Many floodplain regulations focus on not restricting the conveyance of rivers. But the high dikes of many sand mines literally wall off half their floodplains. This can increase the frequency, duration, and severity of flooding opposite the mines as well as erosion of river banks.
According to the computer models of engineers, that raises the height of floods on Shelbelbon’s property 3-4 feet above what they would otherwise be – especially in less than 100-year floods – when water can’t spread out on both sides of the river.
All that extra water concentrated in a smaller space also increases the velocity of flood waters and erosion. Shebelbon says he has lost 7 acres since the mines built their walls.
Schematic Diagrams Illustrate Principle
In principle, it looks like the series of diagrams below.
#1.Floodplains naturally spread out on both sides of river.#2. In a minor flood, water spreads out in both directions.#3. But after a mine walls off the floodplain, water can spread out in only one direction, raising the height of floods on the other side.#4. The extra volume of floodwater now forced into a smaller space increases the velocity of floodwater. That, in turn, increases erosion, too.
The last point may be the hardest to understand. Here’s an imperfect analogy that helps to illustrate it. Most of us have put our thumbs over nozzles of garden hoses to spray dirt off driveways. Decreasing the width of the opening forces water to go faster after it leaves the hose. That peels dirt off the driveway faster. While a hose is a closed system and a river is open, the increased velocity increases erosion regardless.
Photos Vividly Illustrate Danger
This first photo shows the height of the sand mine dike north of Shelbelbon’s property.
Looking NE from over West Fork San Jacinto. That white line in the background is I-45. Note how dikes are half the height of mature trees.Looking NW over part of Shebelbon’s motorsports complex towards mine. Note how Shebelbon’s property is at river level, but dikes around mines wall-off floodway.Looking West from over Shebelbon’s property at river level. Compare height of dikes on right.Looking ENE toward I-45 from over Shebelbon’s property, which is at river level. Note height of dikes on opposite shore.Shebelbon has lost 7 acres since the mines built their dikes.
The same problem exists on the San Jacinto East Fork.
Texas Concrete’s dike on left towers above homes on right. San Jacinto East Fork runs between them.
Perpetual Unintended Consequences
The dikes of these mines are intended to control stormwater within the mine and prevent the escape of sediment. Unfortunately for the people near them, they can have unintended side effects. And those side effects can impact neighbors long after miners abandon mines.
Texas regulations do not require restoring the natural contours of a floodplain when mines are done mining. So miners typically leave dikes in place…along with debris they’d rather not clean up.
Looking SW toward Shebelbon property from over I-45 across abandoned mine (bottom left). Google Earth shows activity on this site before Harvey but not after.
The Montgomery County Appraisal District (MCAD) values the 31-acre abandoned mine at $15,570 despite the fact that it’s right next to I-45 in the fast growing corridor between The Woodlands and Conroe.
A company named 45 SRL INC owns this property. The Texas Secretary of State shows that Williams Brothers Construction Company Inc. owns 100% of 45 SRL INC.
Reclamation of this site would cost far more than the value of the land which likely explains why:
The property has been abandoned without reclamation for more than 3 years
Why we need performance bonds to ensure the reclamation of mines
Why Shebelbon will continue to flood in minor events.
If it can happen to a man with a thriving business, it can happen to you, too.
Posted by Bob Rehak on 12/19/2020
1208 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.
Last year, New York State produced a series of model local laws to increase resilience. The 468-page document is a catalog of ideas for cities and counties to choose from. It covers everything from building in flood-prone areas to maximum lot coverage, land-clearing practices for new developments, stormwater controls, zoning, building elevation and more.
For those who can get past the not-invented-here syndrome, it could provide a valuable resource. As I read it, I found dozens of ideas that could reduce flooding in Houston.
Will New York Approaches Fly in Houston?
While some of the concepts, such as zoning, may seem radical to Houstonians, others have actually already been adopted by Houston. For instance, one of the suggestions was to record the extent of flood-plains on plats, a project the Houston Planning Commission recently adopted. Another is to require elevation of homes that flood repetitively to avoid substantial damage in the future. Houston adopted that one, too, after Harvey.
