Homebuyers beware. Flood risk is a shifting target.
This morning, I began reading more than 100 pages of legal briefs in the appeal of the upstream Addicks and Barker awards. I could not help but think how hundreds of millions of dollars in losses and untold heartbreak could have been averted with more due diligence on the part of all involved – buyers, developers and the Army Corps.
Background of Case
For those new to the area, Addicks and Barker are two reservoirs on Houston’s west side. The Army Corps built them back in the 1930s to protect downtown Houston and the ship channel. However, the Corps did not buy all the land inside the reservoirs that was subject to flooding. Later, developers started building on that land. And people bought the homes despite the risks.
In 2022, a judge ruled in favor of the residents and awarded them more than half a billion in damages. The damages included repair costs, replacement of belongings, and compensation for value lost in their property. But facing hundreds of millions of dollars in payouts, the government isn’t giving up easily. It appealed.
The case has taken more than six years to get to this point and it is far from over. No telling what the legal fees have cost both sides. Or whether plaintiffs will ever see a penny.
This should serve as a lesson to everyone buying a home and to their real estate agents, mortgage lenders, and surveyors.
Tools to Help You Avoid Becoming a Flood Victim
Although tools to identify flood risk may not have been commonly available and readily understandable when the plaintiffs bought homes inside the reservoirs, such tools do exist now.
They both show the extent of potential flooding in this area, but each has different strengths. And they show slightly different results. That should raise some cautions if you think of risk as a black-or-white issue.
Use USGS National Map for Elevations, Slopes, Contours
You can layer these maps and vary their transparency. But the real magic of the USGS National Map is in the measurement tool for elevation profiling. Below is an example.
After activating the elevation profile tool, I drew a line from a residential neighborhood inside the Barker Reservoir, across the dam, to an area outside the reservoir. I chose an area in the southwest corner of the reservoir that flooded during Harvey. It showed this.
The red X shows the height of the dam (108 feet) in the elevation profile. The brown area in the elevation-profile box shows the elevation of the dam, homes, streets and drainage channels.
Next, zooming out, I turned on the hydro layer. The red circle below, indicated the approximate area and location of the map above.
FEMA National Flood Hazard Layer Viewer for Floodplain Information
FEMA actually uses the elevation information from the USGS national map. But FEMA superimposes floodplains to show flood risk in several zones.
The difference noted above raises an important point. FEMA’s maps are estimates of the probability of unknown future events based on the frequency of extremely rare past events. Those estimates may not have been in effect when the neighborhood in question was built around the time of Tropical Storm Allison in 2001. Maps based on Allison weren’t adopted until around 2007 and are still in effect today.
Harris County Flood Control and FEMA update flood maps periodically when new monster storms come along and surpass past rainfall probability estimates. For instance, FEMA is working on new flood maps based on Harvey, but has not yet released them.
So, if you’re thinking of betting your life savings on a home in a risky area, the best things to do are these:
Ask yourself, “Can I afford to lose everything?” Many families in the reservoirs did.
Consult an independent engineer without any financial incentive in the purchase, i.e., making the deal go though.
Evaluate a variety of homes, not just one. And look closely at the safety margins.
If a home is two feet above the 100-year floodplain, look for one that’s higher. Things change regularly, usually in one direction.
Make “flood avoidance” more important than kitchen appliances in your purchase decision.
A Cautionary Tale Based on Personal Experience
Back in the early 1980s, I owned a house in Dallas near a creek that an engineer and the city certified were 2-feet above the 100-year floodplain. The home flooded within two years, due to rapid, insufficiently mitigated growth upstream.
Several years later, when I bought a house in Kingwood, I looked at ten homes and bought the one on the highest ground. More than 30 years later, all nine of the others flooded during Harvey even though they were all reportedly above the 100-year flood plain.
For a thorough description of why flood risk is a moving target, read this post – Why Do We Flood?
After two years of drought, it’s easy to become complacent about flood risk. Don’t. Ask anyone who has flooded. They will tell you. Your life can change overnight. So homebuyers beware.
Posted by Bob Rehak on 10/21/2023
2244 Days since Hurricane Harvey
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Hurricane Harvey flooded 100 percent of all the businesses in Kingwood Town Center. Recovery has been a long, hard road. Some retailers threw in the towel. Others hung on by their nails. The shopping center on the northwest side of Kingwood Drive and West Lake Houston Parkway was one of the hardest hit – caught between rising waters from Lake Houston and descending waters from Bens Branch. For several years, the entire center looked like a ghost town.
Finally, the owner sold it to a buyer with deeper pockets who could make needed repairs.
The remediation efforts seem to have bolstered confidence and encouraged the return of retailers.
Pardon Their Dust
For the last two years, loyal customers had to dodge construction as the shopping center got a facelift. But last month, the construction trailer and fencing disappeared. Today, I counted only four vacancies in the main part of the shopping center. And workmen are busy doing interior buildout on some of those.
Ghost-Town Look Gone
The ghost-town look is gone…replaced by pristine exteriors, new signage, and fresh landscaping. It will only be a matter of time before the remaining spaces refill.
