Recent flood prevention projects in Cy-Fair were put to the test during several major rain events this summer with largely successful results. Officials with the Harris County Flood Control District and the city of Jersey Village both reported minimal damage to homes and businesses in the Cy-Fair area.
“The worst of the flooding took place after Memorial Day, starting the evening of May 25 and lasting through May 27,” HCFCD Communications Department Manager Kimberlye Jackson said. “Some of the creeks experienced flooding in the northwest area, including Cypress Creek and the northern end of Little Cypress Creek, but house flooding was not an issue in this area.”
Statewide, the amount of rainfall in May made it the wettest month in the past 120 years, according to data from climatologists with Texas A&M University. The state averaged 7.54 inches, far surpassing the previous record of 6.66 inches set in June 2004.
Although flooding was much worse within the city of Houston, Jackson pointed out that Cypress did receive its fair share of rainfall. Certain areas in Cypress received more than 7 inches over the Memorial Day event.
Jersey Village City Manager Mike Castro said Jersey Village did not experience any house flooding at all, unlike past major rain events.
“Water in the White Oak Bayou was about 3 feet away from the top of the bank, but we didn’t have any flooding,” he said. “I believe the improvements that the Flood Control District and the city have made have greatly reduced the potential for flooding here.”
Minimal damage
The intensity of a flood is measured by HCFCD by how frequently it is likely to occur. The Memorial Day flood registered as a 100-year flood—one that statistically occurs once every 100 years—along parts of Buffalo, Brays, White Oak and Keegans bayous. In Cypress, flooding hovered around 10-year and 25-year levels.
Of the 3,015 houses in Harris County that were estimated to have flooded during the Memorial Day event, only 110 were located in unincorporated Harris County, according to data from the Federal Emergency Management Administration.
The main reason why flooding was so much worse within Houston’s city limits over the Memorial Day event can simply be chalked up to where the rain fell the hardest, Jackson said. If Cypress Creek had seen the same rainfall Brays and Buffalo bayous did, it would have almost certainly flooded as well.
“If you look at the overall map of Houston of where rainfall occurred during that event, you’ll see the area around where Brays Bayou hit Beltway 8 was really the bullseye,” she said. “If that kind of rainfall fell on [Cypress Creek], there would have been more home flooding. Certain parts of Cypress Creek are most prone to flooding. There is still work to do.”
Ongoing projects
HCFCD is moving forward with a major plan to prevent overflow along Cypress Creek. The proposal, which was sent to the Commissioners Court and the Texas Water Development Board last year for review, would involve creating some combination of storage and conveyance projects—such as reservoirs and channels—to help store and transfer water through Addicks and Barker reservoirs during major rainfall events. During the Memorial Day Flooding event, the reservoirs were close to peak capacity, which could have meant water spilling out to Hwy. 6.
“The reservoirs have very large capacity, but the capacity is limited,” said Dena Green, study manager in HCFCD’s engineering and construction division. “If too much water is released, it can impact the folks living downstream along Buffalo Bayou. If not enough is released, it can affect those upstream of the reservoir.”
The district received a response from TWDB with comments earlier this summer and is incorporating those comments into a final report before moving forward. The process is expected to wrap up August 2015.
In Jersey Village, two types of flooding can affect residents, according to Castro: the regional flooding that occurs when White Oak Bayou overflows and the more local flooding that builds up on streets. Street improvement efforts, the most recent of which wrapped up in 2012, and bayou detention projects have had noticeable effects, he said.
“I can remember driving around when I first got here [in 2005], and we’d have a foot of water in the streets and in people’s front yards,” Castro said. “We go down these same streets now, and the water might come up to the top of the curb—maybe six inches—but it drains very quickly.”
Roughly half of the street improvement process for Jersey Village involves drainage improvements, he said.
“When we go in and tear out the concrete to put in a new street, we’re also adding to the drainage inlets and increasing the size of the drainage lines,” he said. “We’ve heard from the residents who live in those areas and they have been pleased with the efforts.”
Targeting the streets that suffered most from street flooding first, city staff has taken care of about 40 percent of Jersey Village streets so far. Castro said there is still more work to be done.
“We will do another comprehensive review of the roadway conditions before our next effort,” he said. “It’s probably a few years in the future, but we really need to come back in and it just makes sense to start from scratch when we look at this again.”
