dredging, dredge

Ready, Set, Dredge!

11/23/24 – Callan Marine now has a dredge in place to begin the City of Houston’s latest dredging operation. Last month, the City said it hoped its latest Lake Houston dredging program would start in December and now it looks like it will.

Callan’s dredge, the General Pershing, is currently anchored on the West Fork San Jacinto south of where the previous Mouth Bar dredging program ended. And this morning, I spotted a tug pulling lengths of dredge pipe into position.

Program First Announced in 2023

The City of Houston first announced its new Lake Houston dredging program last year. The focus: between Kings Point and FM1960 where the East and West Forks of the San Jacinto come together.

For months, Callan’s General Pershing dredge, was anchored south of the Forest Cove Pool on the West Fork San Jacinto at the old Army Corps mobilization site. Yesterday, Callan moved the General Pershing and its dredge pipe downriver to the starting point of the dredging program.

See the photos below taken this morning with the exception of the last one, which I shot last night.

Start of 2024 dredging between Kings Point (right) and Atascocita Point (left). Looking upstream toward West Lake Houston Parkway Bridge in far upper left.
Looking downstream toward FM1960 bridge and Lake Houston Dam in distance.
Tug pulling sections of dredge pipe into position for use.
Reverse angle showing pipe and dredge.
Only two or three sections of pipe remained upstream last night at the mobilization site south of the Forest Cove Pool.
dredging
Area between FM1960 and Kings Point currently has one of the largest sediment build-ups on the lake.

The dredge program was first announced in October 2023 at former City Council Member Dave Martin’s last town hall meeting.

Former City Flood Czar Stephen Costello outlined the program at that time. East of Atascocita and south of the convergence of the East and West Forks, the City plans to spend another $34 million to remove almost 900,000 cubic yards of sediment.

At the time, Costello said the City hoped to recoup some of its costs by reselling sand that it recovers from “hilltops” in the lake. Dredging will target areas that have sand which can be used for concrete, agriculture and other beneficial uses. At one point, the City reportedly also considered using spoils in the Ike Dike.

Costello showed the heat map above. Notice the heavy sediment concentrations in the lake’s headwaters. This is because sediment drops out of suspension where rivers slow down as they meet standing bodies of water.

Increasing Water Supply Capacity, Reducing Flood Risk

In addition to reducing the water storage capacity of Lake Houston, the sediment increases flood risk. It reduces conveyance of the rivers and lake forcing water up and out during floods.

According to a City of Houston source, the contractor will reportedly pipe the spoils south and east to an area near Spanish Cove. See map below.

The new disposal site (bottom right) is closer to the dredging than another site south of River Grove Park previously used for disposing of the spoils. That should reduce pumping costs. Location is approximate.

Since its construction in the mid-1950s, Lake Houston has lost nearly 20% of its capacity due to sedimentation. The City estimates it currently loses another 360 to 460 acre-feet per year.

This dredging program will help restore some of that capacity and create more room for floodwaters.

Posted by Bob Rehak on 11/23/24

2643 Days since Hurricane Harvey