Regardless, you can see another sign of the shopping center’s success on the Harris County Appraisal District website. The appraised value of the center has more than quadrupled since those bleak days after Harvey.
Welcome Back, Retailers!
If you avoided this center during construction, explore what all the small business owners have to offer.
Posted by Bob Rehak on 9/8/2022
1836 Days since Hurricane Harvey
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When Harris County Flood Control District (HCFCD) and the Army Corps began Project Hunting (the Hunting Bayou Federal Flood Risk Management Project) in 2014, they estimated it would cost $100 million and take until late this year.
Hunting Bayou runs just inside North Loop 610 most of the way from US59 to Wayside. However, starting at Wayside, it dips outside the Loop, then goes back inside again, and finally outside a second time. Eventually, the Bayou works its way to the Houston Ship Channel near the City of Galena Park.
Scope of Project
Project elements include:
Excavating a stormwater detention basin on a 75-acre site near the northeast corner of Homestead Road and Loop 610
Widening and deepening about 4 miles of Hunting Bayou
9 bridge replacements / 8 modifications and channel conveyance improvements under bridges
HCFCD says that most neighborhoods near the bayou will see water surface elevation reductions of 3-4 feet for the 1 percent annual chance (100-year) flooding event. The number of homes and businesses subject to the 1 percent (100-year) flooding event would drop from 5,100 to 650. And all homes and businesses will benefit from the reduced frequency and depth of flooding.
Need for Project
The Hunting Bayou watershed has Harris County’s second highest percentage of Low-to-Moderate Income (LMI) residents – 69%. That means more than two out of every three people earn less than the average income for the region.
Hunting is a small watershed. It comprises only 31 square miles. Its size ranks 19th out of 23 watersheds in the county.
Population grew only by 2,323 residents between 2010 and 2020. It went from 75,908 to 78,231. That now ranks it 14th in population among all watersheds, and 8th highest in people per square mile.
In five major storms between 2000 and today (Allison, Tax Day, Memorial Day, Harvey and Imelda), floods damaged 15,763 structures in the watershed. But virtually all of that damage came from Allison (8,270) and Harvey (7,419). The other three storms combined damaged only 74 structures, according to statistics compiled from HCFCD Federal Reports.
Thus, Hunting ranked 7th in total damage out of 23 watersheds, but because of its small size and high density, it had 508.5 structures per square mile damaged by floods since 2000. That means…
The watershed is highly urbanized with a mixture of residential, commercial and industrial developments. It’s home to one of the largest rail yards in the Houston area.
Aerial Survey Shows Mitigation Construction Almost Complete
On Tuesday this week, I flew over Hunting Bayou with Ken Williams and Bill Callegari. Both are fellow members of the Harris County Community Flood Resilience Task Force. The pictures below show highlights of the construction.
The Curtis M. Graves Detention Basin shown above provides approximately 1,000 acre-feet of stormwater storage capacity. That’s almost 10 inches of rain falling over a square mile. Construction of the basin began in 2020.
Compare Bayou Downstream From Project
Where the bayou narrows to go under a bridge, the increased water pressure during a flood can cause a “jetting” phenomenon that rapidly erodes banks and undermines bridge supports. Hence, the need for concrete reinforcement.
The tank farm is the approximate eastern limit of Project Hunting.
This project began on December 16, 2014, long before Harris County’s Flood Bond in 2018. It was a key project of County Commissioner El Franco Lee (who lived in the area) and Congressman Gene Green. Despite a low benefit/cost ratio, they called in favors and got the project started.
The agreement between the Army Corps and HCFCD lets HCFCD qualify for reimbursement from the Federal government for work completed.
Between the channel widening and detention basin, HCFCD has removed almost a million cubic yards of soil to create more room for floodwaters. Width of the Bayou now varies from about 30 to more than 500 feet between the project limits.
According to data obtained via a FOIA Request, HCFCD and its partners spent $96 million on Hunting Bayou between 2000 and the end of last year. Some of that money has been spent on other projects. To see a complete list of HCFCD projects in Hunting Bayou, visit the District’s Hunting page.
Since 2000, Harris County Flood Control District (HCFCD) and its partners have spent more than a half billion dollars to reduce flooding in the White Oak Bayou watershed. And they aren’t done yet. Before the flood bond is complete, they will have spent at least $575 million to create detention basins, widen channels and make other improvements.
On 7/19/2022, I flew up White Oak Bayou in a helicopter with Bill Calligari and Ken Williams, two fellow members from the Harris County Community Flood Resilience Task Force. Our goal: to learn what the money bought.
This is the second of four posts. The first covered Greens Bayou. The next two will cover Hunting and Halls Bayous.
White Oak Bayou by the Numbers
White Oak Bayou is Harris County’s sixth largest watershed but its third most populous. 51% of its residents qualify as Low-to-Moderate Income (LMI). It’s our fourth most densely populated watershed (people/square mile). Not surprisingly it had the third most damage in 5 major storms since 2000 (Allison, Tax Day, Memorial Day, Harvey, Imelda). The storms damaged 25,739 structures. Look at some of the photos below of structures crowding the bayou and you will understand why.
