Army Corps Moving Forward with Partial Mouth Bar Dredging to Reduce Flood Risk
The Army Corps announced Monday that it will begin dredging approximately 500,000 cubic yards of the giant sand bar at the mouth of the San Jacinto West Fork. It has been linked to flooding in the Humble-Kingwood-Atascocita area. However, previous estimates put the total volume at close to 2 million cubic yards, with the volume due to Harvey at 1.4 million cubic yards.
Text of Press Release
GALVESTON, Texas (June 10, 2019) – 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.”
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.
No Mention of Other Partners
The press release does not mention the City of Houston, Harris County, the State of Texas, or Congressman Dan Crenshaw’s office. Most had been negotiating with FEMA and the Corps as late as last Friday.
On two previous occasions, the City announced agreements in principle with FEMA and the Corps. However, the two sides still had many details to work out relating to volume, storage, permitting and cost. The City and FEMA have tried to reach agreement on the volume of sediment deposited by Harvey since last October – eight months.
In February, the City, hired Tetra Tech to collect and analyze core samples from the mouth bar. In late April, Tetra Tech estimated, through a protocol recommended by FEMA, that Harvey deposited 1.4 million cubic yards of sediment at the mouth of the river.
Two Sides Far Apart in Negotiating Volume
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.
Great Lakes Dredge Moving into Position
Great Lakes finished dredging its half of Phase One on April 12, exactly two months ago. The company has waited patiently ever since for the decision that finally came last Friday.
Today, the Great Lakes dredge has anchored near Kings Harbor. Judging by the weeds and logs in the pictures below, it appears that they will have to dredge their way TO the mouth bar. That could use up some of the precious approved volume. It could also take several weeks to position and calibrate all the equipment necessary to pump sediment 10 miles upriver.
What Comes Next?
Pumping sediment from the mouth bar to PA-2 will require the horsepower of the larger Great Lakes dredge. It will also require several extra booster pumps and miles of additional 24 inch pipeline. The Great Lakes dredge has now moved downstream and is anchored east of the West Lake Houston Parkway bridge near Kings Harbor.
Last week, dredge pipe re-appeared under the 59 bridge after being gone for two months. That fueled rumors that the two sides had finally worked out some kind of deal. At this hour, the mystery is where does the Corps’ decision leave all the other parties in this process? More important, where does it leave the remainder of the mouth bar?
Other Money Available
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 (see item CI-61). 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, 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.
However, money is just part of the problem. The second option might require permitting another placement area. Permitting could delay the project. But permitting a closer placement area might also save money. It gets complicated.
PA 1 is filling up rapidly as the pictures below show. And PA-2 is so far upriver from the mouth bar that would cost extra millions of dollars to use.
Easy Way to Save Money
Shortening the distance between the mouth bar and the placement area could reduce the amount of diesel and manpower needed to run the booster bumps. Each booster uses more than one thousand gallons of diesel per day. So costs add up rapidly. That’s why the Corps is still considering other placement areas.
Berry Madden owns several thousand acres south of River Grove Park between the river and FM1960. According to Madden, using his property could save the government $5.5 million in pumping costs. And that’s just on the first 500,000 cubic yards. If 2 million cubic yards is an accurate estimate for the total mouth bar, using Madden’s property could save $22 million. That’s even more than the remobilization costs we were trying to save.
I hope we don’t stretch this out too much longer or make it any more difficult. My truck needs some repairs and I’m afraid, as a taxpayer, that I may not be able to afford them!
Posted by Bob Rehak on 6/12/19
652 Days after Hurricane Harvey