Retention Treatment Basins

The Acacia Park RTB services an 816-acre watershed, treating approximately 70 million gallons of combined sewer overflows (CSO's) annually. The RTB has a capacity of four million gallons. The facility is designed to provide 30 minutes of detention time for a one-year, one-hour storm.

The Birmingham RTB and Tunnel services a 1,185-acre watershed, treating approximately 71 million gallons of CSO's annually. The RTB has a capacity of 5.5 million gallons and is designed to provide 30 minutes of detention time for a one-year, one-hour storm.

The Bloomfield Village RTB services a 2,325-acre watershed, treating approximately 122 million gallons of CSO's annually. The RTB has a capacity of 10 million gallons and is designed to provide 30 minutes of detention time for a one-year, one-hour storm.

The George W. Kuhn Drainage District (formerly the Twelve Towns Drainage District) serves all or part of 14 communities, encompassing a drainage area of 24,500 acres upstream of the Red Run Drain, a tributary of the Clinton River. During dry weather, all flow is routed to the Detroit Wastewater Treatment Plant, but during heavy rainfall, high volumes of combined sewage (typically more than 93 percent stormwater), exceed the outlet capacity to Detroit, causing excess flow to be diverted to the GWK RTB where it is stored, screened and disinfected prior to discharge to the Red Run Drain.