2014 Implement urban BMPs City of Norman Stormwater Master Plan Programs Nutrients, Sediment, Pathogens 58% overall NPS phosphorus load 68% overall NPS phosphorus load ongoing ongoing OCC – Trailwoods project Nutrients, Sediment 2011 2014 Water quality monitoring programs Municipal Stormwater Monitoring Nutrients, Sediment, Pathogens NA NA ongoing ongoing Lake Thunderbird WBP June 2010 30 Goal Action Parameter to Address Initial Load Reduction Ultimate Total Load Reduction Year to Begin Year to Evaluate and Adjust Year to Complete OWRB – Beneficial Use Monitoring Program Nutrients, Sediment, Pathogens ongoing ongoing OCC – Blue Thumb Program Nutrients, Sediment, Pathogens ongoing ongoing ODEQ – TMDL monitoring, NPDES permitting Nutrients, Sediment, Pathogens ongoing ongoing Table 8. Interim milestones for current OCC 319 project (Trailwoods Demonstration Site). Task Description Time Frame Investigation of site conditions, regulatory constraints, and opportunities pertaining to LID practice implementation at the site November 2009 Determine similar subbasins within project area and conduct preliminary planning of neighborhood design and LID BMP implementation February 2010 Complete necessary planning and draft conceptual design February 2010 Finalize design and complete construction drawings and BMP specs May 2010 Implement construction of demonstration neighborhood Projected completion June 2011 Develop model to assess life cycle costs of selected BMPs compared to conventional design December 2011 Phase I BMP Implementation: Design and Construct Demonstration Neighborhood Update life cycle cost models with actual benefit data realized at the conclusion of the project period / Final analysis report May 2014 Hold Blue Thumb Training in watershed biannually Organize and facilitate LID workshop for OK civic officials December 2010 Informational report September 2011 Model LID code September 2013 Organize and facilitate a LID training program for civic officials May 2014 Watershed Education Track behavioral change Throughout project Water Quality Monitoring in Support of TMDL Development QAPP April 2008 Install autosamplers and begin monitoring May 2008 Trailwoods Demonstration Site Monitoring QAPP December 2010 Install autosamplers and begin Trailwoods demonstration site monitoring January 2011 Update Thunderbird WBP to include ODEQ TMDL modeling results and recommendations August 2011 Perform analysis of monitoring data – One year postconstruction completion December 2011 Perform analysis of monitoring data – Two years postconstruction completion December 2012 Water Quality Monitoring / Assessment Perform final analysis of monitoring data May 2014 Lake Thunderbird WBP June 2010 31 Figure 10. Timeline for Trailwoods LID Demonstration Project. MONITORING PLAN (element i) Every Watershed Based Plan requires a monitoring plan to gauge the overall success of restoration and remediation efforts. The goal of the monitoring plan for this WBP will be to develop a longrange monitoring program that will oversee the restoration of the beneficial use support in the watershed and preserve its natural resources for future generations. The monitoring plan for this WBP provides for development of individual monitoring plans and associated quality assurance plans and Standard Operating Procedures for each underlying project or effort working toward the ultimate goal of restoration of beneficial use support. These monitoring efforts are based on Oklahoma’s Water Quality Standards and Use Support Assessment Protocols which define the process by which beneficial use support can be determined. Technical assistance in developing these plans can come from various sources, including the Oklahoma State Agency peer review process. Methodologies developed for use in this WBP will be selected to provide: 1) a quantifiable measure of changes in parameters of concern, 2) success measures that can be easily understood by cooperators and stakeholders with a variety of technical backgrounds, and 3) consistent, compatible information throughout the watershed. Monitoring will focus on the primary causes of impairment, as listed in the 303(d) list, but will also consider related causes that may exacerbate the impacts of the primary causes or may ultimately reach impairment levels without improved management. As the WBP evolves and expands to be more inclusive of all the parameters of concern, it is anticipated that this list will expand and contract. At this time, the following parameters will continue to be monitored in the Lake Thunderbird watershed: · Water quality: nutrients, sediments, suspended solids, fecal bacteria, dissolved oxygen, temperature, pH, conductivity, alkalinity, hardness, turbidity, chlorophylla, BOD5 Lake Thunderbird WBP June 2010 32 · Parameters for watershed model (TMDL) development: total organic carbon (TOC) and dissolved organic carbon (DOC) · Hydrologic budget: instream flows, infiltration rates, aquifer recovery, groundwater levels · Landuse/land cover: acreage in different landuses, quality and type of land cover, timing and other variables of associated management practices · Riparian condition: extent and quality of riparian zones in the watershed to include quality and type of vegetation, degree of impact or stability, condition of streambanks, and primary source of threat or impact · Aquatic biological communities: assessment of the condition of fish and benthic macroinvertebrate communities related to reference streams and biocriteria · BMP and other implementation efforts: type, extent, and specific location of practices to include an estimate of the potential load reduction due to implementation · Behavioral change: participation in Watershed Based Planrelated activities and behavioral changes of affected communities With each WBPrelated program, as well as for the WBP as a whole, baseline conditions will be established and monitored prior to implementation. A monitoring schedule and Quality Assurance Project Plan (QAPP) will be developed based on the type of project and timing of its implementation. Monitoring results will be reported to the appropriate entities as defined in the QAPPs. Baseline Data Water Quality The baseline data to evaluate progress in the Lake Thunderbird Watershed has been established by several monitoring efforts in the watershed. Until a TMDL is drafted and officially approved, water quality in this WBP will be guided by the following: · Oklahoma Integrated Report – Clean Water Act Section 303(d) List of Waters needing a TMDL, 2008. Lake Thunderbird, Hog Creek, West Hog Creek, Elm Creek, East Elm Creek, and Moore Creek are of concern because they are on the 2008 303(d) list as impaired due to one or more of the following: chlorophylla, turbidity, pathogens, low dissolved oxygen, or TDS. · OCC monitoring – Elm Creek was monitored monthly as part of the “East of I35 Project” from 2/1999 – 3/2001. In addition, West Elm Creek has been monitored as part of the Blue Thumb project from 5/1998 – 6/2006. · OWRB BUMP monitoring – Lake Thunderbird has been monitored quarterly for one year every other year since 1998. This data was the basis for the SWAT modeling performed by Vieux (2007). · City of Oklahoma City Stormwater Division monitoring – Data was collected for Hog Creek, West Hog Creek, and East Elm Creek as part of a watershed characterization project in 2004 and 2005. Lake Thunderbird WBP June 2010 33 Hydrologic Budget · USGS – There is one USGS stream gauge near the watershed, just below Lake Thunderbird on the Little River. Landuse/Land Cover · NRCS and OCC – Color digital orthophotos (2003). · OCC and contractors – Modeling the Lake Thunderbird Watershed Using SWAT 2000 using geospatial data provided by the Association of Central Oklahoma Governments (ACOG) Water Services Division, current as of 2000 (Vieux 2007). ACOG assembled and analyzed future landuse plans projected to the year 2030 based on information provided by the municipalities within the watershed. Riparian Condition · NRCS and OCC – Color digital orthophotos (2003). · OCC and contractors – Modeling the Lake Thunderbird Watershed Using SWAT 2000 (Vieux 2007). Best Management Practices and Other Implementation Efforts (Coverages) · NRCS/FSA – Records of specific practices installed and associated costs of programs such as EQIP · OCC and contractors – Estimates of load reductions related to installation of specific practices through computer modeling · ODEQ – Permit upgrades for NPDES permitees in the watershed · OWRB – Infrastructure upgrades supported through the State Revolving Fund Loan program Data Collection Responsibilities Responsibility for the collection of additional data of the types described above will reside with project managers of the individual projects as detailed in individual work plans. These project managers will be responsible for ensuring that the data is submitted to the ODEQ for inclusion in the Oklahoma State Water Quality Database, which will ultimately be uploaded to the National STORET database. Data reporting under individual workplans will also be the responsibility of the project managers. Monitoring results for all projects will be available and accessible to the public through the posting of final reports on agency websites. In addition to those monitors to be identified in the workplans of the individual projects under this WBP, the following groups will be involved in monitoring activities: · Oklahoma Water Resources Board (OWRB): Beneficial Use Monitoring Program and Oklahoma Water Watch Monitoring Program · Oklahoma Conservation Commission (OCC): Priority Watershed Project Monitoring, Rotating Basin Monitoring, and Blue Thumb Project Monitoring; data Lake Thunderbird WBP June 2010 34 collected will be in support of both the 319 implementation project and the ODEQ’s TMDL/WBP development for Lake Thunderbird · U.S. Geological Survey (USGS): surface and groundwater quality and quantity monitoring and special studies Monitoring Details Stream Monitoring The OCC installed five autosamplers in the Thunderbird Watershed at the locations given in Table 9 and Figure 11. These autosamplers collected continuous, flowweighted composited samples from April 2008 through April 2009. Grab samples were collected at these locations as well, as detailed in Table 10. This data is being used by the ODEQ to develop the TMDL for the lake and to establish preimplementation loads in the major tributaries to the lake. Table 9. Autosampler locations in the Lake Thunderbird Watershed. Site Name WBID Legal Latitude Longitude Little River @ 17th OK520810000080W NW¼ SE¼ SE¼ Section 2210N3W 35.3235 97.4963 West Elm Creek @ 134th OK520810000140P SE¼ SW¼ SW¼ Section 1410N2W 35.334 97.3854 Little River @ 60th OK520810000080H SE¼ SE¼ SE¼ Section 19N2W 35.2778 97.3536 Rock Creek @ 72nd OK520810000090C NW¼ NW¼ NW¼ Section 179N1W 35.261 97.3354 Hog Creek @ 119th OK520810000030G SE¼ SE¼ SW¼ Section 1210N1W 35.3483 97.2585 Table 10. OCC analytical parameters and sampling frequency. Parameter Collection Frequency Dissolved Oxygen, Conductivity, pH, Temperature, Alkalinity, Turbidity, Instantaneous Discharge weekly (insitu) ; high flow events Total Organic Carbon, Orthophosphorus (dissolved), Nitrate/Nitrite (dissolved), Ammonia (dissolved), TSS weekly grab samples; high flow events Total Phosphorus, TKN weekly autosampler samples; high flow events; grab samples when autosampler failure events Dissolved Organic Carbon grab samples every 3 weeks Chloride, Sulfate, Hardness, TDS monthly grab samples; high flow events E. coli, Enterococcus weekly grab samples from April 1 – October 30; high flow events Precipitation, Accumulated Flow weekly download; high flow event download Lake Thunderbird WBP June 2010 35 # # # # # Cleveland Co. Oklahoma Co. Little River West Elm Creek Hog Creek Rock Creek Lake Thunderbird Lake StanleyD raper Lake Thunderbird Watershed # Autosamplers OSAG E TE XAS KA Y ELL IS BE AVE R CADD O CMI AR RO N LE FL O RE WO OD S MCC URT AI N GR AD Y KOI WA ATOK A GRAN T CR EEK BRY AN MA J OR DE WEY BLANI E HAR PE R CUS TE R PTI T S BUR G CR AI G IL NC OLN NO BLE WA S HIT A LO GA N GARV NI GARF I ELD TIL LM AN PAY NE PUSH M AT AH A ALFA LFA CA RTE R LO VE MAY ES WO ODWAR D COAL HUGH ES ADAIR COM ANC H E BE CKH AM TUL SA GREE R CAN AD IA N JA CKS O N LA TIM ER ROG ER MIL LS STEP HE NS RO G ER S CH OC TAW COT T O N KNI G F IS HER MU SK OGE E DE LAWARE HAS KE L CH ER OKEE PA WNEE MC I NTO S H JE FF ERS O N NOWAT A MCC L ANI PON TO T OC OKLA H OM A SE QU OYAH SE MI NO LE OK M ULGEE HAR M ON JO HNS TON OK FUS KEE OT T AWA WA G ON ER MU R RA Y POTTA WAT O MI E CLEV ELAN D MARS HAL L WAS HNI GTO N S N W E Figure 11. Location of autosamplers in the Lake Thunderbird watershed. OCC will rely on OWRB lake monitoring data to assess whether or not practices have resulted in improved lake water quality throughout the project. Biological and habitat monitoring will not be completed as part of this project in order to minimize project expenses and since the project size is unlikely to significantly impact habitat availability in the watershed. In addition, specific single landuse areas will be sampled during runoff events for better model calibration. In the Trailwoods project, storm water quality and quantity differences between the two streets (conventional versus LID) will be assessed using continuous flow monitoring systems (e.g., weirs or flumes with datalogging pressure transducers or bubblers), automatic flowactivated composite samplers, and tippingbucket rain gauges at the base of each street. Composite storm water samples will be analyzed for physical parameters (e.g., pH, dissolved oxygen, temperature, specific conductance, etc.), total suspended solids, biochemical oxygen demand, total and dissolved reactive phosphorus, nitratenitrogen, ammonianitrogen, copper, lead, zinc, oil and grease, and selected common herbicides and pesticides. Suspended sediment concentration may be substituted for TSS if it is cost comparable. Storm hydrographs will be developed and evaluation will include calculation of runoff volumes, peak discharge, runoff depths, lag times, concentration changes, and areaadjusted mass loadings and exports. It is hypothesized that significant differences will be realized between the two watersheds. Monitoring for this project will not begin until construction is complete, tentatively January 