In the rush to mitigate flooding after Hurricane Harvey, most people agreed that we should attack the areas with the worst flooding first. While almost everyone agreed with the “worst first” mantra, no one defined it – until after the flood bond passed.
Alternative Ways to Define “Worst First”
How would you define the “worst” flooding? The area with the:
Most flooded homes?
Most frequent flooding?
Most damage in dollar terms?
Largest population living in a 100-year floodplain?
Most low-to-moderate income residents who can least afford to fix their homes?
Largest minority populations?
Highest Social Vulnerability Index (SVI)?
Most damage to infrastructure (bridges, hospitals, grocery stores, schools, sewage treatment plants, etc.)?
Highest water above the tops of banks in a widespread storm like Harvey?
You could make valid arguments for each. And people have – almost from the day the flood bond passed – as they fought for more funding for their watersheds.
Yesterday, as I reviewed a doctoral thesis from a student at the Colorado School of Mines, I saw a graph that compared the height of the Harvey flood at the San Jacinto West Fork and US59 to other rivers/streams in the region. The West Fork flood towered above the others. So it made me wonder. How did the flood at that location compare to other streams and bayous in Harris County?
Click on the “For more information” link in the pop-up box.
On the new page (dedicated to historical information about that gage), click on the stream elevation tab.
Note the “flooding likely” elevation. This roughly coincides with the top of bank, though banks can vary slightly.
Scroll down to the bottom of the page and note the elevation of the flood at that location during Hurricane Harvey.
Subtract the “flooding likely” level from the Harvey level, to determine the feet above flood stage in Harvey.
Click on the drop-down box with the gage information to compare the same stats for additional gages.
North Harris County Had Highest Floods
This morning, I compiled the data for 33 gages. The chart below shows what I found. Of the gages I sampled, the four highest floods all occurred in the upper San Jacinto River Basin: West Fork at 59, Spring Creek at 45, Cypress Creek at Cypresswood, and West Fork at 99. Also note the preponderance of high water along Greens Bayou at numerous locations.
“Feet above Flood Stage” by itself won’t tell you which area had the worst flooding during Harvey. It’s just one measure. You must consider other factors, too, such as those listed above.
One must also acknowledge the role that topography plays in a chart, such as this. A narrow floodplain with steep banks can force water higher. A wider floodplain through a flat area allows water to spread out, lowering the height of floodwaters.
Variations in rainfall across an area can also skew results.
And finally, I didn’t click on every gage in the region. There are hundreds. You wouldn’t have been able to read the chart because the type would have been so small. So investigate on your own and let me know what you find.
Need for Active Discussion/Debate in Upcoming Elections
The Harris County Community Flood Resilience Task Force just voted to change the way “worst first” is calculated – again! The highest correlation between funding and all of the other factors I have evaluated is now with low-to-moderate-income population. It’s not with damaged structures, dollar damage, watershed size, or population density.
If you want to ensure that outlying areas get their fair share of flood mitigation dollars in the future, you need to demand them when you go to the polls this fall.
Posted by Bob Rehak on 3/29/2022
1673 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.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/03/Feet-Above-Flood-Stage-in-Harvey-e1699502224912.png?fit=1100%2C729&ssl=17291100adminadmin2022-03-29 15:57:372022-03-30 10:13:01How Do You Define “Worst First”?
Since my last post on the Laurel Springs RV Resort, contractors have erected approximately 2000 feet of chain link fence, much of it within feet of Laurel Springs Lane. Exxon Land Development Commercial Development Guidelines generally prohibited chain link fencing except in rare instances where the fence was “not visible from the street or adjacent property.” See Section II-9-3 Screen Walls and Fencing and the pictures below.
Chain link fence along Laurel Springs Lane. Looking north. Photo taken 2/26.
Chain link fence between Edgewater Park and RV Park.
Because Exxon never owned this property, it was not subject to the deed restrictions that apply to Kingwood. So I’m not alleging anything illegal. However, the developer has disregarded community norms. Those deed restrictions give the Kingwood Area its distinctive character. Disregarding them has not endeared the developer to neighbors.
