Thank you for your work with Reduce Flooding to raise awareness about flooding and flood-related issues since Hurricane Harvey. You have done a tremendous job of helping to educate the public on the causes of flooding and providing status updates on current and future flood-related projects and initiatives. Regarding your April 25 post titled ““Caution: SB 2126 Opens Door to Sand Mining in Rivers,” I want to clarify what SB 2126 is and what it is not.
Chuck Gilman, the author of this post, is Director of Water Resources and Flood Management for the San Jacinto River Authority
The concept behind SB 2126 is to create a proactive approach toward removing sediment from the river before it is deposited in Lake Houston. If you’ll recall the KBR report from 2000 noted “For long-term sediment management consideration, sedimentation basins, either on-channel or off-channel, are the most effective approach to minimizing sediment buildups and maintain the life of the channel conveyance.” That is what we are attempting to accomplish with this program.
The strategies and programs that could be implemented if SB 2126 is approved would not be river mining or dredging. Any kind of dredging (either hydraulic or mechanic) would be very limited in scope, allowing conservation and reclamation districts to restore conveyance in the rivers in a strategic location through small-scale, periodic, targeted removal of sediment in the river. This could be as large-scale as the current dredging project currently in progress, or as simple as the construction of sand traps that are dredged annually. Regardless, your point about oversight and management is well noted, and is a requirement for this program to be a success.
The San Jacinto River Authority has secured the support from the sand mining industry through the Texas Aggregates and Concrete Association to explore options to remove sand, gravel, shell, and other aggregates from the river—all without a cost to taxpayers. Ideally, the SJRA would be the public agency overseeing and managing the program, conducting the necessary studies, and coordinating with the appropriate state and federal agencies to determine where and how much material should be removed. Partners from the private sector could then remove the material as directed by SJRA.
After Hurricane Harvey, Governor Abbott tasked all of us with flood control and flood management. SB 2126 creates opportunities for public-private partnerships to help preserve the channel conveyance capacity of the San Jacinto River. As we know in the Lake Houston area, this sediment impedes the flow of storm water where the West Fork converges with Lake Houston.
Senator Creighton has led the effort to develop a flood resiliency funding bill in the Senate this legislative session (SB 7), and continues to seek other options to help create a regional flood management effort in the San Jacinto Basin. This bill would simply create another tool in our toolbox to help reduce potential flooding in the future.
As stewards of the San Jacinto River and its water supply, the SJRA supports Senator Creighton’s proactive approach to managing sediment in the river. We are trusted partners with the State of Texas, Harris County Flood Control District, and FEMA to execute $2.5B in flood control bond projects like the comprehensive San Jacinto Watershed Master Drainage Plan. We value our role as a community partner and appreciate the opportunity to further reduce the risk of flooding by providing oversight and management of this plan.
Chuck Gilman Director of Water Resources and Flood Management San Jacinto River Authority
For additional information on SJRA visit our website at www.sjra.netor like SJRA on Facebook @SanJacintoRiverAuthority
Posted verbatim from SJRA letter by Chuck Gilman on 4/23/2019
602 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/02/SJRA-Logo-2016-250x250.png?fit=250%2C250&ssl=1250250adminadmin2019-04-23 14:40:322019-04-23 14:52:56SJRA Responds to Post about SB 2126 Opening Door to River Mining
Best management practices for sand mining in many states say that miners should avoid clearing land until they’re ready to mine it. The roots of trees and grasses help stabilize soil during floods.
Barren land exposed to three 500-year storms. Vegetation not only binds the soil, it reduces the velocity of floodwaters, reducing the potential for erosion. Picture taken on 9/14/2017 two weeks after Hurricane Harvey.
Land Cleared, Then Three 500-Year Storms
However, on Caney Creek in Porter, a sand miner cleared 60 acres right before three 500-year storms in 2015, 2016 and 2017.
Except for a tiny pond at the far end of this cleared area, no mining had occurred here when I took this photo shortly after Harvey.
With little vegetation to reduce the velocity of floodwaters, the miner lost sand from this area and a significant portion of his stockpile. Below is a closer shot of the stockpile.
34-acre stockpile suffered severe erosion during Harvey.
Sand Damage Downstream from Mine
Meanwhile, downstream from the mine, when Harvey’s floodwaters subsided, Kingwood residents found 30 acres of East End Park covered with sand, including this area that was once wetlands.
Eagle Point section of Kingwood’s East End Park. After Harvey, sand dunes replaced wetlands.
Extreme events like Harvey reveal the need for regulations that protect both miners and the public.
