City of Houston Mayor Pro Tem Dave Martin’s office has supplied ReduceFlooding.com with the Black & Veatch Engineering report on the recommended alternative for adding floodgates to Lake Houston. One key finding immediately jumped out at me that wasn’t in Martin’s press release last week. The recommended gates would have a release capacity that virtually equals the highest release rate of Lake Conroe during Hurricane Harvey.
The Lake Conroe release rate during Harvey maxed out at 79,000 cubic feet per second (CFS).
The eleven tainter gates recommended by Black & Veatch would have a release rate of 78,700 CFS.
New Possibilities, More Certainty
That opens up a world of possibilities. For instance, the City could wait to start releasing water until it knew water was coming downstream from Harvey.
Said Martin, “Once constructed, we can release with a moments notice which gives us great opportunities to coordinate release protocols with the SJRA!!”
Previously, Public Works has been reluctant to release water in advance of a storm because the release rate of the existing gates is so small. They have to start lowering the lake so far in advance of storms that a storm can veer away before it gets here. If it does, that means water has been wasted.
The recommended floodgates should provide much more certainty for operators and avoid waste.
Key Elements of Recommendation
Gates would be placed at the original channel for the San Jacinto River seen in foreground.
Other key elements of the recommendation include:
Locating the floodgates in the earthen eastern portion of the dam near the old channel of the San Jacinto River.
Creating baffles and a dissipation basin downstream from the new gates to break up the flow and reduce water velocity
“Outdenting” the gates (i.e., building them in front of the current dam)
A bridge between the two parts of the earthen dam
Using tainter gates, the same type used at Lake Conroe.
A 3.5 year construction schedule.
The last point means that if construction started in January, the earliest completion date would be mid-2026.
For a complete discussion of the project history, constraints, alternatives, recommended options, construction drawings, rationales, and costs, see the entire 28-page Black and Veatch Report by Chris Mueller, PhD, P.E.
Posted by Bob Rehak on 12/14/22 based on the Black & Veatch Report
1933 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20220722-RJR_0779.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-12-14 19:42:472022-12-14 19:45:58Recommended Floodgates Could Release at Rate of Lake Conroe During Harvey
Harris County Flood Control District will hold a virtual Taylor Gully meeting Wednesday, December 14, 2022 at 6:30 p.m. Purpose: to discuss the findings of its plan to reduce flood risk along Taylor Gully. Register at: PublicInput.com/taylor.
To learn more about the project scope, see this post. It discusses the related effort to virtually double detention capacity on the Woodridge Village Property that HCFCD purchased in 2021. Up to six hundred homes flooded in this area twice in 2019.
About Taylor Gully
The headwaters of Taylor Gully originally started where Woodridge Village is today, just north of the Harris/Montgomery County Line (tan area in map below). From there, it cuts through Elm Grove, Mills Branch and Woodstream Forest before joining White Oak Creek which then joins Caney Creek and the East Fork San Jacinto.
Project being discussed Wednesday night
Taylor Gully Meeting Details
The virtual community engagement meeting will be held on:
December 14, 2022, 6:30 p.m. – 7:30 p.m. Register/Join online at:PublicInput.com/taylor Or join by phone* at 855-925-2801 with Meeting Code: 3364
The Taylor Gully meeting will begin with a brief presentation to share project updates, followed by a moderated Q&A session with Flood Control District team members. Residents will be able to submit questions, comments and input before, during and after the meeting, which will be considered during project development. Any comments not addressed during the Q&A session will receive a response at the conclusion of the public comment period.
Meeting Followup
Even if you are unable to attend the live meeting, residents are encouraged to register for the meeting to receive future project updates. A recorded version of the meeting will be available on the Flood Control District’s website and YouTube channel after the event.
Special Needs?
Meeting accommodations can be made for those with disabilities. If needed, please contact 346-286-4040 at least three business days prior to the meeting. For questions, please contact the Flood Control District at 346-286-4000, or fill out the comment form online at hcfcd.org/taylor.
Posted by Bob Rehak on 12/13/22
1932 Days since Hurricane Harvey and 1181 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20221206-Taylor-Gully.jpg?fit=1200%2C1200&ssl=112001200adminadmin2022-12-13 18:13:402022-12-13 18:13:44Last Reminder: Taylor Gully Meeting Wednesday 6:30 p.m.