Another recommendation: prohibit land clearing by developers until AFTER plats are approved. This could likely have helped prevent a lot of flooding on the San Jacinto East Fork where Colony Ridge cleared thousands of acres before even getting plats approved.
The real target for this document is local government officials interested in addressing resiliency issues in their municipal codes. However, the discussions around each proposal also provide interesting background for flood advocates who are lobbying their elected officials.
Best Practices Codified into Local Regulations
The ideas provide of menu of what has worked elsewhere and why.
For greater resiliency, it is a wise best management practice, claim the authors, to ensure that developers design subdivision layouts in a manner that:
Minimizes land disturbance (tree clearing, land grading, soil compaction);
Avoids steep slopes, flood-prone areas and wetlands;
Protects important natural areas and habitats; Limits impervious surfaces;
Does not negatively impact public infrastructure;
Does not overload the roadway system, and
Provides effective stormwater control.
Other Major Areas of Focus
Other major sections deal with protection alternatives for:
The ideas presented here do not represent a complete program that must be adopted from start to finish. They are more like an à la carte menu. Take a little of this. A little of that. Whatever you need. Wherever you need it.
Once local officials identify ideas they could use, the document even provides templates for the wording of resolutions.
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/2020/12/20201207-Aerial-Dec-2020_836.jpg?fit=1200%2C800&ssl=18001200adminadmin2020-12-18 15:32:152020-12-18 15:36:14Model Local Laws to Increase Resilience
The Liberty County Hazard Mitigation Plan contains no mention of Colony Ridge, the largest and most vulnerable community in the entire county. Like Liberty County’s Strategic Plan, this is another example of shoot-yourself-in-the-foot planning. It, too, has Grand-Canyon-sized disconnects between intention and execution that could jeopardize thousands of lives.
Overlooked or Ignored?
Liberty County last updated its Hazard Mitigation Plan in 2017. Yet it contains no specific mention of Colony Ridge, a 12-13,000 acre development. At buildout, Colony Ridge projects it will cover 22,000 acres. By comparison, Kingwood occupies 14,000 acres.
The former Mayor of Plum Grove estimates more than 20,000 people currently call Colony Ridge home. Exact counts are difficult since many people are undocumented. But if the Mayor was correct, it would make Colony Ridge two timeslarger than the largest cities in the county. Plus…
Colony Ridge has extreme vulnerabilities caused by sub-standard drainage; poverty; language barriers; lack of street lighting and fire hydrants; poor electrical and communications infrastructure; a high percentage of mobil and self-built homes; poor access through flood-prone roads; and leaky sewage systems.
Such risk factors make residents especially vulnerable to floods, hurricanes, wildfires, tornadoes, and extreme temperatures. Moreover, poverty makes it harder for people to recover from such disasters.
Yet the plan does not contain one recommendation to address this high concentration of vulnerabilities in Colony Ridge. Even though the plan addresses vulnerabilities in much smaller areas, “the largest vulnerable population in the county” receives only one mention. That was as an unnamed area near Plum Grove. Plum Grove has a population of approximately 400-500 people compared to Colony Ridge’s 20,000.
It’s as though the people who live in Colony Ridge are invisible. For instance, the plan addresses two mobile homes in Dayton Lakes, but not the thousands in Colony Ridge.
Purpose of Plan
The purpose of Liberty County’s Hazard Mitigation Plan is to “reduce the loss of life and property within the county and lessen the negative impacts of natural disasters.” The plan addresses specific vulnerabilities in a dozen communities, but never the largest.
Educational Programs Targeted to Government Officials
This section starts with the need to develop and implement educational programs for residents and government officials, that address, among other things, the need to improve existing local ordinances. That was a familiar theme from the Liberty County Strategic Plan (which also failed to mention Colony Ridge). The idea: better building codes can enhance survivability of structures during threats such as tornadoes, fires, hurricanes and floods.
But that idea hasn’t yet filtered down to Colony Ridge where the developer caters to a do-your-own-thing, follow-your-American-dream, build-it-yourself-on-weekends crowd. The results are predictably creative and eclectic. See below.
