Engineers provided details on four flood prevention concepts they are recommending city officials implement. They also explained four concepts that were analyzed but ultimately deemed not worth implementing. The presentation concluded with cost estimates and details on how soon each concept could be implemented.
Residents can provide feedback online through July 12. A final recommendation for an implementation plan will be made to Jersey Village City Council at its regular meeting July 17.
1. Channel improvements along White Oak Bayou within city limits
What it means: Dannenbaum recommends the city implement improvements called for in a previous study commissioned by the U.S. Army Corps of Engineers for the White Oak Bayou watershed. The improvements, which are mainly focused on deepening and widening the bayou, would reduce the water surface elevations within the city significantly and would remove several properties from the floodplain.
Cost: $4.6 million (based on federal study)
When to implement: This plan would be carried out by the Harris County Flood Control District and hinges on funding from the federal government, which has stalled. Dannenbaum encourages city officials and residents to put pressure on U.S. representatives in the area to prioritize funding for the project.
2. Modification of Jersey Meadow Golf Course
What it means: Modifications would add stormwater storage capacity by creating an earth berm around the course to retain more water. The water would then be released downstream into the south fork of the White Oak Bayou as flood levels are reduced. The berm also prevents sheet flow from reaching neighborhood streets, including Wall Street.
When to implement: The city can fund and implement this recommendation in the short-term. Dannenbaum advises completing this project before taking on any street drainage improvements.
3. Local street drainage improvements
What it means: The improvements target Wall Street and all streets connected to that system, including Carlsbad and Crawford streets and Capri and Tahoe drives. Improvements include increasing the number of inlets and the storm sewer pipe sizes to reduce street flooding. Combined with White Oak Bayou improvements and golf course modifications, the improvements would help remove 62 homes from the 100-year floodplain.
Cost: $2 million (sewer), $3.75 million (streets)
When to implement: The city can fund and implement this recommendation at its own pace. Dannenbaum advises taking on this project after golf course modifications are implemented.
4. Non-structural flood damage reduction measures
What it means: Recommendations include voluntary home buyouts and home elevations of properties in the floodplain. Dannenbaum presented several strategies with different costs. Roughly 60 homes were identified for nonstructural solutions.
Cost: $10.5 million (58 elevations and zero buyouts), $11.5 million (32 elevations and 26 buyouts)
When to implement: City officials would work with FEMA on nonstructural solutions, but could otherwise begin the process in the short-term.
Projects deemed not worth pursuing
1. Tahoe and Lakeway bridge improvements and Elwood Weir
These projects were not recommended due to minimal effects on flooding demonstrated through hydraulic modeling. They were determined to not significantly impede flow through the bayou.
2. Equador Bridge
Removal of the pedestrian bridge was determined to have a minimal effect on flooding. Dannenbaum also determined that adding a new roadway bridge at Equador Street would not create any adverse flooding impacts on the surrounding area.
3. Modifications to the White Oak Bayou bypass channel
The bypass channel was determined to be functioning successfully. Modifications to increase the flow in the bypass were determined to cause significant adverse flooding impacts in the Jersey Village area.
4. Channel improvements to south fork of White Oak Bayou
Modeling showed that a 100-year flood can be contained within the banks of the south fork of the bayou. Because of that, improvements along this portion were determined to not be a priority.
Residents provide feedback
At the end of the presentation, residents were given the chance to ask questions to a panel of Dannenbaum engineers and Jersey Village city officials. Several questions focused on concepts that were left out of the final recommendation, including modifying the bypass and removing the Elwood Weir.
Although some residents expressed concern that the Elwood Weir causes water to back up in the bayou and flood nearby streets, Maegan Nunley, a lead engineer on the project, said the weir serves an important purpose.
"There's a 5-foot drop between the tributary and the main channel, and the weir prevents erosion that would lead to a major washout," she said. "Water backs up [during a 100-year flood] but it does not leave the banks."
Other residents insisted the the bypass needs to be modified, pointing out that it slopes uphill toward Beltway 8, which causes water to flow back into Jersey Village early on in a flooding event.
"The bypass has been seen by citizens and city staff to flow in the wrong direction," said Fred Ziehe, a resident who has studied flooding as a part of a citizen-led flood committee. "When water flows in the wrong direction, you lose valuable time during the start of the flood."
Dannenbaum officials pointed to their modeling as evidence that the bypass works successfully, but agreed to meet with Ziehe to further discuss the issue.