On December 6, 2022, The Washington Post ran an article titled “America Underwater: Extreme floods expose the flaws in FEMA’s risk maps.” The lengthy story by Samuel Oakford, John Muyskens, Sarah Cahlan and Joyce Sohyun Lee cross-referenced photos and videos with FEMA flood maps from areas around the country that flooded last summer.
The basic premise: FEMA’s flood maps “are failing to warn Americans about flood risk.” The authors then claim, “The resulting picture leaves homeowners, prospective buyers, renters and cities in the dark about the potential dangers they face, which insurance they should buy and what kinds of development should be restricted.”
There’s certainly room for improvement in FEMA flood maps.
However, the authors blame climate change for the inaccuracy far more than other contributing factors which are far more obvious.
FEMA is supposed to update flood maps every 5-10 years. It’s hard to imagine climate change invalidating them in that time period.
Climate is an average of weather occurring over much longer time periods. Depending on whether you talk to a meteorologist or a geologist, the time period could range from 30 to millions of years.
At least five major ice ages have occurred throughout Earth’s history: the earliest was over 2 billion years ago, and the most recent one began approximately 3 million years ago and continues today (yes, we live in an ice age!). Currently, we are in a warm interglacial that began about 11,000 years ago. The last period of glaciation, often called the “Ice Age,” peaked about 20,000 years ago. At that time, the world was on average probably about 10°F colder than today.
Interestingly, one day after The Post article, the New York Times ran a story about the DNA of animals found frozen in the permafrost of northern Greenland, just a few hundred miles from the North Pole. The 135 different species scientists found there paint a picture of an arctic once lush with life typical of warmer climates today.
And to what degree can climate change explain flood map inaccuracy? Many more obvious reasons exist that are less of a stretch for any inaccuracies.
Reasons Listed in Post Article for Inaccuracy of Maps
Here’s a list of the references in The Washington Post story used to explain inaccuracies found within FEMA maps. I’ve broken them into two groups so you can see the weight they gave to climate change.
Climate-Change References:
“As climate change accelerates, it is increasing types of flooding that the maps aren’t built to include.”
“Extreme precipitation events are growing increasingly common.”
“A warming climate allows storms to carry more moisture, producing greater rain or snow in a short period of time.”
“Climate has changed so much that the maps aren’t going to keep up.”
Maps are out of date, some decades-old “in a changing climate.”
“The effects of a changing climate.”
Climate change impacts are getting worse.
Climate change is “pushing FEMA’s maps beyond their limits.”
A gap exists between the data that goes into FEMA maps and current climate conditions.
Climate change baseline is changing.
“Climate change velocities are high.”
“Maps do not take climate change into account.”
“Overestimating the rarity of some events even before climate change…”
Other Possible Explanations Mentioned by The Post:
“Communities may resist expanding designated flood zones because it adds costs and can hamper development.”
Not all areas that flooded are mapped yet.
“Local communities often resist the expansion of federal flood zones”
“Maps do not forecast flooding. Maps only reflect past flooding…”
“Local governments have been opposed to any maps that show an increasing risk.”
Relatively high imperviousness of gentrifying areas.
Maps don’t reflect intense bursts of rainfall in a short period and the resulting street flooding.
Impervious surface is replacing porous surface.
Maps cover mainly coastal and riverine flooding.
“Rain combining with melted snowpack.”
FEMA flood maps don’t even attempt to model urban flooding
“City neglected drainage problems.”
Local opposition to expanding the floodplain.
No sense of urgency to update maps.
“Multiple compounding factors contribute to the flooding”
Floods Can Also Be Explained Without Climate Change
The second group of references in The Post article seems far more immediate, compelling and easily provable when explaining any inaccuracy found in flood maps. They’re certainly typical of what I have found in the Houston area.
For the past five years I have been researching instances of flooding in and around Harris County. I published more than 250 articles on different aspects of the 2019 Elm Grove floods alone. And I don’t recall one person ever blaming those on climate change.
Elm Grove did not flood during Harvey, but did flood on two much smaller rains in 2019. The difference? Clearcutting and insufficiently mitigated upstream development. Contractors clearcut approximately 270 acres immediately north of Elm Grove without building sufficient detention capacity before the rains fell.
