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Coastal Prairie Freshwater Wetland

Project Title: Coastal Prairie Freshwater Wetland Function Project
Funding Agency & Period: TCEQ, 8/17/07 – 7/31/09
Project Management: Steven R. Johnston (TCEQ), Margaret Forbes, Robert Doyle, Lee Nordt, Truell Hyde (Baylor)
Funding Summary: Total Award = $250,000 ($200,000 Federal)

Project Summary: The purpose of the Coastal Prairie Freshwater Wetland Function project is to demonstrate the economic and ecological value of protecting freshwater wetlands in the Galveston Bay watershed. To demonstrate these attributes the project will (1) evaluate the capacity of freshwater wetlands to store water during storm events, eventually removing surface water through evaporation/evapotranspiration and subsequently reducing the potential peak flooding and flood damage; and (2) evaluate the role of freshwater wetlands in processing pollutants, thereby protecting the water quality in bayous, rivers, and ultimately, Galveston Bay.

Only about 1% of the original Coastal Prairie Ecosystem, type of tall grass prairie remains. Freshwater wetlands within the Coastal Prairie are under extreme pressure as urban development continues in the Houston-Galveston area. Current local definitions of wetlands lend protection to only those wetlands closely associated with navigable waters, leaving many formerly jurisdictional wetlands with non-jurisdictional status. Thus there is a critical need to demonstrate the broad-scale function these small wetlands perform in improving water quality and mitigating flooding.

During this two-year study, wetland scientists, hydrologists, and remote sensing specialists from Baylor University and the University of North Texas will quantify the water quality and water storage functions of selected Coastal Prairie wetlands. These functions will be modeled using an approach similar to the hydrogeomorphic (HGM) wetland functional assessment method. For more information on Coastal Prairie Wetlands and wetland functional assessment approaches, see the Annotated Bibliography.

Five draft models have been developed to predict the relative function of Coastal Prairie Freshwater Wetlands. These include models for reducing surface water concentrations of heavy metals, nitrogen, phosphorus, and organic compounds and a model for water storage. Variables in these include such wetland characteristics as soil organic mater content, wetland hydroperiod, vegetation density, wetland volume, and so one. Field work will begin in 2008 to measure these variables at selected wetlands. In addition, wetland water levels, rainfall, and outflow will be measured. Surface water grab samples will be collected to determine levels of contaminants. A draft Quality Assurance Project Plan is currently being reviewed.

Research Team:

Principal Investigators: Robert D. Doyle and Margaret G. Forbes, Baylor University. Research Associates (Baylor University): Joe C. Yelderman, Hydrologist, Bryan W. Brooks, Toxicologist, Sascha Usenko, Environmental Chemist, and Melissa Mullins, Ph.D. candidate and Plant Ecologist. Research Associates (University of North Texas): Bruce Hunter, Director, Center for Spatial Analysis and Mapping.