White Oak Bayou from the Air
White Oak Bayou flows southeast from its headwaters northwest of FM 1960 to its confluence with Buffalo Bayou near downtown Houston. The watershed comprises 111 square miles, with 146 miles of open streams. They include:
White Oak Bayou
Little White Oak Bayou
Our helicopter started the White Oak leg of our flight near the Heights north of downtown. From there, we flew upstream. This is what the Heights looks like from the air – a study in population density which correlates highly with flood damage.
Some projects are still being studied. Some are complete or nearly so. As of June 8, 2022, HCFCD was working out a contractor issue on the largest project, which will delay the originally scheduled completion this summer.
Federal Flood Damage Reduction Project
The largest project is the White Oak Bayou Federal Flood Damage Reduction Project. This $124 million project will substantially reduce flooding risks along White Oak Bayou. It started in 1998 in partnership with the U.S. Army Corps of Engineers, with the Flood Control District designated as the lead. The two segments of the project are fully funded to completion.
Limits of downstream segment of Federal Project
Construction of approximately 15.4 miles of channel conveyance improvements along the bayou from FM 1960 to Cole Creek near West Tidwell in the two segments above.
Excavation of six stormwater detention basins to hold almost one billion gallons of stormwater. That’s enough to hold a foot of rain falling across almost 5 square miles.
Construction of the Jersey Village Bypass Channel
Many smaller detention ponds like those above now line both sides of the bayou and its tributaries from upstream to down.
Arbor Oaks Subdivision Buyout
Since 2003, HCFCD has bought out more than 200 homes in the Arbor Oaks subdivision. It is still buying more on either side of Vogel Creek to build a 431 acre-foot stormwater detention basin and restore the floodplain. That would hold a foot of rain falling over 2/3rds of a square mile.
Acquisition costs in such densely populated neighborhoods can easily exceed construction costs.
Here’s what part of it looks like from a few hundred feet up.
And then there’s the North Canal near downtown. HCFCD and the City of Houston are working to finalize an interlocal agreement. Grant funding calls for completion of the first phase of the project by May 2023.
They all add up to more than a half billion dollars…and counting! Water needs somewhere to go during a storm. If we don’t leave a floodplain for floodwaters to safely expand, they will wind up in peoples’ living rooms.
Posted by Bob Rehak on 7/20/2022
1786 Days since Hurricane Harvey
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In the last few weeks, Michael Bloom, a fellow member of the Harris County Community Flood Resilience Task Force, and I have debated the inherent bias and limitations of a Flood-Mitigation Benefit Index (FMBI) proposed by a majority of the Task Force to Harris County Commissioners Court.
According to Mr. Bloom, the index will:
Reveal and document patterns of historical discrimination.
Help plan where additional flood-risk reduction investments should be made.
Population-Based, Not Damage-Based Mitigation
The formula is:
Cost = total flood-mitigation construction spending (and only construction spending) that benefits a census tract.
Population = the number of people who live in census tracts.
Risk = the annual chance of flooding (applied to census tract(s)) expressed as a whole number. For instance, a 1% annual chance equals 1. And a 10% annual chance equals 10, etc.
The Task Force hopes to calculate and compare the results for each census tract in the county.
According to proponents, “a high benefit score means no more mitigation spending is needed. And a low score means more spending is needed.”
But consider these two examples:
4,000 people live with a 1% annual chance of flooding and have received $200 in prior investment. Their FMBI would be 0.05. That’s extremely low. And scores that low indicate such areas need help “regardless of prior investment.”
8000 people live in the 10-year flood plain and have received $10 million in prior investment. Their FMBI equals 125. That’s 2,500 times higher.
According to a spokesperson for the FMBI, “A high FMBI means we don’t need to make more investments in that location.” Yet twice as many people live with ten times the risk in the area with the higher index.
So, who deserves the most help? Residents with the lowest FMBI? The formulaSAYS they need help the most. But they actually have the lowest risk.
The Value of Market Testing
None of the hypothetical examples used to “sell” the formula hint at the possibility of such an upside-down result.
The example above proves several things:
The formula can produce inconsistent and misleading results.
Adjusting for population doesn’t prove historical discrimination. The most densely populated area has 50,000 times more investment.
The formula needs rigorous testing and ground-truthing before going any further. This is a best practice for any new scientific formula – especially one intended to guide future investment.
In addition to producing unintended results, the formula has several other problems that require discussion.
No Right-Of-Way Acquisition Costs Included
The FMBI formula includes only construction costs. It excludes right-of-way acquisition costs by assuming that they are “uniform throughout the county.” Therefore, “…costs included or excluded will not adversely impact results.”
In fact, Right-of-Way (ROW) Acquisition costs are huge and NOT UNIFORM throughout the county. I have documented that ROW costs typically comprise the second most expensive part of flood-control projects.
A quick glance at the Appraisal District website will tell you that land costs vary widely throughout Harris County and change over time.
In fact, acquiring land in densely populated areas for flood mitigation often costs more than construction, according to several engineers I consulted.
I worry that other methodological issues may compound each other, not cancel each other out.
