Houston: Insights into Preparing for Extreme Weather

Drew Molly, Houston’s assistant director of drinking water operations, offers valuable insights into disaster preparedness after weathering several major storm events over his twelve years with the city.

In the twelve years since Drew Molly began his career with the City of Houston, he’s experienced two hurricanes, a drought of record, and three major storms. “You start to wonder,” he said, “is this really the new normal?” Now the city’s assistant director of drinking water operations, Molly said a lot of time is spent in Houston talking about disaster preparedness, making sure the city’s infrastructure is in the best possible state to deal with these events.

But how do you do that? “People are our biggest asset,” he said, “and we focus on making sure our people are prepared.” There are about 600 employees in drinking water operations, Molly said. In preparation for an emergency and the ensuing response, the employees are divided into groups. Tier 1 employees are designated to ride out these storm events. “For example, during Hurricane Harvey, we had about 100 employees out of the 600 who were pre-staged at key locations in the city of Houston,” said Molly. “They went to critical facilities and they were deployed prior to the storm coming on shore.”

Tier 2 employees, he explained, are assigned to recovery mode. “So, once the Tier 1 employees are able to go home, Tier 2 employees come on site and they could be working around the clock for two, three, four days until the Tier 1s are rested and can come back.”

An intense storm is bound to leave a few lessons in its wake. “One of the major lessons that we’ve learned from this event is making sure that your critical infrastructure is well above, I would say, the 500-year floodplain,” said Molly.

Houston’s East Water Purification Plant, the city’s largest surface water treatment plant, has infrastructure in the 100-year flood plain. After a couple of flood events took out key infrastructure there, they installed stormwater pumping systems. “So, when these hurricanes and major storm events come in,” said Molly, “they’ve got pumping equipment that basically pumps that water out into the surrounding bayous and ultimately out to the Galveston Bay.”

When Mother Nature Hands You Lemons

Houston’s Northeast Water Purification Plant is in the midst of a massive expansion project. The billion-and-a-half-dollar initiative will increase the Northeast plant’s capacity from 80 million gallons per day (mgd) to 400 mgd.

After Hurricane Harvey, the Northeast plant was the most compromised of the city’s three surface water plants — despite the fact that it wasn’t inside the 500-year floodplain. But because of the storm’s timing, there was a silver lining.

“We hadn’t gone into significant construction yet,” Molly noted. And while you never want to have to deal with one of these storms, he said, because of the timing, “we were able to shoot survey grade of where all the high-water marks are.” Armed with that rare bit of practical insight, they essentially went back to the drawing board to ensure key infrastructure would be well above Harvey’s inundation levels.

Houston made the best of the many lessons Harvey had to offer, making sure its infrastructure is hardened going forward. “And if we have one of these events in the future,” said Molly, “we’ll be well positioned to mitigate [our] exposure.”

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