Other “Improvements”
The developer also made several other “improvements” in the last few days. He has:
Removed more trees
Brought in more dirt to raise the property even higher above Lakewood Cove
Approximately doubled the area covered by concrete
Finally erected a silt fence on the west side by the utility corridor, five months into construction
Hydroseeded the south bank of the detention pond and northern part of Edgewater Park where they cut down trees…after severe erosion caused Harris County to threaten a lawsuit.
However, there still appears to be no effort to replant the trees they cut in Edgewater Park. Nor have they placed permanent pumps to drain the retention pond; they’re still attempting to do that with portable pumps.
Photos Taken 3/28/2022
Here’s how the site looked tonight.
The amount of concrete virtually doubled. They poured the dark gray area in the foreground last Saturday.A swimming pool will go between the concrete and the building under construction.
More downed trees litter the northern part of the property. Trucks have been bringing in more dirt to fill in low spots which became apparent after last week’s 2″ rain.
Looking E toward Lakewood Cove and Laurel Springs Laneas crews finish spraying for the day.
The hydroseeding crews were pulling silty water from the detention pond to mix with their material, even as portable pumps attempt to drain the pond before the next rainarrives tomorrow night.
More about Hydroseeding
Contractors use hydroseeding to stabilize slopes and accelerate the germination of grass which can reduce erosion. Water, seed, and nutrients are mixed into a gelatinous material and sprayed onto the ground. The gelatin adheres to slopes and retains just enough moisture to help the seed take root. We should see grass start to grow within 5-10 days. Crews add colored dye to the mix to make it easier to see. That helps them spray it evenly.
Thankfully, at least the chain link fence does not have razor wire on top of it. Regardless, it has all the charm of the prison in Huntsville.
While you review the Commercial Development Guidelines on fencing, scan the rest of the guidelines, too. Especially the ones that talk about setbacks, construction fencing, parking, tree preservation and more. They will give you a greater appreciation for the care taken by thousands who came before the Laurel Springs RV Resort.
Posted by Bob Rehak on 3/28/2022
1672 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.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/03/20220326-RJR_9317.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-03-28 22:38:492022-03-31 12:11:25Chain Link Fencing at Laurel Springs RV Resort Would Not Meet Exxon Land Development Commercial Guidelines
The San Jacinto River Authority (SJRA) recently completed a 246-page conceptual design study, in partnership with the Harris County Flood Control District, that explored the feasibility of implementing sediment trapping facilities (“sand traps”). The purpose: to remove sediment from the West or East Fork of the San Jacinto River. The results and findings of this study have been documented in an engineering report entitled “San Jacinto River and Tributaries Sediment Removal and Sand Trap Development.”
Prior to proceeding to preliminary engineering design and any subsequent project phases, SJRA is seeking public input on the proposed project alternatives detailed in the report. The full report, as well as a brief summary document, are located on SJRA’s Flood Management Division website.
Caution: The full study is dated 1/7/22. But the “brief summary” is dated 3/9/22. Make sure you at least read the executive study of the full report as well as the brief summary. There are important differences.
Overview/Purpose
SJRA says the purpose of the sediment trap study was to assess the feasibility of implementing a pilot project to trap and remove sediment from the West OR East Fork of the San Jacinto. The study only assessed locations where one or more Aggregate Production Operations (APOs) could partner with the the SJRA. They restricted the study this way to reduce costs; the SJRA does not have a source of funding to clean out sand traps and would rely on sand miners.
Initial Concerns
The decisions to:
Define the study objective as sediment reduction, not damage reduction and…
Only consider locations near sand mines…
…give me mixed emotions about this project.
Pros
On one hand, I look at this and say, “It’s a pilot project. Try it and see if there’s a benefit.” Sediment IS a problem and they believe they can remove up to 100% of the annual sediment load (from the West Fork).
Cons
On the other hand, the study authors, Freese & Nichols (F&N) claimed (in the San Jacinto River Basin Master Drainage Study) that of all the sediment coming into Lake Houston, two thirds comes from Spring and Cypress Creeks while only 13% comes from the West Fork upstream of US59.
Perhaps that’s because they’re using model inputs from a sediment gage at I-45 located 8.5 miles upstream from most of the large West Fork sand mines (page 34, paragraph 3 of full study).
