Water Quality Impacts of Reservoirs in Central and South Florida

Under the Comprehensive Everglades Restoration Plan (CERP), which was authorized in the Water Resources Development Act of 2000, several large storage reservoirs will be constructed by the South Florida Water Management District (SFWMD or District) or the U.S. Army Corps of Engineers (USACE). The purpose of these reservoirs is to help reduce the volume and number of harmful stormwater discharges to Lake Okeechobee and coastal estuaries, provide spatial and temporal water redistribution to meet Everglades restoration demands, improve the operation of the stormwater treatment areas (STAs), and provide an alternate source for agricultural irrigation demands to reduce dependency on Lake Okeechobee releases. Through the operation of several prototype and full-scale STAs, considerable data exists on the water quality performance of these treatment areas but little is known about the water quality impacts of the proposed storage reservoirs. This paper discusses the results of the Water Quality Impacts of Reservoirs (WQIR) study. In this study, hydrologic and water quality data collected for reservoirs and natural lakes in Central and South Florida were analyzed to ascertain the impact of these reservoirs on water quality, particularly phosphorus concentrations. In the WQIR study, over 600 water bodies were identified in the study region. For these preliminary sites, only 36 were found to have a reasonable chance of providing calibration data sets. The available hydrologic, climatic, and water quality data for these 36 sites were collected but only eight candidate sites were identified that provided sufficient data for subsequent use in calibrating analytical water quality models.