Census tract population typically varies by up to 4X (2,000 to 8,000), according to the Census Bureau. This will produce deceptive spatial comparisons.
Some Census tracts may comprise dozens of square miles while others comprise a few city blocks. Typically, flood mitigation projects are not considered at the Census-tract level. According to three engineers I consulted, that’s too small in most cases to be workable.
Larger Census tracts may contain multiple watersheds, each with independent levels of risk – or individual watersheds with varying levels of risk. In such cases, the formula would average risk. But averaging can mask a serious problem in one area with a non-problem in another. Thus, the formula has a bias in favor of spatially smaller Census tracts. Smaller tracts tend to be more uniform in risk, so problems will likely stand out rather than get lost in an average. But in larger watersheds, flood risk will feather out with increased elevation and distance from a river. That will make it extremely difficult to calculate the number of people exposed to varying degrees of risk. Averaging takes the simple way out. But averaging risk is like comparing saints and sinners, then declaring “No problem.”
The data collection effort for the index omitsmany sources of funding. So the formula will calculate investment dollars from some entities and areas, but not others. For instance, the formula will NOT measure drainage funding from Harris County Commissioner Precincts, dozens of cities, and 389 municipal utility districts in unincorporated areas. The difficulty of data collection in these areas will produce another spatial bias. Likewise, the FMBI formula will omit the considerable drainage-improvement contributions of reputable private developers.
No one has tested how these inconsistencies will affect each other. But there’s an even bigger data integrity issue.
Partially Updated Data
HCFCD and its partners invested more than $1.5 billion in flood mitigation between Harvey and the end of 2021. Since 2000, they’ve invested more than $3.5 billion. But as of this writing, new MAAPnext flood maps only reflect the POST-mitigation risk associated with projects in FIVE bayous: Brays, Greens, White Oak, Sims, and Hunting. The Army Corps partnered with HCFCD in those.
Unfortunately, according to a knowledgeable source, HCFCD has not yet updated the risk maps for its own Capital Improvement Projects in other watersheds. So if you ran the allocation formula now, it would compare PRE-mitigation risk in 18 watersheds with POST-mitigation risk in 5.
Mitigation in those five watersheds totals $439 million out of $1.5 billion since Harvey. So true, current risk is reflected in only 29% of spending since Harvey and 13% in this century. Those percentages will no doubt increase in the future. But if you ran the numbers today, you would compare numbers with PRE- and POST-mitigation risk.
And consider this. With HCFCD spending at the current rate of about $80 million per quarter, “current risk” is a constantly changing target. So we’ll never be able to compare apples to apples in all watersheds anytime soon.
And we want to use this formula to guide future mitigation spending? Using it could send more money back to fix areas we already fixed!
Difficulty of Assigning Investments to Census Tracts
Another challenge: How do you determine which census tract(s) to apportion project benefits among? Example: Addicks and Barker Reservoirs. The Army Corps developed those back in the 1930s to protect downtown Houston…15-20 miles away!
Do you credit the investment to:
All of downtown?
People living inside the reservoirs (who have their own census tract)?
The current population of the entire Addicks and Barker Watersheds?
All census tracts along Buffalo Bayou and parts of White Oak Bayou, our second and third most populous watersheds?
And virtually all residents of the Addicks and Barker watersheds live upstream from the Corps’ investment, so they will not benefit from the investment either.
Downtown has immense commercial and economic value but relatively few permanent residents.
So, who gets the benefit? Again, lots of room for interpretation and misplaced assumptions here that numbers can easily mask! Now, multiply this problem times thousands of Census tracts.
The population-based FMBI has a built-in bias against commercial areas that have little to no residential population. For example, consider the cases of Downtown, the Texas Medical Center, and the Port of Houston. Such areas support employment throughout the region, but the formula discriminates against them by giving huge weight to population and omitting actual damage.
No Thresholds Defined
To my knowledge, the task force has never discussed threshhold “benefit” levels that correlate to “needs help” or “doesn’t need help.” The extremes may sometimes be easy to determine. But what about outcomes in the middle?
Variables in the formula can offset each other as we saw above. In tight races for funding, who gets the next flood-mitigation investment? The area with the lowest investment, highest risk, or largest population? Such quandaries have not yet been addressed.
No Agreement on Weights of Other Factors
To help make future flood-mitigation decisions, proponents of the formula also suggest weighing (separately) other factors, such as the CDC’s Social Vulnerability Index. It includes the percentage of Low-to-Moderate residents in an area. However, no one has yet discussed the weight given the Benefit Index relative to other factors.
No Consideration of Actual Flood Damage
In deciding where to put flood mitigation projects, engineers traditionally look for damage clusters. It’s that simple. Dollars flow to damage.
Reducing flood damage is a tried and true, measurable way to evaluate projects. So why all the complexity?
What’s The Point?
What is this formula trying to prove? Is it attempting to develop a new approach to mitigation funding that eliminates a perceived bias in Benefit/Cost Ratios?
