Laserfiche WebLink
Ia/IDrabon Dry wells <br />The minimum rock volume and dry well rock layer height are based upon the soil type in the location <br />of the drywell. The soils report will provide the USDA Soil Type. The table below provides the volume <br />of washed rack and height of washed rock required. Roof downspout dry wells shall be designed in <br />accordance with the SWMMWW. <br />"Coarse sand"(more than 50%of 60 OR <br />sand fraction remains on %4 sieve <br />"Medium sand' (more than 511%of 90 T20 <br />sand fraction remains on %40 sieve) <br />None sized. <br />Volume of Washed Rock Required = Tributary Impervious Area (ft)'Standard Volume <br />1000 (fil <br />Note: Stormwater facilities that infiltrate stormwaterbymeans also underground facility such as <br />an infiltration trench or dry well may need to be register as an underground injection well (UIC). <br />For more information, visit everenwa gov/1985/Stormwater-Technical-Resources <br />BMP T5.10B Roof Downspout Dispersion Systems <br />Downspout dispersion systems are splash blocks or trenches, which serve to spread roof runoff over <br />vegetated pervious areas. <br />Downspout Dispersion Trench <br />Roof downspout dispersion trenches shall be designed in accordance with the SWMMWW. <br />Trenches serving up to 700 fu roof area may use a Simple Dispersion Trench (2 ft wide X 10 it <br />length). Multiple simple dispersion trenches maybe used as long as none exceeds 700 ft' of <br />tributary area and the flow paths from the trenches do not overlap. <br />None sized. <br />City of Everett Public Works <br />Small Project Stormwater Sne Plan Report Dec 2019 <br />