The “Mouth Bar,” a giant sand bar that blocked the West Fork of the San Jacinto, backing the river up into Kingwood and Humble. Thousands of homes and businesses flooded behind this blockage. The above-water portion has since been removed, but most of the underwater portion remains.
In the entire 246-page F&N study and the three-page summary, the word “damage” occurs only once…in relation to erosion damage, NOT flood damage.
It appears that F&N did not even look at creating sand traps where they were most needed, in the headwaters of Lake Houston, because of cost and logistical considerations. Yet the Army Corps, City of Houston, and State of Texas are spending $200 million to dredge that area. One wonders whether SJRA should have looked harder for partners to clean out the traps.
Finally, if sediment traps only work financially near sand mines, the “solution” will not work on other tributaries that F&N alleges contribute 5X more sediment than the West Fork. They just don’t have the sand mines that the West Fork has.
Nature of Proposed Solution
Five years after Harvey, we have a conceptual design and a recommended location: rock-lined channels cut through one or two point bars at the West Fork Hallett mine.
The shot below shows the same area in real life. To put the magnitude of the proposed solution into perspective, the solution would cover a little more than an acre. But sand mines like Hallett cover 20 square miles on the banks of the West Fork between US59 and I-45.
2021 photo of sand bar outsde Hallett mine that would have a narrow channel cut through it to trap sand.
My Biggest Fears
My biggest fears with the proposed pilot study are that it:
Asks people to chose from a limited menu.
Could divert attention from better solutions that would reduce flood risk faster in the headwaters of Lake Houston.
Might make the public think the problem is solved.
Could open the door to river mining and further destabilize the riverine environment.
Is not a transferrable solution.
For a pilot study, that last point is troubling.
Also, F&N worries that removing too much sediment from the West Fork could create a “hungry-water” effect that increases erosion downstream. But they have no way of directly measuring how much sediment the West Fork transports. Or what percentage they would remove. That’s because they’re relying on a sediment gage upstream from the sand mines. This introduces an element of risk in the pilot study.
Recommendations Should Be Based on a Holistic Examination of Alternatives
Note lack of vegetation on this steep-sided, eroding bank of Hallett mine on West Fork in foreground.
Before moving forward with the pilot study, I suggest a more holistic examination of additional alternatives that might have a greater impact on reducing flood damage, not just sedimentation. Examples include, but are not limited to:
More on the sand trap proposal in coming days. In the meantime, please review the SJRA’s sediment trap proposal and forward your comments to the SJRA. I will also print thoughtful letters, both pro and con, from responsible parties. Send them to: https://reduceflooding.com/contact-us/.
Posted by Bob Rehak on March 27, 2022
1671 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.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/03/20210303-RJR_5381.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-03-27 21:14:502022-03-28 01:10:10SJRA Seeks Public Input on Sediment Trap Proposal
How Do You Define “Worst First”?
In the rush to mitigate flooding after Hurricane Harvey, most people agreed that we should attack the areas with the worst flooding first. While almost everyone agreed with the “worst first” mantra, no one defined it – until after the flood bond passed.
Alternative Ways to Define “Worst First”
How would you define the “worst” flooding? The area with the:
You could make valid arguments for each. And people have – almost from the day the flood bond passed – as they fought for more funding for their watersheds.
Least Considered Alternative
But the one I have heard talked about the least is the last one: highest water above tops of banks. Surely, the depth of a flood must count for something. It affects the ability to evacuate and rescue people. It puts lives at risk. Can destroy infrastructure. Spread sewage. Increase erosion. Even cause rivers to migrate. And sweep whole apartment buildings into rivers.
Yesterday, as I reviewed a doctoral thesis from a student at the Colorado School of Mines, I saw a graph that compared the height of the Harvey flood at the San Jacinto West Fork and US59 to other rivers/streams in the region. The West Fork flood towered above the others. So it made me wonder. How did the flood at that location compare to other streams and bayous in Harris County?
How to Determine “Feet Above Flood Stage”
There’s an easy way to find out. The Harris County Flood Warning System contains all the pertinent information.
North Harris County Had Highest Floods
This morning, I compiled the data for 33 gages. The chart below shows what I found. Of the gages I sampled, the four highest floods all occurred in the upper San Jacinto River Basin: West Fork at 59, Spring Creek at 45, Cypress Creek at Cypresswood, and West Fork at 99. Also note the preponderance of high water along Greens Bayou at numerous locations.
