Water Resources Research Act Program

Details for Project ID 2010SC73B

Sediment phosphorus flux measurement in Lake Wateree, SC

Institute: South Carolina
Year Established: 2010 Start Date: 2010-03-01 End Date: 2011-02-28
Total Federal Funds: $27,546 Total Non-Federal Funds: $55,092

Principal Investigators: Daniel Tufford, Dwayne Porter

Abstract: For many decades the Catawba River has been a source of excessive nutrient loading to the reservoirs at the lower end of the watershed. As a result, Lake Wateree is eutrophic and appears on the South Carolina 303(d) list (http://www.scdhec.gov/environment/water/tmdl/docs/tmdl_08-303d.pdf) for water quality impairment from total phosphorus. Work is in progress by the SC Department of Health and Environmental Control (SCHDEC) to develop a total maximum daily load (TMDL) for the lower Catawba River because of this impairment. The results of the work we propose to do will fill a gap in the information SCDHEC has about phosphorus loading to Lake Wateree. If significant internal loading is observed it will affect the estimates of the sources of current total loading and how reductions of external point and nonpoint source loading will impact lake recovery over time. If significant loading is not observed this will justify greater confidence in total loading estimates from external sources. This work will also provide broad insight into nutrient dynamics of other Piedmont reservoirs. During the summer of 2009 preliminary data collection took place in Lake Wateree where it was found that the reducing conditions necessary for sediment release of phosphorous do develop. Prior analysis of nutrient inflow-outflow using STORET data showed that more nutrients enter the lake than leave it on an annual basis. Here we propose to follow-up on that work to address: (1) the question of whether internal phosphorus loading occurs in the lake using in situ benthic chambers, (2) the estimated size of the sediment phosphorus stock by laboratory analysis of sediment samples, (3) a spatial and temporal profile of phosphorus conditions in the water column by laboratory analysis of water samples and (4) expansion of the 2009 assessment of the physical conditions that favor nutrient release from sediments, (5) integration of the results into a mass balance model of phosphorus in the lake.