Lake Pocotopaug Lake and Watershed Restoration Evaluation ...

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11.2 Reducing Total Phosphorus and Sediment Loading from the WatershedObjectives are strongly linked to watershed management, and specifically to management ofdeveloped areas. Development of a watershed creates impervious surface that changes thehydrology of the area and tends to increase loading of pollutants to waterways. Pollutants fallingfrom the sky as atmospheric deposition are not incorporated into soils as in forests or meadows,but rather are transported into the aquatic environment. Additional pollutants from humanactivities in developed areas include solids from exposed soils, nutrients from fertilizers andwaste disposal, bacteria from waste disposal, urban wildlife and pets, hydrocarbons fromautomotive and other machine use, and metals from a variety of sources. These are alsocarried into the aquatic environment and can cause water quality degradation and useimpairment. Similar consequences result from agricultural development, but with more solidsand nutrients and less metals and hydrocarbons. Some degree of additional pollutant loading isalmost inevitable with development, but there are methods for minimizing inputs and impacts.In the Lake Pocotopaug watershed there are both residential lands and agricultural lands,although the residential land is more abundant and is close to the lake and more likely to impactwater quality in the lake. Nutrient loading analysis based on recent data suggest that currentloads are excessive, that loads from developed areas are higher than for undeveloped areas,and that protection of water quality can be gained by addressing pollutant sources and transportin developed areas. Techniques for reducing pollutant loads and associated impacts arediscussed below.11.2.1 Source ControlsAgricultural Best Management PracticesAgricultural Best Management Practices (BMPs) incorporate techniques in forestry, animalscience, and crop science to minimize adverse impacts to water resources. This managementapproach actually relies upon a combination of techniques in source reduction and transportmitigation. Such practices include manure management, fertilizer management, use of covercrops, and use of buffer zones. The use of agricultural BMP’s is highly recommended in theLake Pocotopaug watershed. However, with the small amount of land in agriculture, this is notlikely to provide a major change in the water quality of Lake Pocotopaug. Rather, this is aprotective measure to be encouraged, especially where livestock are involved, as their nutrientinput per unit area involved can be very large. Many of the techniques discussed as BMPs forresidential areas are also applicable to agricultural lands.Bank and Slope StabilizationErosion control is an important component of an overall management plan designed todecrease pollutant loading to aquatic ecosystems. This is especially important in areas of newdevelopment or re-development, where soils are both exposed and susceptible to erosion.Stabilization of stream banks and road shoulders in the vicinity of crossings is another importantarea for application, particularly when dirt roads are involved. Other critical areas include stormwater drainage ditches and small tributaries in developed areas. This is a recommendedLake Pocotopaug Restoration Evaluation 94May 2002
management technique in the lake Pocotopaug watershed, and the towns and the CT DEPshould maintain lists of susceptible areas and check them periodically.Source Controls for Residential LandSource controls are methods used to reduce the amount of pollutants generated in thewatershed, or to prevent their release to the environment. Eliminating some sources isimpractical, but minimizing unnecessary pollutant use and keeping the pollutant from contactingstorm water or ground water may be feasible. Helpful texts include Hansen et al. (1988),Humstone Squires (1990) and Maine COLA (1991). The focus is on limiting the amount of anypollutant that is available to be transported in runoff. In most cases this involves behavioralchanges by homeowners.Behavioral modifications involve changing the actions of watershed residents and lake users toimprove water quality. Such changes may include conversion to non-phosphate detergents,elimination of garbage grinders, proper inspection and maintenance of septic systems, limits onlawn fertilization, and eliminating illegal dumping in roadways and watercourses. Behavioralmodifications can be brought about in two principal ways, through public education and/or theimplementation of local bylaws and bans. Education is a critical first step and should precedeany attempt at regulation.Public education can be accomplished by mailing an informative brochure on watershedmanagement to all residents in the watershed, through the use of video programs on localaccess television, by placing informative signs in high access areas, or by holding publicmeetings for watershed residents. Public education relies heavily upon cooperation fromresidents and other lake users, and is not likely