This morning at 10:34 AM, the last remains of another Forest Cove townhome complex toppled to the ground. The HCFCD demolition contractor nibbled away at it last week and earlier this morning. Eventually, all but a narrow strip of the last townhome in the complex had turned into a pile of rubble.
That strip started to lean. Then, suddenly, one more touch from the excavator, and the building collapsed on itself with a billowing cloud of dust and a thunderous boom. When the dust cleared, only one last complex remained standing.
As of Saturday, 7/16/22, one of the last three buildings was completely gone along with half of the second.Early Monday, 7/18/22, demolition of the remaining portion of the second building started again.As the excavator clawed away at the building, it started to lean.Periodically, the excavator would pile more rubble under itself so it could then reach higher. Note falling doors, walls and floors, frozen in space by the camera’s fast shutter speed.What took months to build came down in seconds.Note the severe bowing of the wallon the right.
Final Collapse Caught on Camera
At this point, I sensed the building would soon collapse. So, I switched from the drone to my Nikon which can shoot many more frames per second. And then it started…
With parts of the second and third floors removed, along with most of the truss structure in the attic, the remainder of the building started to collapse in on itself.A chimney came tumbling forward.The final collapse took less than 10 seconds. Three minutes later, the dust had cleared.
Next Steps
Contractors will extract any recyclable waste from the rubble. Then, they will crush what remains so that it takes less space in a landfill. Finally, they will remove the concrete from the foundation and likely recycle that, too.
Eventually, this area will return to nature. However, what form that takes has not yet been determined. Typically, HCFCD partners with other organizations such as the Houston Parks Board to create and maintain improvements such as trails, parks or recreational space. In fact, the Houston Parks Board West Fork Trail currently ends behind the rubble in the photo above. The Parks Board plans to extend it to Edgewater Park at US59, so hikers and bikers can connect from the Kingwood Trail System to the Spring Creek Greenway.
Demo Date for Last Building
After this morning, only one Forest Cove townhome complex remains standing. That’s at 1020 Marina Drive near the community swimming pool. According to Amy Stone, a Flood Control District spokesperson, HCFCD will demolish that building starting August 1, 2022. More news to follow.
Posted by Bob Rehak on 7/18/2022
1784 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/07/20220718-DJI_0249.jpg?fit=1200%2C799&ssl=17991200adminadmin2022-07-18 13:22:152022-07-18 14:54:27Caught on Camera: Moment Forest Cove Townhome Toppled
The San Jacinto River Authority (SJRA) has completed its initial sand trap study, in partnership with Harris County Flood Control, and reviewed public comments. According to Matt Barrett PE, SJRA’s Manager of Water Resources and Flood Management, the SJRA is working toward a pilot study. But a successful pilot will require several things including funding partners and consultation with regulatory agencies, such as TCEQ and Texas Parks and Wildlife.
The goal of the project: intercept and remove sediment migrating downstream to reduce buildups elsewhere.
West Fork mouth bar after Harvey and before dredging. A small area at the far right had been building up before Harvey. The rest appeared when Harvey’s floodwater’s receded.
The proposed pilot sand trap could not possibly remove enough sand by itself to prevent the build up of another giant sand bar like the one above. However, a network of such traps might help.
Consultation with Regulatory Agencies
In Texas, among other things, TCEQ regulates floodplains, sand mining, and water quality. Texas Parks and Wildlife regulates rivers between the vegetation on each bank.
Possible location of trap for pilot study outside Hallett Mine on West Fork. Trap would consist of a trench through the middle of the point bar in the foreground.
But a trench at this location might run afoul of new TCEQ BMPs for sand mining that specify 100-foot buffer zones adjacent to perennial streams greater than 20-feet wide.
Schematic diagram of proposed trap at location above from initial conceptual design study finished before TCEQ adopted new BMPs.
Finding Funding Partners
SJRA must also find funding partners as it does not have a revenue source to pay for a pilot study and full construction costs of sand traps. In that regard, Barrett mentioned Harris County Flood Control and City of Houston as potential partners.
Barrett is also exploring partnerships with APOs (Aggregate Production Operations, aka sand mines). Sand mines can help defray expenses by removing sand from the traps as it accumulates. Of course, their desire to do that will depend on the location of the traps. They would prefer something close to their mines to minimize transportation costs and logistics while maximizing salability of the sand.
