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s <br /> i Y <br /> C <br /> • New pipe outfalls can provide an opportunity for low-cost fish habitat <br /> improvements. For example, an alcove of low-velocity water can be <br /> created by constructing the pipe outfall and associated energy <br /> t dissipater back from the stream edge and digging a channel, over- <br />' widened to the upstream side, from the outfall. Ovenwintering juvenile <br /> r and migrating adult salmonids may use the alcove as shelter during <br /> high flows.Bank stabilization,bioengineering, and habitat features <br /> may be required for disturbed areas. This work may require a HPA. <br /> See Volume V for more information on outfall system design. <br /> V. <br /> Maintenance • Inspect and repair as needed. <br /> 4 Standards Add rock as needed to maintain the intended function. <br /> • Clean energy dissipater if sediment builds up. <br /> fi <br /> E <br /> BMP C220: Storm Drain Inlet Protection <br /> Piupose Storm drain inlet protection prevents coarse sediment from entering <br /> drainage systems prior to permanent stabilization of the disturbed area. <br /> Conditions of Use Use storm drain inlet protection at inlets that are operational before <br /> l permanent stabilization of the disturbed drainage area. Provide protection <br /> for all storm drain inlets downslope and within 500 feet of a disturbed or <br /> construction area,unless conveying runoff entering catch basins to a <br /> i sediment pond or trap. <br /> Also consider inlet protection for lawn and yard drains on new home <br /> f <br /> construction. These small and numerous drains coupled with lack of <br /> gutters in new home construction can add significant amounts of sediment <br /> I into the roof drain system.If possible delay installing lawn and yard drains <br /> E until just before landscaping or cap these drains to prevent sediment from <br /> entering the system until completion of landscaping. Provide 18-inches of <br /> sod around each finished lawn and yard drain. <br /> Table 4.2.2 lists several options for inlet protection. All of the methods for <br /> I storm drain inlet protection tend to plug and require a high frequency of <br /> maintenance. Limit drainage areas to one acre or less. Possibly provide <br /> emergency overflows with additional end-of-pipe treatment where <br /> stormwater ponding would cause a hazard. <br /> j <br /> I <br /> s <br /> E I <br /> f <br /> I <br /> I i <br /> f i <br /> f E. <br /> i <br /> I } <br /> Vohmme H—Constructiomm Storinwater Pollution Prevention-August 2012 <br /> 4-79 <br /> t <br />