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Home My WebLink AboutAquaticWeeds_RoanokeRapids_Rockingham Total Maximum Daily Load for Aquatic Weeds for Rockingham City Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena in North Carolina Final Report August 2006 EPA Approved Date: September 25, 2006 Yadkin-Pee-Dee River Basin, Roanoke River Basin, and Neuse River Basin Prepared by: NC Department of Environment and Natural Resources Division of Water Quality Water Quality Section – Planning Branch 1617 Mail Service Center Raleigh, NC 27699-1617 (919) 733-5083 INDEX OF TMDL SUBMITTAL 1. 303(d) Listed Water Body Information State: North Carolina Counties: Richmond, Halifax, Wake, and Wayne Major River Basins: Yadkin-Pee-Dee, Roanoke, and Neuse Watersheds: Falling Creek, Roanoke River, Sycamore Creek Reedy Creek, and Walnut Creek Impaired Water Body (2000 303(d) List): Water Body Name - (Assessment Unit) Water Quality Classification Sub-basin 8-digit HUC Area (Acres) Rockingham City Lake (13-Rockingham) WS-III CA 03-07-16 03040201 27 Roanoke Rapids Lake (23-(22.5)) WS-IV & B CA 03-06-08 03010106 4893 Big Lake (27-Big Lake_WA) B-NSW 03-04-02 03020201 62 Reedy Creek Lake (27 Reedy Cree) B-NSW 03-04-02 03020201 20 Lake Wackena (27 Lake Wacke) C-NSW 03-04-05 03020202 165 Constituent(s) of Concern: Aquatic Weeds Designated Uses: Biological integrity, water supply, propagation of aquatic life, and recreation. Applicable Water Quality Standards: As defined by North Carolina Aquatic Weed Control Act of 1991, noxious aquatic weed is any plant organism which grows in or is closely associated with the aquatic environment, whether floating, emersed, submersed, or ditch-bank species, and including terrestrial phases of any such plant organism; exhibits characteristics of obstructive nature and either massive productivity or choking density; and is or may become a threat to public health or safety or to existing or new beneficial uses of the waters of the State. Noxious aquatic weed is any plant organism so designated under Article 15 of Chapter 113A of the General Statutes of North Carolina. The North Carolina Aquatic Weed Control Act of 1991 empowers the State of North Carolina to control, eradicate, and regulate plants designated as noxious aquatic weeds. The Aquatic Weed Control Act and the existing powers of the Commissioner of Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 2 Agriculture prohibit importation, sale, use, culture, collection, transportation, and distribution of these plants in North Carolina. Permits for the movement of noxious aquatic weeds may be obtained from the Commissioner of Agriculture pursuant to 2 NCAC 48A .1705 and .1706, subject to the conditions stated therein. A detail of the definition and regulation of aquatic weeds in North Carolina is given in Appendix 12.2. Following allocations for the aquatic weeds are identified in this TMDL. • Non-noxious native aquatic plants along shoreline, which protect bank erosion and provide special habitat for aquatic animals and wildlife: No Control. • Other non-noxious native aquatic plants: Partial Control • Noxious native aquatic plants or exotic aquatic plants: Extensive Control 2. TMDL Development Total Maximum Daily Load (TMDL) is defined as the total amount of pollutant that can be assimilated by a receiving lake while achieving water quality standards. Assimilative capacity of a lake is determined with regards to usefulness of aquatic weeds and management goals. Critical Conditions: Critical conditions are determined by understanding growth patterns of aquatic weeds. Except for Brazilian elodea (Egeria densa), summer period is critical for many aquatic weeds. Winter period is critical for Brazilian elodea. Seasonal Variation: No seasonal variation is studied due to insufficient measurement data. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 3 3. Control Level: Aquatic Weeds Lake/Watershed Scientific Name North Carolina Designation Category Control Level Rockingham City Lake (Falling Creek) Roanoke Rapids Lake (Roanoke River) Big Lake (Sycamore Creek) Reedy Creek Lake (Reedy Creek) Lake Wackena (Walnut Creek) Eleocharis sp. Mayaca fluviatilis Myriophyllum heterophyllum Nymphae odorata. Hydrilla verticillata Myriophyllum spicatum Egeria densa Hydrilla sp. Hydrilla sp. Not known Not Noxious Not Noxious Not Noxious Not Noxious Noxious Noxious Noxious Noxious Noxious Not known Native Native Native Native Exotic Exotic Exotic Exotic Exotic Not known No Control Partial Control Partial Control Partial Control Extensive Control Extensive Control Extensive Control Extensive Control Extensive Control Not known 4. Submittal Date: August 14, 2006 5. Establishment Date: 6. Public Notice Information: A draft of the Aquatic Weed TMDL for Rockingham City Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena was publicly noticed through local newspapers, Richmond CO. Daily Journal, Daily Herald, The News and Observer, and Goldsboro News Argus on June 30, 2006. The TMDLs was also publicly noticed through DWQ web site at http://h20.enr.state.nc.us/tmdl/. A public comment period was through August 7, 2006. • Did notification contain specific mention of TMDL proposals? YES • Were comments received from the public? NO • Was a responsiveness summary prepared? NO 7. EPA Lead on TMDL (EPA or Blank): 8. DOT a Significant Contribution (Yes or Blank): 9. Endangered Species (Yes or Blank): 10. TMDL Considers Point Source, Nonpoint Source, or Both: NA Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 4 Table of Contents 1. Introduction.................................................................................................................. 5 1.1. Types of Aquatic Weeds ..................................................................................................... 6 1.2. Aquatic Weed Control Level............................................................................................... 8 1.2.1. No Control:................................................................................................................... 8 1.2.2. Partial Control: ............................................................................................................. 8 1.2.3. Extensive Control:........................................................................................................ 8 1.3. Aquatic Weed Control Strategies........................................................................................ 9 1.4. Characteristics of Lakes ...................................................................................................... 9 2. Rockingham City Lake.............................................................................................. 12 2.1. General Background.......................................................................................................... 12 2.2. Aquatic Weed Problem...................................................................................................... 13 2.3. Control Strategies.............................................................................................................. 15 2.4. Control Level..................................................................................................................... 15 2.5. Critical condition............................................................................................................... 16 3. Roanoke Rapids Lake................................................................................................ 17 3.1. General Background.......................................................................................................... 17 3.2. Aquatic Weed Problem...................................................................................................... 19 3.3. Control Strategies............................................................................................................... 20 3.4. Control Level..................................................................................................................... 23 3.5. Critical Condition.............................................................................................................. 23 4. Big Lake...................................................................................................................... 25 4.1. General Background........................................................................................................... 25 4.2. Aquatic Weed Problem...................................................................................................... 26 4.3. Control Strategies.............................................................................................................. 27 4.4. Control Level..................................................................................................................... 27 4.5. Critical Condition.............................................................................................................. 27 5. Reedy Creek Lake...................................................................................................... 28 5.1. General Background.......................................................................................................... 28 5.2. Aquatic Weed Problem...................................................................................................... 30 5.3. Control Strategies.............................................................................................................. 30 5.4. Control Level..................................................................................................................... 30 5.5. Critical Condition.............................................................................................................. 30 6. Lake Wackena............................................................................................................ 31 6.1. General Background.......................................................................................................... 31 6.2. Aquatic Weed Problem...................................................................................................... 32 7. Summary and Future Consideration....................................................................... 33 7.1. Lake Monitoring................................................................................................................ 34 7.2. Implementation Plan.......................................................................................................... 34 8. Public Participation ................................................................................................... 35 9. Further Information.................................................................................................. 35 10. References................................................................................................................. 36 11. Appendices................................................................................................................ 38 11.1. Physical parameters of lakes ........................................................................................... 