Morrison was hired in 2008 by the city to perform a flood study after FEMA mapping using best available data would have raised the base flood elevations (BFEs) within the city of Brownwood as much as 8 feet. Morrison explained the method FEMA had used was best available data overlaid on best available typography, which was from 2007. He noted that the last study done in Brown County was 30 years old and FEMA had lost all models from this previous study. Brownwood and Brown County were the only two entities that rejected FEMA’s remapping according to Morrison.
Morrision was also engaged by Brown County and the City to determine the flood elevation of Lake Brownwood. According to Don Hatcher, Engineer for the City of Brownwood, this BFE was necessary for some 1,500 sq. miles of drainage flows through the lake into the city. The flow from the lake as well as an additional 500 sq. miles of area was studied to determine the flood elevations within the city. Hatcher along with Jodie Kelly, also a city engineer, worked with Morrison in collecting data for the study. Morrison also credited the Brown County Water Improvement District as well for providing valuable hydrology from Lake Brownwood.
After consideration of historical data and information provided by Morrison, the city and Brown County settled with FEMA that the elevation of Lake Brownwood would not change.
Morrison will be submitting the required data to FEMA for updating the city’s flood mapping. This process of approval will take about 6 months and it will be another 90 days for the actual final maps to be printed, according to Morrison.
The 100 year flood plain along the Pecan Bayou gets larger on the floodway in this study and shows a more accurate account of areas where properties have flooded and are likely to flood in the future. Maps drafted by Morrison indicate that some homes will now be in a floodplain which were not previously. This accuracy of the new study, according to Morrison, will create better development of both commercial and residential properties.
“Most people don’t understand that this 100 year floodplain does not mean that the area floods only once in every 100 years,” stated Morrison. “It means that there is a 1% chance in any given year to flooding. A floodway is the most dangerous area of conveyance.”
Morrison stated that FEMA mapping only looks at areas studied within the last 30 years and that the city has a more accurate mapping of areas likely to flood. City codes can be enforced according to the flood mapping of a city.
“A city can adopt their own map and enforce according to that,” stated Morrison.
City Manager Bobby Rountree explained that homes in the proposed new flood plain will have the opportunity to purchase flood insurance at the current rates rather than waiting for rates to increase after FEMA accepts the study. According to Rountree, the City of Brownwood plans to send letters to inform homeowners (in the flood prone areas) of the opportunity of buying flood insurance at the lower rates while the option is available.
Hatcher also stated that new construction is not prohibited in floodways or floodplains, it is only required that the new structures within a floodway be elevated above the flood level.
Photo: Don Hatcher and former mayor Bert Massey look at the newly proposed flood maps.
