12/8/24 – Callan Marine moved its dredge down the San Jacinto West Fork to a location between Atascocita Point and Royal Shores more than two weeks ago. But it hasn’t moved yet. Reasons for the delay are unclear at this point.
Still Anchored in Same Spot
This morning, the rain let up long enough to get some drone shots. Unfortunately, it appears that the dredge hasn’t moved since November. It’s anchored in the same spot in the same position as on November 23, 2024. To borrow a phrase from track and field, it hasn’t gotten out of the starting blocks.
There was no sign of any dredge pipe south of FM1960, where Callan had reportedly purchased some property for a disposal site according to a City spokesperson.
The dredge was anchored with its bit up, surrounded by tugs and pontoons.
Tugs and pontoons with supplies and an excavator surround the dredge.Dredge was anchored with bit up between Royal Shores and Atascocita Point on West Fork.
Callan has welded several sections of dredge pipe together. They are strung out along a channel that connects the East and West Forks south of Royal Shores.
See one long section of pipe on the left and two shorter sections on right.Atascocita Point on far shore.
Reason for Pause Uncertain
A source familiar with the dredging industry suggested that delays might have to do with the placement area not yet being ready to receive spoils. But that’s speculation. I hope to learn more in coming days.
Purpose of Project
The purpose of the project is to help remove sediment that restricts the conveyance of the river system and also to help restore some of Lake Houston’s dwindling volume.
Former City Flood Czar Stephen Costello outlined the program approximately a year ago. The City plans to spend $34 million to remove almost 900,000 cubic yards of sediment east of Atascocita and south of the convergence of the East and West Forks.
Posted by Bob Rehak on 12/8/2024
2658 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/12/20241208-DJI_20241208104939_0315_D.jpg?fit=1100%2C650&ssl=16501100adminadmin2024-12-08 15:44:322024-12-08 15:49:30Dredge Still in Starting Blocks
12/7/24 – One of the leading environmental groups in the Houston region is the Bayou Land Conservancy (BLC). Their motto: “We preserve land along streams for flood control, clean water, and wildlife.”
Last year, BLC volunteers logged thousands of hours maintaining and improving natural areas and trails that help others appreciate nature’s wonders.
One such volunteer is Jeff Hodges. He helped restore land along Spring Creek in BLC’s Arrowwood Preserve, which is being used for environmental education. His story is a testament to the tenacity of BLC volunteers in their service of nature.Below are excepts from Hodges’ responses to my questions.
Preserve’s Contribution to Flood Reduction
Rehak: How does the Bayou Land Conservancy help reduce flooding?
Hodges: Development in the Houston area will continue. We need to understand how this can lead to increased flood risk of flooding if not managed correctly.
BLC is a land trust. It protects lands where rain water is absorbed and held as flood waters, slowing down the release of water into creeks, streams and rivers. That helps reduce or eliminate flooding downstream.
These lands are increasingly important. They let water soak into the land providing much needed water, to the water table and aquifers.
Currently, ever major aquifer in the U.S. is being depleted, except in the Pacific Northwest. This depletion contributes to subsidence, which increases flood risk. Areas in the Woodlands have lost two feet of elevation from subsidence.
The lands that BLC protects also provide habitat for wildlife and give people a chance to enjoy nature.
Rehak: Specifically, how does Arrowwood reduce flooding along Spring Creek.
Hodges: Arrowwood is a natural flood plain. It slows and stores rainwater flowing toward Spring Creek. A large portion of the preserve floods in heavy rains. It gives stormwater someplace to sit and wait instead of moving quickly downstream and flooding other areas already developed.
Restoring the Natural Environment
Rehak: I hear that in trying to make Arrowwood more user friendly, you and your fellow volunteers removed more than a mile of silt fence. How did it get there?
Hodges: A sand-and-gravel company installed the silt fence when it applied for a permit to turn the property into a quarry. But neighbors blocked approval of the permit. The mining company, after a number of years, donated the land to Bayou Land Conservancy.
Rehak: Removing that silt fence must have been a chore!
Hodges: We actually made a short movie about it. The preserve comprises 117 acres and the fence surrounded 22 acres. As work began to make the preserve accessible, we realized that we did not have the correct equipment to remove the silt fence.
Bayou Land Conservancy Volunteer Jeff Hodges led the Arrowwood Silt Fence Removal Project
We originally estimated the preserve had 2 miles of silt fencing containing approximately 700 posts, each weighing 5 pounds.
