The U.S. Army Corps of Engineers, Fort Worth District, awarded a $15.9 million contract on September 23 to Aerostar SES LLC of Oak Ridge, Tenn., to construct the Upper Chain of Wetlands along the Trinity River Corridor in Dallas.
The project combines ecosystem restoration with flood risk management by excavating a chain of three wetland ponds, labeled Cell A, B and C, between the Martin Luther King Jr./Cedar Crest Bridge and the Central Wastewater Treatment Plant.
The new wetland ecosystem, composed of 57 acres of water/wetlands and 33 acres of surrounding grasslands, will provide quality wildlife habitat just a few miles southeast of Dallas City Hall and at the northern edge of the Great Trinity Forest.
Building on the earlier construction of the Lower Chain of Wetlands, the two adjacent wetland chains will total 271 acres of improved habitat and be 3.7 miles long. The multi-year contract is part of the Fort Worth District’s Dallas Floodway Extension Project, a partnership with the city of Dallas.
The Upper Chain of Wetlands is designed to operate in conjunction with the Lamar Levee proposed for the opposite side of the Trinity River. That levee would plug a 3-mile gap in the Dallas levee system by linking the Rochester Park Levee with the end of the East Levee below downtown (at the Santa Fe Trestle Trail/DART Bridge). The levee would protect business and residential neighborhoods near South Lamar Street.
When not serving as an alternate river channel during flood stage, the wetland ponds and surrounding prairie will provide improved habitat with a particular focus on supporting resident and migratory birds. Two observation boardwalks, on Cells A and B, will be built under the contract. The Corps of Engineers’ Lewisville Aquatic Ecosystem Research Facility will be in charge of the re-vegetation program. Texas native aquatic and grassland species from this region will be planted that are particularly valuable as a source of food and cover for birds.
Audubon’s Trinity Bird Count has identified 129 species at the Lower Chain of Wetlands since its quarterly visits began in 2011. Corps researchers have documented improved species diversity over time in the Lower Chain ecosystem that seems to have coincided with progress in the establishment and diversity of aquatic vegetation.