WEST, in collaboration with the U.S. Army Corps of Engineers (USACE)–Fort Worth District and the Interagency Flood Risk Management (InFRM) Academic Council, announces the findings of The Texas Storm Study (appendices here). This comprehensive study, which began in May 2021, addresses the challenge of developing design storm standards for large watersheds in Texas.

The study’s scope included seven key tasks:

1. Literature Review

2. Data Collection

3. Storm Analysis

4. Regionalization

5. DARF Verification

6. DARF Database

7. Design DARF Curves

The study created and validated updated Depth-Area-Reduction Factor (DARF) data for various durations (1-, 2-, 3-, 6-, 12-, 24-, and 48-hour) and annual return frequencies (1- to 25-year, 50- to 200-year, and 500-year and beyond). The team also identified three relatively homogeneous DARF zones (East, Northwest, and West Zones) within Texas.

We are particularly excited to introduce the Interactive Texas Storm DARF Explorer. This user-friendly web-based tool allows practitioners to easily access and visualize updated DARF curves. This innovative tool enhances decisionmaking by providing dynamic visualizations and comprehensive data access. As a result, flood risk managers and hydrologic designers will find it an invaluable resource.

Additionally, the study offers recommendations for design storm methodologies and procedures. It also includes an example problem that showcases how DARF values can be incorporated into the conventional design storm process, based on the study’s findings.

This study represents a significant advancement in research supporting flood risk management and will be valuable for engineering practitioners and communities in reducing flood risk across Texas.

~Jerry Cotter, Retired Chief of Water Resources
U.S. Army Corps of Engineers, Fort Worth District

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WEST is an internationally recognized water resources engineering firm with offices in Arizona, California, Oregon, Texas, and Washington. With 70 highly trained professionals, WEST specializes in addressing complex water resource challenges like flood risk management.

Established in 1950 after the disastrous Trinity River floods, USACE–Fort Worth District oversees water resources development for 66% of Texas. Through fiscal year 2020, the District’s reservoirs have prevented more than $150 billion in flood damages since their construction.

The InFRM team unites Federal partners with mission areas of hazard mitigation, emergency management, floodplain management, natural resources management or conservation. In this way, InFRM can combine skillsets, resources, and programs to help reduce long term flood risk throughout the States of Arkansas, Louisiana, New Mexico, Oklahoma and Texas. Currently, the team includes the Federal Emergency Management Agency, USACE, the U.S. Geological Survey, and the National Weather Service.

In 2017, InFRM formed its Academic Council to leverage the expertise of leaders in civil and environmental engineering across universities. These include Rice University, the University of Texas at Austin, Texas A&M University, the University of Texas at Arlington, the University of Texas at San Antonio and Louisiana State University, with researchers from UT Arlington, Rice University, and Texas A&M University contributing to The Texas Storm Study.