2011. Additional water quality monitoring will be necessary to document success of other LID implementation areas as they are implemented. This monitoring Lake Thunderbird WBP June 2010 36 will be funded under future project grants, and details will be provided in updates to the WBP. Lake Monitoring The OWRB will continue to monitor Lake Thunderbird as part of the BUMP. This involves quarterly sampling every other year in which the following parameters are monitored: temperature, pH, dissolved oxygen, salinity, dissolved oxygen % saturation, oxidationreduction potential (redox), specific conductance, total dissolved solids (TDS), turbidity, Secchi disk depths, nitrate nitrogen, nitrite nitrogen, ammonia nitrogen, kjeldahl nitrogen, orthophosphorus, total phosphorus, true color, chloride, sulfate, total alkalinity, chlorophylla, and pheophytin. Vertical water quality profiles are recorded at one meter intervals from the lake surface to the lake bottom for at least three sites per reservoir: in the central pool area near the dam (lacustrine zone), in the upper portion of the lake and in the major arms of the water body (riverine zone), and in the area between the lacustrine zone and the riverine zone (transitional zone). In addition, the OWRB is contracted to monitor the lake annually from April through October to provide information to the COMCD. Landuse/Landcover Comparisons of landuse/landcover will be made throughout the project as new data becomes available. The SWAT model used geospatial landuse data provided by the Association of Central Oklahoma Governments (ACOG) Water Services Division, current as of 2000, and this data will be requested periodically as new coverages become available. In addition, census data will be updated in the WBP as it is released so that the expected urbanization in the watershed is accurately represented. Best Management Practice Implementation Summaries of BMP implementation will be included in final reports at the conclusion of each project in the watershed. Maps showing implementation in relation to hotspot areas (based on SWAT modeling) in the watershed will be included in the assessment of BMP implementation. This information will be inserted into the WBP as it becomes available. Benefits of the Monitoring Plan Implementation of this monitoring plan will enable Lake Thunderbird watershed partners to meet the goals of the WBP, which is ultimately to restore beneficial use support to waters of the watershed. Implementation of the monitoring plan will help further define areas of the watershed where restoration activities should be focused to realize the optimum benefit for the investment as well as evaluate the impacts (realized and potential) of implementation efforts. Collection of the data described under this monitoring plan will help define the relative contributions from various sources in the watershed and the processes contributing to water quality degradation in the watershed. Finally, continued collection of this data and evolution of the monitoring plan for the watershed will allow the program to adapt to meet the changing needs of watershed protection in the Lake Thunderbird Watershed. Lake Thunderbird WBP June 2010 37 TECHNICAL and FINANCIAL ASSISTANCE NEEDED (element d) Funding needs are difficult to anticipate and will likely change over time. The estimated costs associated with the current projects in the watershed are highly conservative and will change as the TMDL is finalized and further information becomes available. Potential project funding in this watershed includes money from the EPA 319 program, state programs (OCC, OWRB, ODEQ), municipalities (Norman, Moore, Oklahoma City), and private entities (COMCD). Additional funds beyond those available in the OCC 20072008 319 grants will be necessary to complete the proposed implementation, so the project will be executed in a phased approach. Initial estimates of the funds to carry out phase 1 of the Trailwoods LID project are shown in Table 11, below, along with activities of other agencies in the watershed. Technical assistance will be in the form of peer review of proposed projects from the NPS working group and datasharing from the entities listed in Table 11. OCC is working with the cities in the watershed to educate, monitor, model, and implement BMPs. Although EPA funds have been and will likely continue to be allocated toward this effort, cities are devoting considerable funds towards activities in the watershed as well. OCC will work with cities to provide a better accounting of their anticipated needs for funding, as well as their ongoing investments in water programs which may be used for inkind match of federal funds, in future iterations of the WBP. Table 11. Funding for specific projects/efforts. Task Program Federal State Total Agency Status Trailwoods 319 LID Demo Project (phase 1) $297,578 $214,656 $512,234 OCC Ongoing Lake Thunderbird Aeration Project $692,773 OWRB Ongoing Erosion Control / Shoreline Stabilization Demo Project $6,500 OWRB Completed BMP Implementation Stormwater Master Plan Projects $83,000,000 City of Norman Planned 319 Project / Blue Thumb $Education and 182,724 OCC Planned Outreach Stormwater Master Plan Projects ? City of Norman Planned Autosampler monitoring in support of TMDL $10,249 OCC / ODEQ Completed Trailwoods 319 LID Demo Project $44,940 OCC Planned Monitoring BUMP & COMCD (Lake Thunderbird only) $90,000 annually OWRB / COMCD Ongoing Computer Modeling SWAT project to target NPS pollution $89,774 $89,774 OCC Completed Lake Thunderbird WBP June 2010 38 HSPF watershed model for TMDL $78,000 ODEQ Ongoing EFDC lake model for TMDL $164,774 ODEQ Ongoing REFERENCES Cole, Carol. 2007. Council to consider storm water plan contract. Norman Transcript, July 9, 2007. COMCD. 2006. Rock Creek Watershed Analysis and Water Quality Evaluation. Prepared for the Central Oklahoma Master Conservancy District by Vieux and Associates, Inc. ODEQ. 2008. Integrated Report. Oklahoma Department of Environmental Quality. McNab, W.H. and P.E. Avers. 1994. Ecological Subregions of the United States. USDA, Forest Service. OWRB. 2001a. Shoreline Erosion Control Plan, Lake Thunderbird, Cleveland County, Oklahoma. AllEnVironment Consulting, for Oklahoma Water Resources Board. OWRB. 2001b. Evaluation of Lake Thunderbird Water Quality Management Practices for the Central Oklahoma Master Conservancy District. Oklahoma Water Resources Board. OWRB. 2002. Lake Thunderbird Capacity and Water Quality 2001, Final Report for the Central Oklahoma Master Conservancy District. Oklahoma Water Resources Board. OWRB. 2003. Lake Thunderbird Algae and Water Quality, Final Report for the Central Oklahoma Master Conservancy District. Oklahoma Water Resources Board. OWRB. 2008. Oklahoma Water Quality Standards, Oklahoma Administrative Code, Chapter 45. Oklahoma Water Resources Board. OWRB. 2008. Implementation of Oklahoma’s Water Quality Standards, Oklahoma Administrative Code, Chapter 46. Oklahoma Water Resources Board. OWRB. 2006. Agency Rule Report, Amendments to Title 785. Oklahoma Water Quality Standards, Oklahoma Administrative Code, Chapter 45. Oklahoma Water Resources Board. Vieux and Associates, Inc. 2007. Lake Thunderbird Watershed Analysis and Water Quality Evaluation. Report for Oklahoma Conservation Commission.
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Okla State Agency |
Conservation Commission, Oklahoma |
Okla Agency Code | '645' |
Title | Watershed based plan for the Lake Thunderbird watershed |
Authors | Oklahoma Conservation Commission. Water Quality Division. |
Publisher | Oklahoma Conservation Commission |
Publication Date | 2010-06 |
Publication type |
Planning Document Research Report/Study |
Subject |
Watershed management--Oklahoma--Thunderbird, Lake, Watershed--Planning. Watershed restoration--Oklahoma--Thunderbird, Lake, Watershed--Planning. Water quality management--Oklahoma--Thunderbird, Lake, Watershed--Planning. Watershed restoration--Oklahoma--Cleveland County--Planning. Watershed management--Oklahoma--Cleveland County--Planning. Water quality management--Oklahoma--Cleveland County--Planning. Thunderbird, Lake (Okla.) |
Purpose | Lake Thunderbird, located in central Oklahoma, is a popular recreational lake as well as a water supply reservoir for the cities of Norman, Del City, and Midwest City, which have a combined population of approximately 178,000. Significant taste and odor problems, linked to eutrophication in the lake, have led to complaints from water users. According to the Oklahoma Department of Environmental Quality (ODEQ) 2008 Integrated Report, Lake Thunderbird is not supporting its Fish and Wildlife Propagation (Warm Water Aquatic Community) designated use due to turbidity and low dissolved oxygen (DO), its Aesthetics use due to color, or its Public Water Supply use due to chlorophylla. The chlorophylla concentration is approximately three times the water quality standard required for a sensitive water supply.; It is projected that various low impact development (LID) practices could dramatically improve the nutrient and sediment loading in the watershed in a relatively short time frame. The Lake Thunderbird Watershed Based Plan (WBP) refers to the initial implementation of actions focused on LID, which are necessary to restore beneficial use support to Lake Thunderbird and its tributaries. |
Contents | Preface; Introduction; Causes and Sources; Load Reductions; NPS Management Measures; Public Outreach; Criteria; Implementation Schedule and Interim Milestones; Monitoring Plan; Technical and Financial Assistance Needed; References |
OkDocs Class# | C4700.3 W331th 2010 |
Digital Format | PDF, Adobe Reader required |
ODL electronic copy | Downloaded from agency website: www.ok.gov/conservation/documents/TbirdWBPdraft2_approved.pdf |
Rights and Permissions | This Oklahoma state government publication is provided for educational purposes under U.S. copyright law. Other usage requires permission of copyright holders. |
Language | English |
Full text | WATERSHED BASED PLAN FOR THE LAKE THUNDERBIRD WATERSHED Photo courtesy of OTRD Prepared By: Oklahoma Conservation Commission Water Quality Division 2800 N. Lincoln Blvd., Suite 160 Oklahoma City, OK 73105 (405) 5224500 Lake Thunderbird WBP June 2010 2 Table of Contents LIST OF TABLES 3 LIST OF FIGURES 3 PREFACE 4 INTRODUCTION 6 CAUSES and SOURCES 7 LOAD REDUCTIONS 17 NPS MANAGEMENT MEASURES 18 PUBLIC OUTREACH 24 CRITERIA 26 IMPLEMENTATION SCHEDULE and INTERIM MILESTONES 28 MONITORING PLAN 31 TECHNICAL and FINANCIAL ASSISTANCE NEEDED 37 REFERENCES 38 Lake Thunderbird WBP June 2010 3 LIST OF TABLES Table 1. Population growth in Cleveland and Oklahoma Counties 10 Table 2. Landuse in the Lake Thunderbird watershed 10 Table 3. Waterbodies in the Lake Thunderbird watershed 12 Table 4. Livestock in Oklahoma and Cleveland Counties 16 Table 5. Possible management practices for urban areas 20 Table 6. Impact of targeted BMPs on phosphorus and chlorophylla 23 Table 7. Schedule and load reduction goals 29 Table 8. Interim milestones for Trailwoods project 30 Table 9. Autosampler locations in the Lake Thunderbird Watershed 34 Table 10. OCC analytical parameters and sampling frequency 34 Table 11. Funding for specific projects/efforts 37 LIST OF FIGURES Figure 1. Lake Thunderbird watershed 7 Figure 2. Municipalities in the Lake Thunderbird watershed 9 Figure 3. Landuse in the Lake Thunderbird watershed 11 Figure 4. Location of highest total phosphorus yields 13 Figure 5. Location of highest sediment yields 14 Figure 6. Percent change in percent impervious area from baseline to buildout 14 Figure 7. Location of permitted total retention lagoons and oil/gas wells …..15 Figure 8. Street design of Trailwoods project and location in watershed 18 Figure 9. Potential wetland development sites 22 Figure 10. Timeline for Trailwoods LID Demonstration Project 31 Figure 11. Location of autosamplers in the Lake Thunderbird watershed 35 Lake Thunderbird WBP June 2010 4 PREFACE Lake Thunderbird, located in central Oklahoma, is a popular recreational lake as well as a water supply reservoir for the cities of Norman, Del City, and Midwest City, which have a combined population of approximately 178,000. Significant taste and odor problems, linked to eutrophication in the lake, have led to complaints from water users. According to the Oklahoma Department of Environmental Quality (ODEQ) 2008 Integrated Report, Lake Thunderbird is not supporting its Fish and Wildlife Propagation (Warm Water Aquatic Community) designated use due to turbidity and low dissolved oxygen (DO), its Aesthetics use due to color, or its Public Water Supply use due to chlorophylla. The chlorophylla concentration is approximately three times the water quality standard required for a sensitive water supply. Other impaired waterbodies in the watershed include 1) Hog Creek, impaired by turbidity and low DO, 2) West Branch of Hog Creek, impaired by low DO, 3) Moore Creek, impaired by total dissolved solids (TDS), 4) Elm Creek, impaired by E. coli, turbidity, and TDS, and 5) East Elm Creek, impaired by low DO. Excessive nutrient loading in the watershed, primarily from urban development, has caused the observed eutrophication in the lake. The Central Oklahoma Master Conservancy District (COMCD), in cooperation with the Oklahoma Water Resources Board (OWRB), has been monitoring chlorophylla and nutrient concentrations in the lake since 2000 and has implemented several management alternatives that have improved the lake’s algae and chlorophyll problems. However, further action is necessary to achieve full attainment of designated beneficial uses in the watershed. The Lake Thunderbird watershed covers 256 square miles (163,840 acres) in Oklahoma and Cleveland Counties, with the major tributary being the Little River. The watershed is approximately 60 percent agricultural (mostly pasture) and 40 percent residential development. Significant, consistent population growth has occurred over the past 30 years and is expected to continue in the area, with a great deal of pasture being converted to urban areas. Without a proactive plan to address the potential impact of this urban expansion, water quality in the area is expected to continue to decline rapidly. Based on SWAT model results by Vieux (2007), it is estimated that approximately 18,000 kg of phosphorus enters Lake Thunderbird