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| Construction & siting issues | |||
| The following are design
guidelines from King County for biofiltration swales:
The length of biofiltration swales should be at least 200 feet,
with slopes up to 6 percent. The exact size of an individual swale
is dependent upon the flow rate (further information of flow rates
provided by King County in Ch. 3) |
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Swales should have a maximum bottom width of 50 feet. Starting 20 feet downstream from the inflow point, 1-foot-high check dams should be placed every 50 feet along the swale’s length. Check dams should have 2:1 side slopes and be constructed of rip rap. No lining is required for infiltration systems; however, an outlet should be provided for excessive water volumes. |
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