Houston Mayor Pro Tem Dave Martin announced a meeting Thursday, July 8, 2021, at the Kingwood Community Center (4102 Rustic Woods) to provide updates on adding more floodgates to Lake Houston. The program to discuss the Lake Houston Dam Spillway Improvement Project will start at 6:00 p.m. The event will conclude at 7:45 p.m.
Floodgate enhancement was one of the three essential elements of the flood reduction strategy after Harvey. The other two were dredging and additional upstream detention.
At the CWA March meeting, directors also approved $4.4 million to begin Phase II of the project. Phase II calls for Black & Veatch to proceed to final engineering of the floodgates and a coffer dam to protect the work area during construction.
Lake Houston Spillway current conditionsPreliminary engineering called for crest gates to be added to the first 1000 feet of this spillway.
Additional Protection for 5,000 Structures, 35,000 Residents
The spillway improvement project will increase outflow capacity of the Lake Houston Dam, bringing it closer to that of the Lake Conroe Dam. Faster releases from Lake Houston floodgates in advance of storms will prevent or reduce upstream flooding, protecting about 35,000 residents and 5,000 structures.
This project is part of the Federal Emergency Management Agency’s (FEMA) Hazard Mitigation Grant Program. A FEMA grant provides $4.3 million for the initial phase and positions the city to receive $42.7 million for construction.
Mayor Pro Tem Dave Martin, Houston Public Works, and Coastal Water Authority have been working together under the direction of Chief Recovery Officer Stephen Costello to plan this public forum to discuss the progress of the floodgates.
Format of Meeting
Black & Veatch, the project engineers, will make a brief presentation followed by a short Q&A session and breakout sessions. The breakout session will let the community engage directly with project management staff and engineers in small groups to ask more detailed questions.
For more information, please contact the District E office at (832) 393-3008 or districte@houstontx.gov.
Posted by Bob Rehak on 6/8/2021 based on information from Dave Martin
1379 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/02/LakeHoustonDam-e1775832315715.jpg?fit=1100%2C593&ssl=15931100adminadmin2021-06-08 12:55:092021-06-08 13:04:28Save the Date: Floodgate Meeting on July 8, 6 PM at Kingwood Community Center
The conceptual feasibility study includes the design of two dams with three alternatives for each. One potential site will be along Birch Creek and another along Walnut Creek.
Spring Creek forms the Harris/Montgomery County Line for most of its length. It also bridges precincts 3 and 4 in Harris County.
Dry Dams with Fixed Height Spillways and Low-Flow Culverts
The San Jacinto River Basin Master Drainage Plan originally identified both sites. And both would feature “dry dams.” That means, they would contain no permanent water. Specs call for building the dams high enough to hold back a hundred year flood.
Each would contain a permanent fixed-height spillway. Water would flow over the spillway when it reaches 100-year level as defined in Atlas 14. The dams would also contain low-flow culverts allowing water lower than the spillway to drain slowly after a flood, as it would from a detention pond. None of the potential designs will consider gated structures.
Initial estimates in the SJR Master Drainage Plan released last year suggest that:
A 41-foot-high, 0.7 mile long dam on Birch Creek could contain 7,731 acre-feet of water in a hundred-year storm. That’s a foot of rain falling over a 12-square-mile area.
Likewise, a 46-foot-high, 1.2 mile long dam on Walnut Creek could contain 12,159 acre-feet. That’s a foot of rain falling over a 19-square-mile area.
Identifying ways to minimize or avoid environmental impacts
Soil surveys with borings up to 75 feet deep
Spillway design
Conceptual recommendations for dam design at each site
Estimating probable construction costs
Estimating land needs and costs
Identification of potential utility issues, such as pipeline crossings
Plans for raising or relocating roads, cemeteries and utilities outside the Atlas-14, 100-year floodplain
Estimating total project costs, financing costs, annual operations and maintenance costs
Developing a benefit/cost ratio based on reductions in flood damages over a 50-year period.
