Simulation of flow and water quality of the Arroyo Colorado, Texas, 1989-99

Water-Resources Investigations Report 2002-4110
In cooperation with the Texas Natural Resource Conservation Commission and the Nueces River Authority
By:  and 



A model parameter set for use with the Hydrological Simulation Program—FORTRAN watershed model was developed to simulate flow and water quality for selected properties and constituents for the Arroyo Colorado from the city of Mission to the Laguna Madre, Texas. The model simulates flow, selected water-quality properties, and constituent concentrations. The model can be used to estimate a total maximum daily load for selected properties and constituents in the Arroyo Colorado. The model was calibrated and tested for flow with data measured during 1989–99 at three streamflow-gaging stations. The errors for total flow volume ranged from -0.1 to 29.0 percent, and the errors for total storm volume ranged from -15.6 to 8.4 percent. The model was calibrated and tested for water quality for seven properties and constituents with 1989–99 data. The model was calibrated sequentially for suspended sediment, water temperature, biochemical oxygen demand, dissolved oxygen, nitrate nitrogen, ammonia nitrogen, and orthophosphate. The simulated concentrations of the selected properties and constituents generally matched the measured concentrations available for the calibration and testing periods. The model was used to simulate total point- and nonpoint-source loads for selected properties and constituents for 1989–99 for urban, natural, and agricultural land-use types. About one-third to one-half of the biochemical oxygen demand and nutrient loads are from urban point and nonpoint sources, although only 13 percent of the total land use in the basin is urban.

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Simulation of flow and water quality of the Arroyo Colorado, Texas, 1989-99
Series title Water-Resources Investigations Report
Series number 2002-4110
DOI 10.3133/wri024110
Year Published 2002
Language English
Publisher U.S. Geological Survey
Contributing office(s) Texas Water Science Center
Description HTML Document; Report: iv, 56 p.
Country United States
State Texas
Other Geospatial Arroyo Colorado
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