Colony Ridge D-I-Y housing. Photo taken 12/7/2020.Typical neighborhood in Colony Ridge. Photo taken 12/7/2020.Note how cream-colored home (bottom left) has apparently fallen off its base.
Public/Private Collaboration to Minimize Hazards
A similar objective to the one above: Foster collaboration between public and private partners throughout the county to create and implement local ordinances and county-level programs that minimize hazards. Here are several common problems:
No evacuation routes marked.
No traffic-control signals along what would be evacuation routes.
Unlit streets at night
People walk on streets because there are no sidewalks.
Only a handful of fire hydrants in 13,000 acres where residents commonly start brush fires and overwhelm the volunteer Plum Grove fire department.
No school-zone warning lights or signs
No grocery stores for emergency supplies.
Missing street signs make emergency response difficult in many areas.
On a special note, as of 9PM tonight, the temperature has dropped into the 30s and reports of widespread power outages are pouring in from Colony Ridge due to poor electrical infrastructure that has not kept pace with the area’s growth.
Improve Drainage to Reduce Flooding and Erosion
Another goal: improve drainage throughout the county to reduce the impact of flooding and erosion on residents and structures.
FM1010 at Rocky Branchhas gone un-repaired for the 3.5 years since Harvey. This road would be the major evacuation route for 20,000.
The Mitigation Plan was developed after Harvey and adopted by Liberty County Commissioner’s Court on October 9, 2018. But the Plan makes no mention of the repairing the washout above.
Create Drainage Ponds Throughout County
The plan calls for widening existing culverts and creating drainage ponds throughout the county. Yet for the entire 13,000 acres, Colony Ridge apparently has one functioning detention pond. A second pond seems to have largely silted in.
One of the few, if not the only functioning detention ponds in Colony Ridge. This is in Sante Fe Section 3 in the extreme southwestern corner of the development.Colony Ridge engineers claim such ponds would make flooding worse. See below.
Beat-The-Peak Analysis Applied to 22,000 Acres
LandPlan Engineering’s Hydraulic Analysis from March 2020 concludes on page 8 that “…detention would increase the overall peak release from [Sante Fe] Section 6 as well as those portions of upcoming Sections 7 and 8 discharging to the Luce Bayou.”
It’s hard to understand how detention ponds would increase the peak flow. The conclusion refers readers to two graphs in Appendix D. But neither mentions anything about detention assumptions such as volume or rate of release. This is yet another “beat the peak” claim which Liberty County Drainage Regulations don’t explicitly bar.
So the Hazard Mitigation Plan encourages detention ponds and the drainage regulations give developers financial incentives NOT to build them. Again, the Grand-Canyon-sized gap between intentions and execution.
As we have seen in Montgomery County, beat-the-peak claims don’t consider changes to upstream or downstream conditions. They rely on infrequently updated data that becomes increasingly out of date with the development of each new subdivision. And they encourage all developers to get their water to rivers ASAP in heavy rains, which is exactly the opposite of what you want people to do in floods.
Posted by Bob Rehak on 12/16/2020
1205 Days since Hurricane Harvey and 454 since Imelda
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/2020/10/20201025-DJI_0919.jpg?fit=1200%2C900&ssl=19001200adminadmin2020-12-16 21:09:122020-12-16 21:46:46Liberty County Hazard Mitigation Plan Contains No Mention of Largest, Most Vulnerable Community in County
Reducing Floodplain Width Increases Flooding, Erosion
Many floodplain regulations focus on not restricting the conveyance of rivers. But the high dikes of many sand mines literally wall off half their floodplains. This can increase the frequency, duration, and severity of flooding opposite the mines as well as erosion of river banks.
West Fork Mines at I-45 Provide Example
The case of Emil Shelbebon who operates a 200-acre motorsports complex on the south bank of the San Jacinto West Fork at I-45 provides an excellent example. Sand mines on the north side of the West Fork built high walls near the river bank. LIDAR surveys taken before and after construction of the dikes suggest the dikes may be higher than 20 feet in places. That’s the height of a 2-story building.
