A Dirty Job, But Someone Has To Do It: Life of a Dredger on the West Fork

Since last September, the Army Corps of Engineers has had two contractors, each with approximately 30 people, working 24/7 on the the West Fork of the San Jacinto.

Moving 1.9 Million Cubic Yards of Earth

Together, they’re removing approximately 1.9 million cubic yards of sediment left behind by Hurricane Harvey that is blocking the conveyance of the river. It’s hard to move that much sand and silt without getting your hands dirty, as these pictures by the Army Corps clearly demonstrate.

One crew started at River Grove and is working downstream toward the mid-point of a 2.1 mile stretch of the West Fork. The other started at the mid-point and is working downstream toward where Ben’s Branch enters the river, just past Kings Harbor.

The Corps uses approximately 10 miles of 22- and 24-inch pipeline weighing more than 5 million pounds to pump sediment from the river back upstream to two placement areas. One is south of Kingwood College off Sorters Road, shown below. The other is off Townsend in Humble.
The pipe floating in the foreground is rubber and designed to float. This gives the dredge room to maneuver. The pipe in the background with the orange flotation collars is rubber and bends a little. The steel pipe above does not bend.
Farm Boy is helping to anchor the dredge while a service boat transfers crew.
Looking toward the rear of the dredge. The blue part is the pump. The red containers in the background house electric motors. Cables tie the dredge to a CenterPoint substation in Forest Cove.
Before dredging, this giant dune almost completely blocked the West Fork about a half mile downstream from River Grove Park. The Great Lakes Dredge and Dock crew is still working to remove it. While it looks like all sand from the air, beneath the surface, crews are encountering dead trees and roots that get caught in cutter baskets on the dredge. (Photo by Bob Rehak)
When that happens, productivity slows and crews must manually pick the material from the chisels on the dredge.
Note the pile of roots and sticks growing the men.
Here you get a better idea of how the roots and vines can clog the intakes on the cutter head. Dredging needs to stop many times each day to remove this material.
The “chisels” on the cutter head break up sand which the “cutter basket” then sweeps up. Pumps inside the steel cage suck the sand into the pipe and pump it back upstream to placement areas.
Once the dredge starts pumping again, the flow must be calibrated with three booster pumps attached to each line. At least one crew member mans each booster pump to coordinate with the others. They must avoid over- or under-pressure situations.
This shows a close up of one of the three booster pumps used by Great Lakes, the Army Corps’ lead contractor on the job. Callan Marine is a subcontractor to Great Lakes and also has three booster pumps.
This shot gives you an idea of how massive these pipelines are…
…and how much sediment they can pump per minute. There’s enough sediment moving here to fill up a dump truck in less than a minute.
The Eagle Sorters Mine is dredging this pit even as Army Corp contractors fill it up. Sand and silt recovered from the river may wind up in roadbeds or be used for mortar in the construction trades.

1.4 Million Cubic Yards Recovered to Date

Corps Engineers said that since Sept. 20, 2018, approximately 1.4 million cubic yards of Hurricane Harvey silt and debris have been pumped into the two placement areas. Ultimately, they expect to pump approximately 1.8 -1.9 million cubic yards to meet FEMA requirements, restore the river to pre-Harvey conditions, and to reduce flood risks.

Safety Warning

These images illustrate why boaters should stay away from the West Fork for now. It’s not safe. The FEMA funded emergency flood action should complete in early May, 2019.

Posted by Bob Rehak on 4/3/2019 with images courtesy of the Army Corps of Engineers

582 Days since Hurricane Harvey