Jeff Hodges
The task seemed overwhelming. But we were very concerned about the impact of the fence on wildlife. Turtles and other small wildlife couldn’t get over or around it.
Volunteers Discover Task is Herculean
Rehak: What kind of problems did you encounter?
Hodges: I started to wonder if we could remove the silt fence manually. Bayou Land Conservancy gave me and a small team permission to work on it. The first day, two of us tried to develop a process to remove the silt fencing. In a half day, we could only remove about 10 posts and 50 feet of fencing.
Most of the posts had to be dug out by hand. Each was four feet and originally pounded into the ground to a depth of two feet. But over time, silt built up around the fence. Many sections were totally buried.
The silt fencing has three components: posts, heavy metal fencing, and a plastic tarp. The combination prevents silt, sand and rocks from washing into the creek.
After the first day, most people would have been discouraged. But our volunteers proved it could be done. It was just going to take a lot of time and effort.
Volunteers decided to separate the fence and post removal operations to speed things up.
We decided we would remove the metal fence along with the black tarp first. We left the posts until we were able to develop a better way to remove them.
But the removal of the fencing was not without problems. Portions of the fencing were buried, so we had to dig them out. Worse, the fencing had become overgrown. Before we could remove it, we first had to remove fallen trees, and cut away vines and brambles.
Triumph of Ingenuity, Sweat and Safety Goggles
Rehak: Did you ever develop a faster system?
Hodges: As we removed fencing over the next couple of months, we worked on developing a technique to remove posts without digging. Eventually, we developed a technique that sped up the operation. We hit the posts with a sledge hammer on all four sides to loosen them. Then we hooked up a farm jack to pry them out of the ground.
Working as a team, we could remove about 15 posts per hour. Some, buried to the top in heavy clay, still had to be dug out by hand. Those just took longer.
Everyone working on this project had to wear long pants, long sleeves, safety glasses, and heavy-duty work gloves. We also had to be up to date on our tetanus shots, too for obvious reasons.
Rehak: What did the final boxscore say?
Hodges: All in all, the team ended up removing 499 posts and more than 1.5 miles of fencing. While working on the fencing, we also removed trash and litter which seemed to be everywhere. Fencing and trash filled two industrial dumpsters.
Some of the trash and fencing materials removed from the BLC Arrowwood Preserve.
It was grueling work. But the transformation of the land is overwhelming. And very satisfying. The beauty of what this preserve will become is now evident.
Postscript: Jill Boullion, Bayou Land Conservancy Executive Director, said, ““Jeff was awarded our Trailblazer Award for 2024 because of his leadership on this project. It’s an important part of our restoration plan for Arrowwood that will make the preserve even more ecologically valuable for the community. We appreciate volunteers like Jeff and the crew that did this very difficult project.”
Posted by Bob Rehak and Jeff Hodges on 12/7/24
2657 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/12/20241207-Bayou-Land-Conservancy-Arrowwood-1.jpg?fit=1100%2C603&ssl=16031100adminadmin2024-12-07 18:17:022024-12-07 18:30:07Bayou Land Conservancy Volunteers Protect Nature’s Flood Protection
12/6/24 – When you look at Harris County Flood Control District (HCFCD) spending figures, it’s clear they are making a major flood-mitigation investment along Cypress Creek. At the end of the third quarter this year, HCFCD had spent more than $190 million on Cypress Creek projects since Hurricane Harvey. That was enough to rank it second among all Harris County watersheds. Only Brays Bayou received more funding.
New stormwater-detention basin under construction in September 2023 at Cypress Creek and TC Jester.
So I asked how much the county’s investment in stormwater detention basins along Cypress Creek could help offset future releases from Lake Conroe by the SJRA during flood events.
Of course, any detention upstream helps offset flooding downstream. So the question is really “Can additional detention offset SJRA releases significantly?”
“Not a 1:1 Storage Question”
Harris County Precinct 3 Senior Project Manager Eric Heppen, P.E., PMP, explained how a professional engineer would answer my seemingly innocent question. It’s far more complex than it looks.
“Significantly” masks several layers of complexity.
For instance, how:
Much can Lake Conroe release compared to the total detention along Cypress Creek?
Fast is the SJRA releasing from Lake Conroe?
Long would the SJRA release last?
Much does the water spread out before reaching Lake Houston?
And then there are the questions of rainfall distribution and the arrival time of peaks. Is it raining as hard along Cypress Creek as it is above Lake Conroe’s dam? What if the flood peaks don’t arrive simultaneously?
