Dec 04, 2017

Plan of Attack

Harris County, Texas, responds to Hurricane Harvey

Texas responds to Hurricane Harvey

Harris County, Texas, is no stranger to floods. In 2001, Tropical Storm Allison dropped 40 in. of rain in the county in five days. The Memorial Day flood of 2015 caused nearly $460 million in damages after 12 in. of rain fell in 10 hours, according to the Houston Chronicle. And during what have been dubbed the Tax Day Floods in April 2016, parts of Harris County saw up to 17 in. of rain in a 24-hour period, according to a Harris County Flood Control District (HCFCD) report. But Hurricane Harvey was different.

Hurricane Harvey was the first major hurricane to make landfall in the U.S. since 2005. From Aug. 25 to 29, 2017, the Category 4 hurricane dropped up to 51 in. of rain in some parts of the county, according to the National Weather Service. Winds reached more than 130 mph in some areas. The storm also had a large geographic reach, stretching across the 1,700-sq-mile county that includes the city of Houston and is larger than the state of Rhode Island.

“This storm was different because it’s the first storm that we know of that flooded the entire county. All of our recent floods have been geographically isolated,” said Matt Zeve, chief operations officer for HCFCD. Tropical Storm Allison, he said, affected the eastern portion of the county, while the Memorial Day and Tax Day floods hit the west.

Before Landfall

In a lucky twist of fate, HCFCD—along with other agencies across the state of Texas—participated in a weeklong hurricane drill in June 2017. Facilitated by the Texas Department of Public Safety Div. of Emergency Management, the exercise included the creation of a fictitious hurricane called Hurricane Charlie. The National Weather Service compiled graphics and news reports about this simulated hurricane and HCFCD personnel watched morning and afternoon news briefings about the storm and its strength, projected rainfall and wind speeds. They then went through their existing hurricane plan, completing tasks as if there were a real emergency.

“It was actually a little bit of good luck that we did that drill,” Zeve said. “We were familiar with [our emergency plan]. We made a lot of updates. A lot of things had changed since the last time we did a drill and updated it, so it actually was some good fortune.” Previously, the simulation was done every five years, but after Harvey, the county now plans to conduct a similar drill and assessment annually, before hurricane season.

HCFCD tracks hurricanes via the National Hurricane Center and the National Weather Service, so when it was clear Harvey was strengthening in the Gulf of Mexico, the district put its plan into action. The plan is designed to begin five days before a hurricane makes landfall and includes a list of tasks across multiple departments.

“We have areas throughout Harris County that we know typically clog with debris, so we send crews out to all of those locations to remove any debris or clogs that might be in the channels that could hamper efficient storm water removal,” Zeve said. “We make sure that we have our gasoline and diesel fuel vendor fill up all of our gas tanks at our two service centers, just in case gasoline and diesel fuel are hard to come by after the storm so that we have a full supply for all of our vehicles and all of our equipment.”

Key HCFCD personnel were notified of their roles, and appropriate arrangements were made with the families of those who would be required to spend days at the office or in the field. The district also assigned staff to the Harris County Office of Emergency Management, which was in full operations mode for the duration of the storm.

Additionally, HCFCD’s onsite meteorologist kept in close contact with the local television stations’ meteorologists to keep the public informed.

After the Storm

When the storm was over, HCFCD immediately began assessing damage. The district is responsible for maintaining the open channels in the county, of which there are approximately 2,500 miles, according to Zeve.

“Our role is to go inspect those channels and start quantifying the amount of debris that has to be removed from those channels,” Zeve said. “We also inspect our other infrastructure, which can be anything from storm sewer outfall pipes to culverts to detention basins, and see if there has been any damage to all those things.”

Along with consultants, HCFCD staff hit the streets and began making assessments. At its peak, Zeve said, the field crew consisted of more than 30 people working all over the county. Each person had the ArcGIS Collector app on his or her phone. When debris or damage was found, the crewmember would take a photo and fill out the form on the app. Then, someone in the office categorized the information, prioritized it and assigned it a preliminary cost estimate.

“We had several of our channels experiencing significant erosion to the channel banks and at channel crossings. That affects not only the channels but sometimes outfall pipes get dislodged and we have to repair those,” Zeve said. “A lot of times, when there’s erosion, the silt gets transported downstream and some channels had so much silt buildup that we had to go out and remove it because it would greatly impair the storm water conveyance capacity for the next rain event.”

Because the county declared a state of emergency, HCFCD was able to skip its usual procurement process and hire engineers and contractors to complete emergency repairs when necessary.

“All the emergency repairs, we paid for out of our budget,” Zeve said. “We know how much money we have left of our current fiscal year and we set aside an amount we could afford. We hope to get reimbursed by the federal government, but that’s all still in the works.”

Zeve estimates the damages to the existing infrastructure will cost approximately $150 million to repair. With an annual budget of $120 million, HCFCD hopes to receive federal assistance to pay for these repairs. At press time, there has been no news as to whether the district will receive what it has asked for.

Lessons Learned

Much of the Houston area’s flooding stems from urbanization. Even before Hurricane Harvey, HCFCD and the Harris County Engineering Department were working to upgrade rules and regulations for development.

“We were actually in the process of revisiting all of our processes and criteria before Harvey, and now, as a result of Harvey, we’re accelerating that process and we’re being pretty bold with some of the changes we’re proposing to our development criteria,” Zeve said.

For current projects in the planning and design phases, such as major detention basin projects, HCFCD is asking consultants to run extreme events in their models to see what any unexpected consequences might be.

“We hadn’t done that in the past because we hadn’t thought something like Harvey could happen in our lifetime. And then it did,” Zeve said. “So we need to make sure we can answer that question [so] if something like Harvey were to happen again we’re not having a consequence we didn’t plan on that could negatively impact someone.”

Words of Advice

Not every municipality faces the threat of hurricanes, but most face at least one type of natural disaster. HCFCD has plenty of experience dealing with flooding events, and Zeve offered a few pieces of advice to help other municipalities prepare for the unexpected.

1. Have a plan and practice it. The Hurricane Charlie drill required HCFCD to put its emergency plan into action, allowing the district to evaluate its methods. Zeve recommends conducting a similar evaluation each year and updating the plan accordingly.

2. Educate the public. Zeve said that before and after Hurricane Harvey he heard from residents who did not think they were at risk of flooding. HCFCD is working on a public education campaign to inform residents of the realities of flooding and how it can impact them. “I really feel like educating the public about natural hazards is a really important responsibility of the local government entity,” Zeve said.

3. Have a reliable phone bank. The phones at HCFCD rang nonstop for three days straight, but callers constantly informed the operators that they were unable to get through to anyone else. The police and fire departments and 911 were all overwhelmed, but HCFCD offered a person on the other end of the phone for distraught residents to speak to. “It really helped a lot of people,” Zeve said. “A lot of people yelled at us, but a lot of people were happy just to be able to talk to us. It was more important than I thought, until I was in the thick of things and understood the psychology of people [who] are scared out of their minds.”

4. Plan for the worst. No one ever expected a storm as strong as Harvey to hit the Houston area, so it was hard, if not impossible, to plan for it. Zeve stressed the importance of role playing and coordinating with other first responders on worst-case scenarios. “Try to anticipate the worst,” he said. “Then add some more ‘worst’ on top of the worst and think about that.”

Horsepen Creek on Houston's northwest side is the site of three emergency repair projects.

About the author

Amy McIntosh is managing editor for SWS. McIntosh can be reached at [email protected] or 847.391.1025.