In the five months since an April 18 storm dumped 15 inches of rain on Cy-Fair, Harris County officials have continued to analyze the event to determine solutions to prevent future floods.

County officials have largely blamed the Tax Day flood on the extreme amount of rainfall in such a short period of time.

“When 15 inches of rain fall, some things are going to flood,” Harris County Precinct 3 Commissioner Steve Radack said at an August town hall forum on flood issues in Cypress. “There’s a good chance [a rain event like this] will never happen again.”

Around 60 percent of the 9,800 homes that flooded in Harris County were not in a 100-year flood plain, said Mike Talbott, the former executive director of the Harris County Flood Control District. Talbott officially retired from his position on Aug. 24 after 35 years with the district.

However, local conservation groups have called for tougher development guidelines. Members of the Houston-based Residents Against Flooding acknowledged the severity of the Tax Day flood, but said there are still things the county can be doing.

“I understand that HCFCD is requiring retention ponds in several new developments near the Grand Parkway,” said Ed Browne, chairman of the Houston-based Residents Against Flooding. “That’s a good approach, which should be expanded to other areas of the county and city. Ideally, the county would build reservoirs on the west side of Houston to store water, not just to capture stormwater, but also for drinking water.”

At an Aug. 10 Commissioners Court meeting, Harris County commissioners discussed HCFCD funding needs. Commissioners were split on whether they would support a property tax increase to fund the HCFCD, but all were open to finding ways to get the district more funding.

Funding challenges

Talbott said HCFCD mitigation projects and buyout efforts over the past decade made flooding less severe than it could have been. Roughly 1,500 of the 2,830 homes bought out by HCFCD since Tropical Storm Allison in 2001 would have flooded from the Tax Day flood, he said. Buyouts take place when a homeowner within the flood plain sells a home to be demolished.

The HCFCD receives about $160 million per year in the county budget. Roughly $60 million goes to new capital projects, which has included an overflow management study at Cypress Creek and several detention basins in Cypress.

The Cypress Creek study, budgeted at $3 million, examined possible ways to manage flooding along Cypress Creek in northwest Harris County. The study yielded two potential solutions—the Mound Creek Reservoir and the Katy-Hockley North Cypress Reservoir—both of which were accepted by the Texas Water Development Board in September 2015.

Both proposed concepts employ a combination of storage and conveyance components. Due to funding challenges, financing the project would likely have to involve partnerships with public, private and nonprofit entities according to the project’s final study report.

Other flood projects in the five-year capital improvement plan include the Upper Langham Creek Frontier Program and the Little Cypress Creek Frontier Program. To fund all the recommended flood mitigation projects throughout the county, Talbott said the HCFCD would need about $200 million per year, well above the $60 million currently available.

Radack said he would support a property tax rate increase with the goal of providing more funding to the HCFCD. He specified the district would need to devise a plan for how it would spend the money before he would officially support the tax increase.

At the Aug. 10 meeting, Precinct 4 Commissioner Jack Cagle said while he was opposed to a property tax increase, he supported redirecting money, possibly from the Harris County Health System, to use on flood-related projects.

Harris County voters also approved a bond referendum in November that provided an additional $64 million per year to the HCFCD. However, this money is strictly set aside for flood mitigation components related to new road construction, officials said.

Development guidelines

The construction of developments that cover open land increases the volume of stormwater runoff, according to area conservation groups. As a result, guidelines have been set in Harris County to offset the effects of new development, particularly commercial projects and new subdivisions.

Regulations vary depending on where the development is located relative to the flood plain, but the most common methods involve the installation of detention and retention elements, both of which aid in the process of storing stormwater runoff.

The county engineer’s office, not HCFCD, regulates and enforces development guidelines in unincorporated Harris County. Harris County guidelines are among the strictest in the U.S. and are regularly updated, County Engineer John Blount said.

“For every call we receive about a developer not following the rules, we’ll look into it,” Blount said. “A lot of the times when people think a developer isn’t building the proper detention, it’s just that they can’t see it. The detention doesn’t have to be on the property; it just has to be tied into the project.”

Browne said existing development requirements only address part of the problem. When the ground is already saturated, detention ponds often lose their effectiveness with regard to containing runoff, he said.

“Guidelines for all of Houston need to be strengthened,” he said.