Hungry-Water Concern
Barrett also mentioned the need for the preliminary engineering design to avoid a “hungry water” effect which might increase erosion downstream. Hungry water results when streams have more power to transport sediment than they have available sediment. As a result, it erodes stream beds and banks to compensate.
Would Program be Extendable if Successful?
In a wide-ranging 45-minute discussion with Barrett, I raised several other potential issues. They included:
Location of the test near APOs, far upstream from the heavily damaged areas near Lake Houston where sand accumulates. There are no active sand mines between Humble and Kingwood – and few on other tributaries.
No sediment gages upstream and downstream from the test site. Not having a way to demonstrate success could limit future expansion of the program.
Potential partners that could remove sand from traps NOT located near APOs. You need a way to get sand out of a trap after it fills up. If the City of Houston or HCFCD established an ongoing maintenance dredging program, that could solve this issue.
How long an APO will remain committed to a location near a trap. After going to the expense of building a trap, SJRA would want to make sure the APO didn’t move operations to another location in a year or two. For example, some sand miners have talked about moving to the East Fork to take advantage of expected growth associated with the new Grand Parkway extension.
The SJRA must work through such issues to protect the public’s investment in the program. It has many moving parts. And the interests of all partners must align before moving forward.
Outline of Next Steps
So the next steps are:
Find partners with money whose interests align.
Obtain commitments from them.
Consult with regulatory agencies to avoid potential conflicts.
Lock down a location near an APO.
Begin preliminary engineering.
Ensure the pilot study (based on proximity to APOs) can extend to other areas (Rehak concern)
Find a way to measure success to help extend the pilot program if successful
In business, there’s an old maxim: “That which can be measured will be repeated.” Doing a pilot study that can’t be measured or replicated elsewhere helps no one.
The Army Corps has also published extensive research about the effectiveness of different sand-trap designs. Search for “Army Corps sand trap studies.” I originally became interested in the concept when I read a Corps study about a test of different trap geometries in the Mississippi River. There are many alternatives including some that could be located where water slows down at the entrance to Lake Houston (where the Harvey mouth bar appeared in 2017). Such a location would have the advantage of intercepting sediment from all upstream sources, not just the West Fork...if all the tumblers aligned.
Posted by Bob Rehak
1783 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/03/Screen-Shot-2022-03-27-at-6.28.40-PM.png?fit=1920%2C1206&ssl=112061920adminadmin2022-07-17 16:31:402022-07-18 11:24:51SJRA’s Next Steps After Public Comments on Sand Trap Study
Mavera, a 1700-acre new development in southern Montgomery County at FM1314 and US242 has finished clearing a large section of land northwest of the intersection and started pouring concrete. Signs welcome visitors to model homes. The area, once laced with wetlands now has a massive linear detention pond and uses FM1314 for outflow control.
Looking east just north of US242 on right from over FM1314. Note wet areas in foreground. They correspond to wetlands in map below.Large green area immediately east of 1314 (diagonal) and north of US242 (bottom) correspond to wet areas in photo above. From US Fish and Wildlife Service National Wetlands Inventory Map
Areas west of FM1314 to Crystal Creek are also being cleared, but their current state of development is not quite as advanced.
Likewise, an area east of FM1314 has expanded north, almost to Gulf Coast Road. Neither is its drainage fully developed.
Looking NE at current limit of development. Gulf Coast Road runs diagonally from left to right just beyond tree line.
Long, Linear Detention
The development relies on a wide linear detention basin – more than a mile long! And that’s only the part east of FM1314!
Looking east toward upstream end of detention basin.
Two smaller basins also exist. One is currently by a small park and recreation center.
Looking WSW.Note small retention pond and rec center in upper right.
In the photo above, also note the small swales that outline lots. Will some drainage go overland? Or is underground drainage just not connected to the detention basin yet?
Same spot. Lower elevation. Looking west from eastern portion of Mavera. I’m not seeing any drainpipes from storm sewers entering pond yet.Note three new model homes near center of frame.
The development seems to have undergone a series of name changes. The land was originally known as the Denbury Tract. Later, construction plans and a drainage analysis refer to it as Madera. But now, the builders are marketing it as Mavera.
Screen capture of cover sheet from drainage planshowing first two names of development.
The drainage plans for Mavera (aka Madera/Denbury tract) rely on a hydrologic timing assessment (see last line in screen capture above).
