Frequently Asked Questions: Tropical Storm Allison Recovery Project
What is TSARP?
The Tropical Storm Alison Recovery Project (TSARP) was a joint project between the Federal Emergency Management
Agency (FEMA) and the Harris County Flood Control District. Originally conceived in June 2001 and officially
launched in October 2001, the goal of TSARP was to help local communities continue their recovery from
Allison's devastating flooding and provide area residents with a greater understanding of flooding and their
flooding risks. This project ultimately resulted in a new Flood Insurance Rate Map (FIRM or floodplain map)
for all 35 National Flood Insurance Program (NFIP) communities in Harris County, better engineering tools
for the Flood Control District and local communities to use in planning and building new flood damage
reduction projects, and an increased knowledge of the risk of flooding for all the citizens of Harris County.
What did the TSARP study produce?
TSARP produced a new Flood Insurance Rate Map (FIRM or floodplain map) for Harris County with an updated Special Flood
Hazard Area. The purpose of the map, along with new engineering tools, is to assist citizens in making important
home-buying and other property-related decisions and to help public agencies responsible for planning and
maintaining the watershed infrastructure in Harris County. The end result of TSARP was a more informed and
disaster-resistant community – one that is better prepared for the next "Allison."
Who funded TSARP?
FEMA and the Flood Control District jointly funded TSARP, which cost approximately $32 million (split equally between
FEMA and the District). In 2001, Congress approved a limited FIRM Modernization fund of $15 million nationwide.
Updating Harris County's FIRM would have taken 10 years or more if not for Allison and a FEMA initiative
called Cooperating Technical Partners, or CTPs.
Were new floodplains created?
New floodplains were NOT created by TSARP. TSARP and the data it produced helped improve the understanding of where
the natural floodplains lie by using the latest information and technology. Every citizen in Harris County
needs to have the most accurate information about their risk of flooding.
Why did Harris County need a new Flood Insurance Rate Map, or FIRM?
At the time of TSARP, new technologies had become commercially available that were not available 20 years ago when
the original FEMA Flood Insurance Study and associated Flood Insurance Rate Map were developed for Harris
County. The original FIRM had been kept up to date over time, but those updates where made using the
technology used to develop them originally. The technologies used to create the new FIRM, which became
effective in 2007, resulted in unprecedented detailed boundaries of the mapped 1 percent (100-year),
0.2 percent (500-year) and coastal floodplains of Harris County.
Were all affected communities in Harris County aware of the study?
Yes, all communities in Harris County were notified of the TSARP effort. A briefing for each community's floodplain
administrator was held in August 2001 to announce the initiation of TSARP. A Memorandum of Agreement was
sent to each community soliciting their participation in TSARP. Communities also participated through
frequent update meetings with FEMA, the Flood Control District and the TSARP team.
How many miles of bayous and creeks were studied?
Approximately 1,100 miles of bayous and creeks in 22 major watersheds were studied along with an additional 100
miles of bayous that were not previously studied with the development of the original floodplain map for
Harris County. However, not all of the 2,500 miles of bayous and creeks in Harris County were studied
because some bayous are very short and flooding is controlled by the receiving bayou, or some have
capacity well in excess of the 1 percent (100-year) flood.
Where all watersheds studied?
Yes, all 22 major watersheds (not all streams) in Harris County were studied including 100 miles of bayous and
creeks that were not previously studied. At the conclusion of the TSARP effort, floodplains in all
watersheds in Harris County were remapped on the new FIRM.
When was the Flood Insurance Rate Map for Harris County adopted?
The FIRM for Harris County produced through TSARP was adopted by the city of Houston, Harris County and the 33
other communities in Harris County in 2007. Once the map was adopted, it became FEMA’s effective FIRM
for Harris County. The FIRM is used by the federal government to set flood insurance rates for NFIP
communities and by local cities and counties to regulate land development. The Harris County Flood
Control District does not regulate land development. Use the Flood Control District’s
Flood Education Mapping Tool
to view the floodplain map for Harris County to learn where your property lies relative to a
How were the results of the TSARP study delivered to the communities of Harris County?
Paper copies of the FIRM developed through TSARP were delivered to all 35 NFIP
communities in Harris County. In addition, each community received several CDs that contained the maps in a
digital format and all of the backup data for the project. Public meetings also were held for the general
public throughout Harris County, and citizens were able to view the new preliminary FEMA FIRM online on a
dedicated website developed for TSARP.
What standard procedures does FEMA follow to ensure the information presented on flood maps and in reports is accurate?
Because the flood hazard information presented on FIRMs and in Flood Insurance Study (FIS) reports form the technical
basis for the administration of the NFIP, FEMA exercises great care to ensure that the analytical methods
employed in the FIS are scientifically and technically correct; that the engineering procedures followed meet
professional standards; and, ultimately, that the results of the FIS are accurate. Although the FIRMs and FIS
reports are prepared according to rigorous technical standards, FEMA recognizes the importance of community
participation in the preparation of the reports and maps and works closely with community officials and other
interested parties to ensure the information presented is accurate, up-to-date and understood.