SJRA would lead the Spring Creek feasibility study. The local partners are seeking up to $1 million in matching funds from the Texas Water Development Board’s Flood Infrastructure Fund.
One Part of an Upstream Detention Solution
The big question is: How much benefit would people downstream in the Lake Houston Area get from Spring Creek dams? The answer is “some, but not as much as you might think.” That’s because, as you move farther downstream, the dam blocks a smaller percentage of the watershed. Think about it. Right below the dam, everything less than a 100-year storm would be intercepted. But by the time you get down to US59, you’re also getting water from Cypress Creek, Lake Creek, the West Fork and dozens of smaller streams and ditches.
So while the Spring Creek Dams could be part of a solution to offset future releases from the Lake Conroe Dam, it’s not the total solution for the Lake Houston Area. Regardless, it still would help many homes and businesses upstream along Spring Creek. Exactly how many? We’ll have to wait to see until we get the study results.
For the full text of the proposed interlocal agreement that Commissioners will vote on Tuesday, click here.
Cost of the study to local partners will depend on the match supplied by TWDB, which has not yet been finalized.
Posted by Bob Rehak on 6/7/2021 based on draft of a proposed Interlocal Agreement and the SJR Master Drainage Plan
1378 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/06/20210607-Screen-Shot-2021-06-07-at-1.39.44-PM.jpg?fit=1200%2C693&ssl=16931200adminadmin2021-06-07 17:32:092021-06-07 17:38:10Harris County Commissioners Vote Tuesday on Feasibility Study of 2 Dams on Spring Creek Tributaries
The time for sitting on the sidelines of the subsidence debate is over. Groundwater Management Area 14 (GMA-14) has finalized its proposed desired future conditions (DFCs). Lone Star Groundwater Conservation District (LSGCD) is fighting them. It wants to exclude any mention of subsidence. So if you disagree with that point of view, speak up now or live with the consequences. LSGCD will hold a board meeting Monday at 2 pm to hear public comments. You can also register your opinions in writing until July 19, 2021.
See more below about the background of this crucial debate including a discussion of the issues; pros and cons; how you can make your voice heard and where you can get more information.
How GMAs Set Goals
GMA-14 comprises most of southeast Texas. See map below. It includes five groundwater conservation districts and two subsidence districts and four counties that have neither.
Every county in Texas belongs to a Groundwater Management Area. SE Texas belongs to GMA-14.
One purpose of a GMA is to bind the people of a region together to meet common goals. Significantly, if one county wants to abandon surface water and pump unlimited amounts of cheaper groundwater, it must first get permission from the other members of the GMA. That’s because pumping groundwater has consequences. It can cause neighboring wells to go dry, leaving rural ranchers without options.
It can also cause subsidence, in which one area sinks relative to surrounding areas. That can alter the gradient of rivers, causing water to move slower and back up more. Subsidence can also trigger geologic fault movement, disrupt pipelines, damage homes, and crack pavement.
In setting goals, GMAs also consider factors such as economic development and population growth. They typically plan 50 years or more ahead to ensure adequate water supplies.
Proposed Desired Future Conditions for GMA-14
GMA-14 has debated its next set of desired future conditions (DFCs) since 2016. At its last meeting, members finally adopted the following statement.
In each county in GMA 14, no less than 70 percent median available drawdown remaining in 2080 and no more than an average of 1.0 additional foot of subsidence between 2009 and 2080.
“In each county” means the numbers below represent county-wide averages or medians.
“70% median available drawdown remaining in 2080” means counties cannot draw down their aquifer(s) more than 30%. Seventy percent must remain at the end of the period – 2080. Each district controls this by monitoring aquifer levels and adjusting annual well permits to meet the goal.
“No more than an average of 1.0 additional foot of subsidence between 2009 and 2080” defines 2009 as the starting point for measuring subsidence and 2080 as the end.