Commissioner Rodney Ellis often talks about how calculating the value of avoided damages in higher value homes disadvantages projects in poorer neighborhoods. That can be true in some instances. Expensive homes can ratchet up benefits (measured in dollars) faster than lower value homes can. And that can result in higher Benefit/Cost Ratios for projects in affluent neighborhoods – assuming density is held constant. But…
One high-value home on an acre would likely appraise less than an apartment building, also on an acre. In Kingwood, I compared the valuations of an expensive single-family home with a large apartment complex one block away. The appraised cost per acre (including structures) of the apartment complex is 4X higher.
Now consider that apartments accommodate almost half of Harris County’s population.
Most Americans aspire to and encourage home ownership, in part, because of the stability it fosters in communities. But this formula – because of its emphasis on population density – favors apartment areas over areas with owner-occupied homes. There’s nothing inherently wrong with that. You just need to understand what the formula does.
Difference Between Vertical and Horizontal Density
The Benefit Index favors all areas with dense population. Proponents argue that helping more people is better. I don’t argue with that. However, the generalization masks the financial pain inflicted by a flood on owners vs. renters, and on the people who live at ground level compared to those who live above it.
Ground floor renters may lose contents in a flood, but they won’t be responsible for making structural repairs. The owner will.
And many living above the ground floor may find themselves more inconvenienced by flooding than financially devastated. So, is it fair to count all people on all floors when determining who suffers the most pain?
In the proposed formula, higher population will lower the benefit index, making it look as though all renters (almost half the county’s population) suffered more than owners of single-family homes.
The premise underlying such “equity” arguments is that poor people can least afford floods. But most people in apartments like those shown above won’t make structural repairs as a homeowner would.
No Perfect Formula
No perfect formula exists that’s equally fair to all in all circumstances. That’s why FEMA, HUD and the Army Corps allow consideration of multiple factors when determining which projects to fund.
The Flood Mitigation Benefit Index focuses totally on population, risk, and past investment. It ignores actual flood damage.
If we use ANY formula to HELP allocate future flood-mitigation funds, we should all strive to:
Understand its built-in biases
Maintain high standards for data integrity.
If we want to test a hypothesis of historical discrimination in flood-mitigation funding, there’s a much simpler way. It’s called direct measurement. Simply locate damage centers from past storms and compare funding in the following decade designed to mitigate those areas.
For More Information
For more background on issues with the formula, see my earlier posts:
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The presentation begins with a history of the relationship between the Army Corps and HCFCD dating back to 1937. It references past joint projects such as work on the Addicks and Barker Reservoirs; and Brays, White Oak, Little Vince, Cypress, Greens and Sims Bayous.
It also references projects not yet completed such as work on White Oak and Hunting Bayous, and Clear Creek. Finally, it looks forward to future collaboration on Buffalo Bayou, Halls Bayou and a County Wide-Study that “lifts up and empowers our diverse communities to thrive.”
The intro contains graphics that summarize:
Damage during Hurricane Harvey
Atlas-14 rainfall vs previous estimates
Current and Active Army Corps projects
A county-wide map of “Recently flooded” (from Harvey) structures overlaid on a social-vulnerability map
The leave-behind then makes three “asks” corresponding with each of the three major projects.
Buffalo Bayou and Tributaries Resiliency Study
The first ask is for help “finding the right solution for Addicks and Barker Reservoirs.” It talks about managing residual risk and liability. Specifically, it asks for support through the completion of the Corps’ Buffalo Bayou and Tributaries Resiliency Study.
It alludes to policies and processes impeding needed progress. Then it says, we must blaze a trail for a new equitable flood risk management paradigm.
An engineer familiar with Buffalo Bayou told me that the study had been cancelled at one time because of a poor Benefit/Cost Ratio. It wasn’t because, as you often hear, that home values were low. It was because land acquisition costs were so high. Possible workarounds: several proposed “innovations” including:
A comprehensive benefits framework that includes more than a strict benefit/cost ratio.
“Emphasis on community resiliency, environmental justice, and climate change adaptation.”
The last update of this study on the Corps’ website is from late 2020. The final report has not yet been released. This post from 2020 summarizes the findings of the interim report.
County-Wide Section 203 Study
Section 203 of the Water Resources Development Act was amended to let non-Federal sponsors conduct feasibility studies that serve as the basis for authorization of new water resources projects, such as flood tunnels. But acceptance of the results is at the discretion of the ASA (CW). One objective of the presentation: to get the ASA(CW) to partner Harris County on a County-wide flood risk study.
The county pitched the partnership as:
A potential “pilot study for Justice40”
Climate change preparedness
Empowering vulnerable communities to withstand and recover from flood events.
Justice40 is a Biden initiative, announced within his first few weeks in office. It uses every lever at his disposal “to advance environmental justice and spur economic opportunity for disadvantaged communities. The “40” refers to Biden’s promise to deliver at least 40 percent of the overall benefits from Federal investments in climate and clean energy to disadvantaged communities. One of the priorities: mitigation initiatives that reduce or eliminate the risk of repetitive flooding.
