Indicator Bacteria TMDL Development in Urban Environment

Buffalo and Whiteoak Bayous frequently exceed water quality criteria for contact recreation. The watersheds for Buffalo and Whiteoak Bayous are highly developed with high-density urban and residential land uses dominating the majority of land area. Historical data show that fecal contamination of both bayous is extensive, with all water quality monitoring stations having geometric means significantly above the contact recreation criterion of 200 colony forming units (cfu)/100 mL. Identified sources of the fecal contamination in the bayous include point sources and dry-weather storm water flows, in addition to sediments, wildlife, and upstream discharges from the Addicks and Barker reservoirs. This paper presents the results of efforts aimed at quantifying the relative contribution of these sources to the observed fecal levels in the bayous. The paper also presents modeling results aimed at developing Total Maximum Daily Loads (TMDLs) and load allocation scenarios for the two watersheds.