Houston homes built after flood plain requirements did not flood

LA Times:

As Hurricane Harvey approached Houston, Kevin Kelly hunkered down in his brick house, which was built in 2009 in a federally designated flood zone.

He set his alarm to ring every two hours throughout the night so he could monitor water creeping closer from a creek overflowing a quarter mile away.

From his upstairs window, as bolts of lightning flashed across the sky and wind battered his walls, he and his wife watched as record-setting rains turned his street into a river.

“The question was how much furniture were we going to put upstairs,” Kelly recalled.

In the end, the water came within 5 feet of his house and no closer. Many of his neighbors were not so lucky.

What helped save Kelly was a Houston building regulation that ensured his house was situated on higher ground than older homes.

No other major metropolitan area in the U.S. has grown faster than Houston over the last decade, with a significant portion of new construction occurring in areas that the federal government considers prone to flooding.

But much of that new real estate in those zones did just fine, a Times analysis has found.

Though Houston has few zoning regulations, it requires that new homes be built at least 12 inches above expected flood levels. The 1985 regulation and others that followed proved widely effective in their biggest test to date — the record-setting rains of Harvey.

Of the nearly 39,000 single-family houses built within city limits since 2007, a total of 3,215 — or 8% — were erected in areas the federal government expects to flood every 100 years, and another 5,529 — or 14% — in areas expected to flood every 500 years, according to property records.

To look at damage to those homes, the Times choose five neighborhoods built inside a flood zone over the last decade and asked a sample of homeowners in each area how they fared. In case after case, owners of the newer homes rode out the hurricane safely.

Their stories are supported by the patterns that are emerging as the city assesses the damage.

The brunt of it appears to be borne by older houses — sometimes just doors away from newer, unscathed real estate — that predate federal and local anti-flooding regulations and account for 79% of the nearly 129,000 houses located in the federal flood zones.

“What you see flooded are housing and structures that were built before the national flood insurance program in the 1980s,” said Carol Haddock, the public works director. “All of those changes since then have increased safety.”
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There is more.

Actually the regulations are for homes not just built in Houston, but also includes homes built in areas that could be annexed by Houston.  It has been in effect since at least the late 1970's and may have been beefed up in the 1980's. 

The newer homes built in those ares were like small islands as the streets and areas around them flooded.  In dealing with the aftermath of the floods, I think the area should consider raising the level of the older homes to that of the newer ones.  It would be expensive, but less expensive than dealing with flood damage in the future. 

Even if a house was built on a concrete slab it can still be raised.  As officials are also looking at developing more reservoirs to control flooding they should consider using the dirt from the new reservoirs to raise the level of existing homes.