Reducing Risk by Delivering Hurricane Harvey Supplemental Projects in the Dallas Metro Area

MODERNIZING WATER INFRASTRUCTURE - SOUTHWESTERN DIVISION

BY EDWARD RIVERA

The U.S. Army Corps of Engineers (USACE) Southwestern Division (SWD) continues steady progress in delivering projects under its $5 billion Hurricane Harvey Supplemental Program. As part of the division’s program, 40 regional projects were identified and divided into short- and long-term portfolios funded by the Bipartisan Budget Act of 2018.

Total obligations across both long-term and short-term portfolios are approximately $700 million. During fiscal year 2022, five contracts were awarded, obligating $300 million. The coming fiscal year outlook includes another $770 million in scheduled obligations and nine scheduled construction awards.

“The benefits of the supplemental program are substantial for residents across the region,” said SWD Deputy Division Commander Col. James M. Schultze.

Under the construction (long-term) portfolio, there are 12 projects, four within the Fort Worth District and eight within the Galveston District, with an approximate total cost of $4.8 billion.

Three Fort Worth District projects are in the Dallas-Fort Worth Metroplex area and will enhance resilience and flood risk management for Dallas residents and businesses. These Trinity River basin projects include construction on Lewisville Lake dam and spillway, along with flood risk management and ecosystem restoration in the Dallas Floodway and Dallas Floodway Extension.

Lewisville Lake is divided into two projects. The first addressed the earthen or grassy portion of the dam, where the focus was to reduce impacts of seepage that would lead to backward erosion. The second project will require construction in the spillway to ensure there is no uplift and sliding.

The Lewisville Lake earthen dam.

PHOTO BY EDWARD RIVERA

The Lewisville Lake Dam Safety Modification Study was funded by several sources and received more than $92 million from the Bipartisan Budget Act, more than $55 million for the 2019 Water Resources Development Act, and $6.6 million from the city of Lewisville to relocate water lines from the downstream part of the dam.

“We have substantially reduced the risk to the more than 430,000 residents downstream of the dam,” said Stacy Gray, project manager for the Fort Worth District.

Not too far downstream from Lewisville Lake, the Dallas Floodway and Floodway Extension projects are underway. Construction projects include restoring floodway capacity to 277,000 cubic feet per second, flattening levee side slopes on the existing levees, modifying the Atchison, Topeka and Santa Fe Railroad Bridge to increase conveyance efficiency, adding three new interior drainage pump stations, renovating two existing pump stations, and the enhancement of wetland habitat.

The Dallas Floodway Margaret Hunt Hill Bridge and Dallas skyline from the wetland area of the floodway.

PHOTO BY EDWARD RIVERA

In 2007, Congress authorized the Dallas Floodway Project for construction in that year’s Water Resources Development Act at a total cost of $459 million. With the passing of the 2018 Bipartisan Budget Act, both Dallas Floodway and the Dallas Floodway Extension received funding for all of the flood risk components of the projects.

“The Dallas Floodway is cost-shared – 65% federal and 35% city of Dallas. The extension project is solely federally funded,” said Carlos Denson, project manager with the Fort Worth District. “To date, we have received $223 million for the floodway and $136 million for the extension.”

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Within the floodway program, there are 12 projects, of which one, the Atchison, Topeka and Santa Fe Railroad Bridge demolition, was completed in 2021. Projects in the construction phase include two pump stations, the $277,000 levee raise, and slope-flattening, which will raise both the east and west levees to sustain a 277,000 cubic feet per second water surface elevation along the levee. Additionally, there will be a side slope-flattening on the river side of the levees.

The Atchison, Topeka and Santa Fe Railroad Bridge removal area and the start of the Dallas floodway extension.

PHOTO BY EDWARD RIVERA

“These improvements will reduce flood risk and minimize the impacts of flooding. The flattening of the embankments will increase [their] stability and decrease overall operations and maintenance costs,” said Denson.

In the floodway extension area, two new earthen levees will be constructed. The Lamar levee will be approximately 3 miles long, and the Cadillac Heights levee will be 2.25 miles long.

“It is very important that we focus on protecting the communities as well as the businesses that are behind those levees,” said Denson.

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