North Central Texas Water Quality
Water quality in North Central Texas reservoirs is a growing concern. Five of the major reservoirs in the Trinity River basin managed by Tarrant Regional Water District (TRWD) now serve 1.6 million people across 11 counties and are expected to serve 2.66 million by 2050. The Texas Water Resources Institute and Texas A&M Agriculture are collaborating with TRWD to study water quality protection and improvements in these fi ve reservoirs in regard to the major problems of sediment and nutrient loading. Sediment loading affects reservoir capacity and water clarity; nutrient loading results in algae growth that impacts water treatment and recreational use.
In 1989, TRWD began addressing these water quality issues with a monitoring program and a modeling program that calibrates water quality models for each reservoir and allows TWRD to assess loadings and impacts to these reservoirs. A team of Texas Agricultural Experiment Station researchers, Texas Cooperative Extension specialists and agents, and selected private consultants will assist TRWD in preparing information for the development and implementation of watershed protection plans.
TRWD’s ultimate goal is to accommodate a growing population and increased urbanization without sacrifi cing water quality. With the watershed protection plans, TRWD can use scientifi cally based methods not only to identify sources for water quality impairment, but also to evaluate the costs and benefi ts of addressing these sources. These watershed management plans will produce useful planning tools for TRWD as well as other groups or entities.
Objectives
- Assemble information on sediment and nutrient loads for specific TRWD-managed reservoirs and associated streams
- Use computer modeling to analyze the biological, physical, and economic feasibility of alternative management practices and facilities
- Conduct public meetings and provide educational programs about water quality protection for stakeholders and customers
- Identify the pollutants that are discharged from point source (i.e. municipal and industrial wastewater treatment plants) that may affect water quality in TRWD reservoirs
Components
- Model Development: The team is using a suite of three EPA-supported computer models:
- SWAT to model watersheds for both point source and nonpoint source nutrient and sediment loads,
- QUAL-2E to route and attenuate the SWAT-generated loadings to the water supply reservoir, and
- WASP to take these loadings and forecast the impact to the reservoir.
- Model Application: Once the watershed, tributary, and reservoir models are calibrated, nutrient/sediment reduction scenarios will be run with varying nonpoint-source and/or point-source loadings. This approach considers best management practices for nonpoint source control and best available technologies for point source control.
- Economic Analysis: The team is conducting fi nancial and budget analyses to estimate costs and returns for alternative management practices simulated with SWAT, QUAL-2E, and WASP.
- Education: The team is developing generalized and watershed-specifi c educational programs about pollutant loadings and management practices. Additionally, the team is working to provide better information to the public about needed changes in activities in the watershed to effect lake water quality improvements.
Collaborators
- Tarrant Regional Water District
- Texas Water Resources Institute
- Texas Agricultural Experiment Station
- Texas Cooperative Extension
- Spatial Sciences Laboratory
- Alan Plummer Associates, Inc.
- Espey Consultants, Inc.
Funding Agencies
- U.S. Environmental Protection Agency
- U.S. Department of Agriculture - Natural Resources Conservation Service