Lone Star GCD Tries to Break Away
LSGCD has used a variety of arguments to fight the subsidence metric in DFCs. All failed to convince other GMA-14 members. Now LSGCD claims it will reach the drawdown limit before it reaches the subsidence limit, so subsidence should not be included in the limits.
Many observers have repeatedly commented on this position. “If it’s not a limiting factor, why fight it so hard?” they ask. LSGCD keeps repeating the argument without offering a satisfactory answer or showing proof. That raises even more suspicions. It’s like when your kid comes home and brags how well (s)he did in one class and refuses to discuss grades in others.
Pros and Cons
Surface water costs more than groundwater for several reasons. In this part of the world, surface water must be trapped in man-made lakes, treated extensively, and then shipped to users via canals or a pipeline network. In contrast, wells can be drilled near users on very little land.
But if everyone used well-water exclusively, aquifers would deplete rapidly, wells would run dry, and subsidence would kick in.
Aquifers can eventually recharge if you leave them alone long enough. But subsidence is forever. It occurs when “clay lenses” get smashed due to dehydration. Rehydrating them is impossible. One water professional used this analogy: Imagine smashing a brownie and then pouring water on it. It won’t return to its original state.
Also consider that the proposed subsidence limit is an average. In its sparsely populated northern reaches in the Sam Houston National Forest, MoCo has little water demand. However, in southern MoCo is growing by leaps and bounds.
Subsidence has already proven to be an issue there. It has triggered faults and cracked home slabs. Many feel they are now more susceptible to flooding because their homes sit in bowls between faults.
Critics of LSGCD’s move to eliminate a subsidence metric point out that without it, groundwater pumpers could exceed the drawdown limit and simply claim that aquifers would magically recharge in the last few years of the plan.
When The Woodlands began using more surface water in 2016 after completion of a surface water pipeline from Lake Conroe, the rate of subsidence dropped 75%.
Some neighborhoods in The Woodlands ALREADY SUBSIDED BY ALMOST A HALF FOOT BETWEEN 2009 and 2019. And four of those years followed a conversion to surface water that reduced the rate of subsidence 75%. So it’s real.
A return to the old rate of subsidence in The Woodlands would result in another 4-foot of drop by 2080.
Modeling also shows that Kingwood and Humble could subside 3 feet because of excessive groundwater pumping in MoCo while the Lake Houston Dam subsides only one foot. That could raise water floodwaters at the top of Lake Houston another 2 feet relative to the spillway at the dam.
Projected subsidence in MoCo with 70% of water in aquifers remaining.
Projected subsidence in Harris County with 70% remaining in aquifers by 2080
What Happens Is Up to You
Some people may prefer cheap water today and not care about the future or downstream neighbors.
The irony is that SJRA already built a surface water treatment plant, which some now advocate abandoning.
What’s more important to you? Short- or long-term savings? Leveling a foundation; repaving your driveway; repairing cracked walls and ceilings; and recovering from a flood cost far more than a few dollars a month on your water bill.
How To Register Your Concerns
Submit comments to LSGCD by:
Email:info@lonestargcd.org with the subject line “DFC Comments” no later than 11:59 p.m. on Jul. 19, 2021.
In Person: 2PM AT THE LONE STAR GCD OFFICE IN THE JAMES B. “JIM” WESLEY BOARD ROOM, 655 CONROE PARK NORTH DRIVE, CONROE, TEXAS 77303.
If you pre-register via the URL meeting link above, a password will be emailed to you in advance of the webinar. If you use the password to log, you WILL have the opportunity to provide live comments during the meeting. Use Webinar ID: 861 0914 6147 Password: Received via pre-registration.
You can also find several articles on this website. The easiest way to find them is by going to the index page and searching for GMA-14, Groundwater Management Area 14, Lone Star Groundwater Conservation District, LSGCD, or subsidence.