Regardless of your position on climate change, this discussion dramatizes the needs to:
Understand your local flood risk and the factors that affect it
Buy flood insurance.
Hopefully, Harris County Flood Control District’s MAAPnext project will address data deficiencies discussed in The Post article. But it will be years before those maps become official. And when they do, the landscape will have already changed.
Posted by Bob Rehak on 12/12/22
1931 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.
The smell of ripe grass. The blinding purples, yellows, and whites of fall wildflowers. The buzz of pollinators deciding which stop to make next on the buffet. These are all elements of a strategic approach to flood mitigation across the Milwaukee, Wisconsin metropolitan area.
Photo Courtesy of Matt Berg. Restored wet prairie in MMSD’s Greenseams program.
US Water Alliance’s One Water Summit Explores Greenseams Program
I was asked to join the Texas delegation at the US Water Alliance’s annual conference earlier this fall. The One Water Summit brings together a wide swath of the water sector in the name of planning and managing all water resources (drinking water, wastewater, and stormwater) as part of an integrated process. Since every single drop has value, it’s only logical to treat it that way.
The week included plenty of time thinking and planning with municipal water departments from Dallas, Austin, San Antonio, and Houston, but day one of the conference featured a number of field trips to different examples of the Milwaukee area’s water infrastructure. I chose to spend my afternoon learning about the Milwaukee Metropolitan Sewerage District’s (MMSD) Greenseams program.
Conservation of Parcels with Low and High Infiltration Rates Help Manage Flood Peaks
There are two broad approaches at the heart of the program: 1) conserve land parcels that are wet under normal conditions or that hold water after a rain event and 2) conserve land parcels with high infiltration rates to get water in the ground quickly. In certain areas, wetlands and prairies also undergo restoration efforts to improve performance even further.
Working together, these approaches mean strategic locations slow and hold water upstream to reduce flood peaks downstream and release it gradually over time at a more manageable rate. This results in reduced flood risk for private property and public infrastructure. A natural approach to flood mitigation!
Financing Programs in Surrounding Counties
Milwaukee County’s location means it lies at the end of multiple rivers flowing together just before they enter Lake Michigan. That also means Milwaukee County and the City of Milwaukee are at the receiving end of every interaction between rainfall and land use upstream, including areas far outside their respective jurisdictions.
For the field trip, our group visited a handful of adjacent former farm fields within the City of Franklin. Over the last couple decades, these have been restored to reintroduce prairie vegetation, reconnect historical hydrological features, and reduce erosion.
Photo Courtesy of Matt Berg. Restored prairie in MMSD’s Greenseams program.
As it so happened, our site visit took place just a day after one of the heaviest rainfalls in the region’s recorded history. Despite the downpour, the site was damp but entirely walkable, assuming you’re wearing something like hiking boots and not dress shoes! This site has moderately high infiltration rates, so water drains downward in a hurry. We saw photos from other sites that took the other approach and held substantial water on the surface before slowly releasing it downstream. We very much saw the action in real time.
Beyond Flood Mitigation to Water Quality Improvements, Too
It doesn’t end with flood mitigation, either. Depending on the characteristics of each site in the program and its conservation agreement, there are additional big benefits via ensuring clean drinking water, preserving wildlife habitat, and providing recreation opportunities for residents and visitors.
At the City of Franklin site we visited, it was obvious the rapidly developing surrounding area was already planning for additional trails to connect new neighborhoods to the site’s open space.
How Ideas Could Translate to Houston
You may be thinking that sounds all well and good for Milwaukee, but how about the Southeast Texas?
Houston locals spend a lot of time talking about the impermeable soils of our region. Yet according to the U.S. Department of Agriculture’s Natural Resources Conservation Service, the soil infiltration rates (how fast water moves down through the soil) of Harris County and Milwaukee County are actually quite comparable.
Granted, data from the National Weather Service’s Atlas 14 makes it clear that the intensity of rain events in Houston is much greater than in Milwaukee.
However, two more things that Houston and Milwaukee do have in common are increasing trends in precipitation intensity and a rapidly growing urban footprint. These two compound each other, with heavier rainfall on ever greater hard surfaces causing more and faster runoff.
