The Army Corps has released a new summary of its progress on dredging the mouth bar. The report indicates that Great Lakes, the contractor is now 70% complete. They have dredged 350,000 out of 500,000 cubic yards.
Great Lakes started dredging the mouth bar on June 25th, 2019, as part of a $17,085,861 extension of the original contract (FEMA mission assignment SWD-30).
Between the start of mouth bar dredging and August 12, Great Lakes dredged an average of 6,363 cubic yards per day. If they can keep that pace up, they should be done by approximately Labor Day – three months ahead of schedule. That’s HALF the predicted time.
Remainder of Project Still Not Decided
What comes next? That still has not been finalized. City, County and State officials have been meeting in the background to determine that. The Army Corps still has not accepted or rejected Berry Madden’s property as a third placement area. And the $30 million appropriated by the State for mouth bar dredging won’t even become available until September 1st.
Meanwhile, Callan Marine, the subcontractor from the original West Fork Emergency Dredging job has pulled its equipment back to the dock opposite Forest Cove. However, Callan has not yet started disassembling its equipment and removing it from the river. According to Houston City Councilman Dave Martin, Callan has agreed to stay temporarily while officials attempt to work out details for the next phase of dredging.
RD Kissling and Tim Garfield, two local geologists who first brought the mouth bar issue to the public’s attention, estimate that 500,000 cubic yards is about one-fourth of the total sediment that must be removed to fully restore conveyance of the West Fork.
How Shallow is It?
The Corps has not yet released (or even developed) plans for mouth bar dredging. We do know the volume they intend to remove, and the general area they intend to remove it from. However, they have refused to divulge how much of a dent their efforts will make in solving the problem.
Problem With Stopping after 500,000 CY
The problem with stopping after the Corps finishes its 500,000 cubic yards is that the river behind this area is much deeper. Where the Corps stopped dredging just past Kings Harbor, the river is now 25-30 feet deep. And places are even deeper according to fishermen. That means water coming downriver will be forced to flow uphill in this area. That will force it to slow down and more sediment will rapidly drop out of suspension. Some experts have suggested dredging a deep channel through this area to help restore full conveyance of the river. However, the Army Corps intends to stop after 500,000 cubic yards.
How Army Corps Sees its Role
The Army Corps has prepared a series of FAQs that represent its position on the remainder of mouth bar dredging. Among them:
“Q: What is USACE Galveston District’s plan for the rest of the mouth bar?“
“A. There is no additional work planned for the mouth bar. The current plan for the modification addressing material near the mouth bar can be found on the placemat. USACE Galveston District has no authority to conduct any additional work in the West Fork of the San Jacinto River or Lake Houston. The San Jacinto River is not an authorized federal waterway, the Corps of Engineers dredging operations are currently limited to dredging Harvey-related material. The ongoing work under the contract modification will remove the remainder of material attributable directly to Hurricane Harvey. The sedimentation from recurring annual flows are not within USACE Galveston District’s mission assignment from FEMA. Water flows on the West Fork of San Jacinto River were restored to pre-Harvey levels in December 2018.”
“Q: Who can the public contact for additional concerns with the maintenance of the San Jacinto River?“
“A. For concerns with the maintenance of the San Jacinto River, please contact Harris County Flood Control District, the San Jacinto River Authority and the City of Houston.”
Meanwhile the City is still arguing with the Corps about how they arrived at 500,000 cubic yards. More on that later. I have obtained the Corps’ estimate through a FOIA request to the City of Houston. It raises many questions that I am still trying to sort through. More on that later.
Posted by Bob Rehak on August 14, 2019
715 Days since Hurricane Harvey