dredging Archives - Page 8 of 10

City Analyzing Samples from Mouth Bar In Hopes of Determining Volume Due to Harvey

According to Stephen Costello, Chief Resiliency Officer for The City of Houston, the City contracted with a company called Tetra Tech to take core samples earlier this week from and around the mouth bar on the West Fork of the San Jacinto.

Why Core Samples?

The mouth bar is a giant sand bar at the mouth of the river where it meets the lake. The size of it has concerned residents throughout the Lake Houston Area since Harvey. It has the potential to back water up on both sides of the river and worsen flooding.

Some background. The Army Corps initially excluded the mouth bar from its current dredging program on the west fork. Their reason: a small part of the bar existed before Harvey. FEMA, which is funding the dredging, by law cannot spend money on remediation for things that existed before the disaster in question.

It took months for the City, FEMA and the Army Corps to agree on a way to estimate the volume of sand deposited by Harvey. The answer says Costello: something called the Stockton protocol that he says was developed after Superstorm Sandy at Stockton University in New Jersey.

Analysis Due by End of February

The core samples will be key to estimating pre- and post-Harvey volumes. Costello says engineers will look at density and color of sand grains to help estimate where sediment from one storm stops and another starts.

Costello hopes engineers will complete their analysis by the end of February. In the meantime two other efforts are proceeding simultaneously.

Search for Suitable Disposal Site Continues

The Corps will evaluate one property for suitability as above-ground storage. Separately, others are also out looking at sub-surface storage sites (i.e., old sand pits). Several have been located. The cost and safety of above ground and below ground storage will be weighed against the possibility of hauling material off by truck. Distance between the dredge and disposal sites also affects pumping costs.

All this will take time, especially if a full-blown environmental study is necessary for the above-ground option. Costello says the Corps has told him that could take four months to two years.

Evaluating Plan B

Because of delays, Costello is starting to worry that delays may cost taxpayers the opportunity to save $18 million. That’s the cost to remobilize a second dredging project if the current dredging project cannot be extended.

Accordingly, Costello is pursuing two options. The first involves praying (that’s a joke). The second involves working back through the Texas Division of Emergency Management to get FEMA to declare the mouth bar part of the original emergency mission. The Corps seems to move much faster when orders come from FEMA, several sources tell me. Maybe we should start praying too. (That’s not a joke.)

Money, according to Costello, should not be a problem. FEMA has approved the use of debris cleanup money from Harvey for dredging. He believes enough money remains in that fund to cover the City’s cost share.

Where Current Dredging Project Stands

The Corps estimates that the current dredging project is 45% complete. They hope to complete dredging by the end of April.

*City contractors are still removing downed trees from Lake Houston as a result of Hurricane Harvey’s destruction.*

The Callan Dredge is currently working the area near Kings Harbor at the West Lake Houston Parkway Bridge.

The immensity of the equipment underscores the need to keep crews working at the end of the current project on the mouth bar. Remobilizing all this equipment could cost $18 million or more if delays create a need to remobilize.

Posted by Bob Rehak on February 7, 2018

527 Days since Hurricane Harvey

Progress to Date on West Fork Dredging

Note: This post contains a correction to Matt Zeve’s title; he is Deputy Executive Director at Harris County Flood Control.

The Army Corps of Engineers today released this graphic showing the extent of West Fork dredging progress to date. Dredging will extend from River Grove Park on the west King’s Harbor on the east.

*Graphic courtesy of the US Army Corps of Engineers. For a larger, high-res version, click here.*

Original Schedule Included Months of Prep

The Corps expected the project to take 270 days or 9 months. The clock started ticking on July 21, 2018, when the Corps awarded the job to Great Lakes Dredge and Dock and its subcontractor Callan Marine.

Great Lakes subcontracted part of the job because it was time sensitive and Callan had a dredge that could start quickly. In fact, Callan began sooner than Great Lakes. Both companies spent considerable time on site assembling the dredges. Welding more than six miles of 24 inch HDPE dredge pipe and maneuvering it into place also required upfront time. Then both companies had to calibrate dredging rates with three booster pumps. Make no mistake; this is a huge undertaking.