Photo Courtesy of Matt Berg. Pickerelweed in Panther Branch watershed in Montgomery County, TX.
MMSD works with local land trusts in its region to make Greenseams a success. In the Houston region, groups like Bayou Land Conservancy, Coastal Prairie Conservancy, Galveston Bay Foundation, and Houston Audubon all play big roles in delivering benefits for flood mitigation and clean water supplies through land conservation from the very top of to the bottom of our region’s watersheds.
Photo Courtesy of Matt Berg. Riparian wetland along Spring Creek on the border between Harris County and Montgomery County.
The need is definitely present, and the pieces are there to make it happen. I guess you could say it sure “seams” like heartily pursuing such a regional strategy would be a great idea for Southeast Texas too.
By Dr. Matthew Berg, CEO & Principal Scientist, Simfero Consultants. Posted on 12/9/22
1928 Days since Hurricane Harvey
Note: Milwaukee is known as Cream City for the distinctive light color of the bricks produced there and widely used in its architecture.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/Wildflower2.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-12-09 12:19:162022-12-09 12:23:16Can Cream City Teach Bayou City about Flood Mitigation?
On Dec. 2, I printed a story about an upcoming virtual community meeting on Taylor Gully. At the time, Harris County Flood Control District (HCFCD) had not yet released details yet on how to attend. They have now. See their press release below. Please share it with family, friends and neighbors if you live anywhere along Taylor Gully. That includes parts of Sherwood Trails, all of Elm Grove, all of North Kingwood Forest, parts of Mills Branch, Woodstream Forest, and even parts of Porter in Montgomery County. Yes, plans will affect Porter also.
Virtual Community Engagement Meeting for the Taylor Gully Flood Risk Reduction Project
HCFCD PROJECT G103-80-03.1-E001
BOND PROJECT F-14
The Harris County Flood Control District will hold a community engagement meeting for the Taylor Gully Flood Risk Reduction Project. The purpose of this meeting is to inform residents about the project’s status, share project information and gather important community input on this effort.
The Taylor Gully Flood Risk Reduction Project focuses on improvements to Taylor Gully and the mitigation required to build the project. This project will be partly funded through the 2018 Bond Program, which was approved by Harris County voters on August 25, 2018. Community engagement is a foundational component of the Bond Program, and we invite your participation and input as projects are implemented.
Register Now
The virtual community engagement meeting will be held on:
Or by phone* at 855-925-2801 with Meeting Code: 3364
The meeting will begin with a brief presentation to share project updates, followed by a moderated Q&A session with Flood Control District team members. Residents will be able to submit questions, comments and input before, during and after the meeting, which will be considered during project development. Any comments not addressed during the Q&A session will receive a response at the conclusion of the public comment period.
Even if you are unable to attend the live meeting, residents are encouraged to register for the meeting to receive future project updates. A recorded version of the meeting will be available on the Flood Control District’s website and YouTube channel after the event. Meeting accommodations can be made for those with disabilities. If needed, please contact 346-286-4040 at least three business days prior to the meeting. For questions, please contact the Flood Control District at 346-286-4000, or fill out the comment form online at hcfcd.org/taylor.
Esta reunión de participación comunitaria se llevará a cabo en inglés; sin embargo, el Flood Control District proporcionará intérpretes de idiomas y materiales traducidos a pedido. En caso de necesidad, comuníquese al 346-286-4040 al menos tres días hábiles antes de la reunión.
*If you attend by phone only, maps and other exhibits will not be visible. However, information will be available after the meeting on the project webpage at hcfcd.org/taylor.
Posted by Bob Rehak on 12/8/2022based on a press release from HCFCD
1927 Days since Hurricane Harvey and 1176 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20221206-Taylor-Gully.jpg?fit=1200%2C1200&ssl=112001200adminadmin2022-12-08 07:25:162022-12-08 07:36:21Save the Date: HCFCD Releases Details of Taylor Gully Meeting
During Harvey, 16,000 homes and 3,300 businesses in the Lake Houston Area flooded. Local leaders identified the disparity in release capacities between the Lake Conroe and Lake Houston Dams as one of the contributing factors to the severity of flooding. The floodgates on Lake Conroe can release water 15 times faster than the gates on Lake Houston. So, adding more floodgates to Lake Houston became one of the area’s primary mitigation goals.
