Hurricane Beryl Tests Houston’s Flood Control Systems

Hurricane Beryl knocked out power to millions of residents and businesses this week, creating days of stifling anxiety as new questions emerged about the ability of Houston’s power grid to withstand a Category 1 storm.

But the hurricane’s aftermath was notable for one impending disaster that didn’t make headlines: The region was able to handle up to a foot of rain without destructive flooding.

Harris County was deluged by Beryl on Monday, with most parts of the city receiving at least 4 to 6 inches of rain in 24 hours. Roads and highways were flooded, creating dangerous conditions for drivers and requiring dozens of water rescues. However, despite several swollen creeks and bayous bursting their banks, very little structural flooding was reported in a region known for devastating flooding.

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The heaviest rainfall recorded in Harris County was 11.4 inches (29 cm) along Clear Creek in the Friendswood area, where 3 inches (7 cm) fell in an hour at the height of the storm. But high totals were reported across the county, with more than 10 inches (25 cm) of rain recorded in areas as far apart as Deer Park, Inwood and Willow Waterhole.

The storm caused several rivers to overflow their banks, including Clear Creek and lower Cedar Bayou, the San Jacinto River and White Oak Bayou. Buffalo Bayou also reached its banks near Shepherd Drive in downtown and waters overflowed into Brays Bayou around Meyerland.

But the county has received fewer than 10 reports of structural flooding, according to the Harris County Flood Control District, the agency responsible for flood control infrastructure.

Part of that success is because rainfall rates have remained manageable, less than three inches per hour, according to Harris County Meteorologist Jeff Lindner.

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“If you go back to some of our other major floods, we’re talking about rainfall rates of five to six inches per hour,” Lindner said.

In 2015, the Memorial Day storm flooded the Houston area, with up to 11 inches of rain falling in just three hours in Brays Bayou and Beltway 8. The following year, some areas received up to 16 inches of rain in 12 hours during the Tax Day storm. Both of these rain events caused significant structural flooding. In 2017, Hurricane Harvey flooded Harris County with up to 47 inches of rain in four days, including up to 6.7 inches of rain in a single hour.

Another reason homes have remained high and dry in Beryl is flood mitigation projects that have been completed in recent years, said HCFCD Director Tina Petersen.

“We found that Bayou Vert has not risen above its level in the upper part of the watershed,” Petersen said. “This is an area that has always flooded.”

Since Hurricane Harvey, the Greens Bayou area has been helped by an expanded stormwater retention basin that Petersen said has made a difference.

Although Lindner said he was concerned about potential flooding along Brays Bayou, that hasn’t happened, which could be partly due to the $480 million Brays project that was completed in 2022, according to Petersen.

“We think this is an area where we see benefits,” Petersen said.

Along Hunting Bayou, a $124 million project is nearly 100 percent complete and having an impact, she added.

“The stormwater reached the top of the banks, but it receded before we thought there was any damage,” Petersen said. “So when we see that, it’s exciting. That’s what we do. Any work we do, that’s what we hope for.”

The Inwood area, which has recorded some of the highest rainfall totals in Beryl County, has a major project underway: the largest stormwater retention basin ever built by HCFCD, Petersen said.

Although the basin still needs two to three years of construction, the work done so far has likely helped the region, she said.

White Oak Bayou also has improvements underway, including one project expected to be completed by the end of September and another expected to be finished early next year.

In the Clear Creek watershed, two projects were recently completed – the Reverend Lawson Pond and the South Shaver Stormwater Retention Pond – that help retain water and keep it out of homes. A third project, the FM 1959 Pond, is still under construction.

“We’re really pleased with the projects we’ve completed. We think they’ve been beneficial,” Petersen said. “But we’re looking forward to finishing the 1959 basin.”