Fort Bend County residents and businesses can probably count on paying a total in the tens of millions of dollars in taxes and insurance beginning in about two years, as the result of a government study intended to accurately determine Brazos River flood levels.
The official Base Flood Elevation for the Brazos in Fort Bend – which represents the river level during a 100-year flood – is very likely to be increased as the result of a years-long study funded by federal and local government, people familiar with that study say.
That means an as-yet-undetermined number of homes, business offices and other buildings will be determined to be within what’s known as the 100-year floodplain, and will require more expensive flood insurance.
It also means the height of the clay-and-grass levees surrounding some residential communities – particularly in the Sugar Land and Richmond areas – probably will have to be increased.
Sugar Land City Engineer Chris Steubing told City Council members a few days ago that digital flood insurance maps of the Brazos River and Oyster Creek drainage basins, now in preliminary form, will show a “potential increase in the base flood elevation,” which will impact both land inside and outside of levees in the city.
“Are we all in the flood plain?” City Councilman Daniel Wong asked Steubing. The engineer said an official base elevation hasn’t yet been set, so the answer is not yet known.
But a major federal contractor working for the Federal Emergency Management Agency has compiled enough data to conclude that a 100-year flood on the Brazos would result in higher water than present estimates indicate. Thus, a new, higher base flood elevation is in the works, Fort Bend County Judge Bob Hebert said Monday.
Redrawing of the flood insurance maps is an undertaking between FEMA, Fort Bend County and the City of Sugar Land. A few years ago, Hebert said, FEMA proposed a less-detailed study to determine new flood insurance maps. However, local officials “said that’s not good enough.”
Hebert said officials long had suspected the Brazos flood level data model was inaccurate, because rainfall at a specific rate, in a specific part of the river was observed to be producing water volume and river levels that differed from what computer models said they should be.
So local officials and FEMA agreed to a study that included mapping the Brazos and Oyster Creek basins using LIDAR – a radar-like process in which a microwave device is used during helicopter flights over an area, producing accurate topographical maps. Hebert said Sugar Land kicked in $200,000 for the project, the county paid $1.1 million and FEMA agreed to pay $1.3 million.
Now the LIDAR survey has been completed, and FEMA’s engineering contractor believes the Brazos base flood elevation must be officially increased in order to be accurate, Hebert said.
“We know the existing levees will have to be raised some,” he said – an expensive undertaking for those who live within the levees and pay taxes to one of the dozen or so Levee Improvement Districts, or LIDs, in Fort Bend County.
Steubing told Sugar Land councilors last week that those levees have to be “recertified,” as the result of a FEMA memo issued shortly after Hurricane Katrina struck New Orleans. That recertification must be based on the new base flood elevation set for the Brazos and/or Oyster Creek.
The theory behind putting major residential communities behind levees was to lessen development costs and essentially take the protected land off the roles of property that is required to carry federal flood insurance.
Fort Bend County communities protected by levees includ First Colony, Sienna Plantation, New Territory and Greatwood either within Sugar Land city limits or in its extraterritorial jursidiction, and Pecan Grove in the Richmond ETJ. Also, the Riverstone community, which is in both Sugar Land and Missouri City, has been building a new levee to open up more acreage to development.
Hebert said the Fort Bend County Drainage District has formed a committee of LID representatives to study issues raised so far in the flood insurance mapping study.
Steubing said preliminary maps are scheduled to be released to the public by January 2008, and there will be a comment period of several months. After that, FEMA will deliberate and then create official new flood insurance maps, including an official base flood elevation for the Brazos, a process Hebert said will not be complete until early 2009.
At that point, it will be clear who has to obtain new flood insurance, and which levees have to be raised.
“They can be expensive,” Hebert said of levee rebuilding projects. “In the aggregate of tens of millions of dollars.” However, if the current inaccurate flood levels continued to be used and those levees were breached, “the property damage would be in the tens of billions of dollars,” Hebert added.
“It’s an expensive undertaking,” he said, “but I would hate to be here as an elected official when the taxpayers found out we did not protect them from the 100-year flood because we used the wrong elevations.”
The official Base Flood Elevation for the Brazos in Fort Bend – which represents the river level during a 100-year flood – is very likely to be increased as the result of a years-long study funded by federal and local government, people familiar with that study say.
That means an as-yet-undetermined number of homes, business offices and other buildings will be determined to be within what’s known as the 100-year floodplain, and will require more expensive flood insurance.
