Posted on December 4, 2018
State and local officials are seeking solutions to remove the notorious Kingwood mouthbars — a large buildup of sand and sediment deposited at least partly by Harvey that could contribute to flooding.
Houston City Councilman Dave Martin has been meeting with Governor Greg Abbott’s Executive Staff, and other state and federal officials to talk about sediment buildups.
Martin said it is important to get the project funded soon because about 25 to 30 percent of dredging costs goes to setting up the needed equipment during Facebook Live chat on Wednesday with the Lake Houston Area Chamber of Commerce.
Martin met with Abbott’s staff, FEMA and the U.S. Army Corps of Engineers in Austin in October to discuss ways to remove the mouthbar after the current dredging project in the San Jacinto River is complete by the end of April 2019.
“Our point in going back to the governor on Oct. 11 with a team of folks was to plead to the governor and the Texas Department of Emergency Management that while we have the equipment in the water why can’t we use some additional dollars that (Houston) Mayor (Sylvester) Turner helped us with along with the resources that the State of Texas and Governor Abbott and continue this dredging project and take it from the West Lake Houston Bridge into the lake where the mouthbars are,” Martin said.
The officials are still determining how much needs to be removed from the San Jacinto River to limit the possibility of flooding, he said in a statement on Nov. 23.
There will be approximately 500,000 cubic yards of additional sediment that needs to be removed from the mouthbar, he said in the statement.
The estimate of how much sediment needs to be removed from the mouthbar is based on a recent Light Detection and Ranging study conducted by the ACOE. The study uses light in the form of pulsing lasers to measure the distance from the water’s surface to the bottom of the river and Lake Houston.
A media release from Martin’s office states the LIDAR study allows the city to map changes in shoreline as well as make digital elevation models. It is this data that is assisting the City and ACOE in determining the amount of sediment that needs to be removed from locations along the West Fork of the San Jacinto River like the mouthbar that is located just south of the Deerwood Country Club, he said.
“Most recently the Texas Water Development Board has completed the bathymetry study of the West Fork of the San Jacinto River for the City of Houston. Data from this study has been given to the ACOE to determine the amount of sediment that resulted from Hurricane Harvey. This information is useful because this study identifies underwater topography allowing the City to understand where the additional sediment brought in by Hurricane Harvey has been deposited in the river and lake as well as changes in depth,” the media release states.
The media release mentioned that FEMA agrees the additional sediment from the mouthbar qualifies as debris resulting from Hurricane Harvey, but 500,000 cubic yards is not directly associated with Harvey.
The City of Houston currently does not have data that would provide information of how much sediment resulted from Harvey. The city is currently waiting on results from the LIDAR study.
“The removal of the mouthbar cannot begin until the existing emergency dredging along the West Fork of the San Jacinto River is completed,” the media release states. “Since this is a reality the city is doing all that it can to be proactive in securing land as well as permits for the mouthbar’s removal once the existing project is completed by the ACOE in April. This will allow the ACOE to keep equipment and crews in place without the need for demobilization and remobilization, saving roughly $18 million.”
The councilman said 300,000 cubic yards of sediment have been removed from the river and the City of Houston has removed 65 tons of vegetative and other types of debris from the West Fork.
“We’re probably not even a third of the way there. So we have a lot more work ahead of it; the dredging companies are doing a phenomenal job and hopefully we’ll have the ability to look back on it and say it was a very successful program as it’s been so far since they started in September,” Martin said.
Lake Houston gates
Martin said one of the top priorities for the 2019 is the construction of 10 additional gates to the Lake Houston Dam.
Martin mentioned the City of Houston now has $265 million in their Hazard Mitigation Fund. Money from the Hazard Mitigation Fund will be used to construct the additional gates.
“It’s probably a three to seven year project. You just can’t build the gates there, you have to study the existing dam. How you would build gates to an existing structure that’s there. Will you compromise the dam in any way which you can never do because then you would flood everybody downstream from us. So there’s going to have to a lot of good engineering studies to come from that,” Martin said.
Source: Chron