Posted by Bob Rehak on 6/6/2021
1377 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.
00adminadmin2021-06-06 18:32:062021-06-06 18:39:32LSGCD Hearing Public Comments 2 PM Monday on Desired Future Conditions, Subsidence
Save the Date: Floodgate Meeting on July 8, 6 PM at Kingwood Community Center
Houston Mayor Pro Tem Dave Martin announced a meeting Thursday, July 8, 2021, at the Kingwood Community Center (4102 Rustic Woods) to provide updates on adding more floodgates to Lake Houston. The program to discuss the Lake Houston Dam Spillway Improvement Project will start at 6:00 p.m. The event will conclude at 7:45 p.m.
Floodgate enhancement was one of the three essential elements of the flood reduction strategy after Harvey. The other two were dredging and additional upstream detention.
Moving into Final Engineering
In its March 10th board meeting, the Coastal Water Authority (CWA) accepted the recommendation of a preliminary engineering report to add one thousand feet of crest gates to the uncontrolled spillway portion the Lake Houston Dam. The additional release capacity would let operators shed water faster before, during or after major storms to reduce the risk of flooding.
At the CWA March meeting, directors also approved $4.4 million to begin Phase II of the project. Phase II calls for Black & Veatch to proceed to final engineering of the floodgates and a coffer dam to protect the work area during construction.
Additional Protection for 5,000 Structures, 35,000 Residents
The spillway improvement project will increase outflow capacity of the Lake Houston Dam, bringing it closer to that of the Lake Conroe Dam. Faster releases from Lake Houston floodgates in advance of storms will prevent or reduce upstream flooding, protecting about 35,000 residents and 5,000 structures.
This project is part of the Federal Emergency Management Agency’s (FEMA) Hazard Mitigation Grant Program. A FEMA grant provides $4.3 million for the initial phase and positions the city to receive $42.7 million for construction.
Mayor Pro Tem Dave Martin, Houston Public Works, and Coastal Water Authority have been working together under the direction of Chief Recovery Officer Stephen Costello to plan this public forum to discuss the progress of the floodgates.
Format of Meeting
Black & Veatch, the project engineers, will make a brief presentation followed by a short Q&A session and breakout sessions. The breakout session will let the community engage directly with project management staff and engineers in small groups to ask more detailed questions.
For more information, please contact the District E office at (832) 393-3008 or districte@houstontx.gov.
Posted by Bob Rehak on 6/8/2021 based on information from Dave Martin
1379 Days since Hurricane Harvey
Harris County Commissioners Vote Tuesday on Feasibility Study of 2 Dams on Spring Creek Tributaries
Harris County Commissioners will vote tomorrow, 6/8/2021, on whether to enter into an interlocal agreement (ILA) for a feasibility study of two dams on Spring Creek tributaries. The ILA is with the San Jacinto River Authority (SJRA), the City of Humble, five Utilities Districts and the Texas Water Development Board.
The conceptual feasibility study includes the design of two dams with three alternatives for each. One potential site will be along Birch Creek and another along Walnut Creek.
Dry Dams with Fixed Height Spillways and Low-Flow Culverts
The San Jacinto River Basin Master Drainage Plan originally identified both sites. And both would feature “dry dams.” That means, they would contain no permanent water. Specs call for building the dams high enough to hold back a hundred year flood.
Each would contain a permanent fixed-height spillway. Water would flow over the spillway when it reaches 100-year level as defined in Atlas 14. The dams would also contain low-flow culverts allowing water lower than the spillway to drain slowly after a flood, as it would from a detention pond. None of the potential designs will consider gated structures.
Initial estimates in the SJR Master Drainage Plan released last year suggest that:
Components of Study
The feasibility study will include:
SJRA would lead the Spring Creek feasibility study. The local partners are seeking up to $1 million in matching funds from the Texas Water Development Board’s Flood Infrastructure Fund.
