1622 E MARINE VIEW DR WHOLE SITE 2022-02-01

Design and Size the pipe to convey the flow. The capacity for temporary drains shall be Installation sufficient to handle the peak flow from a 10-year, 24-hour storm event, Specifications assuming a Type IA rainfall distribution. Alternatively, use 1.6 times the 10-year, 1-hour flow indicated by an approved continuous runoff model. Consult local drainage requirements for sizing permanent pipe slope drains. • Use care in clearing vegetated slopes for installation. • Re-establish cover immediately on areas disturbed by installation. • Use temporary drains on new cut or fill slopes. • Use diversion dikes or swales to collect water at the top of the slope. • Ensure that the entrance area is stable and large enough to direct flow into the pipe. • Piping of water through the berm at the entrance area is a common failure mode. • The entrance shall consist of a standard flared end section for culverts 12 inches and larger with a minimum 6-inch metal toe plate to prevent runoff from undercutting the pipe inlet. The slope of the entrance shall be at least 3 percent. Sand bags may also be used at pipe entrances as a temporary measure. • The soil around and under the pipe and entrance section shall be thoroughly compacted to prevent undercutting. • The flared inlet section shall be securely connected to the slope drain and have watertight connecting bands. • Slope drain sections shall be securely fastened together, fused or have gasketed watertight fittings, and shall be securely anchored into the soil. • Thrust blocks should be installed anytime 90 degree bends are utilized. Depending on size of pipe and flow, these can be constructed with sand bags, straw bales staked in place, "t" posts and wire, or ecology blocks. • Pipe needs to be secured along its full length to prevent movement. This can be done with steel "t" posts and wire. A post is installed on each side of the pipe and the pipe is wired to them. This should be done every 10-20 feet of pipe length or so, depending on the size of the pipe and quantity of water to divert. • Interceptor dikes shall be used to direct runoff into a slope drain. The height of the dike shall be at least 1 foot higher at all points than the top of the inlet pipe. • The area below the outlet must be stabilized with a riprap apron (see . BMP C209 Outlet Protection, for the appropriate outlet material). Volume H — Construction Stormwater Pollution Prevention - August 2012 4-67