to result in major improvements in water qualityby itself. However, some level of improvement has been noted in other studies and theeducation process sets the stage for community involvement and cooperation. Public educationis a recommended management technique for Lake Pocotopaug, and should focus onlandscape management.Information on relevant ordinances has been provided separately to East Hampton officials, butthe most obvious need is control of lawn fertilization. Education is preferable to regulation, butthe latter may be necessary, in which case education should precede regulation.Land Use ConversionLand use conversion involves purchasing properties that contribute excessive amounts ofpollutants and converting these properties to less deleterious land uses. For example, the CTDEP or a town may decide to purchase an agricultural property and convert the land to openspace, thus reducing pollutant generation from this parcel of land. This is a very expensiveproposition and is not practical on a large scale in most cases, but may be practical for targetingspecific properties that could generate excessive amounts of pollutants that eventuallydischarge into Lake Pocotopaug. Since a large portion of the watershed is currentlyLake Pocotopaug Restoration Evaluation 95May 2002
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LAKE POCOTOPAUGLAKE AND WATERSHEDRE
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11.3 Prevent algal blooms from occu
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LAYPERSON’S SYNOPSISLake Pocotopa
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The stocking of walleye in Lake Poc
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Lake Pocotopaug Restoration Evaluat
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Period Covered 1988• Pollution fr
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Recommendations included• Algacid
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Major EventDecember 1999 - Fish kil
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Table 5. Land Use from the CT DEP G
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Figure 4. Lake Pocotopaug Bathymetr
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Table 6. QA/QC on Water Quality Dat
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Soils - USDA at MAGIC UCONN Geograp
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Table 8. Water Quality Variables Me
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Phytoplankton samples were collecte
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where many measurements would have
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Figure 7. 2001 Temperature and Diss
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Table 10 continued. 2001 Lake Pocot
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phytoplankton biomass (Wetzel 1983)
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Figure 9. Annual June, July and Aug
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elow 7:1 occurred on September 22,
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Table 12. 2001 Dry and Wet Weather
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Table 12 continued. 2001 Dry and We
Page 50 and 51: Table 12 continued. 2001 Dry and We
Page 56 and 57: were identified to genus and enumer
Page 58 and 59: Table 13 continued. 2001 Phytoplank
Page 68 and 69: Figure 10. 2001 Phytoplankton Bioma
Page 70 and 71: The late summer bloom of blue-green
Page 72 and 73: Table 15. 2001 Zooplankton DensityZ
Page 74 and 75: Table 16. 2001 Zooplankton BiomassZ
Page 76 and 77: 7.0 RELATIONSHIPS AND TRENDS7.1 Pre
Page 78 and 79: Figure 13. 1991-2001 Surface Water
Page 80 and 81: Figure 15. 2001 Surface and Mid-dep
Page 82 and 83: Figure 16. 1991-2001 Chlorophyll a
Page 84 and 85: Figure 18. 2001 Chlorophyll a vs. S
Page 86 and 87: Figure 20. 1991-2001 July and Augus
Page 88 and 89: Table 17. Empirical Model Calculati
Page 90 and 91: Table 18. Total Phosphorus Loading
Page 92 and 93: Table 19. Wet Weather Loading Summa
Page 94 and 95: With the best possible treatment of
Page 96 and 97: water quality should focus on input
Page 98 and 99: 10.0 MANAGEMENT NEEDS AND OBJECTIVE
Page 102 and 103: undeveloped forest land, an opportu
Page 104 and 105: Figure 22. Buffer Strips for Pollut
Page 106 and 107: Figure 23. Catch Basin with Sump an
Page 108 and 109: early spring to capture what appear
Page 110 and 111: Figure 26. Infiltration Systems.Lak
Page 112 and 113: Figure 27. Constructed Treatment We
Page 114 and 115: Chemical TreatmentIn-stream chemica
Page 116 and 117: TABLE 21. MANAGEMENT OPTIONS FOR CO
Page 118 and 119: TABLE 21 continued. MANAGEMENT OPTI
Page 130 and 131: 12.0 ADDITIONAL DATA NEEDSManagemen
Page 132 and 133: 13.0 RECOMMENDED MANAGEMENT PROGRAM
Page 134 and 135: this point, but as a rough guide, a
Page 136 and 137: 14.0 REFERENCESAd Hoc Lake Advisory
Page 138 and 139: Scheuler T.R., P.A. Kumble, & M.A.
Page 140 and 141: Appendix B:Supplemental Tables and
Page 142: Appendix D:Educational MaterialsLak
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