One Part of an Upstream Detention Solution
The big question is: How much benefit would people downstream in the Lake Houston Area get from Spring Creek dams? The answer is “some, but not as much as you might think.” That’s because, as you move farther downstream, the dam blocks a smaller percentage of the watershed. Think about it. Right below the dam, everything less than a 100-year storm would be intercepted. But by the time you get down to US59, you’re also getting water from Cypress Creek, Lake Creek, the West Fork and dozens of smaller streams and ditches.
So while the Spring Creek Dams could be part of a solution to offset future releases from the Lake Conroe Dam, it’s not the total solution for the Lake Houston Area. Regardless, it still would help many homes and businesses upstream along Spring Creek. Exactly how many? We’ll have to wait to see until we get the study results.
For more information about the Walnut and Birch Creek locations, see pages 39-61 in the San Jacinto River Basin Master Drainage Plan, Appendix G.
For the full text of the proposed interlocal agreement that Commissioners will vote on Tuesday, click here.
Cost of the study to local partners will depend on the match supplied by TWDB, which has not yet been finalized.
Posted by Bob Rehak on 6/7/2021 based on draft of a proposed Interlocal Agreement and the SJR Master Drainage Plan
1378 Days since Hurricane Harvey
LSGCD Hearing Public Comments 2 PM Monday on Desired Future Conditions, Subsidence
The time for sitting on the sidelines of the subsidence debate is over. Groundwater Management Area 14 (GMA-14) has finalized its proposed desired future conditions (DFCs). Lone Star Groundwater Conservation District (LSGCD) is fighting them. It wants to exclude any mention of subsidence. So if you disagree with that point of view, speak up now or live with the consequences. LSGCD will hold a board meeting Monday at 2 pm to hear public comments. You can also register your opinions in writing until July 19, 2021.
See more below about the background of this crucial debate including a discussion of the issues; pros and cons; how you can make your voice heard and where you can get more information.
How GMAs Set Goals
GMA-14 comprises most of southeast Texas. See map below. It includes five groundwater conservation districts and two subsidence districts and four counties that have neither.
One purpose of a GMA is to bind the people of a region together to meet common goals. Significantly, if one county wants to abandon surface water and pump unlimited amounts of cheaper groundwater, it must first get permission from the other members of the GMA. That’s because pumping groundwater has consequences. It can cause neighboring wells to go dry, leaving rural ranchers without options.
It can also cause subsidence, in which one area sinks relative to surrounding areas. That can alter the gradient of rivers, causing water to move slower and back up more. Subsidence can also trigger geologic fault movement, disrupt pipelines, damage homes, and crack pavement.
Because of subsidence, some areas near the coast have actually sunk beneath the waves. Others farther inland have created giant bowls in the landscape that contribute to flooding.
In setting goals, GMAs also consider factors such as economic development and population growth. They typically plan 50 years or more ahead to ensure adequate water supplies.
Proposed Desired Future Conditions for GMA-14
GMA-14 has debated its next set of desired future conditions (DFCs) since 2016. At its last meeting, members finally adopted the following statement.
Click here for the full text surrounding the DFCs.
Let’s break that down:
Lone Star GCD Tries to Break Away
LSGCD has used a variety of arguments to fight the subsidence metric in DFCs. All failed to convince other GMA-14 members. Now LSGCD claims it will reach the drawdown limit before it reaches the subsidence limit, so subsidence should not be included in the limits.
At the last MoCo Commissioners Court Meeting, the LSGCD board chair made pled with commissioners to support omitting subsidence as a metric, even though, he claims, it would never limit pumping.
Many observers have repeatedly commented on this position. “If it’s not a limiting factor, why fight it so hard?” they ask. LSGCD keeps repeating the argument without offering a satisfactory answer or showing proof. That raises even more suspicions. It’s like when your kid comes home and brags how well (s)he did in one class and refuses to discuss grades in others.