Halls Bayou Section 118 Study
According to the presentation, the Federal government had a project to study flood-risk management on Halls Bayou from 1990 to 2016 when it was “de-authorized.” The county wants to restart it. Section 118 refers to “Pilot programs on the formulation of Corps of Engineers’ projects in … economically disadvantaged communities.”
Harris County wants the Corps to include Halls on its list of ten nationwide pilot studies for such communities. HCFCD points out that Halls has the highest percentage of Low-to-Moderate Income residents of any watershed in the county (71%). Halls has a poverty rate of 28% and a social vulnerability index of 0.85 out of 1.00. Halls also has frequent, severe, repetitive flooding.
At one time, HCFCD cancelled Halls’ Bayou studies because they all came back with Benefit/Cost Ratios below 1.0. That means costs exceeded benefits. HCFCD hopes to restart those in 2022. Section 118 gives the ASA (CW) a way to apply other criteria that compensate for a low BCR in disadvantaged areas.
Posted by Bob Rehak on 7/7/22
1773 Days since Hurricane Harvey
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Neither alternative would modify the concrete portion of the spillway, as crest gates would. Black & Veatch, the engineering firm in charge of the project, will explore adding the tainter gates in the earthen embankment to the east of the existing spillway. See below, upper right.
The eastern embankment is a solid earthen area 2800 feet long east of the spillway and existing gates (see upper right of photo above). Water cannot get over it in a storm because it is so much higher than the spillway. By adding various structures in this area, engineers could widen the current spillway capacity, allowing release of more stormwater.
Tainter gates rotate up from a central pivot point. Crest gates rotate down from a bottom hinge, like a piano lid.
Minutes from May CWA Board Meeting
Item IV(B) on Page 3 of the May 11, 2022, minutes states, “…CWA, City of Houston (COH), and Black and Veatch (B&V) met on April 14, 2022. During that meeting the COH requested that an alternate gate location to the east of the existing gate structure be further [emphasis added] evaluated.”
Following the meeting, B&V developed a scope of work to update the gate concepts and construction costs for this area. The COH provided comments and B&V modified its proposal. B&V reportedly began work on the new direction by June 1.
Additional Funding Needed
Each of the new alternatives would require additional funding; neither fit within the existing budget, according to the CWA staff. COH Public Works will pay for the new evaluation.
Wayne Klotz, P.E. and President of the CWA Board, reminded everyone present that COH owns the dam and is the FEMA grantee for this project, while CWA works for and takes direction from COH.
Minutes from the June CWA meeting have not yet been posted. The last post about gates on the COH District E website was almost a year ago on July 8, 2021.
However, City Council member and Mayor Pro Tem Dave Martin did take questions on the project at an April 2022 community meeting. At the time, Martin expected to have a final answer on gates in a “September-ish” time frame.
Currently, the release capacity of tainter gates on the Lake Conroe Dam is 15X greater than those on the Lake Houston Dam (150,000 cubic feet per second (CFS) vs. 10,000 CFS.)
Concept Studied and Rejected Once Already
Adding gates to the eastern embankment was one of the original concepts evaluated. (See Column 5, Offsite Alternative #2, Column 5, Page 4.) But engineers focused on adding crest gates instead, largely because the total estimated costs for adding tainter gates at that time exceeded $90 million for a $50 million budget. However, the Army Corps also had environmental concerns about adding gates to the eastern embankment.
FEMA initially gave the City three years to complete the project (18 months for engineering and 18 for construction). Engineering began in April 2020.
No other details about May’s change in direction have been released to my knowledge.
Posted by Bob Rehak on 7/4/2022 based on minutes from the May CWA Board meeting
1770 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/07/20200911-RJR_1521-2.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-07-04 15:33:252022-07-04 16:13:48CWA Exploring Alternate Plan for Adding Lake Houston Dam Gates
After Hurricane Harvey, people and businesses both upstream and downstream of the Addicks and Barker Reservoirs on Houston’s west side sued the Army Corps. Plaintiffs in both cases alleged that the Army Corps’ operation of the dams flooded their homes and constituted a taking of their property without compensation. The Fifth Amendment of the U.S. Constitution prohibits that.
Difference Between Upstream, Downstream Cases
However, the Upstream and Downstream cases also have important differences. Upstream, the Corps did not own all the land inside the U-shaped reservoirs. Worse, the Corps permitted developers to build homes and businesses inside the reservoirs on land that remained in private hands. The Corps did not anticipate it all flooding based on storms they had studied going back to the 1890s. Yet the Corps still built the walls taller and longer than it needed to hold anticipated floods.
When Harvey came along, the water in the reservoir backed up onto that private property and flooded hundreds of homes.
Lawyers for the flooded property owners asserted that the federal government cannot use private property to store federal floodwaters without providing compensation. The judge agreed.
Although the trial portion of the damage phase just concluded, the case is not yet over. McGhee, Chang, Landgraf & Feiler, one of the law firms representing plaintiffs in the class-action suit, said they must still submit post-trial legal briefings. Then they will make final closing arguments in Washington D.C. in a few months. “We expect a decision to be rendered by the Court thereafter – probably sometime in late fall/winter,” said a press release by the firm.
