A Firm Basis
Last year’s very active hurricane season, complete with above-normal rainfall, reminded Floridians about the importance of knowing exactly where the state’s floodplains lie.
According to the Federal Emergency Management Agency (FEMA), flooding is responsible for more damage and economic loss in the United States than any other natural disaster. In fact, flooding caused more than 900 deaths and more than $55 billion in damages nationwide from fiscal year (FY) 92 to FY01.
Governments, insurance companies and individuals all use FEMA flood insurance rate maps, or FIRMs, to identify flooding risk and to plan for potential flooding, but many FEMA maps are outdated. Florida is located in FEMA’s Region 4 where 37 percent of the FEMA FIRMs are more than 15 years old.
One of FEMA’s current priorities is to update the flood hazard map panels within five years. The plan was started in FY04, and the agency anticipates funding for the plan through FY08. The District’s cooperative efforts with FEMA are part of this plan.
The District became a cooperating technical partner with FEMA in September 2001, long before the recent succession of hurricanes hit the state. As a cooperating technical partner, the District is eligible to receive federal grants to work with FEMA and local communities to update and modernize the FIRMs within the District. In addition to updating the data used for the Flood Insurance Studies (FIS) that the FIRMs are based on, one of the goals is to modernize the maps into a digital product. The digital maps, or DFIRMs, will be available on the Internet. Eventually, all the counties within the District and the state will have new DFIRMs. The projected finish date is 2010.
The District is currently working on updating the maps for Hernando, Marion, Pasco and Sarasota counties. These four counties were chosen by FEMA based on the number of insurance policies in each county and the date of the data used to create the current maps. In some cases, the data is 20 years old! Other factors include population, current and projected growth, and FEMA ranking of communities. FEMA funding for these projects builds upon the District’s Comprehensive Watershed Management Initiative and Watershed Management Program efforts that are under way to provide DFIRM updates across the District.
While Hillsborough and Pinellas counties are more populated and have more insurance policies than these four counties, Hillsborough and Pinellas counties both recently worked with FEMA independently of the District to update their respective flood maps.
Here’s a look at where each county project is in the process:
Hernando County recently finished the scoping phase, which involves assessing, prioritizing and developing the scope of work to address the community’s mapping needs. Work on the 22 watersheds within the county is in various levels of completion. Development of digital topographic information for the 22 watersheds is under way. Field reconnaissance and survey is ongoing, and model development has commenced in three of the watersheds.
During the scoping phase, District staff met with representatives from FEMA and the community to review the current FIRMs to identify areas with flooding issues that are not depicted on the current FIRM panels. The county’s current FIRMs are divided among 24 panels. FEMA approved the District’s proposed countywide paneling scheme of 148 panels. This will provide a higher level of detail for end users. The preliminary DFIRMs are expected to be complete by July 2005.
In Hernando County the District has received $1.8 million from FEMA for the map modernization effort. In addition, the District and local cooperators, including Hernando County, have contributed more than $3.1 million toward various activities necessary to update the FIRMs and FIS.
The Marion County project was undertaken to update portions of the existing watershed management plans, including watershed modeling, and to update the FEMA mapping within select watersheds in Marion County. Existing watershed data was provided to the District’s consultant, additional information was researched, the modeling was completed, and the data was provided for FEMA to produce the DFIRMs. The maps will be provided to Marion County and will be presented to the public for comment this year. County and/or public comments may require changes to the model and the DFIRMs.
In Marion County the District has received $300,000 from FEMA for the map modernization effort. In addition, the District and local cooperators have contributed more than $2.9 million toward the update and modernization of the FIRMs and FIS.
The scoping phase for Pasco County has been completed. During this phase, the entire county was flown over with light detection and ranging laser-based technology (LiDAR) to collect topographic information. The District is currently reviewing the LiDAR information. Consultant crews have also been conducting field reconnaissance in various watersheds. Plans also include production and community outreach activities, as well as hydraulic model updates for Bear Creek and the Pithlachascotee River. New watershed modeling is also proposed in the East Zephyrhills, Hammock Creek, Cypress Creek, Trout Creek, Anclote River and Lake Zephyr watersheds.
The District has received $2 million from FEMA for the Pasco County map modernization effort. The District and local cooperators have contributed more than $2.7 million toward updating and modernizing the FIRMs and FIS.
Within Sarasota County the scoping phase has been completed and a public outreach strategy is being developed. In the 1990s, Sarasota County began to develop watershed models to reflect the development and associated changes that have occurred with the county that were not reflected in FEMA’s FIS and FIRMs. New flood-modeling technologies and Geographical Information Systems (GIS) have been employed to reanalyze the coastal riverine watersheds, including Hudson, Whitaker, Holiday and Elligraw bayous, Phillippi, Catfish, Clower, Matheny, North, South, Curry, Hatchett, Fox, Shakett, Ainger, Alligator, Forked, Gottfried and Woodmere creeks, and Cow Pen Slough.
New digital topographic information has been collected for the entire county using LiDAR and will be used to update the county’s existing FIS and remap the floodplain for the DFIRMs. In addition, the District has three cooperatively funded projects to develop watershed management plans and update the FIRMs for the Braden River, Big Slough and Myakka River watersheds. The watershed evaluations of both the Braden River and Big Slough watersheds are being completed. The watershed management plan for the lower portion of the Myakka River watershed (between U.S. Highway 41 and State Road 72) has been completed, and the development of the watershed management plan for the upper portion of the watershed, including Howard Creek, is currently under way. The preliminary DFIRMs are expected to be completed later this year, at which time they will be presented to the local communities and the public for comment.
In Sarasota County the District has received $2 million from FEMA for the map modernization effort. In addition, the District and local cooperators, including Sarasota County and the City of North Port, have contributed more than $5.9 million toward various activities necessary to update the FIRMs and FIS report.