The drainage analysis claims the development will have no downstream impact, but engineers didn’t study those areas. Nor did they study how new development upstream may have already shifted the peak of a flood.
Impact on FM1314?
Long linear detention schemes typically accelerate the flow of water. This one will rely on one culvert under FM1314 to hold back more than a mile of water collected from hundreds of acres. That will put a lot of pressure on FM1314 in a heavy storm.
Looking NW over FM1314. East is to the right. Water will flow west toward Crystal Creek out of frame to the left.
The roadway will act as a dam to detain water collected from almost all of the area shown in the photo below.
Looking east. Virtually all of the cleared area will drain through one culvert under FM1314. FM1314 runs left to right through the bottom of the frame. US242 is on right. Notice how channel is being widened, making culvert off-center. Did someone initially miscalculate or did plans change?
FEMA mapped most of this area in a ten-year flood zone. For the sake of potential home buyers, let’s also hope the engineers got the drainage calculations right.
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/07/20220716-DJI_0152.jpg?fit=1200%2C799&ssl=17991200adminadmin2022-07-16 15:56:422025-08-19 22:11:03Mavera Wetlands Bite the Dust
Caught on Camera: Moment Forest Cove Townhome Toppled
This morning at 10:34 AM, the last remains of another Forest Cove townhome complex toppled to the ground. The HCFCD demolition contractor nibbled away at it last week and earlier this morning. Eventually, all but a narrow strip of the last townhome in the complex had turned into a pile of rubble.
That strip started to lean. Then, suddenly, one more touch from the excavator, and the building collapsed on itself with a billowing cloud of dust and a thunderous boom. When the dust cleared, only one last complex remained standing.
We are nearing the end of a process that started in 2018.
Sequence of Photos
Final Collapse Caught on Camera
At this point, I sensed the building would soon collapse. So, I switched from the drone to my Nikon which can shoot many more frames per second. And then it started…
Next Steps
Contractors will extract any recyclable waste from the rubble. Then, they will crush what remains so that it takes less space in a landfill. Finally, they will remove the concrete from the foundation and likely recycle that, too.
Eventually, this area will return to nature. However, what form that takes has not yet been determined. Typically, HCFCD partners with other organizations such as the Houston Parks Board to create and maintain improvements such as trails, parks or recreational space. In fact, the Houston Parks Board West Fork Trail currently ends behind the rubble in the photo above. The Parks Board plans to extend it to Edgewater Park at US59, so hikers and bikers can connect from the Kingwood Trail System to the Spring Creek Greenway.
Demo Date for Last Building
After this morning, only one Forest Cove townhome complex remains standing. That’s at 1020 Marina Drive near the community swimming pool. According to Amy Stone, a Flood Control District spokesperson, HCFCD will demolish that building starting August 1, 2022. More news to follow.
Posted by Bob Rehak on 7/18/2022
1784 Days since Hurricane Harvey
SJRA’s Next Steps After Public Comments on Sand Trap Study
The San Jacinto River Authority (SJRA) has completed its initial sand trap study, in partnership with Harris County Flood Control, and reviewed public comments. According to Matt Barrett PE, SJRA’s Manager of Water Resources and Flood Management, the SJRA is working toward a pilot study. But a successful pilot will require several things including funding partners and consultation with regulatory agencies, such as TCEQ and Texas Parks and Wildlife.
The goal of the project: intercept and remove sediment migrating downstream to reduce buildups elsewhere.
The proposed pilot sand trap could not possibly remove enough sand by itself to prevent the build up of another giant sand bar like the one above. However, a network of such traps might help.
Consultation with Regulatory Agencies
In Texas, among other things, TCEQ regulates floodplains, sand mining, and water quality. Texas Parks and Wildlife regulates rivers between the vegetation on each bank.
Legislation exempts the SJRA, HCFCD and its contractors from obtaining state permits before removing sediment from the river. Regardless, the SJRA wants to work with regulatory agencies to ensure it doesn’t recommend anything that runs afoul of agency policy. Example: the newly adopted TCEQ Best Management Practices for Sand Mining. For instance, see section 2.1.1 – Vegetated Buffer Zones.
But a trench at this location might run afoul of new TCEQ BMPs for sand mining that specify 100-foot buffer zones adjacent to perennial streams greater than 20-feet wide.
Finding Funding Partners
SJRA must also find funding partners as it does not have a revenue source to pay for a pilot study and full construction costs of sand traps. In that regard, Barrett mentioned Harris County Flood Control and City of Houston as potential partners.
