Laserfiche WebLink
~ to 95% of modified Proctor density ~ASTM D-1557). The up <br />streaio face of the dam should have a 3:1 slope, as should [he exca- <br />vated sides of the pond area. The embankment s}~ould be re-vegetated <br />with wild grasses. This is particularly important in the spillway area. <br />The construction of this pond should be under the supervision of the <br />soils engineer, and site conditions, soil conditions, and site specific <br />recommendations should be verified prior to construction: Permission <br />to reconstruct the pond in this area has been verbally given by the <br />owner, Afr. Kenneth Moore, and will be confirmed by agreement prior to <br />construction. As can be seen, the pond will have a capacity to hold <br />the runoff from the design storm for the entire watershed area, as well <br />as three years' sediment from that watershed area. 'f he spillway will <br />be to the west side of the pond to preclude contaminating the springs <br />in the bottom of the gulch approximately 600 feet the southeast. Figure <br />S shows the proposed dam cross-sections and details. <br />Typical sections for diversion ditches and culverts are shown on <br />Appendix I. It should be noted that some of these ditches are at the <br />toes of cuts and should be regularly maintained and cleaned, particularly <br />in the spring and fall. The drainage in tl~e roadside ditches east of <br />the new culvert installation leads to an existing culvert under the <br />county road that now handles all of the runnoff from the upper bench at <br />the mine. The placement of the new culvert considerably reduces the <br />flow that will be reaching the existing culvert; therefore, it is our <br />opinion that it is adequate f.or future use. <br />4 <br />