Two months after the contract award, the first dredge moved downriver to its starting position on September 19th. A month later, on October 25th, the second dredge moved downriver. So out of the the 9 months, it took two and three months respectively just to start the dredging. Then we had three floods between December 7 and January 7 that caused pauses in the action.

Slow but Steady Progress

Backing out floods and prep time, we need to evaluate the progress shown above on a SIX month “actual-dredging” timetable, not the nine months budgeted for the entire job. Visually, it appears that they are roughly half completed and roughly half of the six months has expired. That’s reassuring. Especially knowing that the dredging has proved more difficult than expected. Crews periodically must stop to remove roots and aquatic vegetation from the dredge cutter heads.

Nagging Uncertainty Remains about Mouth Bar and Upstream

The questions readers keep asking, though, are “Will we be able to save all of that investment in upfront time?” And “Will we be able to start dredging the mouth bar before the start of next hurricane season starts on June 1?”

Corps bids showed that mobilization and demobilization cost 25% of the total job, roughly $18 million. Starting the mouth bar project as soon as the current project completes could save that money. It’s enough to do a lot more dredging. Maybe even open up the boat launch that the County hopes to build at its new Edgewater Park near US 59.

New Congressman Dan Crenshaw Jumping In

Dan Crenshaw, the Lake Houston Area’s new US Congressman seems to be jumping into flooding issues with both feet. He announced today that he has been appointed to Congressional Budget and Homeland Security committees. The budget committee assignment should put him in a good position to help accelerate flood mitigation measures.

Crenshaw has already met with Harris County with Flood Control District Deputy Executive Director Matt Zeve and Professional Engineer Ian Hudson to get an update on projects in Texas’s Second Congressional District. Those include both cleanup projects and flood mitigation projects. Crenshaw also met on Monday with Houston City Councilman Dave Martin, in which they discussed the importance of these projects. I also hear he is meeting the Army Corps and developers of the new high-rise project proposed for Kingwood.

*New Congressman Dan Crenshaw (center) with Matt Zeve of Harris County Flood Control (r) and Ian Hudson (l).*

Said Crenshaw, “Our district has been through so much because of Hurricane Harvey. I’m grateful for all the hard work our local and federal officials have done to prepare us for the next storm. I’m excited to get to work to ensure the people of TX-02 are able to make a full recovery and put Harvey in the rearview mirror.”

Something tells me that Crenshaw will bring the zeal of a SEAL to this job.

Posted on January 23, 2019 by Bob Rehak

512 days since Hurricane Harvey

Sand Island Losing Ground to Army Corps

Before

After

Keith Jordan, a resident of Kingwood Lake Estates, sent me the pictures below today. They show how quickly Great Lakes Dredge and Dock and the Army Corps are reducing the giant blockage nicknamed “Sand Island” south of Kingwood Country Club. Keith generously consented to let share his pictures with you. He says that much of the island has already been brought down to the water line. It used to jut up 6-10 feet. Still, much dredging remains to reduce the portion below water and restore the conveyance of the West Fork. Progress may look greater than it actually is at the moment because of persistent flooding. As of this posting, the river is still at 46.07 feet according to the USGS gage at US59. That’s about 3.5 feet above normal.

This booster pump keeps sand moving upstream to placement area #2, an old sand mine on Sorters Road south of Kingwood College.

Dredge #2 from Great Lakes Dredge & Dock has been eating away that Sand Island since moving downstream from River Grove Park.

Much of Sand Island is now at the water level.

This wider shot gives you a good feeling for how little is left.

Hopefully, we will get more recent aerial shots from our local drone pilots soon. As the West Fork returns to its normal level, we will see exactly how much of Sand Island remains.