Exponential Growth, Larger Storms, But No Mitigation
After reading the 46-page decision, I gained a better grasp of the history of the dams and the nature of the claims.
The Corps built the dams much higher than they needed to hold a 100-year flood based on what they knew at the time.
But the Corps did not purchase all land inside the reservoirs. They left private property outside the area expected to flood. At the time the dams were constructed, that land was used for ranching and rice farming.
If the land flooded, reasoned the Corps, not much damage would result. But then came Houston’s exponential growth in the 1950s. Those ranchers and rice farmers sold their land to developers. And developers started to build inside the reservoir.
Then the Corps realized that the storms on which it based the reservoirs’ designs (including a storm from the 1890s) were smaller than storms hitting the Houston area in the modern era. But by then, it was too late.
When the Corps realized future floods would likely invade homes, it launched an awareness program and held some public meetings. But the judge felt that information didn’t filter down to most homebuyers.
Also, the Corps took no concrete steps to reduce flood risk when it realized the severity of the problem. Worse, the Corps continued to issue permits and authorizations for more developments.
To sum up 46 pages in a sentence, “The Corps knew it had a problem and did nothing to fix it.” (That’s my takeaway, not the judge’s language.) The Corps remained focused on its primary objective – preventing downstream flooding.
Downstream Focus Looms Large in Upstream Decision
Said Judge Lettow, “Equipped with the knowledge that storms of the design-storm magnitude were probable, the Corps did not stray from its primary objective to prevent downstream flooding (indeed, it probably could not), even when it knew that could well mean impounding water on private property.”
Lettow cites a 2012 Water Control Manual which the Corps followed during Harvey. It instructs the Corps to operate the dams in a manner consistent with their original purpose: to protect downstream property by impounding water in upstream reservoirs. It states “…operate the reservoirs in a manner that will utilize to the maximum extent possible [Emphasis added] the available storage to prevent the occurrence of damaging stages on Buffalo Bayou.”
Knew Larger Floods Probable
According to the judge, the Corps continued to follow that policy even though it understood that rainfall events – larger than ones they designed the dams around – were “probable, rather than merely possible.”
Lettow also found it “undisputed that plaintiffs did not know their properties were located within the reservoirs and subject to attendant government-induced flooding.”
Government Planned for Years to Impound Floodwater on Private Property
Said one hydrologist who reviewed a detailed history of the Corps’ decision making, “The Corps of Engineers did NOT buy the entire area they knew would be inundated if Addicks and Barker reservoirs were at peak storage capacity.”
Judge Lettow said, “The government had made a calculated decision to allow for flooding these lands years before Harvey, when it designed, modified, and maintained the dams in such a way that would flood private properties during severe storms. Defendant cannot now claim that this harm was unavoidable when it planned for years to impound floodwaters onto plaintiffs’ properties.”
The Corps made the best decisions it could with the information AVAILABLE at the time. But as we all know, things change! And that’s what worries me most about this case.
Right now, developers are building projects all around the region based on flood maps that will soon be replaced.
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/2022/06/Flooded-Homes-Addicks-Reservoir.jpg?fit=1200%2C765&ssl=17651200adminadmin2022-06-11 16:03:182022-06-11 21:44:24Upstream Addicks-Barker Trial Concludes, But No Ruling Yet on Damages
And I will look at partner funding from the standpoint of outcomes, not just processes (as in the myth).
Methodology for Analysis
For this analysis I obtained Harris County Flood Control District spending data between 1/1/2000 and 9/31/2021 via a Freedom of Information Act (FOIA) request. I requested the data by watershed, decade, pre-/Post Harvey, source of funding (local vs. partner), and type of activity (i.e., engineering, right-of-way acquisition, construction and more). I cross-referenced this with other data such as flood-damaged structures, population, population density, and percentage of low-to-moderate income (LMI) residents.
When considering grants, the percentage of LMI residents in a watershed takes on special significance. Department of Housing and Urban Development (HUD) grants often require high percentages of LMI residents in the area under consideration.
In the charts below, you will see references to watersheds with LMI populations above and below 50%. Above 50% means more than half the residents in the watershed have an income LESS THAN the average for the region. Below 50% means more than half the residents earn more than the regional average.
Harris County has 23 watersheds. Eight have LMI percentages above 50% (less affluent). Fifteen have LMI percentages below 50% (more affluent).
When reviewing the charts below, pay particular attention to the italicized words: Total, Partner, and On Average. They represent three different ways to look at the same question: Do housing values disadvantage an area when applying for grants?
For this analysis, I focused only on the long term, since decisions on more than a billion dollars in flood-bond grants are still outstanding.
FOIA Analysis Contradicts the Popular Myth
One of the first things you notice when you look at watersheds above and below 50% LMI, is that the eight least affluent watersheds have gotten more than 60% of all dollars actually spent on flood mitigation since 2000.
Because the allegation was that partnership grants favored affluent areas, I then analyzed whether partner dollars went mostly to affluent or less-affluent watersheds. The answer is less affluent…overwhelmingly.
