City of Dallas Pavaho Stormwater Treatment Wetlands & Green Infrastructure

As part of a Consent Decree mandated by the U.S. Environmental Protection Agency (EPA) and the Texas Commission on Environmental Quality (TCEQ), the City of Dallas was required to provide funding for design and construction of a Supplemental Environmental Project (SEP) known as the Pavaho Wetland. 

The objectives of the Pavaho Stormwater Wetland SEP project included the creation of habitats for wetland flora and fauna and water quality improvement for storm runoff reaching the Trinity River. Since the project was within the Dallas Floodway, it significantly impacted a federal project and required approval by the Chief of Engineers under 33 USC 408. As part of this project, Plummer did the following:

• Designed a 65-acre wetland within the Trinity River corridor,
• Prepared an National Environmental Policy Act-compliant Environmental Assessment,
• Prepared Section 404 and Section 408 permit applications,
• Submitted a Workplan Report with an operations and maintenance manual to the EPA for approval, and
• Coordinated with the U.S. Army Corps of Engineers and the EPA.

Due to constraints resulting from multiple projects proposed within the same project area, the Pavaho Wetland design was modified to develop four wetland habitat areas: one within an existing sump for the Pavaho Pump Station, which receives runoff from approximately 1,900 acres of urban watershed, and three within the Trinity River floodway. The Pavaho Wetland improves surface water quality through the retention and pretreatment of storm flows and rainfall runoff, creates habitats for wetland flora and fauna, and serves as a visually appealing amenity for the local community.