each year. Nonpoint source (NPS) pollution associated primarily with increased impervious surfaces due to urban growth appears to be the primary source of the water quality problems in the Lake Thunderbird watershed. Modeling of the watershed has resulted in a recommendation of a 58% percent reduction (about 10,000 kg/yr) of total phosphorus to Lake Thunderbird in order to produce acceptable water quality conditions (chlorophylla concentration of 10 mg/L or less) (OWRB 2006). A TMDL is currently being developed by the ODEQ for the lake to address sediment and dissolved oxygen impairments. Load reduction estimates resulting from this effort will be added to the watershed plan when the TMDL is released. Lake Thunderbird WBP June 2010 5 It is projected that various low impact development (LID) practices could dramatically improve the nutrient and sediment loading in the watershed in a relatively short time frame. The Lake Thunderbird Watershed Based Plan (WBP) refers to the initial implementation of actions focused on LID, which are necessary to restore beneficial use support to Lake Thunderbird and its tributaries. Lake Thunderbird WBP June 2010 6 INTRODUCTION The Nonpoint Source Program and Grants Guidelines for States and Territories for FY 2004 and Beyond requires a Watershed Based Plan (WBP) to be completed prior to any implementation efforts using incremental funds. The guidance describes nine key components to be addressed in a watershedbased plan, much of which builds from the strategies outlined in the Watershed Restoration Action Strategy (WRAS). These components include: 1) identification of causes and sources that will need to be controlled to achieve load reductions, 2) estimate of load reductions expected from the management measures described, 3) a description of the management measures that will need to be implemented to achieve load reductions, 4) an estimate of the amounts of technical and financial assistance needed, associated costs, and/or the sources or authorities who will bear responsibility, 5) an information/education component that will be used to enhance public understanding of the project and encourage early participation in the overall program, 6) a schedule for implementing the NPS management measures identified in this plan that is reasonably expeditious, 7) a description of interim, measurable milestones for determining whether control actions are being implemented, 8) a set of criteria that can be used to determine whether loading reductions are being achieved over time and substantial progress is being made or whether the Watershed Plan or Total Maximum Daily Load (TMDL) needs to be revised, and 9) a monitoring component to evaluate the effectiveness of the implementation efforts over time. In order for the WBP to become an integral part of the entire watershed restoration program, it must be amenable to revision and update. The Lake Thunderbird WBP has been developed as a dynamic document that will be revised to incorporate the latest information, address new strategies, and define new partnerships between watershed stakeholders. It is anticipated that at least biannual revisions may be necessary and that the responsibility for such revisions will rest primarily with the Oklahoma Conservation Commission (OCC), with support from the Oklahoma Department of Environmental Quality (ODEQ), Office of the Secretary of the Environment (OSE) and the NPS Working Group. It is understood that the water quality goals and the technical approach set forth in this WBP may not be comprehensive, so they may be expanded in the future, especially as ODEQ’s work with the TMDL/WMP is completed. Federal and state funding allocations for future water quality projects designed to address the Lake Thunderbird Watershed problems should not be based solely upon their inclusion in this WBP; rather, the WBP should be considered a focal point for initial planning and strategy development. Lake Thunderbird WBP June 2010 7 CAUSES and SOURCES (element a) Watershed Characterization The Lake Thunderbird watershed (HUC 111090203010) covers a 163,840 acre area in Cleveland and Oklahoma Counties. The principal tributary to Lake Thunderbird is the Little River, which was impounded by the Bureau of Reclamation to form the lake in 1965. Other tributaries are shown in Figure 1. Designated uses of the dam and the impounded water are flood control, municipal water supply, recreation, and fish and wildlife propagation. Designated uses of streams in the watershed include aesthetics, agriculture, warm water aquatic community (WWAC), industrial and municipal process and cooling water (I & M), primary body contact recreation (PBCR), public and private water supply (PPWS), fish consumption, and sensitive water supply (SWS). Cleveland Co. Oklahoma Co. Hog Cr. Kitchen Cr. West Elm Cr Elm Cr. Little Riv er Nort h Fork Little Moore Cr. Rock Cr. Dav e Blue Cr. Clear Cr. Jim Blue Cr. West Hog C L. Stanley Draper Lake Thunderbird 0 5 10 15 Miles OSAG E TEXAS KAY ELLIS BEAV ER CADD O CMI AR RO N LE FLO RE WO ODS MCC URTAIN GRAD Y KOI WA ATOKA GRAN T CREEK BRYAN MAJ OR DEW EY BLANI E HARPE R CUST E R PTI T S BURG CRAIG IL NC OLN NOBLE WA S HTI A LO GAN GARV IN GARFI ELD TIL LM AN PAY NE PUSHM AT AH A ALFAL FA CARTE R LO VE MAYES WO ODW AR D COAL HUGH ES AD AI R COM ANCH E BECKH AM TUL SA GRE E R CA NAD IA N JA CKSO N LA TIM ER ROG ER MIL LS STEPHE NS ROG ERS CHOC TA W COTT O N KNI G FIS HER MUSK OGE E DELAW ARE HASKE L CHER OKEE PAW NEE MCI NTOS H JE FF ERSO N NO W ATA MCC LANI PONTO T OC OKLAH OMA SEQU OYAH SEMI NOLE OKM ULGEE HARM ON JO HNS TON OKFUS KEE OTT AW A WA G ON ER MUR RAY POTT AW ATO MIE CLEVEL AN D MARS HAL L W AS HNI GTO N Figure 1. Lake Thunderbird watershed. As a municipal water supply, Lake Thunderbird furnishes raw water for Del City, Midwest City, and the City of Norman under the authority of the Central Oklahoma Master Conservancy District (COMCD). Lake Thunderbird WBP June 2010 8 The morphologic features of Lake Thunderbird are (OWRB 2002): Area 5,439 acres Volume 105,838 acrefeet Shoreline 96 km Mean Depth 4.7 m (15.4 ft) Maximum Depth 17.7 m (58 ft) Water Supply Yield 21,700 acrefeet/ yr (19.4 mgd) Mean Monthly Discharge/Outflow 74.5 cfs All of these values represent a reduction since impoundment in 1966 due to sedimentation. The overall sedimentation rate was estimated as 393 acrefeet per year with a total loss of 13,762 acrefeet, about 12% higher than originally planned. Most of the sediment accumulation has occurred in the upper portion of the conservation pool. The decrease of surface area is mostly due to inflow of largegrained solids from tributaries (OWRB 2002). Although the Lake Thunderbird watershed contains Lake Stanley Draper and its watershed (Figure 1), this area was removed from modeling analyses since discharges are not allowed over the spillway. This means that seepage under the dam is the only way that water from the Lake Stanley Draper watershed could enter Lake Thunderbird. Since any seepage is minimal, Lake Stanley Draper is not considered a source of nutrient loading to Lake Thunderbird and will not be shown in any of the other figures. The Lake Thunderbird watershed is located in the Central Great Plains and Cross Timbers ecoregions (Woods et al. 2005). The Central Great Plains ecoregion is a transition area between mixed grass prairie in the west, now primarily a winter wheat growing region, and forested low mountains in eastern Oklahoma. “Gently sloping narrow ridgetops are separated by steep slopes bordering drainage ways. Some stream valleys with nearly level flood plains and large stream terraces exist. Dissected plains with broad rolling ridgetops and moderately steep valley sides occur. Valleys are usually narrow with broad flood plains and terraces and hilly dissected plains. There are rivers with wide flood plains and terraces and small streams with narrow bottomlands. Rolling plains have a deep mantle of windblown sand and sandy outwash. Elevation ranges from 1,310 to 2,950 ft (400 to 900 m). Soils include Mollisols and Alfisols” (McNab and Avers 1994). Predominant vegetation includes bluestemgrama prairie, sandsagebluestem prairie, northern flood plain forests, and buffalo grass. Precipitation ranges from 20 to 35 inches (500 to 900 mm), and temperature averages 50 to 61 degrees F (10 to 16 degrees C). “Groundwater is abundant in areas associated with sand and gravel deposits; however, it is scarce and may be mineralized in areas where shale, sandstone, clay, and limestone are near the surface” (McNab and Avers 1994). The Cross Timbers ecoregion “is a region of rolling hills and narrow valleys. The terrain generally is more complex than other parts of central Oklahoma. Elevation ranges from 330 to 1,300 ft (100 to 400 m). Soils in the Cross Timbers ecoregion are mainly Ustalfs. Lake Thunderbird WBP June 2010 9 Soils are deep, well drained, and fine to moderate textured; moisture is limited for use by vegetation during part of the growing season” (McNab and Avers 1994). Oakhickory and oakhickorypine forest and extensive areas of tall grassland with a tree layer comprise the ecoregion. Forest cover consists of post, live, and blackjack oaks, and pignut and mockernut hickories. Grasses consist of big and little bluestems, Indian grass, and sunflower. Precipitation averages 35 to 40 inches (900 to 1,050 mm), and temperature averages 55 to 63 degrees F (13 to 17 degrees C) (McNab and Avers 1994). Human Population: The population in Cleveland County, where the majority of the Lake Thunderbird watershed is located, is 224,898 (2005 Census). The city of Norman, which comprises about half of the watershed area (Figure 2), is the largest city in the county, with approximately 102,000 residents (86% urban). The city of Moore makes up about 8 percent of the watershed area and has a population of nearly 45,000. There has been a steady increase in Cleveland County’s population since 1960, especially in urban areas (Table 1). Figure 2. Municipalities in the Lake Thunderbird watershed (Vieux 2007). About 38% of the Lake Thunderbird watershed area is located within the Oklahoma City municipal boundary. In Oklahoma County, the population is 691,266, with 523,303 Lake Thunderbird WBP June 2010 10 located within Oklahoma City (2005 Census). The population in Oklahoma County has also shown consistent growth (Table 1). Table 1. Population growth in Cleveland and Oklahoma Counties. County Parameter 1960 1970 1980 1990 2000 Total population 47,600 81,839 133,173 Cleveland 174,253 208,016 Percent change 71.93% 62.73% 30.85% 19.38% Oklahoma Total population 439,506 527,717 568,933 599,611 660,448 Percent change 20.07% 7.81% 5.39% 10.15% Landuse: As shown in Table 2 and Figure 3, approximately 60 percent of the watershed is agricultural, with pasture comprising the majority of the agriculture land. Most of the remainder of the watershed is developed, primarily residential. Table 2. Landuse in the Lake Thunderbird watershed. Landuse Percent of Watershed Area Residential Medium Density 26.00 Residential High Density 0.07 Agricultural – Pasture 53.84 AgriculturalGeneric (parks and open spaces) 7.62 Commercial 0.68 Industrial 1.39 Transportation 4.18 Institutional 1.17 Open Water 5.05 Lake Thunderbird WBP June 2010 11 Figure 3. Landuse in the Lake Thunderbird watershed (Vieux 2007). Causes The designated beneficial uses for Lake Thunderbird and its tributaries include Aesthetics, Agriculture, Warm Water Aquatic Community, Primary Body Contact Recreation, Public and Private Water Supply, Fish Consumption, Industrial and Municipal Process and Cooling Water, and, for the lake itself, Sensitive Water Supply. The impaired designated uses and the causes of nonattainment of designated uses are shown in Table 3. Lake Thunderbird is listed in Oklahoma’s Integrated Report as a Category 5 waterbody with impairment of the fish and wildlife propagation beneficial use due to excess turbidity and low dissolved oxygen as well as nonattainment of the public and private water supply beneficial use due to high chlorophylla. The three streams in the Thunderbird watershed with enough monitoring data to assess designated beneficial uses (Hog Creek, Elm Creek, and Moore Creek) are listed as impaired for one or more assigned uses. It is likely that other streams in the watershed are impaired as well, but not enough data has existed to make an assessment; for the next reporting cycle, the OCC will have enough data to assess five additional streams in the watershed (Table 9). The WBP will be updated with the results of that assessment when it is performed. Lake Thunderbird WBP June 2010 12 Table 3. Waterbodies in the Lake Thunderbird watershed (ODEQ 2008). Waterbody ID Site Name Impaired Designated Uses Causes of Impairment OK520810000020_00 Thunderbird Lake Warm Water Aquatic Community Public and Private Water Supply turbidity, low DO chlorophylla OK520810000030_00 Hog Creek Warm Water Aquatic Community turbidity, low DO OK520810000040_00 West Hog Creek Warm Water Aquatic Community low DO OK520810000050_00 Clear Creek * OK520810000060_00 Dave Blue Creek * OK520810000070_00 Jim Blue Creek * OK520810000080_00 Little River * OK520810000090_00 Rock Creek * OK520810000100_00 Elm Creek Primary Body Contact Recreation Warm Water Aquatic Community Agriculture E. coli turbidity total dissolved solids OK520810000110_00 East Elm Creek Warm Water Aquatic Community low DO OK520810000120_00 East Elm Creek * OK520810000140_00 West Elm Creek * OK520810000150_00 Kitchen Creek * OK520810000160_00 Kitchen Lake * OK520810000170_00 North Fork Little River * OK520810000175_00 Moore Creek Agriculture total dissolved solids OK520810000180_00 Mussel Shoals Lake Creek * OK520810000190_00 Mussel Shoals Lake * *insufficient information or not assessed Oklahoma Water Resources Board (OWRB) studies on Lake Thunderbird have shown that chlorophylla levels are high, thus indicative of the excessive algae growth causing taste and odor problems for the City of Norman water supply. In 2000, over onehalf of the water samples collected by the OWRB had chlorophylla concentrations greater than 20 μg/L (OWRB 2003). The chlorophylla concentration was reduced in 2002, after aeration of the lake ceased, but the lake still had chlorophylla levels high enough to cause eutrophication. BUMP data collected from 20012003 showed an average chlorophylla concentration