Map Modernization

Mapping Successes: The Tropical Storm Allison Recovery Project (TSARP )

Case Concentration:

Harris County Texas and FEMA partner to assist residents in recovery from Tropical Storm Allison and minimize future flood loss by developing accurate flood hazard information.

Scope of the Project:

Harris County SealIn early June 2001, Tropical Storm Allison ravaged 28 counties in Texas, including many areas of densely populated Harris County, which includes the City of Houston. Widespread flooding caused approximately $5 billion in damage in the Houston area. In the aftermath, local and regional officials recognized the need for accurate and timely flood hazard information. Subsequently, the Federal Emergency Management Agency (FEMA) and Harris County Flood Control District (HCFCD/the District) working under a Cooperative Technical Partner (CTP) agreement engaged in a rapid restudy of approximately 1,200 stream miles in 22 impacted watersheds. Neither historical data nor weather forecasts could adequately predict this extraordinary storm that would dump as much as 80 percent of the area’s average annual rainfall over some Houston and Harris County neighborhoods, affecting more than 2 million people. When the rain finally ended, Allison had left Harris County with 22 fatalities, 95,000 damaged automobiles and trucks, 73,000 damaged residences, 30,000 residents in shelters, and over $5 billion in property damage in its wake. Simply put, everything about Allison was “off the charts.”

The Tropical Storm Allison Recovery Project (TSARP), a partnership between the Harris County Flood Control District (HCFCD) and FEMA Region VI, included an Outreach plan for the flood study rollout process. The TSARP developed technical products to assist the community in recovery from the devastating flooding and provide a greater understanding of flooding and flood risks. The study created new Digital Flood Insurance Rate Maps (DFIRMs), delineating Special Flood Hazard Areas.