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r <br /> Chapter 4 - Best Management Practices. fat Erosiort,and-pediment Control .. . . <br /> _ : - <br /> 4.38 TEMPORARY CHECK DAMS <br /> oefInition <br />. , Small temporary dams constructed across a swale or stormwater conveyance channel . <br /> Epsom <br /> To reduce the velocity of concentrated stormwater flows , thereby reducing erosion of the <br /> Swale or ditch . This practice also traps small amounts of sediment generated in the ditch <br /> .. itself. These sediments will require periodic removal . However, this is not a sediment <br /> trapping practice and should not be used as such . <br /> r Conditions JVhere Fra�tice Apples <br /> This practice is limited:to use in small open channels which drain 10 acres (4 ha) or less . It <br /> .. should not be used in a live stream. This practice is especially applicable to sloping sites <br /> where the gradient of waterways is close to the maximum for a grass lining . Some specific <br /> applications include: <br /> 1 . Temporary ditches orswales which , because of their short length of service , cannot <br /> receive a non-erodible lining but still need some protection to reduce erosion . <br /> r 2. Permanent ditches or swales which for some reason cannot receive a permanent <br /> non-erodible lining for an extended period of time. <br /> r 3 . Either temporary or permanent. ditches or swales which need protection during the <br /> establishment of grass linings. . <br /> Piannino Considerations <br /> .. Temporary check dams can be constructed of filter fence or straw bales far very shortterm <br /> applications ; or either stone or logs for longer or permanent applications . Filterfence and <br /> straw bale check dams are economical to purchase and simple to install. Log .check dams <br /> ,. are economical as for material costs, since logs can usually be salvaged. from clearing <br /> operations. However; log:check dams require more time and hand-labor to install . Stone <br /> for check dams , on the other hand, must generally be purchased . However, this cost is <br /> offset somewhat by the ease of installation. . <br /> Specifications <br /> No formal design is required for a check dam; however, the following criteria should be <br /> adhered to when specifying check dams. <br /> r <br /> 4-105 <br />