2008-009 (5) - Laserfiche WebLink

Home Browse Search

+r Chapter4 - Best Management Practices for Erosion and:Sediment.Ccntrol r Spacing The following table will be used to determine .the spacing of right-of-way diversions: % Slope ' Spacing in feet(m). Less than 5% 300 (90 m) Between 5% and 10% 200 (60 m) Greater than 10% 100 (30 m) Grade r Positive drainage, With less than 2% slope , should be provided to a stabilized outlet or sediment trapping facility. Outlet Interceptor dikes must have an outletwhich is not subject to erosion. The on-site location may need to be adjusted to meet field conditions in order to utilize the most suitable outlet. Concentrated flows should spread over the widest possible area after release. Flows with r high sediment concentrations should pass through a sediment trapping measure. (See Plate 4. 17b) Construction Specifications 1 . The diversion shall be installed as soon as the right-of-way has been cleared and/or graded . 2 . All earthen diversions shall be machine- or hand-compacted in 8-inch (20 cm) lifts. to 3 . The outlet of the diversion shall be located on an undisturbed and stabilized area when at all possible . The field location should be adjusted as needed to utilize a ,r stabilized outlet. Sediment laden flows shall be conveyed . to a sediment trapping device . 4 . Earthen diversions which will not be subject to construction traffic should be stabilized in accordance with TEMPORARY SEEDING - Section 6 . 65 (ES BMP • Maintenance The practice shall be inspected after every rainfall and repairs made if necessary. Approximately once every week, whether a storm has occurred or not, the measure, shall be inspected and repairs made if needed . Diversions which are subject to damage by vehicular traffic should be reshaped at the end of each working day. ,, 4-65