of 30.8 μg/L. Algae species which are known to cause taste and odor problems in drinking water are present in the lake, and two potentially toxic algae have been noted in Lake Thunderbird as well. The concentrations of these algae in the lake corresponded to a low to moderate risk from direct exposure or accidental ingestion in 2001 and low risk in 2002. This risk was for recreational exposure, with no evidence of risk noted for water supply (OWRB 2003). Reducing the amount of nutrients entering the lake is necessary to decrease the algal concentrations. Sources There are no point sources in the Lake Thunderbird watershed; hence, nonpoint sources are the primary contributors to the pollution problems in this watershed. Nonpoint sources are those which supply pollutants to surface water diffusely, rather than as a definite, measurable quantity at a single location. These sources typically Lake Thunderbird WBP June 2010 13 involve land activities that contribute bacteria, sediment, and/or nutrients to surface water as a result of runoff during and following rainfall. Urban Land Use: The primary sources of pollution in the Lake Thunderbird watershed are associated with urban expansion and the accompanying development. As urbanization progresses, runoff from impermeable surfaces and from construction areas (both housing developments and road construction) are increasingly contributing to nutrient and sediment loading from the watershed. Water quality is being severely impacted by increasing runoff volume and velocities, which cause increased erosion of streambanks, destruction of instream and riparian habitat, and siltation, as well as increased nutrient loads. Improper use of fertilizers or overfertilization may increase with the expected population growth in the watershed and contribute to the pollution of lakes and groundwater through loading of soluble and particulate phosphorus as well as nitrogen. Bacteria and nutrients from domestic pets will be expected to increase as well with the expected increase in population growth. According to Vieux (2007), urban runoff should be considered as an increasing, highly significant nonpoint source of pollution in this watershed. Vieux and associates performed a study in the Rock Creek watershed, a tributary to Lake Thunderbird (COMCD 2006). Based on monitoring and analysis of water quality data in Rock Creek, it was determined that a higher level of nutrients was found in runoff from developed versus undeveloped land. Vieux’s modeling efforts of the entire Lake Thunderbird watershed in 2007 supported this finding, indicating that the areas of the watershed contributing the greatest phosphorus (the limiting nutrient of the lake) load per unit area were the highly urbanized areas of Moore and Oklahoma City, as well as a small portion of Norman immediately north of the lake (Figure 4). Figure 4. Location of total phosphorus sources and yields (kg/hectare) in the Lake Thunderbird Watershed as determined from SWAT modeling (Vieux 2007). Lake Thunderbird WBP June 2010 14 Similarly, the greatest sediment load is coming from Moore and the west side of Norman, followed by the Oklahoma City area (Figure 5). Figure 5. Location of sediment sources and yields (kg/hectare) in the Lake Thunderbird Watershed as determined from SWAT modeling (Vieux 2007). The Rock Creek study (COMCD 2006) indicated that the greater loading of nutrients from developed areas was due to increased impervious surface and increased fertilization in urban areas. Vieux’s 2007 SWAT modeling also suggested that imperviousness was a key factor affecting loading rates in the watershed. It is expected that continued conversion of agricultural land to residential land will more than double the phosphorus load to the lake, increasing from an average of 25 kg/ha currently to 54 kg/ha in the future (assuming a buildout scenario with conversion of 50% of agricultural areas to residential). Figure 6 shows the areas which are expected to experience the greatest increases in impervious surface under a buildout scenario. Figure 6. Percent change in impervious area from baseline (current levels) to buildout (projected conversion of 50% of agricultural lands to residential) (Vieux 2007). Lake Thunderbird WBP June 2010 15 Based on Vieux’s SWAT model calculations, the total average phosphorus load to Lake Thunderbird is between 18,000 kg/yr and 23,000 kg/yr. According to Figure 4, the highest phosphorus loading is occurring in the watersheds of the North Fork of the Little River and Moore Creek on the west side of the lake, as well as Hog Creek on the east side of the Thunderbird watershed. The Moore and Norman areas on the west side of the watershed are contributing the highest sediment load, especially in the headwaters of Little River, the North Fork of the Little River, Moore Creek, and Rock Creek (Figure 5). While there are no point source discharges in the Lake Thunderbird watershed, “bypassdischarges” from municipalities may occur due to overflows or sewer main breaks. Several of these events have occurred within the watershed. For example, from June 2004 to August 2006, the sum of these discharges was: City of Moore 59,930 gallons discharged to Little River City of Norman 44,483 gallons discharged to Little River According to Vieux (2007), raw sewage contains approximately 415 mg/L of watersoluble phosphorus, equating to 25 kg of phosphorus over that two year period. This is not considered a significant amount relative to the overall phosphorus entering the watershed. The City of Norman completed a wastewater treatment plant (WWTP) upgrade in March 2010, which should reduce the number of failures in the future. The hydraulic capacity of the plant has increased from 45,000m³ a day to nearly 100,000m³ a day. Permitted Sources: Nonpoint source permitted activities within the watershed include 12 total retention lagoons (Figure 7). Total retention lagoons hold solid and liquid wastes prior to land application and may leak or overflow, thus affecting water quality. In addition, there are over 300 oil and gas permits in the watershed, located on approximately every section in the watershed. Not all of the permitted wells are active; however, oil and gas operations could be a potential source of high TDS values as well as turbidity sources. Figure 7. Location of permitted total retention lagoons and oil/gas wells. # # # # # # # # # # # # $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ # Total Retention Lagoons $ Oil and Gas Wells Lake Thunderbird WBP June 2010 16 Rural Land Use: Pasture/forage land is the prevalent rural land use in the watershed. Cattle are the dominant animal industry in Oklahoma and Cleveland Counties (Table 4). Livestock grazing in pastures deposit manure, making it possible for the nutrients and bacteria to enter surface water with runoff. In addition, livestock often have direct access to waterbodies providing a concentrated source of loading directly into streams. Animals loafing in the stream also contribute to turbidity problems by stirring up sediment, and their travels to and from the stream erode banks and carve trails which serve as direct conduits for NPS contribution during runoff events. Table 4. Livestock in Oklahoma and Cleveland Counties (USDA Census 2002). Livestock County Number of animals Cattle and calves OClkelavheolamnda 2216,,592825 Horses and ponies OClkelavheolamnda 34,,034800 Layers 20 weeks old and older OClkelavheolamnda 12,,472748 Hogs and pigs Cleveland 2,267 Goats Oklahoma 1,696 Sheep and lambs Oklahoma 1,402 Despite the large number of animals, particularly cattle, in these counties, agriculture in the Lake Thunderbird watershed is largely in the form of small, urban ranchettes, where landowners have 520 acres to keep a few horses or a small herd of cattle. Preliminary results from Vieux (2007) suggest that, although these areas contribute to overall loading, urban sources dominate. Septic Systems: Failing septic systems can contribute to pathogen and nutrient problems in both groundwater and surface waters if leakage or illicit discharge occurs. Any loading of bacteria into the groundwater can enter surface water through seeps or springs. Failing septic systems were not likely to be a significant factor in this watershed due to the low density of septic systems. Wildlife: Wild animals which produce fecal bacteria and have direct access to streams include deer, raccoons, other small mammals, and avian species. Wildlife is considered to be a minor contributor of pollution in this watershed. Shoreline / Streambank Erosion: Lake Thunderbird is experiencing considerable shoreline erosion with cut banks exceeding 20 feet in height in some locations (OWRB 2001a). Wave action and runoff on these bare areas are contributing significantly to the turbidity impairment of the lake. A shoreline erosion control demonstration project was intiated by the OWRB in order to reduce the amount of suspended sediment in Lake Thunderbird. During 2003, the OWRB staff installed hundreds of feet of breakwater structures and more than 1,000 aquatic plants along a 450foot area of the southern shoreline. It is expected that the Lake Thunderbird WBP June 2010 17 breakwaters will help settle out sediments and promote the establishment of beneficial shoreline vegetation. In addition, the OCC in partnership with the City of Norman is currently implementing a project to restore a riparian buffer along the North Fork of the Little River. Unstable streambanks could also contribute significantly to phosphorus loading in the watershed, especially since streambank soils are often high in phosphorus. Lake Thunderbird shoreline erosion control LOAD REDUCTIONS (element b) Because of Lake Thunderbird’s impaired status, Total Maximum Daily Load (TMDL) allocations are required for dissolved oxygen and turbidity. The Oklahoma Department of Environmental Quality Water Quality Division (ODEQ) is currently working on a detailed Hydrological Simulation Program Fortran (HSPF) model for the watershed and has contracted to have an EFDC inlake model developed. These two models will be used to develop a comprehensive TMDL for the lake. Until the release of the TMDL, the focus of this WBP will be on reducing phosphorus, since data collected and analyzed by the OWRB indicates that phosphorus is the limiting nutrient in Lake Thunderbird. The subwatersheds in red in Figure 4 will be the primary targets for implementation projects since these are the areas supplying the highest phosphorus loads and, thus, should provide the largest load reductions. Using a SWAT model, Vieux (2007) calculated that the total average phosphorus load to Lake Thunderbird is between 18,000 kg/yr and 23,000 kg/yr. This correlates with a measured average total phosphorus concentration of 0.057 mg/L and chlorophylla concentration of 30.8 mg/L. The primary source of phosphorus loading in the watershed is urbanization, as shown in Figure 4 and discussed in the previous section. Runoff from impervious surfaces in urban areas has the highest potential for contributing pollutants to waterbodies in these areas. The goal of this WBP is to reduce the nutrient loading to Lake Thunderbird so that the chlorophylla concentration is 10 mg/L, a 32% reduction. This corresponds to a reduction of approximately 10,000 kg/yr total phosphorus (58% overall) (Vieux 2007). This reduction in phosphorus should increase the dissolved oxygen concentration of the lake, decrease the turbidity, and allow restoration of the WWAC designated use. In addition, it is expected that measures implemented through this watershed project to address phosphorus will concomitantly reduce the bacteria loading in Elm Creek and sediment loading in Moore Creek. However, urbanization is expected to continue in this watershed, so it is vital to examine the required load reductions in light of future development plans. Lake Thunderbird WBP June 2010 18 Vieux (2007) modeled the loads expected if 50% of the agricultural or vacant land was converted to residential property over the next 30 years. The findings indicate that the total phosphorus load would be 24,907 kg/yr under these conditions, so a reduction of approximately 68% (approximately 16,937 kg/yr) would be necessary to achieve the chlorophylla goal of 10 mg/L in the future. This reduction will be the longterm goal for the project. The following section of the WBP addresses the management measures necessary to achieve these present (shortterm) and future (buildout) load reductions. After the release of the TMDL for Lake Thunderbird, most likely in 2011, management measures and load reduction goals described in this WBP will be updated based on the recommendations of the TMDL. NPS MANAGEMENT MEASURES (element c) SWAT modeling has allowed for estimation of nutrient load reductions expected from certain management measures (Vieux 2007). The results of this modeling effort show that Best Management Practices (BMPs) should focus on reduction of nutrient loading from urban nonpoint sources. Implementation of such practices is expected to achieve an initial NPS phosphorus load reduction goal of 58% and is likely to significantly improve the turbidity, bacteria, and dissolved oxygen issues in the lake and streams. It is recognized that not any one activity could realistically result in the required reduction; instead, numerous strategies will have to work together to achieve the desired result. With this in mind, this document is not intended as a final, static plan, but rather one that will be updated as needed to reflect new information, resources, and necessary adjustments in implementation strategy. The initial watershed implementation program will focus on facilitating Low Impact Development (LID) techniques in the watershed. A local developer has partnered with OCC to implement and assess LID practices in a new residential development, titled the Trailwoods Project. For this project, 18 houses will be built along a street with rain gardens to filter stormwater runoff from the street (dark green in Figure 8) while 18 houses will be built on an adjoining street with conventional curbs and street gutters to convey stormwater. The OCC will install autosamplers for continual monitoring and assessment of Figure 8. Street design (LID side) of Trailwoods project (left), and location of the neighborhood in the watershed (right). Lake Thunderbird