New gates would let the City rapidly lower the water level of Lake Houston in advance of a storm to prevent or reduce upstream flooding.
Lake Houston (l) and Lake Conroe gates (r). Conroe release capacity is 15X greater.
While the City of Houston initially obtained a $50 million grant from FEMA to add gates, two problems became apparent. The project cost more than anticipated and the benefits delivered did not justify the cost – at least the way FEMA was initially calculating them. However, a huge hurdle has been cleared.
The City of Houston has finally secured a favorable ruling from FEMA on a benefit-to-cost ratio, according to a press release from Mayor Pro Tem Dave Martin’s office on 12/7/2022. The key was the FEMA administrator’s decision to allow the inclusion of social benefits, for instance, avoidance of disruptions to business, commerce, schools and the area’s tax base. Those brought the BCR up to 2.88, according to Martin.
Martin, Mayor Sylvester Turner and Chief Recovery Officer Stephen Costello met with the Federal Emergency Management Agency (FEMA) Administrator to discuss the inequities of the Federal BCR formula associated with incorporation of social benefits.
As a result, Martin and Turner have announced that a large hurdle has been removed. The revised draft BCR for the Lake Houston Spillway Dam Improvement Project has been determined to be “federally compliant and is very favorable.”
The change affected the Lake Houston Gates and several other Houston stormwater projects including the massive, new Inwood Forest detention basin.
New BCR Based on Eleven Gates
Atkins, a City of Houston consultant, revised the BCR for an eleven-gate structure. The eleven gates will be built into the existing embankment on the east side of the Lake Houston Spillway Dam.
New gates would be added to the earthen portion of dam in foreground, not spillway at far end as originally planned.
Building the new gate structure in the east embankment removes the high construction risk of modifying the existing gate structure. It also allows continued use of the existing gate structure during construction, and eliminates the need for a coffer dam in the lake, according to Martin.
The new gates would likely align with the original course of the San Jacinto River, the channel on the left.
Cost Quadruples: Additional Funding Sources Now Necessary
The new preliminary cost estimate of $200 million exceeds the City’s original FEMA grant of $48 million.
Martin, Costello, and State Representative Dan Huberty have already met with the Texas House of Representatives Speaker Dade Phelan’s Director of Finance regarding additional funding. They have positioned the project as a “life and safety initiative” that affects the survival of the community and economy of the Lake Houston Area.
Martin has bi-partisan support already lined up for financing. Key partners this legislative session include:
Congressman Dan Crenshaw
State Senator Brandon Creighton
State Senator John Whitmire (who has already announced his intention to run for Houston mayor after Turner retires)
Speaker of the Texas House Dade Phelan
State Representative & Chair of Appropriations Dr. Greg Bonnen
State Representatives Charles Cunningham and Armando Walle.
Martin plans to work with Federal and State partners to ensure the cost of the Lake Houston Spillway Dam Project is fully funded before he leaves office in December 2023.
Said Martin, “Today a significant obstacle has been surpassed as this project moves forward through the financial process.” The new BCR should let federal, state, and local partners work toward fortifying the Lake Houston Area against future storms.
It would be unfair to call this a “start over.” A huge amount of engineering and analysis has gone into the project. However, challenges turned out to be greater than anyone anticipated after Harvey.
The original timetable from 12/16/19 showed the project completed by now. The fact that it is still alive is a tribute to the persistence of Martin, Turner, Costello and others.
Let’s look forward to the benefits, not backwards to the problems. People are working in the right direction. A huge obstacle has been eliminated. We just need to keep tackling new obstacles as they occur. Next step: the House and Senate.
I will post construction plans for the 11 gates and the Atkins’ BCR analysis as soon as the City supplies them; they promised they would.
Posted by Bob Rehak on 12/7/22
1926 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20220722-RJR_0770-2.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-12-07 10:55:302022-12-07 16:56:23City Gets Favorable Ruling on BCR for Lake Houston Gates Project
In the last 1924 days, I’ve researched, written, photographed and posted more than 2,093 stories about flooding and flood mitigation in the Houston region.
Recurring Themes Gradually Became Apparent
As I dug deeper and deeper into the causes of flooding, certain themes became apparent. They include, but are not limited to:
The complexity of coordinating federal, state, county and local governments to address watershed-level issues.