Restoring the trails in the park cost residents hundreds of thousands of dollars. Several months after the storm, trees covered by sand started dying and continue dying to this day. Eagles, other birds, and residents have lost valuable wetlands.
Bills to Regulate Sitting Idle
State Representative Dan Huberty introduced a bill that would establish best management practices for sand miners and another bill that would require miners in the San Jacinto watershed to follow them.
HB 909 calls for the TCEQ to adopt and publish best management practices for sand mines.
HB 1671 creates penalties for non-compliance with best practices defined under HB 909.
The legislature has taken no action on either bill since:
The Environmental Regulation Committee received HB 909 on 2/25/19.
The Natural Resources committee received HB 1671 on 3/4/19.
Time Running Out
With only 37 days left in this legislative session, hopes for both bills are quickly fading. If you would like to see them enacted, please email committee members:
602 Days since Hurricane Harvey with 37 Days Left in the Legislative Session
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/04/Harvey-SanJac_374.jpg?fit=2000%2C1333&ssl=113332000adminadmin2019-04-23 07:05:322019-04-26 10:52:40Earth Week Part 2: Clearing Land for Sand Mining
Engineering firm Freese & Nichols claims that “Incorporating tunneling into Houston’s stormwater portfolio could significantly reduce flood damages and improve the reliability of existing conveyance and detention infrastructure.” Tunneling technology, the firm says, has improved dramatically in the last 30 years, making projects possible that were once deemed impossible.
Rapid Growth Limits Mitigation Possibilities
Houston’s exponential population growth (16X during the last 100 years) has made both flooding and flood mitigation more difficult to deal with. However, tunneling, says Freese & Nichols bypasses the urban sprawl issue – especially in dense neighborhoods, such as those inside Beltway 8. Tunneling’s low-impact can move stormwater with very little effect on the surface, benefiting communities and addressing environmental concerns.
Tunnels Expand Both Conveyance and Storage
Tunnels, they point out, expand conveyance capacity within a watershed. They can also store stormwater during floods. A 30-50 foot tunnel can store 50 to 150 acre-feet of storm water per mile. More important, it can convey 10,000 to 15,000 cubic feet of water per second. To put that in perspective, that’s about 40-60% of the flow coming from Cypress Creek during Harvey. Or almost 20% of the flow coming from the Lake Conroe Dam.
During Harvey, an estimated 24,100 cfs came from Cypress Creek.
Thus, tunneling could significantly reduce total flow coming down rivers and streams during floods by providing an alternative means of conveyance.
How Tunnels Are Built
This detailed video shows how a modern tunneling machine works. It can construct up to 350 meters of tunnel in a week. That’s between a fifth and a quarter of a mile per week. The machine continuously cases the hole with precision, pre-caste, concrete segments as it excavates through loose sandy soil. It also dynamically balances pressure in the tunnel along the cutting head face to prevent cave ins. Working a hundred feet or more below the surface, it can even evacuate ground water.
Editor’s note: This 13-minute industrial video is among the best-produced videos of its kind that I have ever seen. It should satisfy professionals as well as non-technical types. If you have students who lean toward science and engineering, make sure they see this; it shows how human ingenuity can fill the gap between problem and solution.
Gravity-Driven Reliability
Once built, gravity drives the system during floods.
Diagram courtesy of Freese & Nichols. Reproduced with permission. Note that this diagram shows the start point within a detention basin. Starting within a detention basin helps reduce sediment accumulation in tunnels.
Success Stories in Other Parts of Texas
Here in Texas, engineers have used the technology successfully to reduce flooding potential in Dallas, San Antonio and Austin. As urban centers grow, the need to move infrastructure underground grows with them. Disruption to life and the environment on the surface are simply too costly otherwise.
Because of the expense, tunneling isn’t the first technology you would consider for flood mitigation. But it can be a valuable addition to the tool chest…especially when weighed against the $125 billion that Harvey cost Houston residents.
Numerous discussions have been held at the county, state and federal levels re: the potential applications of this technology.
Community Impactreported last week that Brian Gettinger—tunneling services leader with Freese & Nichols —said he thinks the concept could work on Cypress Creek.
The newspaper said that Gettinger pitched the tunnel system to the Cypress Creek Flood Control Coalition in March. He said if the tunnel becomes a reality, it could cost $2 billion-$3 billion, would take years to build, and would require federal support because of the high price tag.