Posted by Bob Rehak on January 6, 2019

496 Days since Hurricane Harvey

Impact of Government Shutdown on West Fork Dredging

For those of you wondering how the federal government shutdown would impact dredging, the answer is “little at present.” Dredging continues. The government allocated funds for the current emergency West Fork dredging program long before the shutdown. As of this evening, prospects for a quick resolution of the budget impasse were dim according to the Associated Press.

*Dredge currently operating near West Lake Houston Parkway*

Shutdown’s Impact on Current Dredging

It’s not immediately clear how the government shutdown will affect Army Corps employees supervising the job. Technically, the Corps is “military,” but many Corps engineers and project managers are civilian employees. The Corps may have listed its inspectors as emergency personnel since the West Fork was an emergency project. However, the Corps’ information office did not return emails to verify that. Holiday vacations likely caused the lack of response. But if the shutdown does affect Corps inspectors, contractors may experience delays at some point.

Possible Impact on Mouth-Bar Project

A bigger question: how the shutdown will affect consideration and approval of Mouth Bar dredging. Readers may remember that at a meeting in Austin on October 11, all agencies involved reportedly gave conditional approval to the mouth bar project subject to a favorable environmental report and the location of a suitable disposal site. After two and a half months, the project still has not been approved. City officials are hopeful that the project could be approved before the end of April when contractors should begin demobilizing from the current job. Remobilizing could cost another $18 million if FEMA or Congress does not approve an extension of the current project that includes the Mouth Bar.

Sources are hard to find between Christmas and New Years. Hopefully, we will have an update from City Hall and greater clarity when people return to work after New Years.

All of this underscores the need for more urgency and timeliness in government decision making, in my opinion. Harvey happened 16 months ago.

Posted by Bob Rehak on December 26, 2018

484 Days since Hurricane Harvey

Over the River and Through the Dune, To Grandmother’s House We Dredge…

‘Twas the night before Christmas and all through the house, not a sound could be heard, except for the distant thrum of Great Lakes’ Dredge #2. After muscling through the giant 12-foot sand dune at River Grove Park, the dredge has moved downriver. Next, it will attack the triangular dune south of Kingwood Country Club.

*Next up, the giant triangular sand bar south of the Kingwood Country Club. This bar was deposited during Harvey and blocks the entire river.*

Before Prep, Note Vegetation around Dune

As of about 2 p.m. on Christmas Eve, the dredge had not quite reached the bar. Meanwhile, a backhoe prepped the bar by removing vegetation that grew up around it since Hurricane Harvey.

*Vegetation around edges of the bar can get stuck in the teeth of the dredge’s cutter head and slow it down.*

The shot above shows the bar from the river in October before any prep work. Vegetation like you see around the edges can get caught in the cutter head or lodged in the pipeline. That impairs productivity. Work must stop as crews manually pick vegetation from the teeth of the cutter head.

After Prep, Note Missing Vegetation

On Christmas Eve around 2 p.m., the scene looked like this (see below). Notice how the backhoe removed vegetation from the margins of the dune. I shot the photo below with a long telephoto lens from a half mile away in River Grove Park. The backhoe provides a sense of scale in this photo that shows just how much sand Harvey deposited virtually overnight!

*Note missing vegetation around edge of dune with backhoe. Also note size of dune!*

Today marks Day 483 since Hurricane Harvey. The length of time it takes to remediate flooding issues like this underscores the need for legislation that reduces sedimentation from sand mines upstream.

Merry Christmas to all! And to all a good legislative fight! Even the sand miners. We don’t want to put them out of business. We just want them to mine outside of the floodway, so we will remain safer.

Posted by Bob Rehak on December 25, 2018

483 Days since Hurricane Harvey

Corps Finishing Touch-Up Dredging at River Grove, Moving Downriver

Good news for residents. Last week, the Army Corps of Engineers and its contractor, Great Lakes Dredge and Dock, finished dredging the area up to the boat dock at River Grove Park. However, because of the size of the hydraulic dredge, it could not quite finish the job. So on Monday, the contractor returned with mechanical dredging equipment to work in the tight drainage ditch area by the boat dock. See the photo below courtesy of Don Harbour.

