Tag Archive for: dredge #2

Second Dredge Starts Dredging

It’s official. There are now two dredges actually dredging on the West Fork. Dredge #2, owned and operated by Great Lakes Dredge and Dock, moved downriver from the command site on October 16.

Getting 2-foot Pipe Through Water One Foot Deep

However, the company had not yet reached placement area #2 with the pipeline. Great Lakes had to dredge their way upstream through water less than one-foot deep in places to get to the placement area with five miles of pipeline that is 2 feet in diameter.

Next Steps: Patches and Pressure Testing

After reaching the placement area with pipe, Great Lakes then had to test it. During testing, dredgers slowly increase pressure in pipe as they look for leaks. The most common place to find leaks is at the joints, but sometimes they need to replace entire sections of pipe. The dredgers then make repairs in the water from pontoons loaded with backhoes and welding equipment. Backhoes bring the pipe up from the bottom of the river and position it in the welding machines.

After that, the dredging company had to test the booster pumps and throttles as they started them up. They also perform dye tests to calibrate velocity measurements. This helps ensure that water in each stage is moving at the same rate of speed. Great Lakes and its subcontractor Callan Marine will each use up to three booster pumps to keep five miles of sediment-laden water moving upriver to their respective placement areas.

One of three booster pumps that Great Lakes will use. This one can be seen from the northbound 59 feeder road.

While dredge #1, which started the same process on September 20 is diesel, dredge #2 is electric. Electric dredges run quieter, but take longer to warm up. As my source said, “An electric dredge slowly heats up the equipment to drive the moisture out; water and electricity don’t mix well.”

Now Working 24/7 Until Completion

With all those steps complete, dredging is now in full swing. By this weekend, both dredgers will be working 24/7 until completion.

To help jumpstart dredging, Great Lakes hired Callan Marine as a subcontractor. Callan had equipment available earlier and started this same process on September 20. The diagram below shows how both companies plan to work together.

Dredge #1 started at the halfway point and will work its way east to the end point. Dredge #2 started at River Grove Park and is working its way toward the midpoint.

Great Lakes will start at the western edge of the project area and work its way to the middle. Meanwhile, Callan, which started in the middle will work its way to the project’s end point – east of the West Lake Houston Parkway Bridge (by Chimichurri’s).

Callan will send its spoils to placement area #1 while Great Lakes will send its to placement area #2.

No News Yet on Next Phase of Dredging

When City of Houston representatives including City Council Member Dave Martin returned from Austin two weeks ago for a high level meeting about the need to remove the mouth bar, hopes were running high. Decisions makers needed only an environmental survey and a placement area before the mouth bar project could proceed. Reportedly, they had reached agreement in principle on all other requirements including funding. However, the City has made no announcements yet about either the survey or a third placement area.

It took 3.5 months for contractors to fully mobilize for the current project. If FEMA, the Corps, the State, and the City can lock down phase two before mid-April, 2019, taxpayers have a chance to save the cost of another mobilization/demobilization – about $18 million.

It would also save precious time. Without having to remobilize, dredgers would have a chance to cut a channel through the mouth bar before the onset of next hurricane season.

Revised, estimated timeline for first phase of the West Fork Emergency Dredging Project

What About River Grove Boat Launch?

Cutting a channel through the side bar at River Grove will probably be the last thing Great Lakes does as part of this phase of dredging. Dredgers are concerned about boater safety and worry that opening the channel now will increase the number of boats on the river and the chance of accidents.

Posted on October 25, 2018 by Bob Rehak

422 Days since Hurricane Harvey

Mistaken Reports of Dredging Near US59 Bridge; Where Things Really Stand

In the last two days, several people have reported dredging near the US59 Bridge. What they actually saw, however, was not a dredge; it was dredge pipe, booster pumps and other related equipment being positioned to pump spoils to Placement Area #2, the Eagle Mine just south of Kingwood College on Sorters Road.

Here’s where things stand a little more than two weeks since the launch of the first dredge on August 20, 2018.

Both the Army Corps and Council Member Dave Martin swear that the scope of the project has not changed. The original scope covered approximately 2.1 miles of the West Fork from River Grove Park to Chimichurri’s just east of the West Lake Houston Parkway Bridge.

Illustration from US Army Corps’ contract plans for West Fork Dredging showing project scope.

Some confusion arose over that when the first dredge anchored WEST of the West Lake Houston Parkway Bridge for almost two weeks. The dredge anchored near the overhead electrical lines in the middle of section C-102.

Last week, the Corps continued to position dredge pipe and booster pumps between the first dredge and the command site just south of Forest Cove. Additionally, Corps engineers scouted out the route upstream to Placement Area #2.

Army Corps personnel scouting area between Placement Area 2 and the command site last week.

This week, the Corps started pre-positioning pipe, booster pumps and other equipment up the West Fork between the Command Center and Placement Area #2. Below are several pictures taken this afternoon that show what’s happening where.

 This is the booster pump mistaken for the dredge. It is anchored between the railroad bridge and the northbound feeder lanes for US59.

Additional equipment started towing pipe up the West Fork past the confluence of Spring Creek, just west of USt59.

Dredge #1 also started to move farther downstream, closer to the West Lake Houston Parkway Bridge.

Taken from West Lake Houston Parkway Bridge looking west, upstream.

Placement Area #1 started receiving sand and was already partially filled when photographed late afternoon Friday.

Placement Area #1 south of the river behind the apartments on Townsend is already receiving spoils.

This portion of the old sand pit has already filled back up with sediment. Notice the slight curvature of the surface. It’s higher on the right than on the left. Wading birds are already picking over the sand looking for a meal that may have been dredged up from the river.

At the opposite end of the pit, water drains out and back to the river after sediment has settled out.

Dredge #2 is scheduled to launch by October 15, according to Lt. Col. Mark Williford with the US Army Corps of Engineers. As of today, though, dredge #2 was still docked at the command site in its usual place.

Dredge #2 is still anchored at the command site as of Friday afternoon, 10/5/18 at 5pm.

Posted by Bob Rehak on 10/5/2018, with photographic help from Kevin Rehak.

402 Days since Hurricane Harvey