The last observation by itself is telling. But because of the widely different number of watersheds in each group, I also wanted to calculate the average partner dollars per watershed in each group. This blows the “rich neighborhoods get all the grants” argument to pieces. Less affluent watersheds got, on average, 4.7X more.
This busts the myth. But digging even deeper into the data reveals two things: wide variation between sources of funding and withinLMI groupings.
USACE Funding Skews Partner Totals
The U.S. Army Corps of Engineers (USACE) accounts for much of the partner funding. USACE has provided significant funding for projects in the Sims, Brays, White Oak, Hunting, and Greens Bayou watersheds. The Clear Creek watershed will also soon see work on a new USACE project. USACE has completed its planning process and proved positive benefits to national economic development. That made projects worthy of Federal investment.
Halls Bayou: Digging Deeper
The Halls Bayou watershed also went through the USACE planning process, but the results did not show enough flood-damage-reduction benefits to outweigh the costs of the proposed projects. Thus, the Halls Bayou watershed currently has no USACE-funded projects.
Despite that, Halls has received more partner funding than 16 other watersheds since 2000. Only two watersheds in the affluent group of 15 received more partner funding. See the table below.
USACE also evaluated the more affluent Buffalo Bayou; results showed that costs outweighed the flood-damage-reduction benefits there.
Despite Halls having the highest percentage of LMI residents in Harris County, Halls has received more total funding and 2.5X more partner funding than Buffalo Bayou in the more affluent group.
FEMA Considers More than Home Values, Not All Grants Come From FEMA
While it’s true that FEMA considers housing values as a factor in benefit/cost ratios, benefit/cost ratios (BCRs) also consider factors such as:
The number of structures damaged
Threats to infrastructure
Proximity to employment centers
Need for economic revitalization
Percentage of low-to-moderate income residents in an area
Number of structures that can be removed from the floodplain by a project.
USACE funds dozens of different types of flood-mitigation programs. Many support national defense, the national economy, strategic interests, the environment, commerce and navigation.
So don’t settle for soundbites. They often mislead.
Posted by Bob Rehak on 12/30/2021
1584 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/12/Screen-Shot-2021-12-29-at-4.53.47-PM.png?fit=1366%2C740&ssl=17401366adminadmin2021-12-29 21:28:052021-12-30 14:37:20Equity Myth Buster: “Rich Neighborhoods Get All the Flood-Mitigation Funding”
Widening of Hunting Bayou, one of the poorest and most flood-damaged watersheds in the county, is kicking into high gear.
Annual Rate of Spending Almost Quadruples since Harvey
According to data obtained as part of a Freedom of Information Act (FOIA) request, Harris County Flood Control District and its partners (mainly the Army Corps and City of Houston), spent $44 million on flood mitigation in the Hunting Bayou watershed between 1/1/2000 and Hurricane Harvey.
That averaged $2.4 million per year for those 18 years. However, in the 4 years since Harvey, HCFCD has spent $37 million – more than $9 million per year.
Here’s a breakdown.
Focus of Current Construction Activities
The upstream portion of Hunting Bayou parallels the south side of Loop 610 for most of its length. Where North Loop 610 turns south, Hunting cuts under it between McCarty and Wallisville Roads. From there it continues east. It then turns southeast at San Pedro Street and eventually joins Buffalo Bayou and the Ship Channel.
Poor, Industrial, Flat, Flood Prone
The Hunting Bayou watershed has the second highest percentage of low-to-moderate income (LMI) residents in the county (69%) after Halls Bayou (71%) immediately to the north.
Hunting also is heavily industrialized with rail yards, tank farms, manufacturing, and shipping companies. The highest points of land are the railroad tracks. Within the red box above, you can see how they affect the flood plain.
After driving around the neighborhoods along Hunting Bayou for an entire day, it appears that the worst storm damage is in the red box above. Many homes are boarded up and abandoned in this area. Others have been elevated. Some have been renovated and are waiting for the next flood.
Current Construction Photos of Bayou Widening Efforts
HCFCD bayou-widening efforts focus on this area right now. They extend from US59 on the west to approximately Wayside Drive on the east. Bayou widening may be an understatement. HCFCD appears to be creating a long series of connected detention basins, some more than 450 feet wide and several city blocks long that narrow at bridges.
This should help drain water from nearby neighborhoods during heavy storms. See pictures below all taken on Sunday, 12/19/2021. They generally trend from west to east, starting at US59 and heading downstream.
Funding Flows to Damage
Altogether, the current excavation work stretches 3.33 miles.
In the last five major storms (Allison, Tax Day, Memorial Day, Harvey, Imelda), 15,763 structures have flooded along Hunting Bayou. That ranks 7th among all Harris County Watersheds. But one must remember, that Hunting, comprises only 31 square miles. That ranks it 19th in size out of 23 watersheds. The damage per square mile ranked #2 (508.5 structures).
Another reason spending has accelerated here is political policy – namely the Equity Prioritization Framework implemented a year after the flood bond passed.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/12/20211219-DJI_0152.jpg?fit=1200%2C799&ssl=17991200adminadmin2021-12-19 20:53:442021-12-19 23:31:42Widening of Hunting Bayou Kicks into High Gear