38 11.2. North Carolina Aquatic Weed Control Act of 1991........................................................ 39 11.3. Lake Chemistry Data ................................................................................................... 43 11.4. Public Notice of draft Aquatic Weed TMDL for Rockingham City Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena.............................................. 49 11.5. The US EPA’s Approval Letter....................................................................................... 53 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 5 1. Introduction Section 303(d) of the Clean Water Act (CWA) requires States to develop a list of water bodies that do not meet water quality standards or have impaired uses. The list, referred to as the 303(d) list, is submitted biennially to the U.S. Environment Protection Agency (USEPA) for review. The 303(d) process requires that a Total Maximum Daily Load (TMDL) be developed for each of the waters appearing on Category 5 of the 303(d) list. This category consists of those waters that are impaired by a pollutant and the proper technical conditions exist to develop TMDLs. As follow up of the CWA, this report presents the development of Total Maximum Daily Loads (TMDLs) for five different lakes in North Carolina: Big Lake, Reedy Creek Lake, Lake Wackena, Roanoke Rapid Lake, and Rockingham City Lake. The first three lakes are located in Neuse River Basin (NEU), while the remaining two lakes are respectively located in Roanoke River Basin (ROA), and Yadkin River Basin (YAD). As identified by the North Carolina Division of Water Quality (NC DWQ), the five lakes are impaired due to aquatic weeds and TMDLs are needed (NCDENR 2003). The US EPA considers any aquatic plant growth in a lake to be a “pollutant” within the meaning of Section 502(6) of the Clean Water Act. In 1978, EPA decided that all pollutants, under proper technical conditions, are suitable for the calculation of TMDLs (43 Fed. Reg. 60662, December 28, 1978). EPA may reevaluate whether materials such as aquatic weeds are pollutants, generally or in individual situations, for Clean Water Act purposes. Because of invasive nature of aquatic weed, a quantitative explanation of its reduction level is difficult and there is no clear instruction on how much control is needed for a particular weed problem. Therefore, this TMDL details types of aquatic weeds and qualitative options to control aquatic weeds in the following paragraphs. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 6 1.1. Types of Aquatic Weeds The staff of Division of Water Quality (DWQ) and Division of Water Resources (DWR) identified seven different aquatic plants in the following four lakes (Table 1.1): Rockingham City Lake, Roanoke Rapids Lake, Big Lake, and Reedy Creek Lake. The types of plants and the dates when the plants were identified are given in Tables 1.1 and 1. 2 respectively. Table 1.1. Identified aquatic weeds and their classes in the North Carolina lakes Aquatic Weeds NC Lakes/Basin Scientific Name Common Name North Carolina Designation Category Rockingham City Lake (YAD) Roanoke Rapids Lake (ROA) Big Lake (NEU) Reedy Creek Lake (NEU) Lake Wakena (NEU) Eleocharis sp. Mayaca fluviatilis, Myriophyllum heterophyllum Nymphae odorata. Hydrilla verticillata Myriophyllum spicatum Egeria densa Hydrilla sp Hydrilla sp. Not known Spike rush Bog moss Watermilfoil Fragrant waterlily Hydrilla Eurasian milfoil Brazilian elodea Hydrilla Hydrilla Not known Not Noxious Not Noxious Not Noxious Not Noxious Noxious Noxious Noxious Noxious Noxious Not known Native Native Native Native Exotic Exotic Exotic Exotic Exotic Not known Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 7 Table 1.2. Field survey periods for identifying aquatic weeds in the North Carolina lakes NC Lakes Data Collection Period Rockingham City Lake Roanoke Rapids Lake Big Lake Reedy Creek Lake Lake Wackena August 24, 1995 July 22, 1999, August 24, 2003 July 12, 2000 July 12, 2000 and August 7, 2000 July 25, 1995 A field study to identify specific aquatic weed type (macrophytes aqauatic plants) in Lake Wackena has not been performed yet. A field study is, therefore, urgent to identify exact types of weeds existed in order to determine specific management options for the lake. If aquatic weeds are not a problem, the lake can be delisted from the 303(d) list. As shown in Table 1.1, Rockingham City Lake carried all native aquatic weeds: spike rush, bog moss, and watermilfoil. These plants naturally grow there and are integral part of the lake. The plants provide food and shelter to aquatic animals and protect shoreline from erosion. However, problems arise when the plants become so numerous that they impede recreational activities such as boating and swimming. When growth becomes very thick, they harm fisheries. The three lakes -- Roanoke Lake, Big Lake, and Reedy Creek Lake -- carried exotic aquatic weeds. These species are sometimes available as ornamental water gardening or aquarium plants. Whether they were deliberately introduced or introduced by happenstance is unclear. Seeds of the species may have been brought to the lakes by the migratory birds. Once introduced the exotic weeds rapidly out compete native plants and form single-species stands. These monocultures reduce habitat for fish, waterfowl, aquatic mammals, and invertebrates. North Carolina State has designated some of the identified aquatic weeds as noxious based on their invasive characteristics in NC lakes. Details of the NC Aquatic Weed Control Act of 1991 and Regulation and Designated noxious aquatic weeds are presented in Appendix 12.2. According to the Act, the plants identified in Roanoke Rapids Lake, Big Lake, and Reedy Creek Lake are noxious (Table 1.1). Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 8 1.2. Aquatic Weed Control Level Some measures need to be implemented in order to control the identified aquatic weeds in the five lakes. There is, however, no clear instruction on how much control is needed for a particular weed problem. Based on usefulness and invasive types of weeds in the lakes, the following three levels of control are recommended for this study. 1.2.1. No Control: Non-noxious native aquatic weeds along shoreline, which protect bank erosion and provide special habitat for aquatic animals and wildlife, should not be controlled. For instance, spikerush (Eleocharis sp.) is a native weed to North Carolina and grows individually or in clumps along shorelines. Seeds and stems of the plants are important food for waterfowl and mammals. Management actions targeting this species may cause more harm than good. 1.2.2. Partial Control: Partial control of non-noxious native aquatic weeds is recommended in order to maintain lake management activities. For instance, fragrant or white water lily (Nymphae odorata), a native weed to NC, provides aesthetic value for the surrounding lake community. However, excessive spatial coverage on surface of lake would interfere with boating, fishing, and swimming. Sometimes an extensive control of non-noxious aquatic weeds might be needed. Level of control depends on the nature of invasion in a lake. Therefore, selection of a control level should be done on a case by case basis. 1.2.3. Extensive Control: Presence of noxious aquatic weeds or exotic aquatic weeds may justify extensive control. For instance, Hydrilla species (Hydrilla verticillata) is a very competitive exotic as well as noxious aquatic weed. This species adversely impacts aquatic ecosystems by forming dense canopies that often shade out native vegetation. Therefore, lake wide extensive control of these aquatic weeds is recommended. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 9 1.3. Aquatic Weed Control Strategies The identified aquatic weeds in Table 1.1 are generally characterized by rapid growth, ability to regenerate by fragmentation (production of new plants from small plant segments) or vegetative hibernating organs (tubers and turions). Factors that contribute to their rapid development are often connected with their normal pattern of succession. Therefore, if control measures are not carried out, the five lakes may eventually fill with aquatic weeds. Normally, the following preventive measures are recommended to control aquatic weeds: Hand Pulling and Bottom Barrier Installation, Aquatic Herbicide Treatment, Triploid Grass Carp, Diver Dredging, and Water Level Drawdown. Intensity of these preventive measures, however, depends upon hydrologic characteristics of lakes and aquatic species. When applying herbicide in a lake, one should follow the North Carolina Pesticide Law of 1971, G.S. 143-434, Article 52. The law establishes programs of pesticide management and control under the authority of the North Carolina Pesticide Board. The purpose of the Law is to protect the health, safety, and welfare of the people of this State, and to promote a more secure, healthy and safe environment for all people of the state. This is accomplished by regulation in the public interest of the use, application, sale, disposal, and registration of pesticides. The North Carolina Pesticide Law of 1971 requires the registration of pesticide products in the state, the licensing and certification of commercial and private applicators and pest control consultants, the proper handling, transportation, storage and disposal of pesticides, and the licensing of dealers selling restricted use pesticides. 1.4. Characteristics of Lakes The five lakes -- Roanoke Rapid Lakes, Rockingham City Lake, Big Lake, Reedy Creek Lake, and Lake Wackena -- are artificially created for water supply and recreation in North Carolina. Rivers and streams are the primary sources of water to the lakes. Water that runs off the land surface also enters the lakes. Water levels in the lakes fluctuate seasonally and annually. During summer season when rains are infrequent; run-off is Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 10 minimal; and sediment loads are insignificant; sunlight penetrates deeper into the water column. The depth light that is able to penetrate the water column is called the photic zone and is measured as twice the secchi depth (measure of transparency of water column). Increased light increases productivity and fosters plant growth, especially when it reaches nutrient rich sediments. Therefore, increased photic zone allows plants to grow at greater depths, which would be normally unattainable without the increased light. Photic zone is important for plant colonization and growth is coupled with the fact that shallow systems with large surface areas are more susceptible to weed infestations than deep systems with small surface areas. Average photic zones and surface areas of the five lakes during summer period are presented in Table 1.3. Table 1.3. Physical and Chemical Properties of the studied lakes in NC NC Lakes Surface Area (Acres) Average Photic Zone During Summer Period (Meter) Average Maximum Depth (Meter) Average Depth (Meter) Average Water Temperature (OC) Average Chlorophyl a (ug/L) Average Turbidity (NTU) Rockingham City Lake Roanoke Rapids Lake Big Lake Reedy Creek Lake Lake Wackena 27 4893 62 20 165 1.53 3.21 1.58 2.29 1.95 2 27 5 4 5 0.7 5 2 2 2 26 27 29 29 32 4.5 6.0 10.0 6.0 15.0 2.6 2.4 17.0 16.0 4.2 The photic zones of the five lakes were considerably high compared to their average water depths during summer period. On average, the photic zones occupied 65% of the average depth in Roanoke Rapids Lake and 80% in Big Lake. The occupation was higher than 90% in the remaining three lakes. The result suggests that the five lakes facilitate the photosynthetic process, promoting rapid and dense growth during summer time. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 11 Water temperature is another important factor that governs growth of plants. Although some plants can photosynthesize and grow at 2O C, it is generally at higher temperatures (20 to 35 O C) that weed problems become most severe (Spencer and Bowes, 1990). Water temperature in the six lakes during summer time reached to more than 25 O C (Table 1.3). The result further suggests that the lakes provided good environment for the weeds to grow profusely during summer time. Soil erosion and nutrient enriched runoff can also increase growth of aquatic plants. Eroded soil particles not only make a lake shallower and allow rooted plants to quickly invade, but soil particles also transport adsorbed nitrogen and phosphorus that stimulate plant growth. In addition, nutrient enriched runoff deposits nitrogen and phosphorus in the bottom soil of lake. The deposited nutrients further stimulate plant growth. However, the five lakes were not contaminated due to nutrient and sediment problems during the study periods; because the lakes did not exceed Chlorophyll a and turbidity values greater than the State’s standard values, 40 ug/L and 50 NTU, respectively (Table 1.3 and Appendix 11.3). Therefore, a control strategy through reducing nutrient and sediment is not discussed in this aquatic weed TMDL study. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 12 2. Rockingham City Lake 2.1. General Background Rockingham City Lake is a secondary water supply reservoir for the City of Rockingham (Figure 2.1). The lake receives permanent water from Falling Creek and supplies water for approximately one-third of the total water use in the City. The volume of the lake is 0.02 x106 m3, the mean depth is 0.7 meter (two feet) and the maximum depth is two meter (7 feet). The drainage area covers 52 km2 (20 mi2). Observed land uses in the watershed include forested areas, agricultural areas consisting of crop production, and slight residential and urban development (Figure 2.2). Figure 2.1. Location of the Rockingham City Lake in the Yadkin River Basin. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 13 Figure 2.2. Aerial view of the Rockingham City Lake (USGS: January 30, 1993). Rockingham City Lake is currently classified as WS-III CA. Class WS-III states that waters are used as sources of potable water where a more protective WS-I or II classification is not feasible. These waters are also protected for Class C uses. WS-III waters are generally in low to moderately developed watersheds. General discharge permits only are allowed near the water supply intake whereas domestic and nonprocess industrial discharges are allowed in the rest of the water supply watershed. The Class CA stands for critical area. 2.2. Aquatic Weed Problem On August 24, 1995, the DWQ staff identified the following aquatic weeds in Rockingham Lake: spike rush (Eleocharis sp.), bog moss (Mayaca fluviatilis), two-leaf watermilfoil (Myriophyllum heterophyllum) and fragrant or white waterlily (Nymphae odorata). The identified plants are native to North Carolina (Godfrey and Wooten 1997 and 1981). These plants are not included on the federal or state noxious weed list (Table 1.1). However, excessive plants like watermilfoil and fragrant waterlily can limit swimming, fishing, boating, and aesthetic appreciation. Characteristics of the plants are as follows: Rockingham City Lake Rockingham City SR 1640 US 1 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 14 Spike rush (Eleocharis sp.): The plant can be recognized by the oval-shaped, brownish- flowering spikes at the tips of smooth, round stems. Spike-rush species grow individually or in clumps along shorelines or in shallow water, sometimes forming ankle- high turf-like mats (http://www.ecy.wa.gov/programs/wq/wqhome.html). Needle spike- rush often appears hair-like when growing underwater. Seeds and stems of the plants are important food sources for waterfowl and mammals. Spike-rushes provide habitat for amphibians and fish and help stabilize shorelines. Therefore, a TMDL to control the plant is not required. Bog moss (Mayaca fluviatilis): This plant is a submersed plant (http://aquat1.ifas.ufl.edu/welcome.html). It may be found in water several feet deep. The stems of bog moss are typically several feet long. The stems are whitish-green. The leaves of bog moss are soft and mossy, like short pieces of fine thread. They are arranged spirally on the stem, and are densely crowded. Bog moss flowers are solitary, on stalks that are one to two inches long. Its massive growth can limit swimming, fishing, skiing, sailing, boating, and aesthetic appreciation. Therefore, its growth should be limited in lakes with secondary recreation uses. Two-leaf watermilfoil (Myriophyllum heterophyllum): The plant is a submerged plant and flowers in the spring through the fall (http://aquat1.ifas.ufl.edu/welcome.html). Its massive growth can limit swimming, fishing, skiing, sailing, boating, and aesthetic appreciation. For this reason, management of the plant is needed. Fragrant or white waterlily (Nymphae odorata): This plant is a rooted, emerged aquatic plant distinctive for its sweet-scented, white, or pink, showy flower (http://www.ecy.wa.gov/programs/wq/wqhome.html). The plant has floating leaves, which are nearly circular in shape. They are notched to the center. Leaves arise on stalks from long rhizomes in the mud. Generally, the plant is not a problem, but significant spatial coverage in the surface of the lake would interfere with boating, fishing, and swimming. Its surface covering would also physically prevent atmospheric oxygen from dissolving into the water. Although relatively slow-spreading, water lilies will eventually Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 15 colonize shallow water depths to six feet deep and can dominate shorelines of shallow lakes. For this reason, the plant needs to be controlled from spreading across the entire lake surface. 2.3. Control Strategies The Rockingham Water Treatment Plant in Richmond County manages Rockingham City Lake. The plant releases triploid grass carps every ten years to control the aquatic plants in the lake. According to the plant supervisor, Mr. Gary Johnson, the last release was in March 2001 and total number of grass carps released was 150. Nevertheless, grass carps will not eat bog moss and watermilfoil. They will consume fragrant waterlily, but the effective control of the plant is not yet well documented. The University of Washington experimented with using triploid grass carp to remove fragrant and other species of waterlilies from Chambers Lake, Thurston County by stocking very high rates of fish (http://www.ecy.wa.gov/programs/wq/plants/weeds/). However, little or no impact of the fish on waterlilies was observed in that lake. Some of the control strategies like bottom barriers and manual harvesting could be effective to control the aquatic plants in the lake. Some lake residents have indicated that extremely persistent "picking" of emerging waterlily leaves every other day during the growing season for two to three seasons will eventually kill the plants. Herbicide application is not necessary, because the identified plants are not noxious for the lake (see section 1.2). Improper application of herbicide could cause toxicity in the lake. Furthermore, use of sophisticated machines to cut or drag the plants from the lake is not recommended. It can result in eroding soils from banks and bottom surface of the lake. 2.4. Control Level Because the identified aquatic weeds in Rockingham City Lake are native to North Carolina and are not listed as noxious weeds (Appendix 12.2), a partial control of these plants might be needed to attain lake management goals. However, there is no need to control spike rush, because it provides good habitat for amphibians and fish and helps Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 16 stabilize shorelines of the lake. Different control levels are described in details in Section 1.2. 2.5. Critical condition Growth patterns of the native weeds suggest summer as the critical period for the Rockingham City Lake. The identified native aquatic weeds are rooted perennial plants. Each spring new shoots appear from rhizomes and grow up through the water until they reach the surface. During summer time, their growths are further enhanced due to prolonged photosynthesis period. In Rockingham Lake, light can reach up to 1.5 meter in the lake (Table 1.3), which is a favorable condition for submerged photosynthesis. Flowers of waterlily appear from June to September. Each blossom opens in the morning and closes in the early afternoon for two to five consecutive days. The plant senesces in fall and over winters as the rhizome. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 17 3. Roanoke Rapids Lake 3.1. General Background Roanoke Rapids Lake, located on the Roanoke River immediately downstream from Lake Gaston, is owned by the Virginia Electric and Power Company. This reservoir is used as a water supply and for recreation. Maximum depth is 27 meter (89 feet), mean depth is five meter (16 feet), and volume is 96 x 106 m3. The Roanoke River is the major tributary to the reservoir and drains nearly all of its 21,482 km2 (8,294 mi2) watershed. Releases from Lake Gaston located directly upstream account for almost all of the inflow into Roanoke Rapids Lake (Figure 3.1). The watershed is characterized by rolling hills where nearly three-fourths is forested and most of the remaining land is agricultural (Figure 3.2). Roanoke Rapids Lake is currently classified as WS-IV & B CA. Class WS-IV states that waters are used as sources of potable water where a WS-I, II or III classification is not feasible. These waters are also protected for Class C uses. WS-IV waters are generally in moderately to highly developed watersheds or Protected Areas, and involve no categorical restrictions on discharges. Class B states that waters are used for primary recreation and other uses suitable for Class C. Primary recreational activities include swimming, skin diving, water skiing, and similar uses involving human body contact with water where such activities take place in an organized manner or on a frequent basis. There are no restrictions on watershed development or types of discharges. Class CA stands for critical area, which is the area adjacent to a water supply intake or reservoir where risk associated with pollution is greater than from the remaining portions of the watershed. The critical area is defined as extending either 1/2 mile from the normal pool elevation of the reservoir in which the intake is located or to the ridge line of the watershed (whichever comes first); or 1/2 mile upstream from and draining to the intake (or other appropriate downstream location associated with the water supply) located directly in the stream or river (run-of-the-river), or to the ridge line of the watershed (whichever comes first). Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 18 Figure 3.1. Location of the Roanoke Rapids Lake in the Roanoke River Basin. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 19 Figure 3.2. Aerial view of Roanoke Rapids Lake (USGS: February, 1994). 3.2. Aquatic Weed Problem In 1994, aerial surveys conducted by North Carolina State University found the following composition of invasive aquatic weeds in Roanoke Rapids Lake: 90% Myriophyllum spicatum, 9% Egeria densa, and 1% Hydrilla verticillata. Nine years later, in August 2003, the DWR-Aquatic Weed Control program surveyed the lake to estimate the composition of invasive aquatic weeds. The program found water milfoil being dominated by hydrilla profoundly. The composition was 1% Myriophyllum spicatum and 99% Hydrilla verticillata. All the identified aquatic weeds in Roanoke Rapids Lake were noxious to the North Carolina lakes (Appendix 12.2). Their physiological characteristics and control methods are well documented in http://www.ecy.wa.gov/programs/wq/plants/weeds/. Roanoke Rapids Lake Lake Gaston Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 20 Hydrilla (Hydrilla verticillata): Hydrilla is the most competitive exotic aquatic weed identified in Roanoke Rapids Lake. The plant is a much- ranched perennial, submerged, rooted, vascular plant. It needs just a little light to grow. Hydrilla adversely impacts aquatic ecosystems by forming dense canopies that often shade out native vegetation. Extensive monospecific stands of hydrilla can provide poor habitat for fish and other wildlife. Hydrilla mats provide good breeding grounds for mosquitoes. Hydrilla interferes with recreational activities such as swimming, boating, fishing and water skiing. Eurasian watermilfoil (Myriophyllum specatum): Eurasian milfoil is a submerged, invasive, and non-native plant. It has feather-like underwater leaves and emergent floral spikes. Its stem sometimes emerges 2 to 4 inches above water; usually, the stem will have no leaves. The plant spreads rapidly, crowding out native species, clogging waterways, and blocking sunlight and oxygen from underlying waters. Brazilian elodea (Egeria densa): Brazilian elodea is also a submerged, invasive, and non-native weed. The plant makes good aquarium plant and is commonly sold as in the United States and Canada. The plant can be a nuisance plant out of its native habitat. It is an underwater and sometimes floating perennial that can form tangled masses near the water surface. Dense masses interfere with recreational uses of a lake by interfering with navigation, fishing, swimming, and water skiing. 3.3. Control Strategies The Aquatic Nuisance Plant Control Program in Halifax County manages Roanoke Rapids Lake. The program applied the herbicides, Copper and Diquat, to control the aquatic plants in the lake (from personal communication with the program manager Mr. Skip Wiegersma). Effectiveness of herbicide application indeed varies with types of aquatic plants. There are three EPA-registered herbicides effective against hydrilla growth: Fluridone Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 21 (Sonar®), endothall (Aquathal®), and copper compounds. Fluridone is a systemic herbicide that has proven effective against hydrilla in Florida and other states. Endothall, a fast-acting contact herbicide, is used when immediate control of vegetation is needed. Copper compounds are often used in conjunction with endothall applications, although copper by itself exhibits herbicidal action against hydrilla. These herbicides do not affect hydrilla seeds, tubers, and turions and repeated applications are needed to control hydrilla regrowth. Westerdahl and Getsinger (1988) report excellent control of Eurasian watermilfoil with 2,4-D, diquat, endothall dipotassium salt, and endothall and complexed copper. They report good control with fluridone. Westerdahl and Getsinger (1988) also report excellent control of Brazilian elodea with diquat and complexed copper, endothall dipotassium salt, and endothall and complexed copper. However, enodthall is considered by general knowledge of aquatic plant managers to be less than effective against Brazilian elodea. Good control was obtained with fluridone. However, improper application of these herbicides can contaminate ground water and surface water. It is, therefore, important that only herbicides that are EPA approved for aquatic use are selected, and that applications strictly adhere to label specifications. It is also important that herbicides are applied only when following strategies fail to control the aquatic plants. Drawdown can be an effective cultural method to control the aquatic weeds. The Tennessee Valley Authority (TVA) uses both winter and summer water level drawdown as an effective way of reducing Eurasian watermilfoil biomass. Poovey (1997) suggested that hydrilla in NC lakes could be managed by a short-term summer drawdown. Manning and Johnson (1975) reported that water level drawdown, in combination with 2,4-D treatment of Hydrilla on exposed substrates, plus diquat application to weed beds in areas still covered by water, formed an effective integrated approach to submerged weed control in a Louisiana reservoir. Goldsby and Sanders (1977) reported that Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 22 consecutive drawdowns in Black Lake, Louisiana eradicated Brazilian elodea. They noted that consecutive drawdowns might be more effective than an individual drawdown. Localized control of the aquatic weeds (in swimming areas and around docks) can be achieved by covering the sediment with an opaque fabric which blocks light from the plants (bottom barriers or screens). Manual harvesting can also be an effective method to control the aquatic plants in the lake. However, a major disadvantage of harvesting Hydrilla is that the underground material is left behind. The tubers of the plant are particularly troublesome, since they serve as a source of regrowth in areas where the hydrilla shoots have been controlled by chemical or mechanical methods. Biological control of Hydrilla by means of grass carp (Ctenopharyngodon idella) is one of the most successful methods of controlling Hydrilla in NC lakes. Species like silver carp (Hypophthalmichthys molitrix) and big head carp (Aristichthys nobilis) that consume phyto- and zooplankton, and the polyphagous Tilapia species are sometimes used in combination with grass carp for weed control. Their role in aquaculture in combination with grass carp is found to be much more effective (Zweerde, 1990). Like Hydrilla, Brazilian elodea is highly palatable to grass carp. The crap has been successfully employed as a management tool in Devils Lake, Oregon to control plant populations (http://www.ecy.wa.gov/programs/wq/plants/weeds/). In practice, grass carp often remove the entire native aquatic community; therefore grass carp should be used with great care. However, grass carp prefers less to eat Eurasian watermilfoil, because the plant is not a highly palatable. In situations where Eurasian watermilfoil is the only aquatic weed species in a lake, grass carp may be a management solution. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 23 Insects can be used to control Eurasian watermilfoil. The North American weevil, Euhyrchiopsis lecontei (Dietz), has been found associated with declining populations of Eurasian watermilfoil in northeastern North America. A researcher at the University of Washington is conducting an evaluation of whether the milfoil weevil will be a suitable control for Eurasian watermilfoil in Washington. The plant pathogenic fungus Mycoleptodiscus terrestris has been shown to significantly reduce Eurasian water milfoil biomass in laboratory studies, but not in field settings. The US Army Corps of Engineers is continuing research on plant pathogens. Similarly, recent research in Brazil has identified a fungus (Fusarium sp.), which damaged Brazilian elodea in laboratory tests. This may have potential as a biological control agent for Brazilian elodea. 3.4. Control Level Because the identified aquatic weeds in the lake are noxious and non-native to North Carolina (Table 1.1), these plants should be removed to the best extent possible. Complete removal is the ultimate goal, but may not be realized due to the limited sources and methods available to combat the weeds. Different control levels are described in details in Section 1.2. 3.5. Critical Condition Growth patterns of hydrilla and Eurasian watermilfoil suggest summer as the critical period for Roanoke Rapids Lake. Light and temperature are the key environmental factors that enhance growth of plants through photosynthesis. In the Roanoke Rapid Lake, light could penetrate to a depth of 3.2 meters (Table 1.3). The defined zone covered approximately 64 % of the mean depth of the lake. Therefore, the lake provides a favorable condition for photosynthesis to occur. In addition, water temperature during summer remained 27O C on average, the temperature at which hydrilla and Eurasian watermilfoil grow profusely (Spencer and Bowes, 1990). Hydrilla is able to survive and spread readily due to its ability to produce structures called turions and tubers. Turions are compact "buds" produced along the leafy stems. They Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 24 break free of the parent plant and drift or settle to the bottom to start new plants. They are 1/4 inch long, dark green, and appear spiny. Tubers develop in the hydrosoil and form at the end of roots. They are small, potato-like, and are usually white or yellowish. Hydrilla produces an abundance of tubers and turions in the fall. Tubers may remain dormant for several years in the sediment. Hydrilla also makes tubers in the spring and will produce nondormant turions throughout the growing season. In the spring, Eurasian watermilfoil begins to grow rapidly as water temperatures approach 15O C. When the plant near the surface, shoots branch profusely, forming a dense canopy. Typically, plants flower upon reaching the surface (usually in mid to late July). After flowering, plant biomass declines as the result of the fragmentation of stems. Where flowering occurs early, plant biomass may increase again later in the growing season and a second flowering may occur. During fall, plants die back to the root crowns, which sprout again in the spring. In contrast, Brazilian elodea behaves differently in its growth. The plant begins to deteriorate when the temperature reaches 30 O C (Spencer and Bowes, 1990). Its growth appears to be increased when water temperature declines to 10 O C. Therefore, the growth pattern of Brazilian elodea suggests winter as the critical period for Roanoke Rapids Lake. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 25 4. Big Lake 4.1. General Background Big Lake is located at Umstead State Park in Raleigh (northwestern Wake County), adjacent to the Raleigh-Durham International Airport. Sycamore Creek is impounded twice within the park, first forming Big Lake and then Sycamore Lake (Figure 4.1). Big Lake has a drainage basin of seven square miles (18 km2). Land use in the watershed is primarily forest and agriculture; however, development has increased considerably over the past years (Figure 4.2). Big Lake has a maximum depth of five meters (16 feet), a mean depth of two meters (six and a half feet), a mean hydraulic retention time of 25 days and a volume of 0.05 x106m3. . Figure 4.1 Location of Big Lake in Neuse River Basin Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 26 Figure 4.2. Aerial view of the Big Lake (USGS: March 29, 1998). Big Lake is currently classified as B NSW. Class B states that water is used for primary recreation and other uses suitable for class C. Primary recreational activities include swimming, skin diving, water skiing, and similar uses involving human body contact with water where such activities take place in an organized manner or on a frequent basis. The supplemental class NSW (Nutrient Sensitive Waters) states that water is needed for additional nutrient management due to their being subject to excessive growth of microscopic or macroscopic vegetation. This supplemental classification is associated with all waters in the Neuse River Basin. In general, management strategies for point and nonpoint source pollution control require limitation of nutrients such that excessive growths of vegetation are reduced or prevented and there is no increase in nutrients over target levels. There are no restrictions on watershed development or discharge types. 4.2. Aquatic Weed Problem Staff of NC Division of Water Resources, noticed hydrilla covering 90 to 100% of the shoreline in Big Lake on July 18, 2000. Characteristics of the plant are described in detail in Section 3.2, above. Raleigh Durham Airport Raleigh Big Lake Big Lake Big Lake Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 27 4.3. Control Strategies The Umstead State Park in Wake County manages Big Lake. The park applied the herbicide Sonar to control Hydrilla. However, improper application of herbicides can contaminate ground water and surface water. It is, therefore, important that only herbicides that are EPA approved for aquatic use are selected, and that applications strictly adhere to label specifications. It is also important that herbicides are applied only when other possible strategies fail to control the aquatic plants. The possible strategies are discussed in detail in Section 3.3, above. The park also releases grass carps every three to four years to control the plant. The total estimated grass carp released from April 1985 through April 1999 was about 2,700 (from personal communication with Mr. Rob Emens, Aqautic Weed Control, Division of Water Resources). 4.4. Control Level Because the identified aquatic weeds in the lake are noxious and non-native to North Carolina (Appendix 12.2), these plants should be removed to the best extent possible. Complete removal is the ultimate goal, but may not be realized due to an extensive and persistent tuber bank that has developed over the last two decades. Different control levels are described in details in Section 1.2. 4.5. Critical Condition Growth pattern of hydrilla suggests summer as the critical period for Big Lake. Light and temperature are the key environmental factors that enhance growth of the plant through photosynthesis. In Big Lake, light could penetrate up to 1.6 meter, on average (Table 1.3). The zone covered approximately 80 % of the mean depth of the lake. Furthermore, water temperature during summer remained 29O C on average in Big Lake. Hydrilla grows profusely between 28 to 37 O C (Spencer and Bowes, 1990). Therefore, the lake provides a favorable condition for hydrilla during the summer period. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 28 5. Reedy Creek Lake 5.1. General Background Reedy Creek Lake is located in Umstead State Park, which is adjacent to the Raleigh Durham International Airport (Figure 5.1). The lake is relatively small with a surface area of 20 acres (eight hectares) and a volume of 0.14 x106m3. The maximum and average depths are four meter (13 feet) and two meters (seven feet), respectively. The lake's watershed is approximately 11 km2 (4 mi2). Land use in the watershed is primarily forest and agriculture (Figure 5.2). Retention time for the lake is eleven days. Reedy Creek is one of three lakes (Big Lake, Reedy Creek and Sycamore) located within the park. Figure 5.1 Location of Reedy Creek Lake in Neuse River Basin Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 29 Figure 5.2. Aerial view of Reedy Creek Lake (USGS: March 29, 1998). Reedy Creek Lake is classified as B NSW and is used primarily for educational and recreational purposes. Class B states that water is used for primary recreation and other uses suitable for Class C. Primary recreational activities include swimming, skin diving, water skiing, and similar uses involving human body contact with water where such activities take place in an organized manner or on a frequent basis. The supplemental class NSW (Nutrient Sensitive Waters) states that water is needed for additional nutrient management due to their being subject to excessive growth of microscopic or macroscopic vegetation. This supplemental classification is associated with all waters in the Neuse River Basin. In general, management strategies for point and nonpoint source pollution control require limitation of nutrients such that excessive growths of vegetation are reduced or prevented and there is no increase in nutrients over target levels. I-40 US-70 Reedy Creek Lake Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 30 5.2. Aquatic Weed Problem Staff of NC Division of Water Resources identified the noxious aquatic weed, Hydrilla verticillata, in Reedy Creek Lake along the shoreline on July 14, 2000. Characteristics of the plant are described in Section 3.2, above. 5.3. Control Strategies The Umstead State Park manages Reedy Creek Lake. The park applied herbicides like Diquat, Cutrine Plus, Aquathol, and Sonar to control Hydrilla. However, improper application of herbicides can contaminate ground water and surface water. It is, therefore, important that only herbicides that are EPA approved for aquatic use are selected, and that applications strictly adhere to label specifications. It is also important that herbicides are applied only when other possible strategies fail to control the aquatic plants. The possible strategies are discussed in detail in Section 3.3, above. The park also releases grass carps every three to four years to control the plant. The total estimated grass carp released from September 1986 through April 1999 was about 1,650 (from personal communication with Mr. Rob Emens, Aqautic Weed Control, Division of Water Resources). 5.4. Control Level Because the identified aquatic weeds in the lake are noxious and non-native to North Carolina (Table 1.1 and Appendix 1), these plants should be removed to the best extent possible. Complete removal is the ultimate goal, but may not be realized due to an extensive and persistent tuber bank that has developed over the last two decades. Different control levels are described in details in Section 1.2. 5.5. Critical Condition Growth pattern of hydrilla suggests summer as the critical period for Reedy Creek Lake. Light and temperature are the key environmental factors that enhance growth of the plant through photosynthesis. In this lake, light will penetrate up to 2.3 meters (Table 1.3) promoting photosynthesis. Furthermore, water temperature during summer remained 29O C on average in the Lake. Hydrilla grows profusely between 28 to 37 O C (Spencer and Bowes, 1990). Therefore, the lake provides a favorable condition for hydrilla to grow during the summer period. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 31 6. Lake Wackena 6.1. General Background Lake Wackena is a privately owned lake located near Goldsboro in Wayne County. The shoreline of the lake is comprised of a residential development (Walnut Creek Estates) and a golf course. The lake has a surface area of 165 acres (67 hectares) with a maximum depth of five meters and a mean depth of two meters. The lake's watershed is approximately 16 mi2 (41.4 km2), consisting mostly of forested and agricultural land. Figure 6.1 Location of Lake Wakena in Neuse River Basin Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 32 Figure 6.2. Aerial view of Lake Wackena (USGS: February 3, 1993). Lake Wackena is currently classified as C-NSW and is used primarily for recreational purposes. Class C states that water is protected for secondary recreation, fishing, wildlife, fish and aquatic life propagation and survival, agriculture and other uses suitable for Class C. Secondary recreation includes wading, boating, and other uses involving human body contact with water where such activities take place in an infrequent, unorganized or incidental manner. The supplemental Class NSW (Nutrient Sensitive Waters) states that water is needed for additional nutrient management due to it being subject to excessive growth of microscopic or macroscopic vegetation. This supplemental classification is associated with all waters in the Neuse River Basin. In general, management strategies for point and nonpoint source pollution control require limitation of nutrients such that excessive growths of vegetation are reduced or prevented and there is no increase in nutrients over target levels. 6.2. Aquatic Weed Problem In 303(d) list, Lake Wackena is listed as an impaired waterbody due to aquatic weeds. However, neither field record indicated that the lake was impaired due to aquatic weeds, Lake Wackena Walnut Creek Estates SR 1728 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 33 nor the 303(d) list suggested any types of aquatic weeds existed in the lake. It is, therefore, recommended to delist Lake Wackena since there is no basis for any impairment decision. 7. Summary and Future Consideration This report presents the development of Total Maximum Daily Loads (TMDLs) for the following five lakes in North Carolina: Rockingham City Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena. The first two lakes are located in Yadkin River Basin and Roanoke River Basin respectively. The last three lakes are located in Neuse River Basin. All the five lakes were identified impaired due to aquatic weeds in the 303(d) list. Available field reports on the aquatic weed types in the five lakes are reviewed and TMDLs are determined to control the aquatic weeds. Growth and development of the aquatic weeds are examined to conclude the critical periods. The necessary reduction levels of the plants to meet the TMDL requirement was then qualitatively determined based on utility of the plants in the respective lakes. The summary of the results is as follows: • Rockingham City Lake was identified impaired due to four different native and non-noxious aquatic weeds: Eleocharis sp. Mayaca fluviatilis, Myriophyllum heterophyllum, and Nymphae odorata. The species of Eleocharis protects lake shorelines and provides food for aquatic animals; therefore removal of this plant is not recommended. The remaining three native plants require partial control. Use of opaque fabric for bottom screens and manual harvesting can be used to control these plants. • Roanoke Rapids Lake was identified impaired due to three exotic and noxious aquatic weeds: Hydrilla verticillata, Myriophyllum spicatum, and Egeria densa. These plants need to be removed 100% from the lake. Different cultural practices such as herbicide application, use of opaque fabric for bottom screens, and manual harvesting can be used successfully for the plants like Hydrilla verticillata and Myriophyllum spicatum. Biocontrol method should be considered as an alternative, or in conjunction with methods stated above. The stocking of sterile grass carp has successfully eradicated hydrilla from some lakes in NC. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 34 • Big Lake was identified impaired due to Hydrilla verticillata. The identified species is an exotic and noxious aquatic weed. It needs to be removed 100% from the lake. Different cultural practices such as herbicide application, use of opaque fabric for bottom screens, and manual harvesting can be used successfully for the plants like Hydrilla verticillata and Myriophyllum spicatum. Biocontrol method (i.e. stocking grass carp) should be considered as an alternative, or in conjunction with methods stated above. • Reedy Creek Lake was identified impaired due to the exotic and noxious aquatic weed Hydrilla verticillata. It needs to be removed 100% from the lake. Different cultural practices such as herbicide application, use of opaque fabric for bottom screens, and manual harvesting can be used successfully for the plants like Hydrilla verticillata and Myriophyllum spicatum. Biocontrol method (i.e. stocking grass carp) should be considered as an alternative, or in conjunction with methods stated above. • Lake Wackena was identified impaired due to aquatic weeds in the 303(d) list, but no specific types of plants were recorded. There is no basis for any impairment decision. It is therefore recommended to delist the lake from the 303(d) list. 7.1. Lake Monitoring Lake monitoring for aquatic weed identification should continue on a quarterly interval. While monitoring, the following additional information should be collected for evaluation of progress towards reaching water quality standards: • Identify types of aquatic weeds. • Draw map of aquatic weed locations in a lake, showing distribution. • Estimation of relative abundance of weeds, % surface area. • Growth and development of weeds. • Collection of sample of weed species. • Identification of substrate types. • Identification of sediment types • Identification of problem areas and beneficial weed zones. 7.2. Implementation Plan Development of a successful implementation plan to control aquatic weeds is an ongoing concern that requires long-term commitment from multiple state, federal agencies, and public participation. The plan should focus on monitoring and determining efficacy of Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 35 control measures and allowing for modification as conditions change. Integration of control methods and best management practices should be implemented. The development of funding strategies and implementation of public outreach program for noxious and invasive weeds are necessary. 8. Public Participation Many local government officials have been notified of DWQ’s intention to develop the Aquatic Weeds TMDL for Rockingham City Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena. The TMDL was publicly noticed through local newspapers, Richmond CO. Daily Journal, Daily Herald, The News and Observer, and Goldsboro News Argus on June 30, 2006 (Appendix 11.4). The TMDLs was also publicly noticed through DWQ web site at http://h20.enr.state.nc.us/tmdl/. A public comment period was through August 7, 2006. No written comments were received. 9. Further Information Technical questions regarding this report should be directed to the following members of the DWQ Modeling/TMDL Unit: Narayan Rajbhandari, Environmental Modeler, (narayan.rajbhandari@ncmail.net), and Michelle Woolfolk, Supervisor (michelle.woolfolk@ncmail.net). Further information concerning North Carolina’s water quality program can be found on the Internet at the Division of Water Quality website: http://h2o.enr.state.nc.us/. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 36 10. References Barko, J. W. and R. M. Smart. 1981. Comparative influences of light and temperature on the growth of selected submerged freshwater macrophytes. Ecological Monographs, 51, 219-35. Bureau of Aquatic Plant Research and Control, Florida Department of Natural Resources. Aquatic Weed Identification and Control Manual. Larson Building, Tallahassee, Florida. 1973. Department of Ecology. Water Quality Program. Washington State. http://www.ecy.wa.gov/programs/wq/wqhome.html Division of Water Resources. North Carolina Aquatic Weed Control Council, North Carolina State. Meeting Minutes. February 21, 2002 and February 20, 2003. Getsinger, K. D., and C. R. Dillon. 1984. Quiescence, growth and senescence of Egeria densa in Lake Marion. Aquatic Botany, 20, 329-38. Gibbon, Maribeth V., Mark G. Rosenkranz, Harry L. Gibbons, Jr, and Mark D. Sytsma. Guide for Developing Intergrated Aquatic Vegetation Management Plans in Oregon. Center for Lakes and Reservoir. Portland State University. Portland OR 97207. 1999. Godfrey Robert K. and Jean W. Wooten. Aquatic and Wetland Plants of Southeastern United States: Dicotyledons. Athens. The University of Georgia Press. 1981. Godfrey Robert K. and Jean W. Wooten. Aquatic and Wetland Plants of Southeastern United States: Monocotyledons. Athens. The University of Georgia Press. 1979. Goldsby, T.L., A.L. Bates, and R.A. Stanley. 1978. Effect of water level fluctuation and herbicide on Eurasian watermilfoil in Melton Hill Reservoir. Journal of Aquatic Plant Management, 16, 34-38. Manning, J.H. and R. E. Johnson. 1975. Water level fluctuation and herbicide application: an intergarted control method for Hydrilla in a Louisiana reservoir. Hyacinth Control Journal, 13, 11-17. North Carolina Department of Environment and Natural Resources. 2003. North Carolina Water Quality Assessment and Impaired Waters List (2002 Integrated 305(b) and 303(d). Division of Water Quality, Water Quality Section, Environmental Sciences Branch, 1617 Mail Service Center, Raleigh, NC –27699-1617. Poovey, Angela Gale. Effects of a summer drawdown on monoecion hydrilla and non- target plants. Master of Science Thesis. North Carolina State University, Ecological Program. Raleigh, NC. 1997. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 37 Spencer W., and G. Bowes. Ecophysiology of the world’s most troublesome aquatic weeds. In Aquatic Weeds: The Ecology and Management of Nuisance Aquatic Vegetation. Edited by Arnold H. Pieterse and Kevin J. Murphy. Oxford University Press. 1990. University of Florida. Center for Aquatic and Invasive Plants. Institute of Food and Agricultural Sciences. http://aquat1.ifas.ufl.edu/welcome.html. U.S. Environmental Protection Agency (USEPA) 2000. Revisions to the Water Quality Planning and Management Regulation and Revisions to the National Pollutant Discharge Elimination System Program in Support of Revisions to the Water Quality Planning and management Regulation; Final Rule. Fed. Reg. 65:43586-43670 (July 13, 2000). U.S. Environmental Protection Agency (USEPA). 1991. Guidance for Water Quality- Based Decisions: The TMDL Process. Assessment and Watershed Protection Division, Washington, DC. U.S. Environmental Protection Agency (USEPA) 1998. Draft Final TMDL Federal Advisory Committee Report. U.S. Environmental Protection Agency, Federal Advisory Committee (FACA). Draft final TMDL Federal Advisory Committee Report. 4/28/98. Wade P. M. Physical control of aquatic weeds. In Aquatic Weeds: The Ecology and Management of Nuisance Aquatic Vegetation. Edited by Arnold H. Pieterse and Kevin J. Murphy. Oxford University Press. 1990. Westerdahl, H.E. and K.D. Getsinger, eds. 1988. Aquatic plant identification and herbicide use guide, volume II: Aquatic plants and susceptibility to herbicides. Technical report A-88-9. Department of the Army, Waterways Experiment Station, Corps of Engineers, Vicksburg, MS. Zweerde W Van Der. Biological control of aquatic weeds by means of phytophagous fish. In Aquatic Weeds: The Ecology and Management of Nuisance Aquatic Vegetation. Edited by Arnold H. Pieterse and Kevin J. Murphy. Oxford University Press. 1990. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 38 11. Appendices 11.1. Physical parameters of lakes Lake Name Date (m/d/yr) Water Temp ( C ) Secchi Depth (meters) Lake Name Date (m/d/yr) Water Temp ( C ) Secchi Depth (meters) Pittsboro 11-Aug-03 25.4 0.5 Rockingham City 17-Aug-00 26.8 0.7 Pittsboro 11-Aug-03 23.5 0.6 Rockingham City 8-Jun-00 25.5 0.7 Pittsboro 16-Jul-03 27.6 0.8 Rockingham City 24-Aug-95 28.6 0.5 Pittsboro 16-Jul-03 28.4 0.8 Rockingham City 19-Aug-92 23.7 1.1 Pittsboro 17-Jun-03 24.4 0.6 Roanoke Rapids 26-Aug-04 25.6 3.2 Pittsboro 17-Jun-03 24.5 0.6 Roanoke Rapids 26-Aug-04 27.2 2.1 Pittsboro 6-Aug-98 25.8 0.4 Roanoke Rapids 26-Aug-04 26.9 2.1 Pittsboro 6-Aug-98 25.6 0.4 Roanoke Rapids 29-Jul-04 25.9 2.6 Pittsboro 8-Jul-98 28.7 0.6 Roanoke Rapids 29-Jul-04 27.6 1.6 Pittsboro 8-Jul-98 29.1 0.4 Roanoke Rapids 29-Jul-04 28.2 2.1 Pittsboro 3-Jun-98 27.4 0.7 Roanoke Rapids 24-Jun-04 24.9 2.8 Pittsboro 29-Jul-93 33.4 0.4 Roanoke Rapids 24-Jun-04 26.2 2.2 Pittsboro 4-Aug-87 31.0 0.5 Roanoke Rapids 24-Jun-04 27.0 2.0 Pittsboro 4-Aug-87 31.0 0.9 Roanoke Rapids 5-Aug-99 27.2 1.7 Pittsboro 19-Aug-81 24.4 0.9 Roanoke Rapids 5-Aug-99 30.6 1.4 Pittsboro 19-Aug-81 24.3 0.9 Roanoke Rapids 5-Aug-99 30.8 1.8 Big 7-Aug-00 31.3 0.3 Roanoke Rapids 22-Jul-99 27.8 2.2 Big 7-Aug-00 30.4 0.3 Roanoke Rapids 22-Jul-99 30.0 2.2 Big 12-Jul-00 29.5 0.7 Roanoke Rapids 22-Jul-99 29.9 2.1 Big 12-Jul-00 29.7 1.3 Roanoke Rapids 2-Jun-99 23.3 2.0 Big 27-Jun-00 29.5 0.3 Roanoke Rapids 2-Jun-99 23.8 1.6 Big 27-Jun-00 29.4 1.0 Roanoke Rapids 2-Jun-99 24.1 1.5 Big 21-Aug-96 27.8 0.7 Roanoke Rapids 9-Aug-94 26.2 2.2 Big 21-Aug-96 27.7 0.7 Roanoke Rapids 9-Aug-94 26.8 1.7 Big 3-Jul-95 26.1 0.8 Roanoke Rapids 9-Aug-94 27.7 1.6 Big 3-Jul-95 25.9 0.8 Roanoke Rapids 30-Jul-87 25.6 1.4 Big 3-Jul-91 29.5 0.2 Roanoke Rapids 30-Jul-87 29.0 0.9 Big 3-Jul-91 29.7 0.6 Roanoke Rapids 30-Jul-87 29.4 1.5 Big 31-Jul-87 28.9 0.6 Roanoke Rapids 30-Jul-85 25.1 1.8 Big 31-Jul-87 29.2 0.6 Roanoke Rapids 30-Jul-85 25.0 1.6 Big 13-Aug-81 29.5 -- Roanoke Rapids 30-Jul-85 25.6 2.6 Big 13-Aug-81 29.7 1.6 Roanoke Rapids 29-Aug-84 25.8 2.0 Reedy Creek 7-Aug-00 29.8 0.2 Roanoke Rapids 29-Aug-84 25.2 1.3 Reedy Creek 12-Jul-00 29.7 0.8 Roanoke Rapids 29-Aug-84 25.7 1.0 Reedy Creek 27-Jun-00 29.4 1.2 Roanoke Rapids 12-Jul-83 25.3 1.4 Reedy Creek 10-Aug-95 26.6 0.7 Roanoke Rapids 12-Jul-83 26.0 2.0 Reedy Creek 12-Aug-91 28.0 2.0 Roanoke Rapids 12-Jul-83 26.8 1.9 Wackena 25-Jul-95 33.0 0.5 Roanoke Rapids 16-Jul-82 24.5 0.9 Wackena 25-Jul-95 32.7 1.5 Roanoke Rapids 16-Jul-82 24.5 1.1 Wackena 14-Jul-88 30.2 0.6 Roanoke Rapids 16-Jul-82 25.9 1.4 Wackena 14-Jul-88 30.4 1.3 Roanoke Rapids 6-Aug-81 27.5 1.3 Roanoke Rapids 6-Aug-81 27.7 0.5 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 39 11.2. North Carolina Aquatic Weed Control Act of 1991 North Carolina Aquatic Weed Control Act of 