*Mechanical dredging equipment was able to maneuver into the tight location that the hydraulic dredge could not. Photo courtesy of Don Harbour, a local resident.*

The Kingwood Service Association also requested the Corps to reduce the angle on the edge of the remaining side bar. Young people frequently played on the bar. Community leaders were concerned that a cave in near the steep edge could cause a bad accident.

*Contractors scraped back edge of sand bar to prevent cave-ins caused by curious kids.*

As you can see from the edge of the bar in the photo above, the Corps has addressed that issue.

This afternoon when I visited the park, I saw a survey boat checking to ensure the contractors had reached the proper depth.

*Survey boat checks for proper depth while mechanical dredge stands by.*

Multiple Activities Create Hazards for Recreational Boaters

The River Grove area today was busier than Santa’s workshop on Christmas Eve. However, the main focus of dredging activity will soon move east. Dredge #1, operated by subcontractor Callan Marine is now working close to the West Lake Houston Parkway Bridge. Dredge #2, operated by Great Lakes, is now operating just east of River Grove (see point #4 in photo below).

*The river is busy. Stay off it for your own safety.*

From the boat dock today, I saw five different clusters of activity in different areas: 1) survey boat, 2) mechanical dredge, 3) debris removal on far side of river, 4) Hydraulic dredge moving towards the country club, and 5) a back hoe removing vegetation from the triangular sand dune in the distance.

Both dredges will continue to work their way east until they reach their respective goals.

Latest Schedule

The Corps’ schedule originally called for completion in mid-April 2019. However, crews have been delayed by recent storms and floods, as well as greater than expected sedimentation in the river. Their most recent schedule calls for completion by April 30 and demobilization during the first two weeks of May.

Status of Mouth Bar Project Still Uncertain

Everyone I talk to hopes FEMA and the Corps will grant approval for a second project that addresses the huge sand bar at the mouth of the West Fork before this project reaches completion. If that does not happen, demobilization and remobilization at a future date would cost about $18 million.

The “Mouth Bar,” a giant sand bar that blocks the West Fork of the San Jacinto, backing the river up into Kingwood and Humble. The mouth bar is not within the scope of the current Army Corps dredging project, but officials have been trying to get FEMA and the Corps to include it. Water depth is generally 1-3 feet around this bar. Max channel depth in places is just 5 feet.

Sources in Austin expected an announcement weeks ago on the mouth bar. Congressman Ted Poe requested a meeting with the head of the Army Corps to discuss the project. However, the meeting originally scheduled for November 28th was delayed into next year. That means Congressman-elect Dan Crenshaw will inherit the battle. Meanwhile, Senator Ted Cruz has thrown the weight of his office behind the effort to dredge the mouth bar.

Corps to Meet with Super Neighborhood Council Wednesday Night

Eduardo Irigoyen, the project manager of the Emergency West Fork Dredging Project (the dredging currently underway), will meet with the Kingwood Super Neighborhood Council tomorrow night. The meeting at the Kingwood Community Center starts at 7PM. Mr. Irigoyen will update local leaders on the status of the Corps’ project. The meeting is open to the public, but seating is very limited.

Posted by Bob Rehak on December 18, 2018

476 Days since Hurricane Harvey

Drone Footage of River Grove Park Shows Scope of Last Flood

Jim Zura, owner of Zura Productions, sent me three clips shot from his drones last Saturday at River Grove Park. They show just how wide the river got at this low point at the peak of the flood. They also show the impact of dredging on the massive side bar that blocked the drainage ditch which runs through the park.

At this point, dredging is only about 20% complete. So we have not yet seen the full effect, nor will we until the mouth bar issue is addressed.

Flying into River Grove and looking down on parking lot.

Flying out over river to dredged area

Flying out over playing fields

My thanks to Jim Zura for letting me share his work with the community. This impressive footage enhances our understanding of the world around us.