According to the computer models of engineers, that raises the height of floods on Shelbelbon’s property 3-4 feet above what they would otherwise be – especially in less than 100-year floods – when water can’t spread out on both sides of the river.
All that extra water concentrated in a smaller space also increases the velocity of flood waters and erosion. Shebelbon says he has lost 7 acres since the mines built their walls.
Schematic Diagrams Illustrate Principle
In principle, it looks like the series of diagrams below.
The last point may be the hardest to understand. Here’s an imperfect analogy that helps to illustrate it. Most of us have put our thumbs over nozzles of garden hoses to spray dirt off driveways. Decreasing the width of the opening forces water to go faster after it leaves the hose. That peels dirt off the driveway faster. While a hose is a closed system and a river is open, the increased velocity increases erosion regardless.
Photos Vividly Illustrate Danger
This first photo shows the height of the sand mine dike north of Shelbelbon’s property.
The same problem exists on the San Jacinto East Fork.
Perpetual Unintended Consequences
The dikes of these mines are intended to control stormwater within the mine and prevent the escape of sediment. Unfortunately for the people near them, they can have unintended side effects. And those side effects can impact neighbors long after miners abandon mines.
Texas regulations do not require restoring the natural contours of a floodplain when mines are done mining. So miners typically leave dikes in place…along with debris they’d rather not clean up.
The Montgomery County Appraisal District (MCAD) values the 31-acre abandoned mine at $15,570 despite the fact that it’s right next to I-45 in the fast growing corridor between The Woodlands and Conroe.
A company named 45 SRL INC owns this property. The Texas Secretary of State shows that Williams Brothers Construction Company Inc. owns 100% of 45 SRL INC.
Williams Brothers is the largest highway contractor in Texas, one of the largest in the country, and claims to have completed more than $12 billion in projects. The company says it does 95% of its work for TxDOT.
Reclamation of this site would cost far more than the value of the land which likely explains why:
If it can happen to a man with a thriving business, it can happen to you, too.
Posted by Bob Rehak on 12/19/2020
1208 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.
Model Local Laws to Increase Resilience
Last year, New York State produced a series of model local laws to increase resilience. The 468-page document is a catalog of ideas for cities and counties to choose from. It covers everything from building in flood-prone areas to maximum lot coverage, land-clearing practices for new developments, stormwater controls, zoning, building elevation and more.
For those who can get past the not-invented-here syndrome, it could provide a valuable resource. As I read it, I found dozens of ideas that could reduce flooding in Houston.
Will New York Approaches Fly in Houston?
While some of the concepts, such as zoning, may seem radical to Houstonians, others have actually already been adopted by Houston. For instance, one of the suggestions was to record the extent of flood-plains on plats, a project the Houston Planning Commission recently adopted. Another is to require elevation of homes that flood repetitively to avoid substantial damage in the future. Houston adopted that one, too, after Harvey.
Another recommendation: prohibit land clearing by developers until AFTER plats are approved. This could likely have helped prevent a lot of flooding on the San Jacinto East Fork where Colony Ridge cleared thousands of acres before even getting plats approved.
Best Practices Codified into Local Regulations
The ideas provide of menu of what has worked elsewhere and why.
For greater resiliency, it is a wise best management practice, claim the authors, to ensure that developers design subdivision layouts in a manner that:
Other Major Areas of Focus
Other major sections deal with protection alternatives for:
It’s interesting how some municipalities in New York applied the concept of performance bonds (see Chapter 5) to reduce erosion coming from new developments. I wonder if that could be adapted to sand mines on the San Jacinto?
A’ La Carte Menu
The ideas presented here do not represent a complete program that must be adopted from start to finish. They are more like an à la carte menu. Take a little of this. A little of that. Whatever you need. Wherever you need it.
Once local officials identify ideas they could use, the document even provides templates for the wording of resolutions.
For the complete text of Model Local Laws to Increase Resilience, click here.
Posted by Bob Rehak on 12/18/2020
1207 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.
