Arroyo Colorado

4 City Wetland Project

Funding Source

Funding provided by the Texas Commission on Environmental Quality and EPA as part of a Clean Water Act Section 319(h) Grant.

Project Summary - Wetland Systems in the Arroyo Colorado Watershed

Cities of San Juan, San Benito, La Feria and Mercedes

In association with the Arroyo Colorado Watershed Partnership, the TCEQ produced a Watershed Protection Plan (WPP) for the Arroyo Colorado in January of 2007. The WPP is a comprehensive strategy of voluntary actions designed to address the water quality impairments and concerns identified on the State's 303(d) List. The Arroyo Colorado Partnership is a coalition of public and private organizations and concerned individuals in the watershed who have committed their time and resources to developing and implementing the WPP. The WPP compliments the ongoing development of the TMDL for the Arroyo Colorado by supporting the technical assessments of the watershed and identifying management practices to be implemented to restore water quality conditions. The TMDL for the Arroyo Colorado is scheduled to be completed during state fiscal year 2008.

The WPP for the Arroyo Colorado was submitted to EPA Region 6 for review under its Nonpoint Source program and received a favorable review, thus making projects in the watershed eligible for continued federal funding assistance. In cooperation with four municipalities in the watershed (the cities of San Juan, San Benito, Mercedes, and La Feria), the TCEQ sought and received approval for federal funding assistance for enhanced wastewater treatment projects identified in the Arroyo Colorado WPP (see Near-Term Goals for Wastewater Infrastructure on page 79 and Table 10 of the WPP). These projects consist of the design, construction, maintenance, operation, and monitoring of wetland systems which will receive treated effluent from municipal wastewater treatment facilities. Treated effluent discharged from municipal wastewater treatment facilities will be diverted to the wetlands after the point of compliance with the applicable TPDES permits. Therefore, the wetlands are not part of the treatment works covered by the permit. However, the diversion of the treated effluent to the wetlands must be authorized in the permit and described as part of the discharge route for the facility.

Multiple benefits are to be derived from the wetland systems. Wetlands have the capacity to remove pollutants in water through physical, chemical and biological processes. Nutrients are of particular concern since they are believed to contribute to the water quality impairments observed in the Arroyo Colorado. Wetlands are particularly well suited to remove nutrients with removal efficiencies on the order of 80% to 90%. The wetlands will also benefit the local communities by creating recreational, educational, and aesthetic assets. The projects include provisions for recreational appurtenances including boardwalks, all-weather paths, signage, and kiosks. The City of La Feria project incorporates the wetland as a water feature in a regional city park being developed with funding assistance from the Texas Parks and Wildlife Department. Wetlands also provide benefits to wildlife by providing desirable habitat.