For all these reasons, said Heppen, “It’s never going to be a 1:1 storage question. From a Lake-Houston-Area perspective, you can’t say that an acre foot of water held back on Cypress Creek exactly equals an acre-foot of water released from Lake Conroe.” Then he went on to answer my question as best he could given the uncertainties involved.
Comparison of Total Stormwater Detention
Heppen began by pointing out that studies show Cypress Creek needs another 25,000 acre-feet of floodwater storage. “Our initial goal is to add another 12,000-14,000 acre feet,” he said.
Lake Conroe, on the other hand, has a surface area of 21,000 acres. And the SJRA has an easement that gives it the ability to raise the lake six feet. For comparison, that’s 126,000 acre feet of additional detention, roughly 10X more than the detention volume being added to Cypress Creek initially or 5X more than the desired 25,000 acre feet.
So additional Cypress detention, when complete, would equal 10-20% of the variable storage that SJRA has to work with at Lake Conroe. That can make a dent in Lake Houston Area flooding.
Comparison of Release Rates and Durations
However, Heppen did not stop there. He also calculated how long Cypress Creek’s additional detention could offset releases from Lake Conroe. “IF the dam releases at 6,000 cubic feet per second (CFS) then that is approximately an acre foot every 7 seconds or so,” said Heppen. “That would mean SJRA was releasing approximately 500 acre feet per hour.”
“So…very, very, very simplified, if Harris County adds 10,000 acre feet along Cypress, and Lake Conroe releases 6,000 CFS, then the additional detention along Cypress Creek could take the increased release rate for nearly 20 hours,” added Heppen.
Compare that to actual release rates during a large flood. Affidavits by SJRA engineers show that releases above 70,000 CFS from Lake Conroe lasted 26 hours during Harvey.
Shaving 6,000 CFS off those releases for 20 hours could well have saved many homes and businesses on the periphery of the flood.
Conclusion: Blunted Peaks
The initial 12,000 to 14,000 acre feet of stormwater detention being added to Cypress Creek could have blunted the peak of Harvey had it been there at the time. The desired 25,000 acre feet would have made an even greater impact.
Of course, flooding is all about timing, i.e., when peaks arrive. But if the Lake Conroe and Cypress Creek peaks arrived at the US59 bridge simultaneously, the Cypress Creek storage could have reduced the combined peak significantly in my opinion.
Additional upstream detention was one of the three main goals advocated by the Lake Houston Area Task Force after Harvey. And I, for one, am all for the improvements being made to Cypress Creek stormwater-detention capacity.
Posted by Bob Rehak on 12/6/2024
2656 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/09/20230925-DJI_0502.jpg?fit=1100%2C733&ssl=17331100adminadmin2024-12-06 17:09:092024-12-06 19:40:58Can Cypress Creek Stormwater Detention Offset SJRA Releases from Lake Conroe?
Dredge Still in Starting Blocks
12/8/24 – Callan Marine moved its dredge down the San Jacinto West Fork to a location between Atascocita Point and Royal Shores more than two weeks ago. But it hasn’t moved yet. Reasons for the delay are unclear at this point.
Still Anchored in Same Spot
This morning, the rain let up long enough to get some drone shots. Unfortunately, it appears that the dredge hasn’t moved since November. It’s anchored in the same spot in the same position as on November 23, 2024. To borrow a phrase from track and field, it hasn’t gotten out of the starting blocks.
There was no sign of any dredge pipe south of FM1960, where Callan had reportedly purchased some property for a disposal site according to a City spokesperson.
The dredge was anchored with its bit up, surrounded by tugs and pontoons.
Callan has welded several sections of dredge pipe together. They are strung out along a channel that connects the East and West Forks south of Royal Shores.
Reason for Pause Uncertain
A source familiar with the dredging industry suggested that delays might have to do with the placement area not yet being ready to receive spoils. But that’s speculation. I hope to learn more in coming days.
Purpose of Project
The purpose of the project is to help remove sediment that restricts the conveyance of the river system and also to help restore some of Lake Houston’s dwindling volume.
Former City Flood Czar Stephen Costello outlined the program approximately a year ago. The City plans to spend $34 million to remove almost 900,000 cubic yards of sediment east of Atascocita and south of the convergence of the East and West Forks.