Liberty County Hazard Mitigation Plan Contains No Mention of Largest, Most Vulnerable Community in County
The Liberty County Hazard Mitigation Plan contains no mention of Colony Ridge, the largest and most vulnerable community in the entire county. Like Liberty County’s Strategic Plan, this is another example of shoot-yourself-in-the-foot planning. It, too, has Grand-Canyon-sized disconnects between intention and execution that could jeopardize thousands of lives.
Overlooked or Ignored?
Liberty County last updated its Hazard Mitigation Plan in 2017. Yet it contains no specific mention of Colony Ridge, a 12-13,000 acre development. At buildout, Colony Ridge projects it will cover 22,000 acres. By comparison, Kingwood occupies 14,000 acres.
The former Mayor of Plum Grove estimates more than 20,000 people currently call Colony Ridge home. Exact counts are difficult since many people are undocumented. But if the Mayor was correct, it would make Colony Ridge two times larger than the largest cities in the county. Plus…
Such risk factors make residents especially vulnerable to floods, hurricanes, wildfires, tornadoes, and extreme temperatures. Moreover, poverty makes it harder for people to recover from such disasters.
Yet the plan does not contain one recommendation to address this high concentration of vulnerabilities in Colony Ridge. Even though the plan addresses vulnerabilities in much smaller areas, “the largest vulnerable population in the county” receives only one mention. That was as an unnamed area near Plum Grove. Plum Grove has a population of approximately 400-500 people compared to Colony Ridge’s 20,000.
Purpose of Plan
The purpose of Liberty County’s Hazard Mitigation Plan is to “reduce the loss of life and property within the county and lessen the negative impacts of natural disasters.” The plan addresses specific vulnerabilities in a dozen communities, but never the largest.
Part 7, which starts on Page 132, outlines several plan objectives.
Educational Programs Targeted to Government Officials
This section starts with the need to develop and implement educational programs for residents and government officials, that address, among other things, the need to improve existing local ordinances. That was a familiar theme from the Liberty County Strategic Plan (which also failed to mention Colony Ridge). The idea: better building codes can enhance survivability of structures during threats such as tornadoes, fires, hurricanes and floods.
But that idea hasn’t yet filtered down to Colony Ridge where the developer caters to a do-your-own-thing, follow-your-American-dream, build-it-yourself-on-weekends crowd. The results are predictably creative and eclectic. See below.
Public/Private Collaboration to Minimize Hazards
A similar objective to the one above: Foster collaboration between public and private partners throughout the county to create and implement local ordinances and county-level programs that minimize hazards. Here are several common problems:
On a special note, as of 9PM tonight, the temperature has dropped into the 30s and reports of widespread power outages are pouring in from Colony Ridge due to poor electrical infrastructure that has not kept pace with the area’s growth.
Improve Drainage to Reduce Flooding and Erosion
Another goal: improve drainage throughout the county to reduce the impact of flooding and erosion on residents and structures.
Create Drainage Ponds Throughout County
The plan calls for widening existing culverts and creating drainage ponds throughout the county. Yet for the entire 13,000 acres, Colony Ridge apparently has one functioning detention pond. A second pond seems to have largely silted in.
Beat-The-Peak Analysis Applied to 22,000 Acres
LandPlan Engineering’s Hydraulic Analysis from March 2020 concludes on page 8 that “…detention would increase the overall peak release from [Sante Fe] Section 6 as well as those portions of upcoming Sections 7 and 8 discharging to the Luce Bayou.”
It’s hard to understand how detention ponds would increase the peak flow. The conclusion refers readers to two graphs in Appendix D. But neither mentions anything about detention assumptions such as volume or rate of release. This is yet another “beat the peak” claim which Liberty County Drainage Regulations don’t explicitly bar.
As we have seen in Montgomery County, beat-the-peak claims don’t consider changes to upstream or downstream conditions. They rely on infrequently updated data that becomes increasingly out of date with the development of each new subdivision. And they encourage all developers to get their water to rivers ASAP in heavy rains, which is exactly the opposite of what you want people to do in floods.
Posted by Bob Rehak on 12/16/2020
1205 Days since Hurricane Harvey and 454 since Imelda
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.