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Paye 2.23 SECTION 2- S17E OPERATIONS PLAN Table 2.3 MAINTENANCE FOR STORMWATER FACILITIES Drainage Frequency of Facility Condition When Maintenance Recommended Inspection Ditches Sediment exceeds 20% of design depth Weekly and after • Trash/debris exceeds 5 cubic fee:per 1000 square feet of major storm events ditch • Vegetation reduces free movement of water through ditch • Rock lining out of place/native soil visible Pipes/ Sediment/debris exceeds 20%of pipe diameter Monthly and after Culverts Dents that reduce end area of pipe by 20%or more major storm events • More than 50%deterioration to any part of pipe • Vegetation reduces free movement of water through pipe Detention Erosion around inlet, outlet or downstream channel Weekly and after Basins Accumulated sediment within one foot of lowest outlet major storm events orifice • Rock lining out of place/native sc;i visible • Trash/debris blocking more than 20% of outlet structure Berms For lined berms, damaged liners including tears and Monthly and after punctures major storm events • Erosion damage or slumping of berm OiVwater Accumulation of sediment reduces operational efficiency Weekly and after separators Trash/debris blocks more than 2C%of outlet structure major storm events Ditches will be inspected weekly and after major rain storms. Any ditches showing signs of substantial erosion will be armored with the original lining material or riprap (four to six inch angular rock). Ditches will be kept free from blown refuse, built up sediments and slumped material. If any ditch continues to have erosion problems, it will be fitted with check dams to reduce flow velocity and allow sediments to settle. F*peslculverts will be inspected at least once per month and after major rain storms. Pipes and culverts will be kept free of sediment, debris and vegetation. Detention basins will be inspected weekly and after major storm events. Basins will be kept free of debris and outlet structures will be cleaned regularly. Any signs of erosion around the inlet, outlet, or downstream channel (to the natural waterway), will be addressed immediately. In such an event, the rock aprons protecting the inlet and outlet may be replaced and enlarged and the drainage channel lined with rock, if necessary. The basins will be emptied of accumulated sediment by using a front-end loader or similar equipment once a year or as necessary to keep the level of trapped sediment at least one foot below the lowest outlet orifice. Farms will be inspected at least once a month and after major storm events. Evidence of excessive erosion, settlement or slumping will be repaired, as required. Oillwater separators on the detention/sedimentation basins will be inspected weekly and cleaned of sediment/debris whenever the accumulation reduces the operational efficiency of the unit. C.-:of Stockton, R.W.Beck and Associates 1811.002