Posted on December 12, 2018, by Bob Rehak with permission from Jim Zura, Zura Productions

470 Days since Hurricane Harvey

U.S. Army Liberates River Grove Park

465 Days after Hurricane Harvey, the U.S. Army has finally liberated River Grove Park in Kingwood. They literally took the beach.

Drainage ditch at River Grove is now open to the San Jacinto River.

Actually, they took the giant sand bar that Harvey deposited one night. It had been blocking the drainage ditch that runs through the park and that caused excessive flooding. The two shots immediately below show what that sand bar looked like before dredging.

Sandbar deposited by Hurricane Harvey at River Grove forced water to make a 90 degree turn before it could reach the river. This slowed the velocity of runoff and backed up water into subdivisions, like the Barrington in the background. While the sandbar looks low from the air it was up to 15 feet high directly in front of the drainage ditch (middle left). See below.

The same dune in the previous image photographed from the boat dock.

Dredge Now Moves Downriver

Dredge is now moving downriver.

Work to Date

Dredge #1 is working alongside the West Lake Houston Parkway bridge. It has dredged approximately 135,000 cubic yards of sand and silt to date, according to the Corps’ project manager.

Dredge #2 is working on the upstream end of the project, still near River Grove. It has dredged approximately 226,000 cubic yards to date. After dredging the access channel to River Grove, surveys showed there were some areas that the dredge could not reach. Great Lakes, the contractor will use a barge-mounted excavator to perform final clean-up work. Updated surveys will then confirm achievement of plan goals.

Dredging plans for River Grove indicate a channel width of 50 feet and a depth of 15 feet near the boat ramp.

For all the people who live upstream from the drainage ditch that runs through River Grove, this is an early Christmas present. It will be interesting to see what happens to flood levels in the park now that the bar blocking the ditch has been removed…just in time for a major fall storm that could drop up to 10″ on the US59 corridor. However, we also need to remember that the City is dropping the level of the Lake by at least 18″.

Posted on December 7, 2018 by Bob Rehak

465 Days since Hurricane Harvey

River Grove Boat Ramp May Open Next Week

Some unexpected good news! The River Grove boat ramp could soon open…as early as next week. The Great Lakes Dredge is starting to chew its way through the massive side bar that has had Kingwood’s only boat dock shut down for 16 months.

The original speculation was that the Army Corps would leave River Grove alone until the rest of the job was complete. Corps officials told me that they worried about the safety of recreational boaters around the massive dredging equipment and pipelines.

Something must have changed because at 8 a.m. this morning, Bruce Casto snapped this shot on his cell phone. Bruce heard second hand from another person in the park that someone on the dredge yelled across the water that, “The boat dock will be open in a week.”

I try not to repeat rumors but I’ve known Bruce for a long time and trust him. And given the location of the dredge in this photo, there is a better than 50/50 chance that River Grove will soon open. I have not verified that yet with the Army Corps of Engineers because of the timing of this surprise (on the weekend).

Posted on 12/3/18 by Bob Rehak

461 Days since Hurricane Harvey

Additional Dredging on the Horizon in 2019

Reprinted verbatim from Council Member Dave Martin’s announcement:

The “Mouth Bar,” a giant sand bar that blocks the West Fork of the San Jacinto, backing the river up into Kingwood and Humble. Water depth is generally 1-3 feet around this bar. Max channel depth in places is just 5 feet.

Houston, TX – Council Member Martin would like to make District E residents aware that the City of Houston continues to make progress towards Harvey Recovery with both state and federal agencies. Over the last fifteen months Council Member Martin has been working diligently with Chief Resiliency Officer Stephen Costello, Mayor Sylvester Turner, Governor Abbott, Chief Nim Kidd, as well as the offices of Senator Ted Cruz and Senator John Cornyn towards several initiatives that would have a positive impact on the Lake Houston Area.

Most recently the Texas Water Development Board (TWDB) has completed the bathymetry study of the West Fork of the San Jacinto River for the City of Houston. Data from this study has been given to the Army Corps of Engineers (ACOE) to determine the amount of sediment that resulted from Hurricane Harvey. This information is useful because this study identifies underwater topography allowing the City to understand where the additional sediment brought in by Hurricane Harvey has been deposited in the river and lake as well as changes in depth.