Feasibility and Alignment Studies
Harris County Flood Control should soon begin Phase 1 of a $400,000 study. Once started, it could take four months to confirm whether tunneling is feasible in this area. Future phases of the study will dig deeper into specific alignments (Buffalo, Brays, Cypress, etc.), evaluating inflow and outflow points, and specific routes.
Posted by Bob Rehak on 4/22/2019 (Earth Day)
601 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/04/Screen-Shot-2019-04-22-at-10.18.42-AM-copy.jpg?fit=1500%2C966&ssl=19661500adminadmin2019-04-22 13:13:322019-04-22 13:14:10Tunneling: A Potentially Valuable Flood Mitigation Tool
SJRA Responds to Post about SB 2126 Opening Door to River Mining
Letter to the Editor
RE: “Caution: SB 2126 Opens Door to Sand Mining in Rivers”
Bob,
Thank you for your work with Reduce Flooding to raise awareness about flooding and flood-related issues since Hurricane Harvey. You have done a tremendous job of helping to educate the public on the causes of flooding and providing status updates on current and future flood-related projects and initiatives. Regarding your April 25 post titled ““Caution: SB 2126 Opens Door to Sand Mining in Rivers,” I want to clarify what SB 2126 is and what it is not.
Director of Water Resources and Flood Management for the
San Jacinto River Authority
The concept behind SB 2126 is to create a proactive approach toward removing sediment from the river before it is deposited in Lake Houston. If you’ll recall the KBR report from 2000 noted “For long-term sediment management consideration, sedimentation basins, either on-channel or off-channel, are the most effective approach to minimizing sediment buildups and maintain the life of the channel conveyance.” That is what we are attempting to accomplish with this program.
The strategies and programs that could be implemented if SB 2126 is approved would not be river mining or dredging. Any kind of dredging (either hydraulic or mechanic) would be very limited in scope, allowing conservation and reclamation districts to restore conveyance in the rivers in a strategic location through small-scale, periodic, targeted removal of sediment in the river. This could be as large-scale as the current dredging project currently in progress, or as simple as the construction of sand traps that are dredged annually. Regardless, your point about oversight and management is well noted, and is a requirement for this program to be a success.
The San Jacinto River Authority has secured the support from the sand mining industry through the Texas Aggregates and Concrete Association to explore options to remove sand, gravel, shell, and other aggregates from the river—all without a cost to taxpayers. Ideally, the SJRA would be the public agency overseeing and managing the program, conducting the necessary studies, and coordinating with the appropriate state and federal agencies to determine where and how much material should be removed. Partners from the private sector could then remove the material as directed by SJRA.
After Hurricane Harvey, Governor Abbott tasked all of us with flood control and flood management. SB 2126 creates opportunities for public-private partnerships to help preserve the channel conveyance capacity of the San Jacinto River. As we know in the Lake Houston area, this sediment impedes the flow of storm water where the West Fork converges with Lake Houston.
Senator Creighton has led the effort to develop a flood resiliency funding bill in the Senate this legislative session (SB 7), and continues to seek other options to help create a regional flood management effort in the San Jacinto Basin. This bill would simply create another tool in our toolbox to help reduce potential flooding in the future.
As stewards of the San Jacinto River and its water supply, the SJRA supports Senator Creighton’s proactive approach to managing sediment in the river. We are trusted partners with the State of Texas, Harris County Flood Control District, and FEMA to execute $2.5B in flood control bond projects like the comprehensive San Jacinto Watershed Master Drainage Plan. We value our role as a community partner and appreciate the opportunity to further reduce the risk of flooding by providing oversight and management of this plan.
Chuck Gilman
Director of Water Resources and Flood Management
San Jacinto River Authority
For additional information on SJRA visit our website at www.sjra.netor like SJRA on Facebook
@SanJacintoRiverAuthority
Posted verbatim from SJRA letter by Chuck Gilman on 4/23/2019
602 Days since Hurricane Harvey
Earth Week Part 2: Clearing Land for Sand Mining
Best management practices for sand mining in many states say that miners should avoid clearing land until they’re ready to mine it. The roots of trees and grasses help stabilize soil during floods.
Land Cleared, Then Three 500-Year Storms
However, on Caney Creek in Porter, a sand miner cleared 60 acres right before three 500-year storms in 2015, 2016 and 2017.
Except for a tiny pond at the far end of this cleared area, no mining had occurred here when I took this photo shortly after Harvey.
With little vegetation to reduce the velocity of floodwaters, the miner lost sand from this area and a significant portion of his stockpile. Below is a closer shot of the stockpile.