WBP June 2010 19 the runoff of both streets. This project will be primarily a demonstration and research project. Results will be presented to City of Norman officials in the hope that more projects like this will be approved. Before more broadreaching projects can be tackled, a significant portion of the implementation strategy will be to work with cities in the watershed to revise their building codes as needed to allow for construction of LID systems. Special approval was granted for the Trailwoods project from the City of Norman. OCC will compile and review examples of existing codes from nearby communities that support LID and provide for water quality friendly construction techniques. These examples will be presented to the watershed cities for possible incorporation into their municipal codes. In addition, OCC will send city planners from the area to LID workshops and related training such as the one offered by the Water Conservation Resource Center in Fayetteville, Arkansas. OCC will also organize and facilitate tours of LID implementation in nearby areas to demonstrate possibilities for the city planners and relevant personnel. Since most of the project area is incorporated and zoned, the OCC will also work with municipalities to achieve pollution control through zoning and ordinance regulations. Vieux’s modeling results clearly indicate the subwatersheds contributing the greatest loads currently, as well as those where the greatest future load is expected (Figures 4, 5, and 6). These urban areas of the watershed will be targeted for the initial demonstration of lowimpact development (LID) so that the most efficient load reductions can be accomplished. Examples of urban practices that will be suggested are given in Table 5. The efficiency of each of these practices in removing phosphorus is included in the table, as well as the practical application and constraints associated with each practice. Combining certain types of practices and implementing them throughout the watershed could result in reductions in total phosphorus load beyond the required reduction to meet the chlorophylla goal of 10 mg/L (Vieux 2007). Initial implementation will be focused in the subwatersheds with the highest phosphorus loading (Figure 4). As mentioned previously, these areas are the most developed and actively developing areas in the watershed, so it will be vital to work with officials from Norman, Moore, and Oklahoma City to get approval for LID implementation. An additional strategy for inlake reduction in sediment and nutrient loads would be to work with management authorities to institute new/amended boat traffic limitations. Because of its proximity to the urban community, Lake Thunderbird experiences particularly heavy powered boat traffic, which is thought to contribute significantly to shoreline erosion and thus nonpoint delivery of sediment and nutrients. Lakewide limitations on engine size and/or speed restrictions could aid in reducing this problem. Urban raingarden Lake Thunderbird WBP June 2010 20 Table 5. Possible management practices for urban areas. Highlighted rows are practices recommended for this project by Vieux (2007). Best Management Practice Phosphorus Removal Efficiency Maintenance Required Other Benefits Problems Applicable Landuse Conditions Sediment Forbay Required to achieve Phosphorus removal efficiency for structural practices. Sediment should be removed every 35 years or when 612 inches have accumulated, whichever occurs first. To reduce maintenance costs, an onsite sediment disposal area should be included in the design. Improves phosphorus and sediment removal efficiency of primary MPs. Facilitates maintenance of MPs and extends the "life expectancy" of primary management practice. Phosphorous removal efficiencies are based on the inclusion of sediment forbays in the project design. Required to improve efficiency and life span of most other management practices. Also facilitates maintenance of other management practices. Vegetated Filter Strip 10% Requires regular maintenance. This management practice usually has short life span due to lack of maintenance, improper location, and poor vegetative cover. Maintenance includes inspections, fertilizing, watering, and replanting. Also repair from gully erosion, traffic, and concentrated flow. After established (several years), maintenance requires removal of accumulated sediment, reestablishing vegetations, weeding invasive weeds, pruning woody growth. May also result in reduction of nitrogen in storm water. For Overland Sheet Flow!!! Max contributing area 5 acres. From Center for Watershed Protection (1996), runoff changes from sheet flow to concentrated flow after traveling 75 feet on impervious surfaces and 150 on pervious surfaces. Requires soils with infiltration rate of 0.52 in/hr (sand and sandy loams). Residential (1621%) impervious or as a pretreatment component to structural management practices. Grassed Swale 15% Maintain thick vegetation at 36 inches. Remove debris, and sediment, and reestablish vegetation if needed. Excellent for residential areas. Requires matenance agreements included in land titles. Maintenance responsibility of each land owner. (Monograph 14, pg 400) Cost effective compared to concrete gutters and efficient sediment removal. Landowners are likely to mow the grass in the swale too short reducing pollutant removal efficiency. Requires soils with infiltration rates of 0.27 in/hr (silty loams) or better. Residential 1621% impervious cover. If water quality swales are incorporated, will work with higher density development up to 37% impervious area. 10% with voluntary reduction May be difficult to obtain "buyin" from the community. Requ Urban ires annual soil testing. Nutrient Management Up to 22% with statutory reduction Urban nutrient management involves the reduction of fertilizer (especially phosphorus) to grass lawns and other urban areas. Implementation of urban nutrient management is based on public education and awareness, with emphasis on reducing excessive fertilizer use. May also result in reduction of nitrogen in storm water. Requires implementing an ordinance such as the Minnesota Phosphorus Lawn Fertilizer Law. Percent impervious cover 1621%. Constructed Wetlands 30% Second season reinforcement plantings are often needed. Mow biannually to reduce woody growth on outer boundary. Maintain sediment forbay. Pretreatment management practices will reduce the cost of maintenance and the effective life expectancy of the constructed wetland. Remove sediment from forbay every 35 years or when 612 inches of sediment has accumulated. High removal rate of particulate and soluble pollutants (nutrients) and sediment. Wildlife preservation. Bird watching. Permeable soils are not suited for wetlands construction. Requires large land areas (2% of the size of the contributing watershed). Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and may not be located near (within 100 feet) of septic systems. Permeable soils are not suited for constructed wetlands. May not be suited for highly visible sites or adjacent to highly manicured sites. Extended Detention Basin (2xWQ Vol) 35% Mow 2x's per year; remove debris from spill way and trash rack at control structure; and maintain sediment forbay. Excellent option for watershed approach. Function as designed for long periods without routine maintenance. Not aesthetically pleasing. Requires 20 foot vegetative buffer. Drainage areas over 5075 acres require provisions for base flow. Not suitable for highly permeable soils. Percent impervious cover 2237%. Low visibility sites. Appropriate for regional or watershed approach. Extended DetentionEnhanced 50% Mow two times per year; remove debris from spill way and trash rack at control structure; and maintain sediment forbay. The enhanced extended detention basin has a shallow marsh which provides additional pollutant removal and reduces resuspension of settled pollutants. To increase the phosphorus removal of the extended detention basin one must increase the volume of the marsh. Wildlife habitat and associated recreation. Not aesthetically pleasing. Requires a 20 foot vegetative buffer. Drainage areas over 5075 acres require provisions for base flow. Not suitable for highly permeable soils. Percent impervious cover 3866%. Lake Thunderbird WBP June 2010 21 Best Management Practice Phosphorus Removal Efficiency Maintenance Required Other Benefits Problems Applicable Landuse Conditions Retention Basin I (3XWQ Vol) 40% Mow two times per year; remove debris from spill way and trash rack at control structure; maintain sediment forbay. Aeration may be needed in Oklahoma. High nutrient, sediment and phosphorous removal efficiencies. Can help with flood control and downstream channel erosion when coordinated within a Watershed Management Plan. Increase water table. Needs to be part of "watershed management plan" as too many detention/retention basins in a basin can severely alter the natural flow conditions with combined peak flows and increased flow durations, resulting in downstream flooding and stream channel degradation. Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and not located near (within 100 feet) of septic systems. Permeable soils are not suited for retention basins. Retention Basin II (4xWQ Vol) 50% Mow two times per year; remove debris from spill way and trash rack at control structure; maintain sediment forbay. Aeration may be needed in Oklahoma. High nutrient, sediment and phosphorous removal efficiencies. Can help with flood control and downstream channel erosion when coordinated within a Watershed Management Plan. Increase water table. Needs to be part of "watershed management plan" as too many detention/retention basins in a basin can severely alter the natural flow conditions with combined peak flows and increased flow durations, resulting in downstream flooding and stream channel degradation. Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and not located near (within 100 feet) of septic systems. Permeable soils are not suited for retention basins. Retention Basin III (4xWQ Vol with aquatic bench) 65% Mow two times per year; remove debris from spill way and trash rack at control structure; maintain sediment forbay. Aeration may be needed in Oklahoma. High nutrient, sediment and phosphorous removal efficiencies. Can help with flood control and downstream channel erosion when coordinated within a Watershed Management Plan. Increase water table. Needs to be part of "watershed management plan" as too many detention/retention basins in a basin can severely alter the natural flow conditions with combined peak flows and increased flow durations, resulting in downstream flooding and stream channel degradation. Percent impervious cover 2237%. Basin requires minimum drainage of 10 acres and not located near (within 100 feet) of septic systems. Permeable soils are not suited for retention basins. Bioretention basin or Rain Gardens 50% Annual soil pH testing and application of lime to adjust pH; routine mulching and maintenance of plant material. Removal of hazardous and toxic soil/plant material required when the system "dies". Degradation of oily pollutants, clay absorbs heavy metals, nutrients and hydrocarbons. Reduce peak discharge and provides groundwater recharge. Accumulation of toxins and heavy metals within 5 years. Requires permeable soil! Life expectancy as little as 5 years. May require removal of infiltration media and plant material. Percent impervious cover 3866%. Highly visible development. Residential to fairly high density commercial projects. Bioretention filter 50% Annual soil pH testing and application of lime to adjust pH; routine mulching and maintenance of plant material. Removal of hazardous and toxic soil/plant material required when the system "dies". Filter is connected to storm sewer which can lead to structural or other primary management practices. Requires permeable soil. Life expectancy as little as 5 years. May require removal of infiltration media and plant material when the system dies. This material may be classified as hazardous or toxic upon removal. Percent impervious cover 3866%. Infiltration (1 x WQ Vol) 50% Inspection monthly and after large storm events until operations are stable. After the system is stable, inspect semiannually and after large storm events. Control sediment and maintain vegetation. Reduce peak discharge and provide groundwater recharge Does not control large volumes of runoff, works for 2year design storm. Requires permeable soil and lower water table. Does not work for oily sites due to clogging from sediment, oil, and grease. Percent impervious cover 3866%. Not suitable for roadways, parking lots and car service facilities unless a settling basin or "cell" is used for pretreatment. Infiltration (2xWQ Vol) 65% Inspection monthly and after large storm events until operations are stable. After the system is stable, inspect semiannually and after large storm events. Control sediment and maintain vegetation. Reduce peak discharge and provide groundwater recharge Does not control large volumes of runoff, works for 2year design storm. Requires permeable soil and lower water table. Does not work for oily sites due to clogging from sediment, oil, and grease. Percent impervious cover 3866%. Not suitable for roadways, parking lots and car service facilities unless a settling basin or "cell" is used for pretreatment. Sand Filter 65% Properly sized filters have a life span of up to 20 years. However, the top few inches of sand needs to be replaced every 35 years. Requires accessibility (manholes) for vacuum trucks. Removal of heavy metals, BOD, nutrients, and hydrocarbons. Aerobic filters enriched with iron may attain nearly complete removal of phosphorus. Can be placed underground. Subject to failure by clogging by sediment and heavy hydrocarbon loads. Underground vaults are classified by OSHA confined spaces. Will not function properly if subjected to continuous or frequent flows. Essential to exclude flow containing chlorine (such as pool water). Ultraurban settings with percent impervious cover 67100%. Suited for high pollutant removal on medium to high density development. Not suitable for basins with high sediment loads due to clogging. Lake Thunderbird WBP June 2010 22 Vieux (2007) found that the Little River Arm of Lake Thunderbird reduced