Limitations of Measure
“Feet above Flood Stage” by itself won’t tell you which area had the worst flooding during Harvey. It’s just one measure. You must consider other factors, too, such as those listed above.
But this chart sure makes it hard to ignore the fact that something is happening in north Harris County to exacerbate flooding. I’ve chronicled many of those things in the pages of this website: sand mining, development, rapid growth, impervious cover, loss of wetlands, lack of detention ponds, lax regulation/enforcement and more.
One must also acknowledge the role that topography plays in a chart, such as this. A narrow floodplain with steep banks can force water higher. A wider floodplain through a flat area allows water to spread out, lowering the height of floodwaters.
Variations in rainfall across an area can also skew results.
And finally, I didn’t click on every gage in the region. There are hundreds. You wouldn’t have been able to read the chart because the type would have been so small. So investigate on your own and let me know what you find.
Need for Active Discussion/Debate in Upcoming Elections
The Harris County Community Flood Resilience Task Force just voted to change the way “worst first” is calculated – again! The highest correlation between funding and all of the other factors I have evaluated is now with low-to-moderate-income population. It’s not with damaged structures, dollar damage, watershed size, or population density.
If you want to ensure that outlying areas get their fair share of flood mitigation dollars in the future, you need to demand them when you go to the polls this fall.
Posted by Bob Rehak on 3/29/2022
1673 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.
Chain Link Fencing at Laurel Springs RV Resort Would Not Meet Exxon Land Development Commercial Guidelines
Since my last post on the Laurel Springs RV Resort, contractors have erected approximately 2000 feet of chain link fence, much of it within feet of Laurel Springs Lane. Exxon Land Development Commercial Development Guidelines generally prohibited chain link fencing except in rare instances where the fence was “not visible from the street or adjacent property.” See Section II-9-3 Screen Walls and Fencing and the pictures below.
Because Exxon never owned this property, it was not subject to the deed restrictions that apply to Kingwood. So I’m not alleging anything illegal. However, the developer has disregarded community norms. Those deed restrictions give the Kingwood Area its distinctive character. Disregarding them has not endeared the developer to neighbors.
Other “Improvements”
The developer also made several other “improvements” in the last few days. He has:
However, there still appears to be no effort to replant the trees they cut in Edgewater Park. Nor have they placed permanent pumps to drain the retention pond; they’re still attempting to do that with portable pumps.
Photos Taken 3/28/2022
Here’s how the site looked tonight.
More about Hydroseeding
Contractors use hydroseeding to stabilize slopes and accelerate the germination of grass which can reduce erosion. Water, seed, and nutrients are mixed into a gelatinous material and sprayed onto the ground. The gelatin adheres to slopes and retains just enough moisture to help the seed take root. We should see grass start to grow within 5-10 days. Crews add colored dye to the mix to make it easier to see. That helps them spray it evenly.
Should Have Hydroseeded Earlier
After the a five-inch rain in January, the south wall of the detention pond started slumping into Edgewater Park. Sediment several inches deep fanned out into the wetlands of Edgewater for approximately 150 yards, according to the TCEQ. And Harris County issued its cease-and-desist letter threatening the developer with a lawsuit. Since then, the developer has spent much of the last month trying to move the pond wall back onto his own property. I imagine the contractor now wishes he would have hydro seeded earlier.
Chain Link Fence Disregards Community Norms
Assuming surveyors were accurate, the chain link fence should now identify the southern boundary of the RV resort. However, given the history of this project, that could be a big assumption.
Thankfully, at least the chain link fence does not have razor wire on top of it. Regardless, it has all the charm of the prison in Huntsville.
While you review the Commercial Development Guidelines on fencing, scan the rest of the guidelines, too. Especially the ones that talk about setbacks, construction fencing, parking, tree preservation and more. They will give you a greater appreciation for the care taken by thousands who came before the Laurel Springs RV Resort.
Posted by Bob Rehak on 3/28/2022
1672 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.