Fragmented and often conflicting priorities among local governments within the same watersheds.
Political processes that sometimes seem to favor growth over protection of existing residents.
Insufficiently mitigated upstream development that often offsets downstream mitigation investments.
Environmental destruction.
The tug-of-war for limited mitigation funding.
Disaster relief dollars that still can’t seem to find their intended targets.
The back-seat role that preservation and conservation often play.
People building in risky places using assumptions that later prove to be invalid.
I have hundreds of examples of each of these and more. Frankly, the examples are becoming too redundant. And their sheer volume deters new readers from getting the big picture.
Forest-For-The-Trees Dilemma Prompts Changes
It’s a classic forest-for-the-trees dilemma. There’s so much detail, it’s often hard to see the patterns. Therefore, changes are coming to ReduceFlooding.com.
Effective immediately, I’m going to start weaving those details into a book about flooding in Harris County. It will be a more manageable size than the website which now contains more than 1.5 million words and 8,785 images.
To make time for writing the book, I plan to cut back on daily website posts. Posts will become weekly or whenever major news breaks. So if you don’t see me everyday, please don’t think I’ve abandoned the cause.
I also hope to reorganize the website to make existing content support the themes above.
Sally Geis rescue during Harvey. North of Kingwood Drive about 8 feet above West Lake Houston Parkway.
Not Possible Without Your Support
My goal is to make all these changes before the start of next hurricane season. Thanks for all of your support during the last five years. Without your input, encouragement, and generous sharing of your experiences, none of this would have been possible. Together, we are documenting the many dimensions of flooding that may, just may, help reduce flooding in the future. Here and elsewhere.
Posted by Bob Rehak on 12/5/2022
1924 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/09/20170829-IMG_9819.jpg?fit=1200%2C900&ssl=19001200adminadmin2022-12-05 14:49:122022-12-05 21:58:40Changes Coming to ReduceFlooding.Com
Texas and Maryland represent opposite ends of the political spectrum. So, it’s not too surprising that floodplain regulations in the two areas differ radically. When it comes to building in harm’s way, most municipalities and counties in the Houston region allow development in the floodplain with certain precautions. But several counties in Maryland prohibit floodplain building altogether. One even requires developers to deed floodplain land to the county.
In contrast, Texas developers even fight for the right to build in floodways!
Looking E toward Lake Houston in distance along the floodway of the San Jacinto West Fork. Photo taken July 2020.
FEMA defines a floodway as the main channel of a river PLUS adjacent land that must remain free of development in order to avoid flooding areas upstream.
A floodplain extends farther out, usually to the edge of a valley. Floodplains flood repeatedly. Frequency and depth depend on rainfall and elevation within the floodplain. The area in the photo above flooded 53 times since Lake Houston was built 67 years ago. It even flooded SIX times in ONE year.
After Hurricane Harvey, Houston made its building regulations in floodplains more stringent. This table by the engineering firm WGA summarizes the changes.
“Zero net fill” prohibits elevating a home by bringing fill dirt in from outside the floodplain.
However, builders can still move dirt around inside the floodplain. They use a practice called “cut and fill.” Example: they take dirt out of a stormwater detention basin and use it to elevate slabs. That way they don’t reduce the area available to store floodwater.
These regulations do nothing to make homes already built in a floodplain safer. They only affect new building.
And they only make people safer to the extent that engineers can accurately predict the future. The future includes both rainfall and upstream development.
In the case of Harvey, remember that FEMA had revised flood maps just 10 years earlier. Now it’s revising them again.
The point: under the “there are ways to build here safely” philosophy, your “safety” is based on imperfect knowledge, changing conditions, changing regulations and shifting estimates.
Sample Maryland Regulations
Maryland takes a different approach to building in harm’s way. It says “Don’t.”
The State of Maryland provides model floodplain regulations. Section 4.2(b)1 states: “Subdivision proposals shall be laid out such that proposed building pads are located outside of the special flood hazard area and any portion of platted lots that include land areas that are below the base flood elevation shall be used for other purposes, deed restricted, or otherwise protected to preserve it as open space.”
Counties and Communities implement their own floodplain regulations. I haven’t checked every county, but found that Howard County:
Prohibits any new structures in the 100-year floodplain. See page 152.