The TWDB continues to survey the entire lake for the Coastal Water Authority (CWA), the agency that contracts with the City for management of the Lake Houston Spillway Dam. The schedule for the TWDB to complete their survey of Lake Houston is Summer 2019. In addition to conducting a bathymetric study the City of Houston is currently reviewing data collected by the ACOE during a recent Light Detection and Ranging (LIDAR) study which uses light in the form of pulsing lasers to measure the distance from the water’s surface to the bottom of the river and lake. Capacity losses due to sedimentation in the lake as well as East and West Forks of the San Jacinto River will be determined using the LIDAR data along with the completed bathymetric study once the TWDB has completed their survey and report.

The LIDAR study allows the City to map changes in shoreline as well as make digital elevation models. It is this data that is assisting the City and ACOE in determining the amount of sediment that needs to be removed from locations along the West Fork of the San Jacinto River like the “mouthbar” that is located just south of the Deerwood Country Club. The LIDAR Study results will also be used by the Harris County Flood Control District (HCFCD) for the creation of new flood insurance rate maps because of the changing rainfall patterns published by the National Oceanic and Atmospheric Administration. The flood insurance map study will utilize updated LIDAR surveys of the entire county and will take several years to complete, however HCFCD is already hiring consultants to assist with this work.

On October 11, 2018, Council Member Martin met with Governor Abbott’s Executive Staff, TDEM, FEMA, and ACOE in Austin where a lengthy discussion was had about the amount of sediment deposit that will still remain in the San Jacinto River after the current emergency dredging project is completed. The current emergency dredging contract is not scheduled to be complete until the end of April 2019. At this meeting the City’s consultant estimated that after the completion of the existing dredging project that there will be approximately 500,000 cubic yards of additional sediment that needs to be removed from the river known in the community as the “mouthbar”.

This estimate however was based on a comparison between the LIDAR study completed by the ACOE this year and a bathymetric study completed by the TWDB in 2011. The important takeaway from this meeting in October is that FEMA agreed that the additional sediment qualifies as Harvey debris however, the estimate of 500,000 cubic yards was not a true amount directly associated with Hurricane Harvey. The City does not have survey data that is immediately pre and post-Harvey which would provide us a true amount of residual sediment that is a direct result of Hurricane Harvey. The City is currently waiting on the ACOE to complete its analysis of the City’s data.

At the meeting in Austin the ACOE indicated that an additional disposal site would be needed in order to remove the additional material. As a result the City of Houston has been proactive in identifying a site, thanks to the assistance of a local landowner that has property on the south side of the West Fork of the San Jacinto. The land owner has retained an environmental consultant to determine any possible wetland issues that may prevent use of the property for disposal. As of right now it appears the property is a viable site and a formal permit was filed with the ACOE this week.

In summary, the process to have the “mouthbar” removed from the West Fork of the San Jacinto River has been an arduous one. All parties from local, state, and federal agencies have been working together to accurately define the area needed for additional removal so that capacity can be restored to the river and reduce the effects of future flooding. The removal of the “mouthbar” cannot begin until the existing emergency dredging along the West Fork of the San Jacinto River is completed. Since this is a reality the City is doing all that it can to be proactive in securing land as well as permits for the “mouthbar’s” removal once the existing project is completed by the ACOE in April. This will allow the ACOE to keep equipment and crews in place without the need for demobilization and remobilization, saving roughly $18 million.

In observance of Thanksgiving the District E office will be closed Thursday, November 21 and Friday, November 22. The District E team will return to the office on Monday, November 26. Council Member Martin would like to wish all District E residents a safe and happy Thanksgiving holiday. For more information regarding this release, please contact Council Member Martin’s office at (832) 393-3008or via email at districte@houstontx.gov.

-end-

By Dave Martin’s Office on 11/21/2018

449 Days Since Hurricane Harvey

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