Feasibility of BASINS and WinHSPF as an assessment tool for water quality in the Lower Rio Grande River (Texas, Mexico)

The study region of Lower Rio Grande extends from Laredo to Brownsville including the Laguna Madre/Port Mansfield coastal zone. The water quality in this region has been deteriorating steadily, and there are competing needs for the surface water in the basin. The primary aim of this project was to determine the feasibility of BASINS and WinHSPF (Windows interface of HSPF) model to assess the water quality of the Lower Rio Grande. WinHSPF is a planning level watershed model that integrates both point and non-point sources. The model was developed for the part of the river segment ‘Rio Grande below Amistad Reservoir (2304)’ for the years 1993–1994. Existing data was used to calibrate the surface flow. The first step towards determining feasibility of the model i.e. calibration of the surface flow or water balance, was successfully completed. The project demonstrated that by with some limitations, BASINS and WinHSPF could be applied to the region. It also showed the necessity of more adequate data from U.S. and Mexican side of the river for more accurate results.