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<br />1 <br /> <br />' Straw Bwle Sediment Check Dwme <br />' Constructed with straw bales far- low head situations, a detention <br />storage area is created which detains storm water. The primary <br />functi~~n of the dam is to inter•ceot and detain sediment laden <br />flow long enough to allow the larg er• sized particles to settle <br />' out pr•ior• to passage of runoff to downstream areas. Other <br />functions include storage of the deposited sediment, reduction uf' <br />the peak flow rate, and diversion to a non-erosive channel. <br />' Bales deteriorate within 3 to 6 months and are, therefore, only a <br />temporary control measure. <br />' Chute Spillway of Rubble <br />An overcall structur^e of rubble is applicable where it is <br />desirable to drop the watercourse elevation over a very short <br />t horizontal distance. The spillway outlet Should be designed so <br />that its function or stability will not be reduced by scour of <br />deposits in the exit channel. Generally chutes ar•e designed in <br />' conjunction with other erosion control practices to handle peak. <br />storm flows. Rubble size is based on water velocity to be <br />withstood. <br />' 6ediment Control Basin with Rubble Spillway <br />This is a bar•rier• or• dam c~~nstructed acr•~~ss a water•cour•se ~~r• <br />' gully to form a silt or• sediment trap, its purpose is to reduce <br />erosion ft•onr construction sites. The rubble spillway must be <br />designed to convey expected peak runoff. Basin sediment storage <br />' capacity should not exceed two acre-feet and basin capacity <br />should be maintained at 30X Cur greater) of original volume by <br />cleaning out as needed. A minimum embankment width of ten feet <br />1s required for• dams less than ten feet high, twelve feet fur• <br />' dams exceeding ten feet. <br />Those areas not impacted by winter/spring flows in Coal Creek are <br />' best reclaimed by drilling seed directly into the standing <br />stubble of a warm season cover crop. fa "120 day grain sorghum" <br />Cthe seed won't nrat ure here) will be planted in early June. <br />10,000-IS0,000 plants per- acre are needed. Weeds can be <br />' controlled with herbicides during the summer/early fail. Then we <br />will drill directly into the standing cover crop stubble after- <br />about November- 1, when the ground is not frozen. <br />1 <br /> <br />1 <br />c z <br />