the phosphorus load to the main body of the lake by 36% by allowing sediment and the phosphorus bound to it to settle as the water velocity decreases upon entering this area. It is possible that increasing the residence time of sediment in shallow arms of the lake such as this may significantly improve water quality. One of the tasks in the current OCC project will be to create a wetland development plan for the Upper Little River (above the bridge) and Hog Creek arms to promote more extensive settling of sediment and associated nutrients before entering the lake Figure 9. Potential wetland development (Figure 8). sites. The City of Norman has recently completed a 682 page, comprehensive “Storm Water Master Plan” (SWMP) which considers issues such as water quality, creek corridor environmental features, creek erosion / stabilization, and greenbelt / open space expansion opportunities at a very detailed subwatershed level. One of the goals of the plan is “to protect natural creek riparian environments, as well as comprehensively managing floodplains to include recreational opportunities, trails and open spaces” (Cole 2007). This document describes 12 subwatersheds in great detail, including proposed BMPs to address problems causing flooding and stream erosion. The establishment and expansion of riparian buffers is one of the top recommendations for improving water quality and addressing flooding in the city. The City of Norman realizes that the restoration of the bottomland hardwood forest and riparian wetlands that once were widespread along the Little River and its tributaries could improve overall quality of the lake. In addition, streambank stabilization projects and LID are to be encouraged. The OCC is currently cooperating with the City in a streambank stabilization project and hopes to participate in the development of different aspects of the larger SWMP. The entire SWMP may be viewed at this link: http://www.ci.norman.ok.us/sites/default/files/WebFM/Norman/Public%20Works/Storm WaterMasterPlanFinalDraft.pdf Oversight of OCC project activities will be the responsibility of the Project Coordinator with assistance from the City of Norman, the Cleveland County Conservation District, and additional OCC staff. This WBP will be presented to cities, developers, and other appropriate groups in the watershed in an attempt to further the adoption of these practices. Activities in the watershed will be designed to complement projects that the Cleveland Co. Oklahoma Co. Hog Cr. Kitchen Cr . West Elm Cr Elm Cr. Little Riv e r North F ork Lit tle M oore Cr. Rock Cr. Dav e B lue Cr. Clear Cr. Jim Blue Cr. West Hog C L. Stanley Draper Lake Thunderbird 0 5 Proposed wetland development sites Little River in Norman Lake Thunderbird WBP June 2010 23 cities have planned, for example, those detailed in the City of Norman SWMP. Soil tests may be offered as part of this project in order to reduce nutrients in runoff from lawns, gardens, parks, and golf courses in the watershed. The average soil test phosphorus (STP) level of lawn and garden soils in Oklahoma is several times higher than that required by plants. This suggests that too much fertilizer and/or incorrect fertilizer formulas are being used for those areas. Studies have shown that dissolved reactive phosphorus (which is linked to algae blooms directly) in the runoff from lawn and golf courses increases as STP and fertilizer rates increase. Education efforts will be tied to soil test results so that proper fertilizer application is emphasized. Vieux modeled several combinations of BMPs that would result in the necessary reduction in total phosphorus (TP) loading to achieve a chlorophylla concentration below 10mg/L. As shown in Table 6, below, constructing wetlands and installing some structural controls would reduce TP loading by 66%, and if coupled with fertilizer reductions, these BMPs are expected to result in the appropriate decrease in TP and, subsequently, chlorophylla. Table 6. Impact of targeted BMPs on percent reduction of total phosphorus (TP), TP loads, TP concentration, and chlorophylla concentration. The small acreage size managed by the typical agricultural producer, coupled with the respectively large number of small landowners, adds to the difficulty of significantly reducing loads from agricultural areas in this watershed. In the future projects, agricultural BMPs may be funded, including: (1) riparian area establishment to include fencing, vegetative establishment, offsite watering, livestock shelters and incentive payments; (2) streambank stabilization to include fencing and vegetative plantings; (3) animal waste storage facilities / heavy use areas; and (4) pasture management / pasture establishment. Cooperation with NRCS in Cleveland and Oklahoma Counties may allow expansion of EQIP and CSP programs (CSP began in 2005 in this area as part of the Little River priority watershed) which include practices to reduce soil erosion and improve livestock watering facilities. The OWRB conducted a shoreline erosion control demonstration project at Lake Thunderbird through EPA’s §319 NPS program. Depending on the success of this project, other similar projects may be implemented in the lake to reduce lake margin Lake Thunderbird WBP June 2010 24 sediment contributions. Through this project, the OWRB seeks to educate lake managers on the benefits of establishing aquatic plants to improve the health of the aquatic community and reduce erosion. In addition, the OWRB and COMCD have partnered to install an aeration system in the lake to increase the dissolved oxygen and improve overall water quality. The project will withdraw water from the lake bottom, oxygenate it to 300% (310 mg/l), and return the supersaturated water back into the lower lake layer, restoring the dissolved oxygen to levels that will allow attainment of the designated uses and reduce summer chlorophylla levels. Funding ($692,773) for this effort was derived from the Oklahoma Water Resources Board’s Clean Water State Revolving Fund obtained through the American Recovery and Reinvestment Act of 2009. The aerator is scheduled to begin operating in the summer of 2010. BMPs, planned and implemented, will be tracked for future watershed modeling and for reporting project performance. Project staff will make regular site visits to assess progress in implementing planned BMPs. Details will be summarized in the project final report. PUBLIC OUTREACH (element e) Much of the initial focus of the WBP will involve educating personnel and changing city ordinances. This section identifies agencies, organizations, and services that are already active in the watershed or that will be collaborators in the Lake Thunderbird watershed. These groups will help develop the WBP and assist in other planning efforts in the watershed to varying degrees. Cooperation and implementation by cities in the watershed is imperative to achieve the water quality improvement goals. The specific roles of the groups and programs which are likely to contribute to the public outreach efforts in the Lake Thunderbird Watershed are summarized in no particular order below: 1. Local Conservation District Offices The Cleveland County Conservation District will provide substantial support for the implementation of this project. The Oklahoma County Conservation District will also provide support for the project, but to a lesser degree than Cleveland County due to difference in district area in the watershed. The Districts may participate in educational activities such as seminars, training sessions, and meetings to interact with local people and provide technical assistance and information. 2. Municipalities Cities in the watershed maintain active, welldeveloped education programs. However, education programs are rarely funded to a level that meets existing needs and can always use additional technical support and other resources. The Lake Thunderbird WBP June 2010 25 Lake Thunderbird education program will supplement rather than replace the existing education programs in the watershed in cooperation with local stakeholders. The City of Norman specifically plans to establish a program to educate residents about fertilizer usage. 3. OCC Education Programs The education component of the Lake Thunderbird Watershed Implementation Project will be developed around the following goals: (1) Work within the MS4 coordinators of Moore, Norman, and Oklahoma City to assist their programs with NPS pollution education. (2) Educate city staff about low impact development, nonpoint source pollution, water quality, and water conservation. (3) Involve cities and residents in the targeted areas in education programs designed to explain the water quality problems and what can be done to reduce potential impacts. (4) Write frequent articles for area newsletters and/or newspapers about project activities. (5) Work with Conservation Districts on a Blue Thumb program in the watershed. (6) Develop a display for the project that can be used to educate the public on the 319 Program. Display should include basic information on the program, its cooperators, and contact people of ongoing programs in the watershed. (7) Track how participation in the education program has changed people’s behaviors. Project coordinator will follow five to ten percent of people intercepted through different aspects of this and related project activities and will contact them on an annual basis throughout the project period to determine whether they have made any changes that would affect NPS pollution. (8) Plan and conduct educational meetings to include: tours, earth days, fairs, etc. These education programs will be designed to explain the water quality problems and what can be done to reduce potential impacts, both agricultural and urban. (9) Coordinate education of public on nutrient management and water quality through the Master Gardener Programs of Oklahoma and Cleveland Counties. Master Gardeners will be educated on water quality issues and technologies. They will participate in the bioretention cell program by helping to evaluate the performance of vegetation in the rain gardens and by explaining their performance to the public. The Master Gardeners will also conduct demonstrations for the public at visible locations and at public functions like the County Fair and other events. Initially, the OCC will organize and hold one regional LID workshop through the Institute for Quality Communities. This will allow for indepth education on stormwater BMPs and allow civic officials training in Oklahoma and the southcentral plains region. The OCC will provide educational programs as part of other projects in the watershed as well. For instance, as part of a 2003 Riparian Area Restoration project, three seminars, targeted at City planners, local officials, and students of various ages, will be held to Lake Thunderbird WBP June 2010 26 relate the importance of riparian wetland areas within urban and rural environments. Demonstration of riparian management practices will also be part of the education program for this project. In general, youth education is a significant effort that will be pursued in the Lake Thunderbird watershed. Most youth education activities focus on general water quality maintenance and improvement and include activities such as 4H group water quality monitoring and education, “EarthDayEveryDay” activities fair where hundreds of elementary school children and some of their parents are exposed to environmental education, and various other training sessions. Blue Thumb educators will play an important role in youth education in this watershed. The success of water quality protection programs in the watershed depends on the approval and cooperation of the local landowners and various government agencies. In summary, public outreach to assure support of this and future evolutions the Watershed Based Plan will come from: · Regular media coverage of activities/issues (both at local and State levels). · Education programs that involve segments of the community ranging from school children to agricultural producers to homeowners. · Programs that encourage local citizens to experience “ownership and understanding” of environmental issues such as volunteer monitoring, cleanup events, and other educational grassroots efforts to address the problem. The goal of the public outreach portion of this project is to develop a program that will help the citizens of the Lake Thunderbird Watershed reduce NPS pollution. CRITERIA to DETERMINE PROGRESS (element h) The ultimate goal of this WBP is to reduce the nutrient loading to Lake Thunderbird by approximately 10,000 kg total phosphorus per year, as well as reduce the pathogen and sediment loads in the tributaries to the lake, so that all designated uses of waterbodies in the watershed are fully attained. These goals are guided by the water quality criteria described in this section, all of which are based on Oklahoma’s Water Quality Standards (OWRB 2008). However, in 2000, the COMCD, OWRB, and the three municipalities receiving water from Lake Thunderbird (Norman, Midwest City, and Del City) set goals for an upper limit of 20 μg/L of chlorophylla for open water sites during the growing season (OWRB 2001b). This will be an interim target for improvement in the lake. Lake Thunderbird’s designated beneficial uses include Aesthetics, Agriculture, Warm Water Aquatic Community, Primary Body Contact Recreation, Public and Private Water Supply, Fish Consumption, and Sensitive Water Supply. The tributaries to Lake Thunderbird have these same designated uses, with the exception of Moore Creek, which does not have the Sensitive Water Supply designation. Only the criteria for the listed causes of impairment (from Table 3) are presented below, along with the criteria Lake Thunderbird WBP June 2010 27 for the Sensitive Water Supply (SWS) and Nutrient Limited Watershed (NLW) designation. To determine attainment of the Primary Body Contact Recreation use (for streams), samples must be collected during the recreation season, from May 1September 30, and at least ten samples are required to make an attainment assessment. To attain the PBCR use: · Escherichia coli (E. coli) a) No sample shall exceed 406 colonies/100 ml. b) Monthly geometric mean must be less than 126 colonies/100 ml. To attain Warm Water Aquatic Community use: · Turbidity (only