Barrett is also exploring partnerships with APOs (Aggregate Production Operations, aka sand mines). Sand mines can help defray expenses by removing sand from the traps as it accumulates. Of course, their desire to do that will depend on the location of the traps. They would prefer something close to their mines to minimize transportation costs and logistics while maximizing salability of the sand.
Hungry-Water Concern
Barrett also mentioned the need for the preliminary engineering design to avoid a “hungry water” effect which might increase erosion downstream. Hungry water results when streams have more power to transport sediment than they have available sediment. As a result, it erodes stream beds and banks to compensate.
Would Program be Extendable if Successful?
In a wide-ranging 45-minute discussion with Barrett, I raised several other potential issues. They included:
The SJRA must work through such issues to protect the public’s investment in the program. It has many moving parts. And the interests of all partners must align before moving forward.
Outline of Next Steps
So the next steps are:
In business, there’s an old maxim: “That which can be measured will be repeated.” Doing a pilot study that can’t be measured or replicated elsewhere helps no one.
For more information, see this post about potential sites and designs for traps. It features the most likely spot for a pilot study.
The Army Corps has also published extensive research about the effectiveness of different sand-trap designs. Search for “Army Corps sand trap studies.” I originally became interested in the concept when I read a Corps study about a test of different trap geometries in the Mississippi River. There are many alternatives including some that could be located where water slows down at the entrance to Lake Houston (where the Harvey mouth bar appeared in 2017). Such a location would have the advantage of intercepting sediment from all upstream sources, not just the West Fork...if all the tumblers aligned.
Posted by Bob Rehak
1783 Days since Hurricane Harvey
Mavera Wetlands Bite the Dust
Mavera, a 1700-acre new development in southern Montgomery County at FM1314 and US242 has finished clearing a large section of land northwest of the intersection and started pouring concrete. Signs welcome visitors to model homes. The area, once laced with wetlands now has a massive linear detention pond and uses FM1314 for outflow control.
Areas west of FM1314 to Crystal Creek are also being cleared, but their current state of development is not quite as advanced.
Likewise, an area east of FM1314 has expanded north, almost to Gulf Coast Road. Neither is its drainage fully developed.
Long, Linear Detention
The development relies on a wide linear detention basin – more than a mile long! And that’s only the part east of FM1314!
Two smaller basins also exist. One is currently by a small park and recreation center.
In the photo above, also note the small swales that outline lots. Will some drainage go overland? Or is underground drainage just not connected to the detention basin yet?
The Mavera website by Centex homes says the swimming pool at the rec center will open late this summer. Pulte will also build homes in Mavera.
Name Changes and a “Beat the Peak” Drainage Analysis
I previously posted about Mavera in January. Compare the pictures taken then.
The development seems to have undergone a series of name changes. The land was originally known as the Denbury Tract. Later, construction plans and a drainage analysis refer to it as Madera. But now, the builders are marketing it as Mavera.
The drainage plans for Mavera (aka Madera/Denbury tract) rely on a hydrologic timing assessment (see last line in screen capture above).
Harris County has tried to discourage neighboring counties from using such analyses. They encourage developers to get stormwater to streams and rivers faster rather than slower. The theory is that if you can beat the peak of a flood then you aren’t adding to it. But if everybody tries to “beat the peak,” eventually you shift the peak and flood downstream neighbors. For a full discussion of drainage issues, see my previous post.
The drainage analysis claims the development will have no downstream impact, but engineers didn’t study those areas. Nor did they study how new development upstream may have already shifted the peak of a flood.
Impact on FM1314?
Long linear detention schemes typically accelerate the flow of water. This one will rely on one culvert under FM1314 to hold back more than a mile of water collected from hundreds of acres. That will put a lot of pressure on FM1314 in a heavy storm.
The roadway will act as a dam to detain water collected from almost all of the area shown in the photo below.
Let’s hope all that water doesn’t blow out the road like Colony Ridge drainage blew out FM1010 in Liberty County.
For Potential Home Buyers
FEMA mapped most of this area in a ten-year flood zone. For the sake of potential home buyers, let’s also hope the engineers got the drainage calculations right.
Potential homebuyers may also be interested in reading about the risks of building homes over wetlands.
Posted by Bob Rehak on 7/16/2022
1782 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.