population Archives - Reduce Flooding

Five Watersheds Lose Population While Harris County Gains Slightly

Like damage, population is one of the “weighting factors” considered in the distribution of flood-mitigation dollars. Compared to 2017 estimates of watershed populations in Harris County, 2022 estimates show that five watersheds have lost population. But overall, the county has gained 155,254 people.

*Data compiled from information provided by HCFCD in response to FOIA Requests*. *Alphabetical by watershed.*

The map below shows the location of each of these watersheds.

*Harris County Watersheds by Harris County Flood Control District*

Reasons for Shifts Unclear

I had wondered whether the five major floods in Harris County between 2000 and 2020 (Allison, Tax Day, Memorial Day, Harvey and Imelda) would cause the most heavily flood-damaged areas to lose population. But that seems not to be the case.

The most heavily damaged watershed (Brays) lost the most population (in raw numbers). But the second most heavily damaged watershed (Greens) gained more than 16,000 people, the second largest gain.

I found no meaningful correlation between flood damage and population loss or growth. Nor do data suggest that flood-mitigation spending has much influence either. Contradictory examples abound. And statistical correlations rate as negligible to weak.

Five Watersheds Lost Population

Compared to the previous Census estimates from 2017:

Brays lost 5,822 people (0.8%)
Cedar lost 4,153 people (11.1%)
Hunting lost 1,112 people (1.4%)
Little Cypress lost 727 people (1.6%)
Vince lost 176 people (0.2%).

In percentages, Cedar Bayou lost the most population. Cedar was the sight of the Arkema disaster which blocked evacuation routes along Highway 90 during Harvey. The watershed currently has only about 37,000 people, ranking it 20th among the 23 watersheds in Harris County.

In five major storms between 2000 and today (Allison, Tax Day, Memorial Day, Harvey and Imelda), flood damage varied widely within those five watersheds:

Brays flooded 32,240 structures, the most of any watershed.
Cedar flooded 2,274.
Hunting flooded 15,763.
Little Cypress flooded 1,040.
Vince flooded 4,152.

18 Watersheds Gained Population

Eighteen other watersheds gained population and also had widely varying degrees of flood damage. These, too, showed little correlation.

Altogether, the county’s watersheds gained 155,254 people, despite 226,729 damaged structures during the five major storms.

Negligible Correlation of Flooding and Population Gain/Loss

The “population flees flooding” hypothesis didn’t hold much water.

Flood damage and “number of residents lost” correlated at only a 0.16 level – insignificant. Flood damage and “percent of residents lost” correlated at only 0.28, extremely weak.

A perfect correlation is 1.0. It indicates that for every unit of change in one variable, there is a corresponding unit of change in another variable. However, that was far from the case here. Variations seemed random.

If long-time Harris County residents are moving to higher ground, they may be replaced by newcomers unaware of flood risks.

The County has a strong draw: jobs. Also, family, friends, neighbors and support networks remain powerful attractions that keep most people anchored.

The new HCFCD data do not suggest why gains and losses occurred.

Top reasons for relocation typically include: greater safety, better schools, better housing, new jobs, and upgrading from apartments to homes.

LMI Population Trends

HCFCD also measures “LMI population.” LMI stands for Low-to-Moderate Income. The Census Bureau defines LMI as “families making less than the average for the region.”

Harris County has 42.6 % LMI residents. So 57.4% of residents make above the average for the region.

This is important because the LMI percentage plays a huge role in partnership grants from the US Department of Housing and Urban Development (HUD). Most, but not all, HUD grants go to areas with LMI populations higher than 70%. A notable exception is the pending $750 million HUD Harvey flood-mitigation grant. It only requires that 50% of the money benefits LMI households.

The latest HCFCD data shows that watersheds at both ends of the income spectrum lost LMI population. We still have the same eight LMI-majority watersheds we had in 2017. However, one deserves special mention.

Brays’ LMI population declined so significantly that it almost flipped from the “majority LMI” category to “majority upper income.” It went from 58% to 51% LMI.

Sixteen other watersheds gained LMI population. Some had huge flood losses; others had few.

The correlation between total flood damage and LMI Population Gain/Loss is .34, slightly higher than for the entire population but still considered “weak.”

Here are Harris County’s watersheds ranked in order of LMI population percentage.

My next post will discuss how the distribution of flood-mitigation funds relates to population changes and other factors. I will also discuss what the prospects for flood mitigation in the Lake Houston Area are during Lina Hidalgo’s second administration. Don’t miss it.

Posted by Bob Rehak on 11/21/22, based on data provided by HCFCD in response to a FOIA Request

1910 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.

Response to Concerns About Flood Mitigation Benefits Index (Part II)

The letter below expresses disagreement with two recent ReduceFlooding.com posts about a proposed Flood Mitigation Benefits Index. It is from Michael Bloom, P.E. While I disagree with almost all of his claims, I am reprinting his letter verbatim because I encourage healthy debate. Compare the posts and draw your own conclusions. – Bob Rehak, Host, ReduceFlooding.com.

