1403 ROCKEFELLER AVE 2024-10-25 - Laserfiche WebLink

Option 3. Detention Design Worksheet Table 3: Small Project Detention Sizing Total Contributing Area to Detention System Riser Height,overflow Riser Detention Detention Pipe Sizing Acres Orifice Size elevation above invert Diameter Pipe Diameter Length Required Selected At least but less than* (max) (in) of outlet pipe,(ft) (in) (in) (ft) 200 400 0.0092 0.375 1.5 6 18 20 400 600 0.0138 0.375 1.5 8 18 24 600 800 0.0184 0.375 1.5 8 18 28 800 1000 0.0230 0.5 1.5 8 18 33 1000 1200 0.0275 0.5 1.5 8 18 40 1200 1400 0.0321 0.5 1.5 8 18 55 1400 1600 0.0367 0.5 1.5 8 18 70 1600 1800 0.0413 0.5 2.0 8 24 60 1800 2000 0.0459 0.5 2.0 8 24 65 *For projects directing more than this total area draining to the detention facility, size using a continuous runoff model(WWHM, MGS Flood etc.). Do not use this table to size facility. Outlet pipe shall be set 3" above bottom of detention pipe to allow for sediment storage. • Net new impervious area requiring mitigation (ft2): • Contributing impervious area to BMP: • Total contributing area including landscaped area (ft2): All underground stormwater facilities shall be setback from any structure or property line a distance equal to the depth of the ground disturbed in setting the structure. Applicable access requirements of DCSS 4-4.2 (3) have been met.