SJRA Seeks Public Input on Sediment Trap Proposal
The San Jacinto River Authority (SJRA) recently completed a 246-page conceptual design study, in partnership with the Harris County Flood Control District, that explored the feasibility of implementing sediment trapping facilities (“sand traps”). The purpose: to remove sediment from the West or East Fork of the San Jacinto River. The results and findings of this study have been documented in an engineering report entitled “San Jacinto River and Tributaries Sediment Removal and Sand Trap Development.”
Prior to proceeding to preliminary engineering design and any subsequent project phases, SJRA is seeking public input on the proposed project alternatives detailed in the report. The full report, as well as a brief summary document, are located on SJRA’s Flood Management Division website.
How to Provide Input or Ask Questions
Please submit input and questions via email to floodmanagementdivision@sjra.net.
Deadline: No later than April 29, 2022
Caution: The full study is dated 1/7/22. But the “brief summary” is dated 3/9/22. Make sure you at least read the executive study of the full report as well as the brief summary. There are important differences.
Overview/Purpose
SJRA says the purpose of the sediment trap study was to assess the feasibility of implementing a pilot project to trap and remove sediment from the West OR East Fork of the San Jacinto. The study only assessed locations where one or more Aggregate Production Operations (APOs) could partner with the the SJRA. They restricted the study this way to reduce costs; the SJRA does not have a source of funding to clean out sand traps and would rely on sand miners.
Initial Concerns
The decisions to:
…give me mixed emotions about this project.
Pros
On one hand, I look at this and say, “It’s a pilot project. Try it and see if there’s a benefit.” Sediment IS a problem and they believe they can remove up to 100% of the annual sediment load (from the West Fork).
Cons
On the other hand, the study authors, Freese & Nichols (F&N) claimed (in the San Jacinto River Basin Master Drainage Study) that of all the sediment coming into Lake Houston, two thirds comes from Spring and Cypress Creeks while only 13% comes from the West Fork upstream of US59.
Perhaps that’s because they’re using model inputs from a sediment gage at I-45 located 8.5 miles upstream from most of the large West Fork sand mines (page 34, paragraph 3 of full study).
Also, in their discussion of downstream sedimentation mitigation (page 51, paragraph 3 of full study), F&N says that their evaluation was confined to areas where natural processes rather than breeches of sand mine ponds likely contributed to sediment deposition. To see how limiting that is, see the photos of sand mine breeches and their results in this post.
In the entire 246-page F&N study and the three-page summary, the word “damage” occurs only once…in relation to erosion damage, NOT flood damage.
It appears that F&N did not even look at creating sand traps where they were most needed, in the headwaters of Lake Houston, because of cost and logistical considerations. Yet the Army Corps, City of Houston, and State of Texas are spending $200 million to dredge that area. One wonders whether SJRA should have looked harder for partners to clean out the traps.
Finally, if sediment traps only work financially near sand mines, the “solution” will not work on other tributaries that F&N alleges contribute 5X more sediment than the West Fork. They just don’t have the sand mines that the West Fork has.
Nature of Proposed Solution
Five years after Harvey, we have a conceptual design and a recommended location: rock-lined channels cut through one or two point bars at the West Fork Hallett mine.
The shot below shows the same area in real life. To put the magnitude of the proposed solution into perspective, the solution would cover a little more than an acre. But sand mines like Hallett cover 20 square miles on the banks of the West Fork between US59 and I-45.
My Biggest Fears
My biggest fears with the proposed pilot study are that it:
For a pilot study, that last point is troubling.
Also, F&N worries that removing too much sediment from the West Fork could create a “hungry-water” effect that increases erosion downstream. But they have no way of directly measuring how much sediment the West Fork transports. Or what percentage they would remove. That’s because they’re relying on a sediment gage upstream from the sand mines. This introduces an element of risk in the pilot study.
Recommendations Should Be Based on a Holistic Examination of Alternatives
Before moving forward with the pilot study, I suggest a more holistic examination of additional alternatives that might have a greater impact on reducing flood damage, not just sedimentation. Examples include, but are not limited to:
More on the sand trap proposal in coming days. In the meantime, please review the SJRA’s sediment trap proposal and forward your comments to the SJRA. I will also print thoughtful letters, both pro and con, from responsible parties. Send them to: https://reduceflooding.com/contact-us/.
Posted by Bob Rehak on March 27, 2022
1671 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.