The United States Army Corps of Engineers (USACE) Galveston District staff have executed a modification to the West Fork San Jacinto River Emergency Debris Removal Contract effective June 7.
Houston City Councilman Dave Martin addressed the dredging, and the contract modification, at the June meeting of the Lake Houston Redevelopment Authority/Tax Reinvestment Zone No. 10 June 13.
Martin explained that after Hurricane Harvey, the City of Houston did an analysis – a core study called a Stockton Survey – on the area referred to as the “mouth bar” to determine how much silt and debris contributed to the flooding experience in Kingwood during the storm.
The data was shared with the Corps, who arrived at a different amount of contributing debris than the city.
“We are still communicating about how much of the volume is due to Harvey. The Corps has one number and we have another, but for now, we agreed to their number,” Martin said, adding that they will meet this week to discuss their differences.
“I did not want to risk the dredging being idle. We are already mobilized and will be adding more pipe due to the expanded area. We will be dredging the mouth bar in less than five weeks,” he said.
The Corps announced June 3 that it will begin dredging approximately 500,000 cubic yards of the sand bar at the mouth of the San Jacinto West Fork. Some estimates put the total volume at close to 2 million cubic yards, with the volume due to Harvey at 1.4 million cubic yards. The Corps says they are committed to removing 497,000 cubic yards, leaving a difference somewhere around 900,000 cubic yards.
“My biggest fear is that the dredges would be sitting there with hurricane activity picking up,” Martin said.
This USACE modification will begin the removal of the mouth bar immediately before the height of hurricane season is reached. Martin and City of Houston Chief Resiliency Officer Stephen Costello, working with the Texas Department of Emergency Management, continue to engage with FEMA and USACE on further expanding the modification.
Martin said the difference in perspective went unexplained by the Corps, who did not do their own research. They used the core data but ultimately did not agree with the city’s analysis.
“They gave no reason or specifics in their conclusion. They had no tactical data and did not share how they arrived at their conclusion,” he said.
The meeting set for later this month will result in us “hopefully meeting somewhere in the middle,” Martin added.
The Corps of Engineers began the dredging of sand and silt from the San Jacinto River in October; the mouth bar, however, was not identified in the original order.
The Corps released a statement June 3:
“The U.S. Army Corps of Engineers Galveston District staff executed a modification to the West Fork San Jacinto River Emergency Debris Removal contract June 7, 2019, to dredge an additional 497,400 cubic yards of material that was deposited in the mouth of the San Jacinto River from Hurricane Harvey. ‘This contract modification will ensure a decrease in threats to critical infrastructure and lower the risk to potential loss of life,’ said Charles Wheeler, USACE Galveston District project manager. This is an ongoing contract that is part of a Federal Emergency Management Agency mission assignment.”
Bob Rehak, author of ReduceFlooding.com, expanded on the mission and the possible outcomes of the dredging. He wrote:
“According to USACE Galveston District officials, the dredged material will be placed at the existing location referred to as Placement Area 2, which is located approximately 10 miles upriver. The additional dredging is scheduled to be completed by the end of 2019, with the demobilization of the equipment completed by early 2020. The Corps’ announcement reveals just how far apart the two sides were in their volume estimates – about 900,000 cubic yards. That difference means much of the mouth bar area will remain undredged – at least for now.
“With approval to remove only about 500,000 cubic yards, the dredgers will have to cut a channel around the mouth bar, most likely on the deeper Atascocita side. Ironically, that would mean leaving behind sand deposited above water by Harvey – a decision that could confuse the public. The state approved an additional $30 million for dredging the mouth bar last week. The county also allocated $10 million in the flood bond approved by voters last year. That $40 million, along with another $18 million committed by the City of Houston, would add up to $58 million. In addition to the unspecified sum FEMA is fronting now, that might be enough to remove the entire mouth bar. That could happen one of two ways: the city, the Corps, FEMA and TDEM would have to increase the approved volume after the next phase starts, or the city, county and TDEM would have to remove the rest without FEMA and the Corps.”