applicable during baseflow) a) No more than 10% of samples will exceed 25 NTU (for lakes). b) No more than 10% of samples will exceed 50 NTU (for streams) · Dissolved oxygen (DO) a) No more than 50% of the water column at any given sample site in a lake or an arm of a lake will be below 2 mg/L due to other than naturally occurring conditions (for lakes). b) No more than 10% of samples will be below 5 mg/L, or 4 mg/L from June 16October 15, based on at least 10 samples (for streams). A minimum of ten samples is required to make an attainment determination for any agriculture parameter. To attain the Agriculture use (for streams): · Total dissolved solids (TDS) a) Samples shall not exceed 700 mg/L. If any sample exceeds 700 mg/L, then the yearly mean shall not exceed 265 mg/L, and no more than 10% of the samples shall exceed 294 mg/L (values specific to waterbody segment 520810). Sensitive Water Supply designation: The "sensitive water supply" (SWS) designation means that new point source discharges of any pollutant and increased load of any pollutant from any point source discharge shall be prohibited in these waterbodies or watersheds unless the discharger “demonstrates to the satisfaction of the permitting authority that a new point source discharge or increased load from an existing point source discharge will result in maintaining or improving the water quality of both the direct receiving water and any downstream waterbodies designated SWS.” In addition, a waterbody designated SWS shall not have longterm average concentrations of chlorophylla at 0.5 meters below the lake surface of greater than 10 mg/L. Nutrient Limited Watershed designation: A nutrient limited watershed is one in which a designated beneficial use is adversely affected by excess nutrients as determined by Carlson’s Trophic State Index using chlorophylla of 62 or greater. Lake Thunderbird WBP June 2010 28 All of the above criteria stem from Oklahoma’s Water Quality Standards (OAC 785:45, OWRB 2008). Attainment of these criteria will indicate full success of the WBP. The procedures by which the data must be collected and analyzed to verify whether or not these criteria have been met are identified in Oklahoma’s Use Support Assessment Protocols (OAC 785:46, OWRB 2008). Progress toward achieving these criteria will be gauged through monitoring by both the OWRB (inlake data) and the OCC (stream data). Any improvement in the parameters described above will be considered indicative of success in the watershed. It is expected that complete attainment of the water quality criteria will not occur for several years after implementation of BMPs, especially in the lake itself, since there is a lag time between BMP implementation and observable water quality changes, especially in large waterbodies. After release of the TMDL, more specific interim criteria can be set. For the initial LID project, the OCC will compare water quality from runoff events in the control side of the neighborhood (built with conventional curbs and storm drains) to the LID side of the neighborhood (built with rain gardens to filter runoff from the street and lots). The effect of this single project in the watershed is expected to be small; however, the results of this monitoring (details in a later section) will be used to guide future LID projects in the watershed. As future projects are implemented by the OCC or other entities, the WBP will be updated, and expected load reductions will be calculated. Data from ambient monitoring in the watershed will be assessed on a regular basis and compared with modeling results to determine whether revisions are necessary. IMPLEMENTATION SCHEDULE and INTERIM MILESTONES (elements f and g) Education, implementation, and demonstration of BMPs should reduce the overall load of nutrients, sediment, and bacteria entering the waterbodies of the Lake Thunderbird watershed and ultimately reaching the lake. Implementation of best management practices will focus on low impact development in urban areas as well as some riparian reestablishment and stream bank protection. The effects of implementation programs in the watershed on bacteria, nutrient, and sediment loading from the various sources will be evaluated at the end of the project as well as every five years to determine the future strategy to be followed. This Watershed Based Plan will be revised approximately every two years to reflect new information and address shortcomings identified with earlier plans. The initial goal is that at least a fiftyeight percent total phosphorus load reduction will be achieved through multiple activities in the watershed. Until this load reduction can be proven with water quality data, it will be demonstrated by modeling the expected load reductions from implemented practices. Goals for improvement in dissolved oxygen and turbidity will be added to the plan once these TMDLs have been completed. Table Lake Thunderbird WBP June 2010 29 7 details the schedule of the goals and actions of the WBP and longterm load reductions, as well as some interim activities. The “ultimate total load reduction” goal is based on the expected 2030 buildout scenario as described in Vieux (2007). Table 8 presents interim milestones planned for the current LID project (Trailwoods). Figure 10 shows the timeline of the Trailwoods project, which will be implemented in two phases, as denoted by the vertical dashed line in that figure. More specific timeframes are given in the workplans and QAPPs related to this project. There is ongoing longterm monitoring to assess water quality in the lake. The OWRB will continue to collect water quality data and source information, and the OCC will install autosamplers to insure that load reductions in the watershed can be measured throughout the project period. Trend analyses will be performed on the various data sets (bacteria, turbidity, lake chlorophylla concentrations, TSIs, and nutrient concentrations and loading) and will be evaluated at three year intervals with the revisions of the WBP to determine whether measurable changes have occurred in water quality. Table 7. Schedule and Load Reduction Goals Associated with Activities Planned. Goal Action Parameter to Address Initial Load Reduction Ultimate Total Load Reduction Year to Begin Year to Evaluate and Adjust Year to Complete SWAT modeling and targeting Nutrients, Sediment complete complete TMDL development Dissolved oxygen, Turbidity 2008 2011 Characterize NPS contributions and evaluate nutrient dynamics and impacts in watershed Treatment Wetlands study Nutrients, Sediment NA NA 2010 2013 Compile and review LID ordinances in nearby states complete complete Send city planners / staff to LID training workshop 2010 annually Implement LID tour for city planners / staff 2011 annually OCC Blue Thumb Program ongoing annually ongoing Education and outreach programs Municipal Stormwater Programs ongoing ongoing Trailwoods 319 project 2008 2011 2014 Implement urban BMPs City of Norman Stormwater Master Plan Programs Nutrients, Sediment, Pathogens 58% overall NPS phosphorus load 68% overall NPS phosphorus load ongoing ongoing OCC – Trailwoods project Nutrients, Sediment 2011 2014 Water quality monitoring programs Municipal Stormwater Monitoring Nutrients, Sediment, Pathogens NA NA ongoing ongoing Lake Thunderbird WBP June 2010 30 Goal Action Parameter to Address Initial Load Reduction Ultimate Total Load Reduction Year to Begin Year to Evaluate and Adjust Year to Complete OWRB – Beneficial Use Monitoring Program Nutrients, Sediment, Pathogens ongoing ongoing OCC – Blue Thumb Program Nutrients, Sediment, Pathogens ongoing ongoing ODEQ – TMDL monitoring, NPDES permitting Nutrients, Sediment, Pathogens ongoing ongoing Table 8. Interim milestones for current OCC 319 project (Trailwoods Demonstration Site). Task Description Time Frame Investigation of site conditions, regulatory constraints, and opportunities pertaining to LID practice implementation at the site November 2009 Determine similar subbasins within project area and conduct preliminary planning of neighborhood design and LID BMP implementation February 2010 Complete necessary planning and draft conceptual design February 2010 Finalize design and complete construction drawings and BMP specs May 2010 Implement construction of demonstration neighborhood Projected completion June 2011 Develop model to assess life cycle costs of selected BMPs compared to conventional design December 2011 Phase I BMP Implementation: Design and Construct Demonstration Neighborhood Update life cycle cost models with actual benefit data realized at the conclusion of the project period / Final analysis report May 2014 Hold Blue Thumb Training in watershed biannually Organize and facilitate LID workshop for OK civic officials December 2010 Informational report September 2011 Model LID code September 2013 Organize and facilitate a LID training program for civic officials May 2014 Watershed Education Track behavioral change Throughout project Water Quality Monitoring in Support of TMDL Development QAPP April 2008 Install autosamplers and begin monitoring May 2008 Trailwoods Demonstration Site Monitoring QAPP December 2010 Install autosamplers and begin Trailwoods demonstration site monitoring January 2011 Update Thunderbird WBP to include ODEQ TMDL modeling results and recommendations August 2011 Perform analysis of monitoring data – One year postconstruction completion December 2011 Perform analysis of monitoring data – Two years postconstruction completion December 2012 Water Quality Monitoring / Assessment Perform final analysis of monitoring data May 2014 Lake Thunderbird WBP June 2010 31 Figure 10. Timeline for Trailwoods LID Demonstration Project. MONITORING PLAN (element i) Every Watershed Based Plan requires a monitoring plan to gauge the overall success of restoration and remediation efforts. The goal of the monitoring plan for this WBP will be to develop a longrange monitoring program that will oversee the restoration of the beneficial use support in the watershed and preserve its natural resources for future generations. The monitoring plan for this WBP provides for development of individual monitoring plans and associated quality assurance plans and Standard Operating Procedures for each underlying project or effort working toward the ultimate goal of restoration of beneficial use support. These monitoring efforts are based on Oklahoma’s Water Quality Standards and Use Support Assessment Protocols which define the process by which beneficial use support can be determined. Technical assistance in developing these plans can come from various sources, including the Oklahoma State Agency peer review process. Methodologies developed for use in this WBP will be selected to provide: 1) a quantifiable measure of changes in parameters of concern, 2) success measures that can be easily understood by cooperators and stakeholders with a variety of technical backgrounds, and 3) consistent, compatible information throughout the watershed. Monitoring will focus on the primary causes of impairment, as listed in the 303(d) list, but will also consider related causes that may exacerbate the impacts of the primary causes or may ultimately reach impairment levels without improved management. As the WBP evolves and expands to be more inclusive of all the parameters of concern, it is anticipated that this list will expand and contract. At this time, the following parameters will continue to be monitored in the Lake Thunderbird watershed: · Water quality: nutrients, sediments, suspended solids, fecal bacteria, dissolved oxygen, temperature, pH, conductivity, alkalinity, hardness, turbidity, chlorophylla, BOD5 Lake Thunderbird WBP June 2010 32 · Parameters for watershed model (TMDL) development: total organic carbon (TOC) and dissolved organic carbon (DOC) · Hydrologic budget: instream flows, infiltration rates, aquifer recovery, groundwater levels · Landuse/land cover: acreage in different landuses, quality and type of land cover, timing and other variables of associated management practices · Riparian condition: extent and quality of riparian zones in the watershed to include quality and type of vegetation, degree of impact or stability, condition of streambanks, and primary source of threat or impact · Aquatic biological communities: assessment of the condition of fish and benthic macroinvertebrate communities related to reference streams and biocriteria · BMP and other implementation efforts: type, extent, and specific location of practices to include an estimate of the potential load reduction due to implementation · Behavioral change: participation in Watershed Based Planrelated activities and behavioral changes of affected communities With each WBPrelated program, as well as for the WBP as a whole, baseline conditions will be established and monitored prior to implementation. A monitoring schedule and Quality Assurance Project Plan (QAPP) will be developed based on the type of project and timing of its implementation. Monitoring results will be reported to the appropriate entities as defined in the QAPPs. Baseline Data Water Quality The baseline data to evaluate progress in the Lake Thunderbird Watershed has been established by several monitoring efforts in the watershed. Until a TMDL is drafted and officially approved, water quality in this WBP will be guided by the following: · Oklahoma Integrated Report – Clean Water Act Section 303(d) List of Waters needing a TMDL, 2008. Lake Thunderbird, Hog Creek, West Hog Creek, Elm Creek, East Elm Creek, and Moore Creek are of concern because they are on the 2008 303(d) list as impaired due to one or more of the following: chlorophylla, turbidity, pathogens, low dissolved oxygen, or TDS. · OCC monitoring – Elm Creek was monitored monthly as part of the “East of I35 Project” from 2/1999 – 3/2001. In addition, West Elm Creek has been monitored as part of the Blue Thumb project from 5/1998 – 6/2006. · OWRB BUMP monitoring – Lake Thunderbird has been monitored quarterly for one year every other year since 1998. This data was the basis for the SWAT modeling performed by Vieux (2007). · City of Oklahoma City Stormwater Division monitoring – Data was collected for Hog Creek, West Hog Creek, and East Elm Creek as part of a watershed characterization project in 2004 and 2005. Lake Thunderbird WBP June 2010 33 Hydrologic Budget · USGS – There is one USGS stream gauge near the watershed, just below Lake Thunderbird on the Little River. Landuse/Land Cover · NRCS and OCC – Color digital orthophotos (2003). · OCC and contractors – Modeling the Lake Thunderbird Watershed Using SWAT 2000 using geospatial data provided by the Association of Central Oklahoma Governments (ACOG) Water Services Division, current as of 2000 (Vieux 2007). ACOG assembled and analyzed future landuse plans projected to the year 2030 based on information provided by the municipalities within the watershed. Riparian Condition · NRCS and OCC – Color digital orthophotos (2003). · OCC and contractors – Modeling the Lake Thunderbird Watershed Using SWAT 2000 (Vieux 2007). Best Management Practices and Other Implementation Efforts (Coverages) · NRCS/FSA – Records of specific practices installed and associated costs of programs such as EQIP · OCC and contractors – Estimates of load reductions related to installation of specific practices through computer modeling · ODEQ – Permit upgrades for NPDES permitees in the watershed · OWRB – Infrastructure upgrades supported through the State Revolving Fund Loan program Data Collection Responsibilities Responsibility for the collection of additional data of the types described above will reside with project managers of the individual projects as detailed in individual work plans. These project managers will be responsible for ensuring that the data is submitted to the ODEQ for inclusion in the Oklahoma State Water Quality Database, which will ultimately be uploaded to the National STORET database. Data reporting under individual workplans will also be the responsibility of the project managers. Monitoring results for all projects will be available and accessible to the public through the posting of final reports on agency websites. In addition to those monitors to be identified in the workplans of the individual projects under this WBP, the following groups will be involved in monitoring activities: · Oklahoma Water Resources Board (OWRB): Beneficial Use Monitoring Program and Oklahoma Water Watch Monitoring Program · Oklahoma Conservation Commission (OCC): Priority Watershed Project Monitoring, Rotating Basin Monitoring, and Blue Thumb Project Monitoring; data Lake Thunderbird WBP June 2010 34 collected will be in support of both the 319 implementation project and the ODEQ’s TMDL/WBP development for Lake Thunderbird · U.S. Geological Survey (USGS): surface and groundwater quality and quantity monitoring and special studies Monitoring Details Stream Monitoring The OCC installed five autosamplers in the Thunderbird Watershed at the locations given in Table 9 and Figure 11. These autosamplers collected continuous, flowweighted composited samples from April 2008 through April 2009. Grab samples were collected at these locations as well, as detailed in Table 10. This data is being used by the ODEQ to develop the TMDL for the lake and to establish preimplementation loads in the major tributaries to the lake. Table 9. Autosampler locations in the Lake Thunderbird Watershed. Site Name WBID Legal Latitude Longitude Little River @ 17th OK520810000080W NW¼ SE¼ SE¼ Section 2210N3W 35.3235 97.4963 West Elm Creek @ 134th OK520810000140P SE¼ SW¼ SW¼ Section 1410N2W 35.334 97.3854 Little River @ 60th OK520810000080H SE¼ SE¼ SE¼ Section 19N2W 35.2778 97.3536 Rock Creek @ 72nd OK520810000090C NW¼ NW¼ NW¼ Section 179N1W 35.261 97.3354 Hog Creek @ 119th OK520810000030G SE¼ SE¼ SW¼ Section 1210N1W 35.3483 97.2585 Table 10. OCC analytical parameters and sampling frequency. Parameter Collection Frequency Dissolved Oxygen, Conductivity, pH, Temperature, Alkalinity, Turbidity, Instantaneous Discharge weekly (insitu) ; high flow events Total Organic Carbon, Orthophosphorus (dissolved), Nitrate/Nitrite (dissolved), Ammonia (dissolved), TSS weekly grab samples; high flow events Total Phosphorus, TKN weekly autosampler samples; high flow events; grab samples when autosampler failure events Dissolved Organic Carbon grab samples every 3 weeks Chloride, Sulfate, Hardness, TDS monthly grab samples; high flow events E. coli, Enterococcus weekly grab samples from April 1 – October 30; high flow events Precipitation, Accumulated Flow weekly download; high flow event download Lake Thunderbird WBP June 2010 35 # # # # # Cleveland Co. Oklahoma Co. Little River West Elm Creek Hog Creek Rock Creek Lake Thunderbird Lake StanleyD raper Lake Thunderbird Watershed # Autosamplers OSAG E TE XAS KA Y ELL IS BE AVE R CADD O CMI AR RO N LE FL O RE WO OD S MCC URT AI N GR AD Y KOI WA ATOK A GRAN T CR EEK BRY AN MA J OR DE WEY BLANI E HAR PE R CUS TE R PTI T S BUR G CR AI G IL NC OLN NO BLE WA S HIT A LO GA N GARV NI GARF I ELD TIL LM AN PAY NE PUSH M AT AH A ALFA LFA CA RTE R LO VE MAY ES WO ODWAR D COAL HUGH ES ADAIR COM ANC H E BE CKH AM TUL SA GREE R CAN AD IA N JA CKS O N LA TIM ER ROG ER MIL LS STEP HE NS RO G ER S CH OC TAW COT T O N KNI G F IS HER MU SK OGE E DE LAWARE HAS KE L CH ER OKEE PA WNEE MC I NTO S H JE FF ERS O N NOWAT A MCC L ANI PON TO T OC OKLA H OM A SE QU OYAH SE MI NO LE OK M ULGEE HAR M ON JO HNS TON OK FUS KEE OT T AWA WA G ON ER MU R RA Y POTTA WAT O MI E CLEV ELAN D MARS HAL L WAS HNI GTO N S N W E Figure 11. Location of autosamplers in the Lake Thunderbird watershed. OCC will rely on OWRB lake monitoring data to assess whether or not practices have resulted in improved lake water quality throughout the project. Biological and habitat monitoring will not be completed as part of this project in order to minimize project expenses and since the project size is unlikely to significantly impact habitat availability in the watershed. In addition, specific single landuse areas will be sampled during runoff events for better model calibration. In the Trailwoods project, storm water quality and quantity differences between the two streets (conventional versus LID) will be assessed using continuous flow monitoring systems (e.g., weirs or flumes with datalogging pressure transducers or bubblers), automatic flowactivated composite samplers, and tippingbucket rain gauges at the base of each street. Composite storm water samples will be analyzed for physical parameters (e.g., pH, dissolved oxygen, temperature, specific conductance, etc.), total suspended solids, biochemical oxygen demand, total and dissolved reactive phosphorus, nitratenitrogen, ammonianitrogen, copper, lead, zinc, oil and grease, and selected common herbicides and pesticides. Suspended sediment concentration may be substituted for TSS if it is cost comparable. Storm hydrographs will be developed and evaluation will include calculation of runoff volumes, peak discharge, runoff depths, lag times, concentration changes, and areaadjusted mass loadings and exports. It is hypothesized that significant differences will be realized between the two watersheds. Monitoring for this project will not begin until construction is complete, tentatively January 2011. Additional water quality monitoring will be necessary to document success of other LID implementation areas as they are implemented. This monitoring Lake Thunderbird WBP June 2010 36 will be funded under future project grants, and details will be provided in updates to the WBP. Lake Monitoring The OWRB will continue to monitor Lake Thunderbird as part of the BUMP. This involves quarterly sampling every other year in which the following parameters are monitored: temperature, pH, dissolved oxygen, salinity, dissolved oxygen % saturation, oxidationreduction potential (redox), specific conductance, total dissolved solids (TDS), turbidity, Secchi disk depths, nitrate nitrogen, nitrite nitrogen, ammonia nitrogen, kjeldahl nitrogen, orthophosphorus, total phosphorus, true color, chloride, sulfate, total alkalinity, chlorophylla, and pheophytin. Vertical water quality profiles are recorded at one meter intervals from the lake surface to the lake bottom for at least three sites per reservoir: in the central pool area near the dam (lacustrine zone), in the upper portion of the lake and in the major arms of the water body (riverine zone), and in the area between the lacustrine zone and the riverine zone (transitional zone). In addition, the OWRB is contracted to monitor the lake annually from April through October to provide information to the COMCD. Landuse/Landcover Comparisons of landuse/landcover will be made throughout the project as new data becomes available. The SWAT model used geospatial landuse data provided by the Association of Central Oklahoma Governments (ACOG) Water Services Division, current as of 2000, and this data will be requested periodically as new coverages become available. In addition, census data will be updated in the WBP as it is released so that the expected urbanization in the watershed is accurately represented. Best Management Practice Implementation Summaries of BMP implementation will be included in final reports at the conclusion of each project in the watershed. Maps showing implementation in relation to hotspot areas (based on SWAT modeling) in the watershed will be included in the assessment of BMP implementation. This information will be inserted into the WBP as it becomes available. Benefits of the Monitoring Plan Implementation of this monitoring plan will enable Lake Thunderbird watershed partners to meet the goals of the WBP, which is ultimately to restore beneficial use support to waters of the watershed. Implementation of the monitoring plan will help further define areas of the watershed where restoration activities should be focused to realize the optimum benefit for the investment as well as evaluate the impacts (realized and potential) of implementation efforts. Collection of the data described under this monitoring plan will help define the relative contributions from various sources in the watershed and the processes contributing to water quality degradation in the watershed. Finally, continued collection of this data and evolution of the monitoring plan for the watershed will allow the program to adapt to meet the changing needs of watershed protection in the Lake Thunderbird Watershed. Lake Thunderbird WBP June 2010 37 TECHNICAL and FINANCIAL ASSISTANCE NEEDED (element d) Funding needs are difficult to anticipate and will likely change over time. The estimated costs associated with the current projects in the watershed are highly conservative and will change as the TMDL is finalized and further information becomes available. Potential project funding in this watershed includes money from the EPA 319 program, state programs (OCC, OWRB, ODEQ), municipalities (Norman, Moore, Oklahoma City), and private entities (COMCD). Additional funds beyond those available in the OCC 20072008 319 grants will be necessary to complete the proposed implementation, so the project will be executed in a phased approach. Initial estimates of the funds to carry out phase 1 of the Trailwoods LID project are shown in Table 11, below, along with activities of other agencies in the watershed. Technical assistance will be in the form of peer review of proposed projects from the NPS working group and datasharing from the entities listed in Table 11. OCC is working with the cities in the watershed to educate, monitor, model, and implement BMPs. Although EPA funds have been and will likely continue to be allocated toward this effort, cities are devoting considerable funds towards activities in the watershed as well. OCC will work with cities to provide a better accounting of their anticipated needs for funding, as well as their ongoing investments in water programs which may be used for inkind match of federal funds, in future iterations of the WBP. Table 11. Funding for specific projects/efforts. Task Program Federal State Total Agency Status Trailwoods 319 LID Demo Project (phase 1) $297,578 $214,656 $512,234 OCC Ongoing Lake Thunderbird Aeration Project $692,773 OWRB Ongoing Erosion Control / Shoreline Stabilization Demo Project $6,500 OWRB Completed BMP Implementation Stormwater Master Plan Projects $83,000,000 City of Norman Planned 319 Project / Blue Thumb $Education and 182,724 OCC Planned Outreach Stormwater Master Plan Projects ? City of Norman Planned Autosampler monitoring in support of TMDL $10,249 OCC / ODEQ Completed Trailwoods 319 LID Demo Project $44,940 OCC Planned Monitoring BUMP & COMCD (Lake Thunderbird only) $90,000 annually OWRB / COMCD Ongoing Computer Modeling SWAT project to target NPS pollution $89,774 $89,774 OCC Completed Lake Thunderbird WBP June 2010 38 HSPF watershed model for TMDL $78,000 ODEQ Ongoing EFDC lake model for TMDL $164,774 ODEQ Ongoing REFERENCES Cole, Carol. 2007. Council to consider storm water plan contract. Norman Transcript, July 9, 2007. COMCD. 2006. Rock Creek Watershed Analysis and Water Quality Evaluation. Prepared for the Central Oklahoma Master Conservancy District by Vieux and Associates, Inc. ODEQ. 2008. Integrated Report. Oklahoma Department of Environmental Quality. McNab, W.H. and P.E. Avers. 1994. Ecological Subregions of the United States. USDA, Forest Service. OWRB. 2001a. Shoreline Erosion Control Plan, Lake Thunderbird, Cleveland County, Oklahoma. AllEnVironment Consulting, for Oklahoma Water Resources Board. OWRB. 2001b. Evaluation of Lake Thunderbird Water Quality Management Practices for the Central Oklahoma Master Conservancy District. Oklahoma Water Resources Board. OWRB. 2002. Lake Thunderbird Capacity and Water Quality 2001, Final Report for the Central Oklahoma Master Conservancy District. Oklahoma Water Resources Board. OWRB. 2003. Lake Thunderbird Algae and Water Quality, Final Report for the Central Oklahoma Master Conservancy District. Oklahoma Water Resources Board. OWRB. 2008. Oklahoma Water Quality Standards, Oklahoma Administrative Code, Chapter 45. Oklahoma Water Resources Board. OWRB. 2008. Implementation of Oklahoma’s Water Quality Standards, Oklahoma Administrative Code, Chapter 46. Oklahoma Water Resources Board. OWRB. 2006. Agency Rule Report, Amendments to Title 785. Oklahoma Water Quality Standards, Oklahoma Administrative Code, Chapter 45. Oklahoma Water Resources Board. Vieux and Associates, Inc. 2007. Lake Thunderbird Watershed Analysis and Water Quality Evaluation. Report for Oklahoma Conservation Commission. |
Date created | 2011-09-15 |
Date modified | 2013-02-14 |
OCLC number | 819810490 |
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