1991 & Aquatic Weed Control Regulations (Article 15 of Chapter 113A of the General Statutes of North Carolina) §113A-220. Short title. This Article shall be known as the Aquatic Weed Control Act of 1991. §113A-221. Definitions. Unless a different meaning is required by the context, the following definitions shall apply throughout this Article: (1) "Department" means the Department of Environment, Health, and Natural Resources. (2) "Secretary" means the Secretary of Environment, Health, and Natural Resources or his designee. (3) "Noxious aquatic weed" means any plant organism so designated under this Article. (4) "Waters of the State" means any surface body or accumulation of water, whether publicly or privately owned and whether naturally occurring or artificially created, which is contained within, flows through, or borders upon any part of this State. §113A-222. Designation of noxious aquatic weeds. (a) The Secretary, after consultation with the Director of the North Carolina Agricultural Extension Service, the Wildlife Resources Commission, and the Marine Fisheries Commission, and with the concurrence of the Commissioner of Agriculture, may designate as a noxious aquatic weed any plant organism which: (1) Grows in or is closely associated with the aquatic environment, whether floating, emersed, submersed, or ditch-bank species, and including terrestrial phases of any such plant organism; (2) Exhibits characteristics of obstructive nature and either massive productivity or choking density; and (3) Is or may become a threat to public health or safety or to existing or new beneficial uses of the waters of the State. (b) A plant organism may be designated as being a noxious aquatic weed either throughout the State or within specified areas within the State. (c) The Secretary shall designate a plant organism as a noxious aquatic weed by rules adopted pursuant to Chapter 150B of the General Statutes. (d) The Secretary may modify or withdraw any designation of a plant organism as a noxious aquatic weed made previously under this section. Any modification or withdrawal of such designation shall be made following the procedures for designation set out in this section. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 40 NC Aquatic Weed Control Act of 1991 continued: §113A-223. Powers and duties of the Secretary. (a) The Secretary shall direct the control, Control, and regulation of noxious aquatic weeds so as to protect and preserve human health, safety, and the beneficial uses of the waters of the State and to prevent injury to property and beneficial plant and animal life. The Secretary shall have the power to: (1) Conduct research and planning related to the control of noxious aquatic weeds; (2) Coordinate activities of all public bodies, authorities, agencies, and units of local government in the control and Control of noxious aquatic weeds; (3) Delegate to any public body, authority, agency, or unit of local government any power or duty under this Article, except that the Secretary may not delegate the designation of noxious aquatic weeds; (4) Accept donations, grants, and services from both public and private sources; (5) Enter into contracts or agreements, including cost-sharing agreements, with public or private agencies for research and development of methods of control of noxious aquatic weeds or for the performance of noxious aquatic weed control activities; (6) Construct, acquire, operate, and maintain facilities and equipment necessary for the control of noxious aquatic weeds; and (7) Enter upon private property for purposes of conducting investigations and engaging in aquatic weed control activities. (b) The Secretary may control, remove, or destroy any noxious aquatic weed located in the waters of the State or in areas adjacent to such waters wherever such weeds threaten to invade such waters. The Secretary may employ any appropriate control technology which is consistent with federal and State law, regulations, and rules. Control technologies may include, but are not limited to drawdown of waters, application of chemicals to shoreline and surface waters, mechanical controls, physical removal from transport mechanisms, quarantine of transport mechanisms, and biological controls. Any biological control technology may be implemented only after the environmental review provisions of the State Environmental Policy Act have been satisfied. (c) In determining the appropriate strategies and technologies, the Secretary shall consider their relative short-term and long-term cost-efficiency and effectiveness, consistent with a margin of safety adequate to protect public health and the resources of the State. (d) All activities carried out by the Secretary, his designees, and others authorized to perform any function under this Article shall be consistent with all applicable federal and State law, regulations, and rules. §113A-224. Powers of the Commissioner of Agriculture. (a) The Commissioner of Agriculture may regulate the importation, sale, use, culture, collection, transportation, and distribution of a noxious aquatic weed as a plant pest under Article 36 of Chapter 106 of the General Statutes. (b) This Article shall not be construed to limit any power of the Commissioner of Agriculture, the Department of Agriculture, or the Board of Agriculture under any other provision of law. §113A-225. Responsibilities of other State agencies. All State agencies shall cooperate with the Secretary to assist in the implementation of this Article. §113A-226. Enforcement. (a) Any person who violates this Article or any rule adopted pursuant to this Article shall be guilty of a misdemeanor and, upon conviction, shall be fined not less than fifty dollars ($50.00) or more than one thousand dollars ($1000), or imprisoned for not less than 10 days nor more than 180 days, or both, for each offense. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 41 NC Aquatic Weed Control Act of 1991 continued: (b) Whenever there exists reasonable cause to believe that any person has violated this Article or rules adopted pursuant to this Article, the Secretary may request the Attorney General to institute a civil action for injunctive relief to restrain the violation. The Attorney General may institute such action in the name of the State upon relation of the Department in the superior court of the county in which the violation occurred. Upon a determination by the court that the alleged violation of the provisions of this Article or of rules adopted pursuant to this Article has occurred or is threatened, the court shall grant the relief necessary to prevent or abate the violation or threatened violation. Neither the institution of the action, nor any of the proceedings thereon shall relieve any party to such proceedings from any penalty otherwise prescribed for violations of this Article. §113A-227. Adoption of rules. The Secretary may adopt rules necessary to implement the provisions of this Article pursuant to Chapter 150B of the General Statutes. AQUATIC WEED CONTROL REGULATIONS (Title 15A, Chapter 2, Subchapter 2G of the North Carolina Administrative Code) SECTION .0600 - AQUATIC WEED CONTROL SECTION .0601 THE AQUATIC WEED CONTROL ACT The North Carolina Aquatic Weed Control Act of 1991 empowers the State of North Carolina to control, eradicate, and regulate plants designated as noxious aquatic weeds. The Aquatic Weed Control Act and the existing powers of the Commissioner of Agriculture prohibit importation, sale, use, culture, collection, transportation, and distribution of these plants in North Carolina. Permits for the movement of noxious aquatic weeds may be obtained from the Commissioner of Agriculture pursuant to 2 NCAC 48A .1705 and .1706, subject to the conditions stated therein. History Note: Statutory Authority G.S. 106-420; 113A-222; 113A-223; 113A-224; Eff. September 1, 1992. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 42 NC Aquatic Weed Control Act of 1991 continued: SECTION .0602 NOXIOUS AQUATIC WEED LIST The Secretary of the Department of Environment, Health, and Natural Resources has determined that the following aquatic plants exhibit characteristics which threaten or may threaten the health or safety of the people of North Carolina or beneficial uses of the waters of North Carolina: (1) Aquatic Species Listed on the Federal Noxious Weed List. Azolla pinnata R. Brown Pinnate mosquitofern Eichhornia azurea (Sw.) Kunth Anchored waterhyacinth Hydrilla verticillata (L. f.) Royle Hydrilla Hygrophila polysperma (Roxb.) T. Anderson Indian hygrophila Ipomoea aquatica Forsk. Swamp morningglory, water spinach Lagarosiphon major (Ridley) Moss African Elodea Limnophila sessiliflora (Vahl) Blume Limnophila Melaleuca quinquenervia (Cav.) Blake Melaleuca Monochoria hastata (L.) Solms Arrowleaved monochoria Monochoria vaginalis (Burm. f.) Kunth Monochoria Sagittaria sagittifolia L. Arrowhead Salvinia auriculata Aubl. Giant salvinia Salvinia biloba Raddi Giant salvinia Salvinia herzogii de la Sota Giant salvinia Salvinia molesta Mitch. Giant salvinia Sparganium erectum L. Branched burreed Stratiotes aloides L. Crab's-claw (2) Additional Noxious Aquatic Weeds. Crassula helmsii R. Brown Swamp stonecrop Lagarosiphon spp. (All species) African elodea Salvinia spp. (All except S. rotundifolia) Water fern Trapa spp. (All species) Water Chestnut Ludwigia uruguayensis (Camb.) Hara Uruguay waterprimrose Lythrum salicaria L. Purple loosestrife Phragmites australis (Cav.) Trin. ex Steud. Common reed Alternanthera philoxeroides (Mart.) Griseb Alligatorweed Egeria densa Planch. Brazilian elodea Myriophyllum spicatum L. Eurasian watermilfoil Najas minor All. Brittleleaf naiad History Note: Statutory Authority G.S. 113A-222; Eff. September 1, 1992. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 43 11.3. Lake Chemistry Data 1. Surface data: Water Secchi Lake Name Date DO Temp pH Cond. Depth Percent m/d/yr mg/L C s.u. µmhos/cm meters SAT BIG LAKE 7-Aug-00 10.9 31.3 8.5 86 0.3 147.5% BIG LAKE 7-Aug-00 10.1 30.4 7.8 91 0.3 134.4% BIG LAKE 12-Jul-00 7.4 29.5 7.6 132 0.7 97.1% BIG LAKE 12-Jul-00 8.2 29.7 8.2 132 1.3 108.0% BIG LAKE 27-Jun-00 6.1 29.5 7.3 127 0.3 80.2% BIG LAKE 27-Jun-00 7.3 29.4 7.7 125 1.0 96.0% BIG LAKE 21-Aug-96 8.7 27.8 8.5 101 0.7 110.8% BIG LAKE 21-Aug-96 9.1 27.7 8.2 99 0.7 115.7% BIG LAKE 3-Jul-95 5.3 26.1 6.2 83 0.8 65.5% BIG LAKE 3-Jul-95 4.9 25.9 6.4 84 0.8 60.3% BIG LAKE 3-Jul-91 7.4 29.5 6.8 98 0.2 97.1% BIG LAKE 3-Jul-91 7.2 29.7 7.1 98 0.6 94.8% BIG LAKE 31-Jul-87 7.2 29.3 7.6 112 1.0 94.1% BIG LAKE 31-Jul-87 7.5 28.9 7.9 114 0.6 97.4% BIG LAKE 31-Jul-87 7.4 29.2 7.7 113 0.6 96.6% BIG LAKE 13-Aug-81 5.1 29.5 7.5 81 66.9% BIG LAKE 13-Aug-81 5.3 29.7 7.2 79 1.6 69.8% LAKE WACKENA 25-Jul-95 8.5 33 6.3 98 0.5 118.4% LAKE WACKENA 25-Jul-95 9 32.7 8.2 95 1.5 124.7% LAKE WACKENA 14-Jul-88 7.6 30.2 7.1 87 0.6 100.9% LAKE WACKENA 14-Jul-88 8 30.4 7.2 88 1.3 106.6% REEDY CREEK LAKE 7-Aug-00 10.4 29.8 8.2 61 0.2 136.5% REEDY CREEK LAKE 12-Jul-00 7.3 29.7 7.4 119 0.8 96.1% REEDY CREEK LAKE 27-Jun-00 7.6 29.4 7.7 109 1.2 99.3% REEDY CREEK LAKE 10-Aug-95 7.3 26.6 6.6 70 0.7 91.0% REEDY CREEK LAKE 12-Aug-91 5.8 28 6.4 62 2.0 74.1% Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 44 Surface data Continued Water Secchi Lake Name Date DO Temp pH Cond. Depth Percent m/d/yr mg/L C s.u. µmhos/cm meters SAT ROANOKE RAPIDS LAKE 26-Aug-04 5.6 25.6 7.2 101 3.2 68.5% ROANOKE RAPIDS LAKE 26-Aug-04 7.9 27.2 7.6 100 2.1 99.5% ROANOKE RAPIDS LAKE 26-Aug-04 7.8 26.9 7.5 100 2.1 97.7% ROANOKE RAPIDS LAKE 29-Jul-04 4.4 25.9 7.3 106 2.6 54.1% ROANOKE RAPIDS LAKE 29-Jul-04 7.1 27.6 7.4 103 1.6 90.1% ROANOKE RAPIDS LAKE 29-Jul-04 8 28.2 7.7 103 2.1 102.6% ROANOKE RAPIDS LAKE 24-Jun-04 6.5 24.9 7.3 96 2.8 78.5% ROANOKE RAPIDS LAKE 24-Jun-04 8.3 26.2 7.7 96 2.2 102.7% ROANOKE RAPIDS LAKE 24-Jun-04 8.4 27 7.9 95 2.0 105.5% ROANOKE RAPIDS LAKE 5-Aug-99 6.4 27.2 6.9 114 1.7 80.6% ROANOKE RAPIDS LAKE 5-Aug-99 8.2 30.6 8 113 1.4 109.6% ROANOKE RAPIDS LAKE 5-Aug-99 7.9 30.8 7.8 113 1.8 106.0% ROANOKE RAPIDS LAKE 22-Jul-99 6.7 27.8 7.1 110 2.2 85.3% ROANOKE RAPIDS LAKE 22-Jul-99 8.4 30 7.8 109 2.2 111.2% ROANOKE RAPIDS LAKE 22-Jul-99 8.4 29.9 7.9 109 2.1 111.0% ROANOKE RAPIDS LAKE 2-Jun-99 8.4 23.3 8.4 108 2.0 98.5% ROANOKE RAPIDS LAKE 2-Jun-99 8.6 23.8 8.6 108 1.6 101.8% ROANOKE RAPIDS LAKE 2-Jun-99 9.1 24.1 9 109 1.5 108.3% ROANOKE RAPIDS LAKE 9-Aug-94 5.3 26.2 7 101 2.2 65.6% ROANOKE RAPIDS LAKE 9-Aug-94 7.5 26.8 7.1 98 1.7 93.8% ROANOKE RAPIDS LAKE 9-Aug-94 7.5 27.7 7.1 97 1.6 95.3% ROANOKE RAPIDS LAKE 30-Jul-87 3.8 25.6 6 103 1.4 46.5% ROANOKE RAPIDS LAKE 30-Jul-87 7.5 29 6.8 100 0.9 97.5% ROANOKE RAPIDS LAKE 30-Jul-87 8.1 29.4 7.1 102 1.5 106.1% ROANOKE RAPIDS LAKE 30-Jul-85 6.6 25.1 6.9 107 1.8 80.0% ROANOKE RAPIDS LAKE 30-Jul-85 7.8 25 6.3 108 1.6 94.4% ROANOKE RAPIDS LAKE 30-Jul-85 8.2 25.6 7.6 105 2.6 100.4% ROANOKE RAPIDS LAKE 29-Aug-84 5.2 25.8 6.3 99 2.0 63.9% ROANOKE RAPIDS LAKE 29-Aug-84 5.8 25.2 6.4 96 1.3 70.5% ROANOKE RAPIDS LAKE 29-Aug-84 7.4 25.7 6.5 97 1.0 90.7% ROANOKE RAPIDS LAKE 12-Jul-83 7.3 25.3 6.2 96 1.4 88.9% ROANOKE RAPIDS LAKE 12-Jul-83 7.8 26 6.6 97 2.0 96.2% ROANOKE RAPIDS LAKE 12-Jul-83 7.6 26.8 6.6 100 1.9 95.1% ROANOKE RAPIDS LAKE 16-Jul-82 4.7 24.5 6.2 142 0.9 56.4% ROANOKE RAPIDS LAKE 16-Jul-82 4.7 24.5 6.2 141 1.1 56.4% ROANOKE RAPIDS LAKE 16-Jul-82 7.1 25.9 7.2 135 1.4 87.4% ROANOKE RAPIDS LAKE 6-Aug-81 6.2 27.5 7.1 109 1.3 78.5% ROANOKE RAPIDS LAKE 6-Aug-81 8.3 27.7 7.7 112 0.5 105.5% ROCKINGHAM CITY LAKE 17-Aug-00 3.2 26.8 5.3 28 0.7 40.0% ROCKINGHAM CITY LAKE 8-Jun-00 3.9 25.5 5.7 27 0.7 47.6% ROCKINGHAM CITY LAKE 24-Aug-95 3 28.6 5.1 32 0.5 38.7% ROCKINGHAM CITY LAKE 19-Aug-92 2.6 23.7 4.1 21 1.1 30.7% Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 45 2. Photoc Zone Data Lake Name Date TP TN TON TIN CHL a T. Solids TSS Turbidity m/d/yr mg/L mg/L mg/L mg/L µg/L mg/L mg/L NTU BIG LAKE 7-Aug-00 0.08 0.77 0.50 0.27 100 22 45 BIG LAKE 7-Aug-00 0.07 0.75 0.48 0.27 100 15 40 BIG LAKE 12-Jul-00 0.05 0.41 0.39 0.02 110 11 7.4 BIG LAKE 12-Jul-00 0.03 0.51 0.50 0.01 100 20 3.9 BIG LAKE 27-Jun-00 0.03 0.91 0.87 0.04 95 20 11 BIG LAKE 27-Jun-00 <0.01 0.71 0.68 0.03 70 12 2.9 BIG LAKE 21-Aug-96 0.01 0.41 0.40 0.01 100 13 BIG LAKE 21-Aug-96 0.03 0.51 0.49 0.02 94 10 5.6 BIG LAKE 3-Jul-95 0.03 0.41 0.39 0.02 9 80 2 6.4 BIG LAKE 3-Jul-95 0.03 0.41 0.39 0.02 10 82 2 5 BIG LAKE 3-Jul-91 0.05 0.41 0.27 0.14 11 100 2 35 BIG LAKE 3-Jul-91 0.03 0.21 0.17 0.04 5 89 <1.0 24 BIG LAKE 31-Jul-87 0.20 0.41 0.36 0.05 11 BIG LAKE 31-Jul-87 0.30 0.41 0.38 0.03 11 BIG LAKE 31-Jul-87 0.30 0.51 0.47 0.04 13 BIG LAKE 13-Aug-81 0.03 0.51 0.50 0.01 11 BIG LAKE 13-Aug-81 0.03 0.41 0.40 0.01 9 LAKE WACKENA 25-Jul-95 0.18 0.61 0.55 0.06 11 150 22 6.6 LAKE WACKENA 25-Jul-95 0.02 0.41 0.35 0.06 4 110 4 1.8 LAKE WACKENA 14-Jul-88 0.13 0.72 0.67 0.05 27 83 9 4.6 LAKE WACKENA 14-Jul-88 0.05 0.51 0.48 0.03 18 83 8 3.8 REEDY CREEK LAKE 7-Aug-00 0.08 0.61 0.55 0.06 150 18 50 REEDY CREEK LAKE 12-Jul-00 0.04 0.31 0.14 0.17 99 11 5.3 REEDY CREEK LAKE 27-Jun-00 0.01 0.41 0.32 0.09 76 2 2.7 REEDY CREEK LAKE 10-Aug-95 0.04 0.41 0.40 0.01 6 68 5 7.8 REEDY CREEK LAKE 12-Aug-91 0.05 0.42 0.34 0.08 6 83 20 13 ROANOKE RAPIDS LAKE 26-Aug-04 0.02 0.34 0.24 0.10 3 86 <2.5 1.6 ROANOKE RAPIDS LAKE 26-Aug-04 0.02 0.29 0.26 0.03 6 78 <2.5 2.2 ROANOKE RAPIDS LAKE 26-Aug-04 0.02 0.31 0.27 0.04 8 82 2.5 2.1 ROANOKE RAPIDS LAKE 29-Jul-04 0.02 0.36 0.23 0.13 3 80 <2.5 1.3 ROANOKE RAPIDS LAKE 29-Jul-04 0.02 0.32 0.26 0.06 5 74 <2.5 1.7 ROANOKE RAPIDS LAKE 29-Jul-04 0.02 0.30 0.25 0.05 7 72 <2.5 1.8 ROANOKE RAPIDS LAKE 24-Jun-04 0.02 0.37 0.23 0.14 3 74 <2.5 4 ROANOKE RAPIDS LAKE 24-Jun-04 0.02 0.36 0.25 0.11 4 74 <2.5 3.1 ROANOKE RAPIDS LAKE 24-Jun-04 0.02 0.33 0.24 0.09 5 70 <2.5 2.4 ROANOKE RAPIDS LAKE 5-Aug-99 0.01 0.31 0.30 0.01 90 7 2.6 ROANOKE RAPIDS LAKE 5-Aug-99 0.01 0.41 0.40 0.01 81 6 2.6 ROANOKE RAPIDS LAKE 5-Aug-99 0.01 0.21 0.20 0.01 79 4 2.3 ROANOKE RAPIDS LAKE 22-Jul-99 0.01 0.35 0.26 0.09 81 5 1.7 ROANOKE RAPIDS LAKE 22-Jul-99 0.01 0.22 0.16 0.06 71 3 1.9 ROANOKE RAPIDS LAKE 22-Jul-99 0.01 0.21 0.16 0.05 76 2 2.3 ROANOKE RAPIDS LAKE 2-Jun-99 0.01 0.30 0.20 0.11 77 3 2.8 ROANOKE RAPIDS LAKE 2-Jun-99 <0.01 0.31 0.20 0.12 88 3 3 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 46 Photoc Zone Data Continued Lake Name Date TP TN TON TIN CHL a T. Solids TSS Turbidity m/d/yr mg/L mg/L mg/L mg/L µg/L mg/L mg/L NTU ROANOKE RAPIDS LAKE 2-Jun-99 0.03 0.37 0.28 0.09 85 2 3 ROANOKE RAPIDS LAKE 9-Aug-94 0.02 0.27 0.18 0.09 1 79 3 1.7 ROANOKE RAPIDS LAKE 9-Aug-94 0.02 0.24 0.19 0.05 2 96 4 2.4 ROANOKE RAPIDS LAKE 9-Aug-94 0.02 0.24 0.18 0.06 2 88 3 2.2 ROANOKE RAPIDS LAKE 30-Jul-87 0.02 0.38 0.27 0.11 7 68 2 3.1 ROANOKE RAPIDS LAKE 30-Jul-87 0.02 0.31 0.29 0.02 13 76 4 4.3 ROANOKE RAPIDS LAKE 30-Jul-87 0.02 0.32 0.29 0.03 13 62 2 3 ROANOKE RAPIDS LAKE 30-Jul-85 0.01 0.36 0.27 0.09 1 110 2 2.3 ROANOKE RAPIDS LAKE 30-Jul-85 0.01 0.23 0.19 0.04 5 130 6 1.6 ROANOKE RAPIDS LAKE 30-Jul-85 0.43 0.31 0.05 0.26 4 110 3 1.1 ROANOKE RAPIDS LAKE 29-Aug-84 0.01 0.32 0.19 0.13 4 65 4 2 ROANOKE RAPIDS LAKE 29-Aug-84 0.02 0.42 0.29 0.13 6 67 4 2.9 ROANOKE RAPIDS LAKE 29-Aug-84 0.02 0.35 0.18 0.17 1 78 3 3.6 ROANOKE RAPIDS LAKE 12-Jul-83 0.03 0.25 0.19 0.06 3 75 6 2.8 ROANOKE RAPIDS LAKE 12-Jul-83 0.03 0.21 0.18 0.03 3 75 1 2.3 ROANOKE RAPIDS LAKE 12-Jul-83 0.02 0.31 0.29 0.02 6 80 3 2.3 ROANOKE RAPIDS LAKE 16-Jul-82 0.03 1.58 0.23 1.35 7 133 11 ROANOKE RAPIDS LAKE 16-Jul-82 0.03 1.24 0.37 0.87 13 118 6 ROANOKE RAPIDS LAKE 16-Jul-82 0.03 3.00 0.40 2.60 13 134 9 ROANOKE RAPIDS LAKE 6-Aug-81 0.02 0.31 0.29 0.02 ROANOKE RAPIDS LAKE 6-Aug-81 0.04 0.41 0.38 0.03 17 ROCKINGHAM CITY LAKE 17-Aug-00 0.03 0.51 0.39 0.12 65 10 2 ROCKINGHAM CITY LAKE 8-Jun-00 0.02 0.31 0.17 0.14 46 7 2.5 ROCKINGHAM CITY LAKE 24-Aug-95 0.03 0.51 0.47 0.04 8 48 4 2.3 ROCKINGHAM CITY LAKE 19-Aug-92 0.02 0.41 0.36 0.05 1 55 2 3.6 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 47 3. Bottom Data Lake Name Region/Type Date Sampling TP NH3 TKN NOx TON m/d/yr Station mg/L mg/L mg/L mg/L mg/L BIG LAKE PIEDMONT 7-Aug-00 NEU035G BIG LAKE PIEDMONT 7-Aug-00 NEU035H 0.10 0.87 2 0.07 1.13 BIG LAKE PIEDMONT 12-Jul-00 NEU035G BIG LAKE PIEDMONT 12-Jul-00 NEU035H BIG LAKE PIEDMONT 27-Jun-00 NEU035G BIG LAKE PIEDMONT 27-Jun-00 NEU035H 0.03 0.19 0.5 <0.01 0.31 BIG LAKE PIEDMONT 21-Aug-96 NEU035G BIG LAKE PIEDMONT 21-Aug-96 NEU035H 0.06 0.13 0.8 0.03 0.67 BIG LAKE PIEDMONT 3-Jul-95 NEU035G 0.03 0.02 0.4 <0.01 0.38 BIG LAKE PIEDMONT 3-Jul-95 NEU035H 0.03 0.10 0.5 <0.01 0.40 BIG LAKE PIEDMONT 3-Jul-91 NEU035G 0.21 0.06 0.5 0.16 0.44 BIG LAKE PIEDMONT 3-Jul-91 NEU035H 0.14 0.60 0.9 0.01 0.30 BIG LAKE PIEDMONT 31-Jul-87 BL3 BIG LAKE PIEDMONT 31-Jul-87 NEU035G BIG LAKE PIEDMONT 31-Jul-87 NEU035H BIG LAKE PIEDMONT 13-Aug-81 NEU035G BIG LAKE PIEDMONT 13-Aug-81 NEU035H LAKE WACKENA PIEDMONT 25-Jul-95 NEU0714A LAKE WACKENA PIEDMONT 25-Jul-95 NEU0717A 0.06 0.15 0.6 <0.01 0.45 LAKE WACKENA PIEDMONT 14-Jul-88 NEU0714A LAKE WACKENA PIEDMONT 14-Jul-88 NEU0717A 0.05 0.03 0.6 <0.01 0.57 REEDY CREEK LAKE PIEDMONT 7-Aug-00 NEU035A7 REEDY CREEK LAKE PIEDMONT 12-Jul-00 NEU035A7 REEDY CREEK LAKE PIEDMONT 27-Jun-00 NEU035A7 0.02 0.40 0.6 <0.01 0.20 REEDY CREEK LAKE PIEDMONT 10-Aug-95 NEU035A7 0.04 0.02 0.4 <0.01 0.38 REEDY CREEK LAKE PIEDMONT 12-Aug-91 NEU035A7 0.04 0.04 0.4 0.02 0.36 ROANOKE RAPIDS LAKE PIEDMONT 26-Aug-04 ROA039C ROANOKE RAPIDS LAKE PIEDMONT 26-Aug-04 ROA039D ROANOKE RAPIDS LAKE PIEDMONT 26-Aug-04 ROA039E ROANOKE RAPIDS LAKE PIEDMONT 29-Jul-04 ROA039C ROANOKE RAPIDS LAKE PIEDMONT 29-Jul-04 ROA039D ROANOKE RAPIDS LAKE PIEDMONT 29-Jul-04 ROA039E ROANOKE RAPIDS LAKE PIEDMONT 24-Jun-04 ROA039C ROANOKE RAPIDS LAKE PIEDMONT 24-Jun-04 ROA039D ROANOKE RAPIDS LAKE PIEDMONT 24-Jun-04 ROA039E ROANOKE RAPIDS LAKE PIEDMONT 5-Aug-99 ROA039C <0.01 0.01 0.2 <0.01 0.20 ROANOKE RAPIDS LAKE PIEDMONT 5-Aug-99 ROA039D 0.01 0.01 0.3 <0.01 0.30 ROANOKE RAPIDS LAKE PIEDMONT 5-Aug-99 ROA039E 0.01 0.01 0.3 0.01 0.30 ROANOKE RAPIDS LAKE PIEDMONT 22-Jul-99 ROA039C 0.01 0.08 0.2 0.06 0.12 ROANOKE RAPIDS LAKE PIEDMONT 22-Jul-99 ROA039D ROANOKE RAPIDS LAKE PIEDMONT 22-Jul-99 ROA039E 0.02 0.22 0.4 0.05 0.18 ROANOKE RAPIDS LAKE PIEDMONT 2-Jun-99 ROA039C 0.01 0.01 0.1 0.11 0.10 ROANOKE RAPIDS LAKE PIEDMONT 2-Jun-99 ROA039D <0.01 0.04 0.1 0.09 0.06 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 48 Bottom Data Continued Lake Name Region/Type Date Sampling TP NH3 TKN NOx TON m/d/yr Station mg/L mg/L mg/L mg/L mg/L ROANOKE RAPIDS LAKE PIEDMONT 2-Jun-99 ROA039E 0.04 0.04 0.2 0.11 0.16 ROANOKE RAPIDS LAKE PIEDMONT 9-Aug-94 ROA039C 0.02 0.01 0.2 0.08 0.20 ROANOKE RAPIDS LAKE PIEDMONT 9-Aug-94 ROA039D 0.02 0.01 0.2 0.03 0.19 ROANOKE RAPIDS LAKE PIEDMONT 9-Aug-94 ROA039E 0.02 0.17 0.3 0.03 0.13 ROANOKE RAPIDS LAKE PIEDMONT 30-Jul-87 ROA039C 0.02 0.04 0.3 0.08 0.26 ROANOKE RAPIDS LAKE PIEDMONT 30-Jul-87 ROA039D 0.03 0.08 0.3 0.08 0.22 ROANOKE RAPIDS LAKE PIEDMONT 30-Jul-87 ROA039E 0.02 0.06 0.3 0.08 0.24 ROANOKE RAPIDS LAKE PIEDMONT 30-Jul-85 ROA039C 0.02 0.07 0.3 0.07 0.23 ROANOKE RAPIDS LAKE PIEDMONT 30-Jul-85 ROA039D 0.02 0.02 0.3 0.04 0.28 ROANOKE RAPIDS LAKE PIEDMONT 30-Jul-85 ROA039E 0.04 0.47 0.7 <0.01 0.23 ROANOKE RAPIDS LAKE PIEDMONT 29-Aug-84 ROA039C 0.02 0.01 0.2 0.12 0.19 ROANOKE RAPIDS LAKE PIEDMONT 29-Aug-84 ROA039D 0.02 0.01 0.2 0.12 0.19 ROANOKE RAPIDS LAKE PIEDMONT 29-Aug-84 ROA039E 0.02 0.01 0.2 0.09 0.19 ROANOKE RAPIDS LAKE PIEDMONT 12-Jul-83 ROA039C ROANOKE RAPIDS LAKE PIEDMONT 12-Jul-83 ROA039D 0.04 0.05 0.2 0.08 0.15 ROANOKE RAPIDS LAKE PIEDMONT 12-Jul-83 ROA039E 0.05 0.13 0.4 0.2 0.27 ROANOKE RAPIDS LAKE PIEDMONT 16-Jul-82 ROA039C ROANOKE RAPIDS LAKE PIEDMONT 16-Jul-82 ROA039D ROANOKE RAPIDS LAKE PIEDMONT 16-Jul-82 ROA039E ROANOKE RAPIDS LAKE PIEDMONT 6-Aug-81 ROA039C ROANOKE RAPIDS LAKE PIEDMONT 6-Aug-81 ROA039E ROCKINGHAM CITY LAKE SANDHILLS 17-Aug-00 YAD265C ROCKINGHAM CITY LAKE SANDHILLS 8-Jun-00 YAD265C ROCKINGHAM CITY LAKE SANDHILLS 24-Aug-95 YAD265C 0.06 0.56 1.3 <0.01 0.74 ROCKINGHAM CITY LAKE SANDHILLS 19-Aug-92 YAD265C Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 49 11.4. Public Notice of draft Aquatic Weed TMDL for Rockingham City Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena. Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 50 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 51 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 52 Aquatic Weed Management Strategy: Rockingham Lake, Roanoke Rapids Lake, Big Lake, Reedy Creek Lake, and Lake Wackena 53 11.5. The US EPA’s Approval Letter