Tag Archive for: dredging district

Support Creation of Dredging District to Reduce Floods, Improve Lake Capacity

In the 2021 Legislation session, State Rep. Dan Huberty introduced HB2525, a bill to create a Dredging and Maintenance District for Lake Houston. Senator Brandon Creighton introduced an identical companion bill in the senate, SB1892. It deserves the support of everyone in the Houston region who depends on the lake for water as well as those whose homes and businesses flooded during Harvey.

Why We Need Perpetual Maintenance Dredging

For those who may not remember, during Harvey enough sand and silt came down the San Jacinto West Fork to block the river by 90% according to the US Army Corps of Engineers.

South of the Kingwood Country Club’s Island Course, Hurricane Harvey deposited several feet of sand that reduced the carrying capacity of the West Fork by 90%, according to the Army Corps.

Massive sediment and tree deposits dammed the river at the Union Pacific Railroad Bridge, south of the Kingwood County Club, West Lake Houston Parkway and Kings Point. The blockages contributed to the flooding of 16,000 homes and 3,300 businesses.

Union Pacific Railroad Bridge over West Fork after Harvey had turned into a “beaver dam” because of deadfall washed downstream and caught in the supports.
After Harvey, sand deposits at the West Lake Houston Parkway bridge reached the tree tops.
West Fork Mouth Bar immediately after Harvey virtually blocked the river between Kings Point and Atascocita Point (top right).

Two years later, Tropical Storm Imelda made similar deposits on the East Fork where thousands of additional homes flooded.

Wherever moving bodies of water meet standing bodies, the current decelerates and sediment tends to drop out of suspension. You can see the same phenomenon where smaller streams and channels enter the lake.

Brown & Root Report, 2000
Rogers Gully mouth bar in Atascocita

History of Disputes with FEMA, Corps Over Deferred Maintenance

After Harvey, leaders in the Humble/Kingwood Area fought with the Corps to remove the biggest of the blockages – the West Fork Mouth Bar. The Corps fought back.

The Corps and FEMA believed the massive mouth bar had been growing for years and that it resulted from deferred maintenance.

There was some truth to that. That reach of the West Fork had never been dredged at least in the previous 40 years. The ensuing debate lasted more than a year.

That’s why, shortly after the Corps started its Emergency Dredging program in 2018, it emphasized the need for maintenance dredging to a) avoid such disputes and b) keep problems at a subacute level.

Two Years Later, FEMA/Corps Agreed to Partial Mouth Bar Dredging

Then, in 2019, the City of Houston commissioned Tetra Tech to harvest core samples from the bar. The samples showed that most sand and silt was recently deposited. FEMA later relented and agreed to have the Corps dredge 500,000 cubic yards from a six hundred acre area south of the mouth bar. The Corps finished that dredging in late 2019. The City continued the program with mechanical dredges in January of 2020. They’re still at it. And people are still at risk from the next big flood.

Lake Houston Has Lost 22,000 Acre Feet of Capacity

Meanwhile, Lake Houston, which supplies water to millions of people has been steadily losing capacity. In 2018, the Texas Water Development Board found the lake had lost more than 22,000 acre feet of capacity. The problems are most apparent around the edges of the lake and in its upstream reaches. Both natural streams and man-made channels have become silted in. Mouth bars on both the East and West Forks have reduced the depth of the San Jacinto to approximately 3 feet (from 25 to 30 feet), except where it has already been dredged.

Atascocita resident walking across the river in 2019 without getting his shirt wet.

This cannot continue indefinitely. Nor can we expect the federal government to pay for deferred maintenance in the future; we have been warned. If we expect help again in the future after disasters, we must be able to show what bottom depths were before the storms. And those kinds of surveys are regular parts of maintenance dredging programs.

Safety and Future at Stake

In the three and a half years since Harvey, according to boaters and residents, we have not yet been able to restore the area between Kings Point and Atascocita Point to its pre-storm depth. We haven’t even removed all of the mouth bar.

Three mechanical dredges are still trying to reduce the West Fork Mouth bar more than 15 months after they started. Photo taken 3/19/21.

We need to figure how much sediment comes downriver every year and remove at least that much with a maintenance dredging program to:

  • Stop or reduce the loss of reservoir capacity
  • Reduce the risk of flooding
  • Show good faith to FEMA, eliminate contentious arguments with regular river bottom surveys, and demonstrate how much build-up resulted from a particular disaster.

We also need to be able to quickly accelerate the program after major storms such as Harvey and Imelda.

Dredging needs to be a continuous activity because one major flood can deposit more sediment than humans can remove in years.

How You Can Help

I urge you to support HB2525. Write as many local leaders on the City, County and State levels as possible. Pay particular attention to the House Natural Resources Committee where the bill is pending hearings right now. State Senator Brandon Creighton has filed an identical companion bill, SB1892, which has been referred to the Local Government Committee.

Posted by Bob Rehak on 3/28/2021

1307 Days after Hurricane Harvey