Requires subdivisions to either a) deed land in floodplains to the county or b) grant floodplain easements to the county. (Page 136)
Prohibits storing building materials in a floodplain. (Page 136)
Prohibits clearing, excavating, filling or altering drainage in floodplains. (Page 136)
Will not issue variances for projects within floodways that result in any flood discharge levels (Page 139)
Montgomery County, Maryland, has prohibited residential development in 100-year floodplains since 2007. (Page 4).
The Texas philosophy says, “There are ways to build safely in flood-prone areas.” The Maryland philosophy seems to say, “It’s safer not to.”
It’s difficult to say objectively which is better/safer. The regulations are designed for different different people in different areas: Rural vs urban. Hilly vs. flat. Temperate vs. Subtropical.
But I will say this. As I read Howard County’s Hazard Mitigation Plan, the number of homes that could be damaged in a 100-year flood – ten – and a 500-year flood – twenty – shocked me. (Page 39). Compare that to the 154,000 structures damaged in Harris County during Harvey. Well, no, don’t. There is no comparison.
Posted by Bob Rehak on 12/4/2022
1923 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/2022/12/20200718-DJI_0150.jpg?fit=1200%2C900&ssl=19001200adminadmin2022-12-04 16:15:432022-12-04 16:56:20In Harm’s Way – To Build or Not to Build?
For decades, we have had wetland mitigation banks. If you want to fill in wetlands, you need to preserve wetlands somewhere else. But what about those vast swaths of ecologically less valuable forest that still play valuable roles in flood reduction? Developers routinely mow them down for new starter homes, apartment complexes, strip centers, RV parks and the like. Should there be mitigation for clearcutting, too?
Imagine how much more attractive, healthier, and flood-resilient communities could become if all developers:
Planted a young tree for every old tree they cut, or…
Donated trees to community groups, or…
Preserved floodplains on their perimeters with conservation easements, or…
Committed to replanting trees on their own developments as homes are built.
Here’s why that’s important and two ways it could work without turning into a huge cost burden for developers and without onerous regulation.
That erosion eventually reaches streams and can reduce their conveyance. In extreme cases, eroded sediment can even block streams and back floodwaters up into homes.
How Clearcutting Can Increase Flood Risk
Clearcutting on the other had accelerates runoff. As runoff gets to streams faster, it carries more exposed sediment. That sediment can reduce the conveyance of streams, partially block them, back floodwater up, and necessitate dredging programs which can take years and cost tens of millions of dollars.
Clearcutting makes more money for developers. But it also can also foist cleanup, repair, and mitigation costs off on neighbors and the public sector as we saw with Woodridge Village.
Notice the stark contrast in each photo below between the mature canopy of trees surrounding each newly clearcut development.
One of the primary draws of SE Texas is the gorgeous, lush forests. Yet high-density development is gradually destroying the very thing that attracts people. So should there be some sort of mitigation for clearcutting?
A Modest Proposal
Most companies make charitable donations of some sort. If you’re a developer, why not make them in a way that builds goodwill with neighbors, supports community values, makes everyone safer, and creates a tax deduction?
Contrast the systemic, mechanized deforestation above with the underfunded efforts of volunteer and charitable groups trying to plant trees and preserve forests. Perhaps the first group could help the second…and help themselves at the same time.
And the tax breaks from a conservation easement can easily turn difficult-to-develop floodplain land into revenue-producing land.
Let’s look at examples of each.
Trees for Kingwood
Mayor Pro Tem Dave Martin’s most recent newsletter contained a short article about a new group called “Trees For Kingwood.”
Martin says, “Over the last 5 decades, Kingwood has lost more than ten thousand trees due to disease, storms, and drought.”
And I would point out that that doesn’t even include new developments that practice clearcutting.
Mayor Pro Tem Martin (front row, center) joined leaders of seven Kingwood Community Associations that contributed funds to support the first planting event of Trees for Kingwood. “This is a good thing for the neighborhood and wonderful for the community,” said Martin.
Trees for Kingwood needs both volunteers and financial support to achieve its mission.
Volunteers to help plant and care for new trees.
Financial support to purchase trees.