Pros and Cons
Surface water costs more than groundwater for several reasons. In this part of the world, surface water must be trapped in man-made lakes, treated extensively, and then shipped to users via canals or a pipeline network. In contrast, wells can be drilled near users on very little land.
But if everyone used well-water exclusively, aquifers would deplete rapidly, wells would run dry, and subsidence would kick in.
USGS describes subsidence as an issue in 45 states, chief among them Texas, California and Florida.
Aquifers can eventually recharge if you leave them alone long enough. But subsidence is forever. It occurs when “clay lenses” get smashed due to dehydration. Rehydrating them is impossible. One water professional used this analogy: Imagine smashing a brownie and then pouring water on it. It won’t return to its original state.
Also consider that the proposed subsidence limit is an average. In its sparsely populated northern reaches in the Sam Houston National Forest, MoCo has little water demand. However, in southern MoCo is growing by leaps and bounds.
Subsidence has already proven to be an issue there. It has triggered faults and cracked home slabs. Many feel they are now more susceptible to flooding because their homes sit in bowls between faults.
Critics of LSGCD’s move to eliminate a subsidence metric point out that without it, groundwater pumpers could exceed the drawdown limit and simply claim that aquifers would magically recharge in the last few years of the plan.
Some neighborhoods in The Woodlands ALREADY SUBSIDED BY ALMOST A HALF FOOT BETWEEN 2009 and 2019. And four of those years followed a conversion to surface water that reduced the rate of subsidence 75%. So it’s real.
Modeling also shows that Kingwood and Humble could subside 3 feet because of excessive groundwater pumping in MoCo while the Lake Houston Dam subsides only one foot. That could raise water floodwaters at the top of Lake Houston another 2 feet relative to the spillway at the dam.
What Happens Is Up to You
Some people may prefer cheap water today and not care about the future or downstream neighbors.
People downstream from Montgomery County in Harris and Galveston Counties have already seen the damage subsidence can cause. They have decided collectively to move to more surface water. And they have invested heavily to bring more of it to the area and treat it – with the Luce Bayou Interbasin Transfer Project and the City of Houston’s new Northeast Water Purification Plant.
The irony is that SJRA already built a surface water treatment plant, which some now advocate abandoning.
What’s more important to you? Short- or long-term savings? Leveling a foundation; repaving your driveway; repairing cracked walls and ceilings; and recovering from a flood cost far more than a few dollars a month on your water bill.
How To Register Your Concerns
Submit comments to LSGCD by:
Email: info@lonestargcd.org with the subject line “DFC Comments” no later than 11:59 p.m. on Jul. 19, 2021.
In Person: 2PM AT THE LONE STAR GCD OFFICE IN THE JAMES B. “JIM” WESLEY BOARD ROOM, 655 CONROE PARK NORTH DRIVE, CONROE, TEXAS 77303.
Via Webinar: Register at https://us02web.zoom.us/webinar/register/WN_VnPqSCCnSFGfHMQDZ6pd_Q. After registering, you will receive a confirmation email containing information about joining the webinar. You can pre-register for the webinar at any time.
If you pre-register via the URL meeting link above, a password will be emailed to you in advance of the webinar. If you use the password to log, you WILL have the opportunity to provide live comments during the meeting. Use Webinar ID: 861 0914 6147 Password: Received via pre-registration.
To see a live broadcast, but not comment: https://lonestargcd.new.swagit.com/views/58.
For More Information
A group of informed and concerned MoCo residents have started a website called StopOurSinking.com. Click on their Learn More Page for videos, FAQs, presentations, and news stories. And don’t miss, the legal page “Does a groundwater pumper have the right to cause sinking?”
You can also find several articles on this website. The easiest way to find them is by going to the index page and searching for GMA-14, Groundwater Management Area 14, Lone Star Groundwater Conservation District, LSGCD, or subsidence.
Posted by Bob Rehak on 6/6/2021
1377 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.