Nearly three months after Hurricane Harvey, Harris County is proposing using 500-year floodplains instead of 100-year floodplains for new development, the first significant overhaul of county elevation requirements in nearly two decades.
The regulations, which still must be approved by Commissioners Court, would force developers to build new homes eight feet higher than previously required in some flood-prone areas.
They would also, for the first time, open up a broader geographic area to regulation by forcing developers building in 500-year floodplains to meet stricter elevation standards. Currently, there is little regulation outside the 100-year floodplains.
“Any time we can figure out how to make our regulations better and our infrastructure more resilient, we want to do it,” said county engineer John Blount. “We don’t want to be permitting houses that would flood. It’s not good for the county. It’s not good for people that are in the houses. You shouldn’t be building houses at an elevation you know they’re going to flood.”
The newly proposed regulations focus on the booming unincorporated region as opposed to areas within Houston city limits. Unincorporated Harris County has added nearly 1 million people since 2000, more than three-quarters of the growth in the county since 2000.
For some areas along the San Jacinto River, Spring Creek and Cypress Creek, the difference between the new and old regulations — 500-year versus 100-year flood levels — could be several feet of elevation required for new homes, which could increase the cost of development by thousands of dollars.
You can see the proposed new regulations here. This is in line with the larger vision County Judge Ed Emmett proposed in September. If this winds up making some new development more expensive, that’s fine. All that’s doing is more accurately pricing in the flood risk. As the story notes, though, the newest construction in the unincorporated county mostly escaped destruction during Harvey. It’s existing development that was the hardest hit, and that’s going to be a much more difficult and expensive problem to solve. And as Jim Blackburn says in the story, the 500 year zone may not be big enough to address this. Still, this is a positive step, and the Court will take up the proposal in early December.
One more thing:
Meanwhile, the proposed regulations would not govern development in the city of Houston. City regulations require new homes built in 100-year floodplains to be elevated one foot above the 100-year flood level — less than the 18 inches that the county currently requires.
Houston Chief Resilience Officer and “flood czar” Steve Costello said the city has not yet made any proposals regarding new floodplains, but has called a meeting in December among city staff to start the discussion. He said the city would consider the county’s changes.
“There’s no guarantee we will formally adopt everything that they have done,” he said. “Obviously we don’t want different criteria at the end of the day.”
I agree that the city should be in line with the county. I hope we have been involved in the discussion over these changes.