SWAT Literature Database for Peer-Reviewed Journal Articles

Title:A Comprehensive modeling approach for reservoir water quality assessment and mangement due to point and nonpoint source pollution 
Authors:Narasimhan, B., R. Srinivasan, S.T. Bednarz, M.R. Ernst and P.M. Allen 
Journal:Transactions of the ASABE 
Article ID: 
URL (non-DOI journals):http://ddr.nal.usda.gov/dspace/handle/10113/46718 
Broad Application Category:hydrologic & pollutant 
Primary Application Category:model interface 
Secondary Application Category:pollutant cycling/loss and transport 
Watershed Description:Cedar Creek in north central Texas, USA 
Calibration Summary: 
Validation Summary: 
General Comments: 
Abstract:A comprehensive modeling approach has been developed for use in formulating a watershed management plan to improve the water quality of Cedar Creek reservoir, one of five large water supply reservoirs in north central Texas operated by Tarrant Regional Water District. Eutrophication, or specifically the increase in concentrations of chlorophyll‐a (chl'a') over the last 18 years, is a major concern for the water managers. To develop a watershed management plan, the watershed model SWAT was linked with the lake eutrophication model WASP. Several intensive field campaigns and surveys were conducted to collect extensive water quality and land management data for model setup and calibration. In addition to the streamflow, the SWAT model was well calibrated for sediment (including channel erosion) and nutrients. Further, a simple modification to the SWAT in‐stream routine allowed simulation of the nutrient load due to channel erosion. The in‐stream water quality parameters for SWAT were based on an independent QUAL‐2E model calibration. The calibrated SWAT model showed that more than 85% of the total N and total P loading to the lake are from watershed nonpoint sources. Although cropland occupies only 6% of the watershed area, it contributed more than 43% of the sediment, 23% of total N, and 42% of total P loading from the watershed. The channel erosion contributed about 35% of the total sediment load. The watershed model identified subbasins that contribute considerable amounts of sediment and nutrients. Based on these loads, the calibrated WASP model showed that the watershed nonpoint‐source nutrient load (total N and total P) should be reduced by at least 35% to see a significant reduction in chl'a' concentrations when compared to the WASP calibration levels. 
Keywords:Channel erosion, Eutrophication, Hydrologic modeling, QUAL-2E, Reservoir water quality, SWAT, WASP, Watershed management plan