Charitable contributions can be made to the KSA Parks Foundation for the Trees for Kingwood effort. For more information please visit treesforkingwood.org or email treesforkingwood@gmail.com.
Bayou Land Conservancy
Another worthy group is the Bayou Land Conservancy (BLC). Since 1996, BLC has preserved land along streams for flood control, clean water, and wildlife. BLC’s focus area includes the Lake Houston Watershed, which is 4,000 square miles. The group has preserved 14,000 acres and has identified another 100,000 worthy of protection. The tax benefits of a conservation easement can help developers profit from flood-prone land that would be difficult and expensive to safely develop.
To put 14,000 acres in perspective, that’s the size of Kingwood.
Bottom Line
By supporting such groups, developers can help restore and protect the forests that attract people to this region. They can also help mitigate their development practices and reduce costs by harnessing the power of volunteers.
Posted by Bob Rehak on 12/3/22
1922 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/2022/12/20221126-DJI_0426.jpg?fit=1200%2C799&ssl=17991200adminadmin2022-12-03 17:53:372022-12-03 18:04:00Mitigation for Clearcutting: Two Ways It Could Work Cost Effectively
The Harris County Flood Control District (HCFCD) has scheduled a community meeting to reveal the results of an engineering study of the Taylor Gully watershed and Woodridge Village, the aborted development that flooded Elm Grove and North Kingwood Forest twice in 2019. The virtual meeting will be on:
December 14, 2022
6:30 PM – 7:30 PM
Two Related Efforts
Because Woodridge Village sits at the headwaters of Taylor Gully, the volume of stormwater detention upstream and the amount of conveyance needed downstream are related. More of one could mean less of the other. HCFCD has been working to find the optimum solution, which should be discussed at the meeting.
Areas of Concern Identified by Community Members
Community members previously expressed concerns, including:
Straightening a Taylor Gully oxbow adjacent to Woodstream Forest where numerous homes flooded.
Replacing the old culvert-style bridge on Rustic Elms with an open-span bridge.
The Rustic Elms Bridge on Taylor Gully has a twin-culvert design with less conveyance than more open bridges like the one at West Lake Houston Parkway farther downstream in this image. Nearly every home behind this bridge on adjacent streets flooded in 2019.
Hundreds of homes adjacent to Woodridge Village and Taylor Gully flooded twice in 2019 after a developer clearcut approximately 270 acres before building required stormwater detention basins.
The developer then sold the troubled project to HCFCD in March 2021 after building 271 acre feet of stormwater detention capacity – an amount sufficient to meet Montgomery County’s pre-Atlas-14 standards, which were in effect at the time of permitting.
Taylor Gully One of Top Two Priorities in Kingwood Area
The Kingwood-Area Drainage Analysis from October 2020 recommended Taylor Gully as one of the top two priorities for Kingwood. However, HCFCD also recommended the Taylor Gully project be re-analyzed to determine how the use of Woodridge Village for detention could modify the recommended plan.
Since February 2022, Sprint Sand & Clay has removed an average of more than 1,700 cubic feet of dirt each week from Woodridge. That’s roughly one acre foot per week. An acre foot equals 1613.33 cubic yards of material.
So, HCFCD has increased detention capacity by almost 42 acre feet since signing the contract with Sprint. That means detention capacity has already increased by about 16 percent, not quite half of what it needs to meet new Atlas-14 requirements.
Stats from HCFCD show cubic feet of dirt removed from Woodridge Village by Sprint Sand & Clay each week since start of E&R contract.
Pictures Showing Woodridge Village Status
Here are some pictures that show the extent of excavation on November 26, 2022.
Looking NE along Harris/Montgomery county line (tree line on right).Close-up shot of active work area.Looking S toward Sherwood Trails Village
Excavation and removal contracts give HCFCD a head start on construction of stormwater detention basins. The final dimensions may not be known yet, but HCFCD can make adjustments as it finalizes construction plans.
We should learn more about those on December 14th. Block out the date for the Taylor Gully, Woodridge Village meeting.
Posted by Bob Rehak on 12/2/2022
1921 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20221126-DJI_0406.jpg?fit=1200%2C799&ssl=17991200adminadmin2022-12-02 15:56:062022-12-02 20:26:17Taylor Gully-Woodridge Village Meeting Scheduled for Dec. 14
