Belle Isle Facility
CSO & RTBThe Belle Isle CSO retention treatment basin (RTB) is the smallest RTB and was sized to provide 10 minutes of detention for the peak flow of the 10-year, 1-hour storm. Located on Belle Isle along the Detroit River, this RTB has a storage capacity of 300,000 gallons. It eliminated one untreated CSO outfall and has been operational since March 2008.