Posted by Bob Rehak on 12/8/2024
2658 Days since Hurricane Harvey
Bayou Land Conservancy Volunteers Protect Nature’s Flood Protection
12/7/24 – One of the leading environmental groups in the Houston region is the Bayou Land Conservancy (BLC). Their motto: “We preserve land along streams for flood control, clean water, and wildlife.”
Last year, BLC volunteers logged thousands of hours maintaining and improving natural areas and trails that help others appreciate nature’s wonders.
One such volunteer is Jeff Hodges. He helped restore land along Spring Creek in BLC’s Arrowwood Preserve, which is being used for environmental education. His story is a testament to the tenacity of BLC volunteers in their service of nature. Below are excepts from Hodges’ responses to my questions.
Preserve’s Contribution to Flood Reduction
Rehak: How does the Bayou Land Conservancy help reduce flooding?
Hodges: Development in the Houston area will continue. We need to understand how this can lead to increased flood risk of flooding if not managed correctly.
BLC is a land trust. It protects lands where rain water is absorbed and held as flood waters, slowing down the release of water into creeks, streams and rivers. That helps reduce or eliminate flooding downstream.
These lands are increasingly important. They let water soak into the land providing much needed water, to the water table and aquifers.
Currently, ever major aquifer in the U.S. is being depleted, except in the Pacific Northwest. This depletion contributes to subsidence, which increases flood risk. Areas in the Woodlands have lost two feet of elevation from subsidence.
The lands that BLC protects also provide habitat for wildlife and give people a chance to enjoy nature.
Rehak: Specifically, how does Arrowwood reduce flooding along Spring Creek.
Hodges: Arrowwood is a natural flood plain. It slows and stores rainwater flowing toward Spring Creek. A large portion of the preserve floods in heavy rains. It gives stormwater someplace to sit and wait instead of moving quickly downstream and flooding other areas already developed.
Restoring the Natural Environment
Rehak: I hear that in trying to make Arrowwood more user friendly, you and your fellow volunteers removed more than a mile of silt fence. How did it get there?
Hodges: A sand-and-gravel company installed the silt fence when it applied for a permit to turn the property into a quarry. But neighbors blocked approval of the permit. The mining company, after a number of years, donated the land to Bayou Land Conservancy.
Rehak: Removing that silt fence must have been a chore!
Hodges: We actually made a short movie about it. The preserve comprises 117 acres and the fence surrounded 22 acres. As work began to make the preserve accessible, we realized that we did not have the correct equipment to remove the silt fence.
The task seemed overwhelming. But we were very concerned about the impact of the fence on wildlife. Turtles and other small wildlife couldn’t get over or around it.
Volunteers Discover Task is Herculean
Rehak: What kind of problems did you encounter?
Hodges: I started to wonder if we could remove the silt fence manually. Bayou Land Conservancy gave me and a small team permission to work on it. The first day, two of us tried to develop a process to remove the silt fencing. In a half day, we could only remove about 10 posts and 50 feet of fencing.
Most of the posts had to be dug out by hand. Each was four feet and originally pounded into the ground to a depth of two feet. But over time, silt built up around the fence. Many sections were totally buried.
The silt fencing has three components: posts, heavy metal fencing, and a plastic tarp. The combination prevents silt, sand and rocks from washing into the creek.
After the first day, most people would have been discouraged. But our volunteers proved it could be done. It was just going to take a lot of time and effort.
We decided we would remove the metal fence along with the black tarp first. We left the posts until we were able to develop a better way to remove them.
But the removal of the fencing was not without problems. Portions of the fencing were buried, so we had to dig them out. Worse, the fencing had become overgrown. Before we could remove it, we first had to remove fallen trees, and cut away vines and brambles.
Triumph of Ingenuity, Sweat and Safety Goggles
Rehak: Did you ever develop a faster system?
Hodges: As we removed fencing over the next couple of months, we worked on developing a technique to remove posts without digging. Eventually, we developed a technique that sped up the operation. We hit the posts with a sledge hammer on all four sides to loosen them. Then we hooked up a farm jack to pry them out of the ground.
Working as a team, we could remove about 15 posts per hour. Some, buried to the top in heavy clay, still had to be dug out by hand. Those just took longer.
Everyone working on this project had to wear long pants, long sleeves, safety glasses, and heavy-duty work gloves. We also had to be up to date on our tetanus shots, too for obvious reasons.
Rehak: What did the final boxscore say?
Hodges: All in all, the team ended up removing 499 posts and more than 1.5 miles of fencing. While working on the fencing, we also removed trash and litter which seemed to be everywhere. Fencing and trash filled two industrial dumpsters.
