Practice Design Summary Clause Samples

Practice Design Summary. The following table summarizes the data used to design wet detention basin #1. Contributing drainage area to basin (subwatershed A & B) 70 acres Distance to nearest private well (including off-site ▇▇▇▇▇) > 100 feet Distance to municipal well (including off-site ▇▇▇▇▇) > 1200 feet Wellhead protection area involved? No Ground slope at site of proposed basin average 3% Any buried or overhead utilities in the area? No Proposed outfall conveyance system/discharge (w/ distances) 35 ft. to CTH “U” Road ditch 1000 ft. to wetland Any downstream roads or other structures? (describe) Yes – 36” CMP road culvert Floodplain, shoreland or wetlands? No Number of soil investigations completed 3 (in basin area) Do elevations of test holes extend 3 ft. below proposed bottom? Yes (see map) Average soil texture at pond bottom elevation (USDA) Clay loam Distance from pond bottom to bedrock > 5 feet Distance from pond bottom to seasonal water table Pond bottom 2 ft. below mottling No water observed in test holes Permanent pool surface area 1.5 acres Design permanent pool water surface elevation elev. 900.0 Top of berm elevation (after settling) and width elev. 905.0 / 10 feet wide Length/width (dimensions/ratio) 445 ft. (L) x 145 ft. (W) = 3:1 Safety shelf design (length, grade, max. depth) 10 ft. @ 10% slope/1.5’ deepest Ave. water depth (minus safety shelf/sediment) 5 ft. (in center) Sediment forebay size & depth .16 acres (13% pool size)/5 feet Sediment storage depth & design maintenance 2 ft. depth for forebay & pool 15 year maintenance schedule Inflow Peak/Volume Maximum Outflow Rate Max. Water Elevation Storage Volume at Max. Elev. (above perm. pool) Outflow Control Structures* * #1 = 6 inch orifice in water level control ▇▇▇▇ plate – flow line elev. @ 900.0 (1.3 ft. max. head) #2 = 2 foot wide rectangular ▇▇▇▇ – flow line elev. @ 901.3 (.7 ft. hydraulic head) #3 = 30 inch diameter smooth wall pvc pipe – flow line elev. @ 900.0 (3.0 ft. max. hydraulic head) #4 = 30 foot wide earthen/grass emergency spillway – flow line elev. @ 903.0 (1.0 ft. max. depth)