Sediment Forebay

A sediment forebay is a separate cell within or immediately upstream of a structural stormwater BMP designed to capture, temporarily store, and settle coarse sediment and debris from runoff in an accessible area. A sediment forebay is formed by a barrier such as an earthen berm, concrete weir, granite curbing, or stone gabion baskets. Sediment forebays are highly flexible and can be adapted to meet site-specific constraints. The forebay has a non-erosive outlet into the primary stormwater BMP and can be configured as a riser and pipe, overflow weir, or culvert. The elevation of the outlet should be set such that the forebay is sized to temporarily store 10% to 25% of the Water Quality Volume (WQV).

sediment forebay diagram
sediment forebay information