Lake Pocotopaug Lake and Watershed Restoration Evaluation ...

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13.0 RECOMMENDED MANAGEMENT PROGRAMWatershed management is the crux of controlling incoming sediment and nutrients. This shouldinclude both source controls and transport mitigation techniques, with the objective of reducinginputs to the maximum degree possible. In-lake techniques may be necessary to abate pastinputs, as with the 2001 alum treatment. Additional in-lake measures may aid achievement ofthe desired conditions, including additional alum treatment (if warranted by further investigation)and adjusting the fish community to foster larger and more zooplankton to more effectivelygraze available algae.13.1 Source ControlsWith regard to source controls, education followed by local ordinances is recommended tocurtail practices that result in unnecessary solids and nutrient releases. Paramount amongthese is lawn fertilization, demonstrated in many studies to be the most major contributor ofphosphorus from residential areas. We have a cultural problem in our society today, in thatpeople have attached status and appeal to a very green monoculture of grass around theirdwellings. This is a difficult cultural issue to address, and education about the benefits andbeauty of a more natural landscape is needed before we are likely to see a cultural shift inlandscaping preferences.Yet even without a major shift in thinking we can make progress, as a mature lawn requiresalmost no phosphorus additions in the form of fertilizer. The use of no phosphate or at least lowphosphate fertilizer is highly desirable, and avoidance of fertilizer use on lawns where a soil testindicates no need represents a savings for both the homeowner and the lake. Additionally,application of fertilizer should be avoided prior to predicted major storms. Minimizing the area oflawn fertilized can also be helpful, leaving a peripheral buffer zone through which fertilizer mustpass with runoff before it can leave the property.The recommended approach is first to educate town residents (not just those on the lake or inits watershed, although this is the target of this study) to their role in protecting water quality andthe town’s precious water resources, like Lake Pocotopaug. Brochures that can be placedconspicuously in public places and in homes are useful, as are public service advertisementsand programs on the local cable access network. The education effort would be followed by atown ordinance controlling fertilizer use, the key provision of which would be a required soil testto demonstrate the need for fertilizer before any application is made. Enforcement can bedifficult, and it is suggested that this ordinance be approached slowly and with as much publicinput as possible. The education phase can be instrumental in getting residents to understandand accept the desired restriction.A review of other residential practices should be conducted to determine which of these mightalso be targets for education and regulation. Although much of the watershed is sewered,septic system maintenance is important for those with such systems, and what is good for theLake Pocotopaug Restoration Evaluation 126May 2002
environment is generally good for the homeowner in that case (a properly functioning systemlimits impact and also reduces long-term cost). It is not clear how much yard waste disposaland vehicle washing might affect the lake in this case, but an assessment is worthwhile.An intensive educational program for the town would be expected to cost on the order of$25,000 over perhaps two years. The cost of ordinance development and enforcement wouldbe internalized and is not easily estimated, but is not negligible.13.2 Transport MitigationWith regard to mitigation of the transport of pollutants to the lake, the installation of deeper andlarger catch basins as roads are re-worked, maintenance of these and existing coarse sedimentand debris traps, expansion of existing detention systems, creation of new detention systems,use of wetland features where practical, and establishment of infiltration chambers whereverpossible are all appropriate actions. Easy and relatively inexpensive practices include theinstallation of silt fences around beach locations during periods of high runoff and increasing thefrequency of street sweeping and catch basin cleaning, with emphasis on early spring cleaning.Deciding exactly which combination of structural techniques is to be applied in each case is asite-specific matter. Making such determination goes beyond the scope of this project, but thereport filed by WMC in 1995 is an excellent start in this regard. While more emphasis on waterquality management and less focus on flood control would have been better for lakemanagement, the review of drainage systems and suggestions for improvement are largely ontarget. Be cautious of enlarging culverts, however; associated flood control benefits are beingtraded against more rapid delivery of sediment and nutrients to the lake. It would be better tolook for ways to detain the water in the watershed, providing both flood control and water qualitybenefits.Wherever possible, infiltration should be the preferred management alternative for solids andnutrient control. This will entail some form of detention, both for initial solids settling (to avoidclogging) and to provide holding capacity where soil permeability is not extremely high. Off-linesystems are suggested as most desirable, with the first half inch of runoff as an appropriatedesign capacity. That means that for a 10 acre area, the system would have to process 18,150cubic feet (136,125 gallons) of runoff, possibly in as little as an hour. These systems can beunderground, avoiding the use of valuable or scenic surface area, but this does increase theprice.The infiltration approach is especially recommended for areas to the east of the lake, wheresubstantial developed land is at a much higher elevation than the lake and soils appear suitablefor this approach. Areas farther from the lake to the north and west are also viable candidates,although these areas have limited development at this time. Costs are difficult to estimate atLake Pocotopaug Restoration Evaluation 127May 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
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were identified to genus and enumer
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Table 13 continued. 2001 Phytoplank
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Figure 10. 2001 Phytoplankton Bioma
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The late summer bloom of blue-green
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Table 15. 2001 Zooplankton DensityZ
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Table 16. 2001 Zooplankton BiomassZ
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7.0 RELATIONSHIPS AND TRENDS7.1 Pre
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Figure 13. 1991-2001 Surface Water
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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 100 and 101: 11.2 Reducing Total Phosphorus and
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 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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