Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Emily Herbst makes this connection here…

The news entitled, “Trinity River wetlands construction brings Dallas Floodway Extension Project closer to city’s core” was reported by the Dallas Morning News in their February 3, 2013 online news. The news relates to the WRE domain of hydrology and the specific issue of the magnitude and occurrence of floodwater. In brief, this news article reports on the Dallas Floodway Extension Project. Currently the U.S. Army Corps of Engineers and the city of Dallas are completing the work by building levees and wetlands along the Trinity River. The goal of this construction is to protect the surrounding property and reduce flooding. Unfortunately, due to federal budget cuts, this 11 year Floodway Extension project has now been reduced to simply continuing the wetland development. This development is going to result in three connecting wetland cells located next to Trinity River. The creations of man-made wetlands are resulting in tearing down 200 acres of trees and leveling the land near the river. However, in attempts to compensate for the loss of this ecosystem the city will preserve 1,200 acres of grassland and woodland and plant additional vegetation. Some construction problems have arisen: the soil needs lead smelter pollution eradication and the previously mentioned funding problems have stopped levee and wastewater treatment progress. Previous construction has resulted in a chain of wetlands already created downstream, further away from the city. These cells ease the flow, reduce floodwater height, both upstream and downstream, and offer habitat for wildlife. Once the wetland extension project has been completed, both chains of wetland will span almost four miles and offer 270 acres of improved habitat. The average size will be approximately 600 ft wide and 7ft deep when full. The wetland will receive water coming from city’s wastewater treatment plant which gravity pulls through the chain. The 40 plant species in this ecosystem absorb nutrients in the water and clean effluents before it drains into Trinity River.

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Figure 1 – Wetland cell constructed upstream of the Trinity River in Dallas, Texas.

In addition to plant biodiversity, there are multiple mammal and reptile species and 91 species of birds. Wetlands are forgiving so even if the wetland experiences extreme flooding or drought the diversity should continue to thrive and improve. I believe the article is accurately representing WRE facts regarding the Trinity River watershed construction. The flood protection measures that were initially planned coincide with the Trinity Watershed Management Department Flood Control (Welcome to the City of Dallas, Texas). Additionally, the use of these watersheds biodiversity allow for removal of pollutants from Trinity River without the use of a treatment facility as also stated in “Water Pollution”. This article failed to mention the impact on the surrounding community both regarding the increased water quality and wildlife and thoughts of the community on the aesthetics of the wetlands replacing the woodland.

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Figure 2 – Satellite image of wetland construction along Trinity River in Dallas, Texas.

 

Water resource engineering is considered an interdisciplinary field that has impacts among global, economic, environmental, and societal realms. The Floodway Extension Project deals with societal and environmental areas. The occurrence and magnitude of floods impact the community’s ability to exist and function during flood seasons. Environmentally, this project is offering an entirely new system of biodiversity and ecosystems. Additionally, the use of wetlands creates a natural water cleansing system. I found the flood protection of the Dallas Floodway also reported on Dallas’ city hall website (referenced below). Without this Floodway Extension Project, the city of Dallas would experience more floods with a larger magnitude than they would if the wetland cells were not implemented. Also, they would have to have wastewater treatment plants filter all their water, whereas in this case, the wetlands can assist with some cleansing.

 

References

Appleton, Roy. “Trinity River Wetlands Construction Brings Dallas Floodway Extension Project Closer to City’s Core.” Dallasnews.com – News for Dallas, Texas – The Dallas Morning News. N.p., 3 Feb. 2013. Web. 24 Feb. 2013.

King Thomas, Lashun, Dr. “Water Pollution.” CIE 341: Introduction to Environmental Engineering. Syracuse, New York. 23 Oct. 2012. Lecture.

“Welcome to the City of Dallas, Texas – Trinity Watershed.” Welcome to the City of Dallas, Texas – Trinity Watershed. City of Dallas, Texas, 2012. Web. 24 Feb. 2013.

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