Sand Damage Downstream from Mine
Meanwhile, downstream from the mine, when Harvey’s floodwaters subsided, Kingwood residents found 30 acres of East End Park covered with sand, including this area that was once wetlands.
Extreme events like Harvey reveal the need for regulations that protect both miners and the public.
Restoring the trails in the park cost residents hundreds of thousands of dollars. Several months after the storm, trees covered by sand started dying and continue dying to this day. Eagles, other birds, and residents have lost valuable wetlands.
Bills to Regulate Sitting Idle
State Representative Dan Huberty introduced a bill that would establish best management practices for sand miners and another bill that would require miners in the San Jacinto watershed to follow them.
The legislature has taken no action on either bill since:
Time Running Out
With only 37 days left in this legislative session, hopes for both bills are quickly fading. If you would like to see them enacted, please email committee members:
House Environmental Regulation Committee
House Natural Resources Committee
Click here to see my top ten recommendations for sand mining practices that could reduce erosion. Each represents an opportunity for improvement relative to other states.
Posted by Bob Rehak on 4/23/2019
602 Days since Hurricane Harvey with 37 Days Left in the Legislative Session
Tunneling: A Potentially Valuable Flood Mitigation Tool
Engineering firm Freese & Nichols claims that “Incorporating tunneling into Houston’s stormwater portfolio could significantly reduce flood damages and improve the reliability of existing conveyance and detention infrastructure.” Tunneling technology, the firm says, has improved dramatically in the last 30 years, making projects possible that were once deemed impossible.
Rapid Growth Limits Mitigation Possibilities
Houston’s exponential population growth (16X during the last 100 years) has made both flooding and flood mitigation more difficult to deal with. However, tunneling, says Freese & Nichols bypasses the urban sprawl issue – especially in dense neighborhoods, such as those inside Beltway 8. Tunneling’s low-impact can move stormwater with very little effect on the surface, benefiting communities and addressing environmental concerns.
Tunnels Expand Both Conveyance and Storage
Tunnels, they point out, expand conveyance capacity within a watershed. They can also store stormwater during floods. A 30-50 foot tunnel can store 50 to 150 acre-feet of storm water per mile. More important, it can convey 10,000 to 15,000 cubic feet of water per second. To put that in perspective, that’s about 40-60% of the flow coming from Cypress Creek during Harvey. Or almost 20% of the flow coming from the Lake Conroe Dam.
Thus, tunneling could significantly reduce total flow coming down rivers and streams during floods by providing an alternative means of conveyance.
How Tunnels Are Built
This detailed video shows how a modern tunneling machine works. It can construct up to 350 meters of tunnel in a week. That’s between a fifth and a quarter of a mile per week. The machine continuously cases the hole with precision, pre-caste, concrete segments as it excavates through loose sandy soil. It also dynamically balances pressure in the tunnel along the cutting head face to prevent cave ins. Working a hundred feet or more below the surface, it can even evacuate ground water.
Gravity-Driven Reliability
Once built, gravity drives the system during floods.
Success Stories in Other Parts of Texas
Here in Texas, engineers have used the technology successfully to reduce flooding potential in Dallas, San Antonio and Austin. As urban centers grow, the need to move infrastructure underground grows with them. Disruption to life and the environment on the surface are simply too costly otherwise.
This presentation gives an overview of the technologies involved several case studies in Texas and the U.S. Here’s a shorter two-page summary. And a link to the Freese & Nichols blog that provides a more detailed discussion of the possibilities.
Weighing Expense Against Flood Cost
Because of the expense, tunneling isn’t the first technology you would consider for flood mitigation. But it can be a valuable addition to the tool chest…especially when weighed against the $125 billion that Harvey cost Houston residents.
Numerous discussions have been held at the county, state and federal levels re: the potential applications of this technology.
Community Impact reported last week that Brian Gettinger—tunneling services leader with Freese & Nichols —said he thinks the concept could work on Cypress Creek.
The newspaper said that Gettinger pitched the tunnel system to the Cypress Creek Flood Control Coalition in March. He said if the tunnel becomes a reality, it could cost $2 billion-$3 billion, would take years to build, and would require federal support because of the high price tag.
Feasibility and Alignment Studies
Harris County Flood Control should soon begin Phase 1 of a $400,000 study. Once started, it could take four months to confirm whether tunneling is feasible in this area. Future phases of the study will dig deeper into specific alignments (Buffalo, Brays, Cypress, etc.), evaluating inflow and outflow points, and specific routes.
Posted by Bob Rehak on 4/22/2019 (Earth Day)
601 Days since Hurricane Harvey