It was grueling work. But the transformation of the land is overwhelming. And very satisfying. The beauty of what this preserve will become is now evident.
Postscript: Jill Boullion, Bayou Land Conservancy Executive Director, said, ““Jeff was awarded our Trailblazer Award for 2024 because of his leadership on this project. It’s an important part of our restoration plan for Arrowwood that will make the preserve even more ecologically valuable for the community. We appreciate volunteers like Jeff and the crew that did this very difficult project.”
Posted by Bob Rehak and Jeff Hodges on 12/7/24
2657 Days since Hurricane Harvey
Can Cypress Creek Stormwater Detention Offset SJRA Releases from Lake Conroe?
12/6/24 – When you look at Harris County Flood Control District (HCFCD) spending figures, it’s clear they are making a major flood-mitigation investment along Cypress Creek. At the end of the third quarter this year, HCFCD had spent more than $190 million on Cypress Creek projects since Hurricane Harvey. That was enough to rank it second among all Harris County watersheds. Only Brays Bayou received more funding.
So I asked how much the county’s investment in stormwater detention basins along Cypress Creek could help offset future releases from Lake Conroe by the SJRA during flood events.
Of course, any detention upstream helps offset flooding downstream. So the question is really “Can additional detention offset SJRA releases significantly?”
“Not a 1:1 Storage Question”
Harris County Precinct 3 Senior Project Manager Eric Heppen, P.E., PMP, explained how a professional engineer would answer my seemingly innocent question. It’s far more complex than it looks.
“Significantly” masks several layers of complexity.
For instance, how:
And then there are the questions of rainfall distribution and the arrival time of peaks. Is it raining as hard along Cypress Creek as it is above Lake Conroe’s dam? What if the flood peaks don’t arrive simultaneously?
For all these reasons, said Heppen, “It’s never going to be a 1:1 storage question. From a Lake-Houston-Area perspective, you can’t say that an acre foot of water held back on Cypress Creek exactly equals an acre-foot of water released from Lake Conroe.” Then he went on to answer my question as best he could given the uncertainties involved.
Comparison of Total Stormwater Detention
Heppen began by pointing out that studies show Cypress Creek needs another 25,000 acre-feet of floodwater storage. “Our initial goal is to add another 12,000-14,000 acre feet,” he said.
Lake Conroe, on the other hand, has a surface area of 21,000 acres. And the SJRA has an easement that gives it the ability to raise the lake six feet. For comparison, that’s 126,000 acre feet of additional detention, roughly 10X more than the detention volume being added to Cypress Creek initially or 5X more than the desired 25,000 acre feet.
So additional Cypress detention, when complete, would equal 10-20% of the variable storage that SJRA has to work with at Lake Conroe. That can make a dent in Lake Houston Area flooding.
Comparison of Release Rates and Durations
However, Heppen did not stop there. He also calculated how long Cypress Creek’s additional detention could offset releases from Lake Conroe. “IF the dam releases at 6,000 cubic feet per second (CFS) then that is approximately an acre foot every 7 seconds or so,” said Heppen. “That would mean SJRA was releasing approximately 500 acre feet per hour.”
“So…very, very, very simplified, if Harris County adds 10,000 acre feet along Cypress, and Lake Conroe releases 6,000 CFS, then the additional detention along Cypress Creek could take the increased release rate for nearly 20 hours,” added Heppen.
Compare that to actual release rates during a large flood. Affidavits by SJRA engineers show that releases above 70,000 CFS from Lake Conroe lasted 26 hours during Harvey.
Shaving 6,000 CFS off those releases for 20 hours could well have saved many homes and businesses on the periphery of the flood.
Conclusion: Blunted Peaks
The initial 12,000 to 14,000 acre feet of stormwater detention being added to Cypress Creek could have blunted the peak of Harvey had it been there at the time. The desired 25,000 acre feet would have made an even greater impact.
Of course, flooding is all about timing, i.e., when peaks arrive. But if the Lake Conroe and Cypress Creek peaks arrived at the US59 bridge simultaneously, the Cypress Creek storage could have reduced the combined peak significantly in my opinion.
Additional upstream detention was one of the three main goals advocated by the Lake Houston Area Task Force after Harvey. And I, for one, am all for the improvements being made to Cypress Creek stormwater-detention capacity.
Posted by Bob Rehak on 12/6/2024
2656 Days since Hurricane Harvey