This is Part II of my two-part article providing responses to concerns raised by my colleague on the Community Flood Resilience Task Force (CFRTF), Mr. Bob Rehak about the FMBI. If you missed Part I, you can read it here.

Why are we Using the Index When it Produces Inconsistent Results that are Not Intuitive? Mr. Rehak provides an example that holds the current population and current risk the same, but changes the total prior investment amounts, as illustrated in the table below:

	Prior Investment ($)	Current Population (Number)	Current Risk (% Annual Chance)	FMBI
Area A	100,000	5,000	10	2
Area B	1,000,000	5,000	10	20

Mr. Rehak looks at these results and writes: “So, spending more money to get the same results increases benefits? Shouldn’t it be the opposite? That’s both depressing and confusing. You spend 10X the money; flood risk remains the same; and the “benefit” increases!!!??? You would think spending less money to achieve identical results would be more beneficial. It certainly is for taxpayers.”

Everyone should be depressed and confused by this result if the FMBI was illustrating the results for the same location. Mr. Rehak appears to make that inference when he writes: “spending more money to get the same results increases benefits.”

But Area A and Area B are two different locations. The FMBI is just telling us what the current conditions are at two different locations in the county. One location had 10 times the prior investment than the other – but both locations still have the same current risk.

Worse, in this case, BOTH locations have risks that are ten times the current standard of care for new developments – which require structures to have less than a 1% annual chance of inundation. Clearly, both locations need more flood risk investment. The FMBIs of 2 and 20 both are extremely low, meaning they need help, regardless of the prior investments. A high FMBI indicates that no additional help is needed in that location. A low FMBI indicates that additional help is needed in that location.

The table included in the middle of my February 17, 2022, post entitled “How Should We Decide Where to Invest in Flood Risk Reduction?” presents additional examples showing how the FMBI changes from location to location with only one changed variable. It also provides narrative explanations of each sequence. Notice how the index values are greater than 3,000 (sometimes greater than 20,000 or 100,000) in locations where the current annual chance of inundation is less than 1%? Again, a high FMBI means we don’t need to make more investments in that location. A low FMBI means that location needs more help.

Isn’t the FMBI Trying to Prove Inequitable Investments in Flood Risk Reduction? To some extent, partially, yes, it is. This was always an important aspect of the FMBI, when it was originally proposed as the “Flood Benefits Index (FBI)” by Dr. Erthea Nance and Iris Gonzalez in May 2021. I have continued to advocate for its use as one of four input variables we should use to create our county-wide “heat map.” This is explained in more detail in my other article. Mr. Rehak is concerned about the taxpayer. I am also. I don’t think the taxpayers of Harris County should pay for flood risk reduction projects in areas that already have a high FMBI. Said another way, it is a waste of taxpayer money to invest in additional flood risk reduction projects in areas currently with less than a 1% annual chance of inundation.

Isn’t the FMBI Measuring per capita Investment Associated with a Certain Level of Flood Risk and Mistakenly Calling that a “Benefit?” Mr. Rehak writes: “The more people you help with any given sum, the more the benefit goes down. Voila! That makes it look as though the highly populated watersheds (that have received the overwhelming majority of prior investments) have received little benefit. And that may be the point of this formula. It will send even more money to those same areas.”

This interpretation again seems to stem, I think, from Mr. Rehak’s belief that the index will be used to compare the same location at different times – before and after various investments. This is not the proposed use of the index. The proposal is to use the index to describe the current conditions at all locations in the county at the same time.

I’m not sure I understand Mr. Rehak’s concern about the index being a per capita value. The more people in an area who benefit from prior investments the better. Wouldn’t we want to invest in areas that help the most people?

The blue-shaded area of the table in my earlier post illustrates how population differences between locations will change the index value among those locations. For convenience I’ve repeated the table below:

Mr. Rehak accurately notes that the index goes up in locations with fewer people and down in locations with more people; this will incentivize planners to direct future investments in those higher population areas. He writes: “The more people you help with any given sum, the more the benefit goes down.” This is true, but Mr. Rehak’s statement doesn’t connect it to the past and it omits how the index will be normalized by area size. Index values will be calculated for similarly sized areas. This will allow an apples-to-apples comparison of per capita investments. The index is intended to incentivize future investments in areas with more people in cases where risk and prior investments are equal because we want to help as many people as possible.

By Michael Bloom, P.E.

Posted by Bob Rehak on 7/10/2022

1776 Days since Hurricane Harvey

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Latest Flood-Mitigation Funding Trends

New data obtained from Harris County Flood Control District via a FOIA Request breaks down flood-mitigation funding by watershed through the end of 2021. It shows where your flood-bond money is going. It also debunks some popular myths. Those include the oft repeated:

Rich watersheds get all the funding; poor watersheds get none.
Partner funding favors rich watersheds because home values are higher.
HCFCD has historically discriminated against low-to-moderate income (LMI) watersheds.

Eight out of 23 watersheds in Harris County have a majority of residents that fall into the LMI category. That means a majority make less than the average annual income for the region. As the data below shows, those eight LMI watersheds get the vast majority of county, partner, and total funding. In fact, four have received 54% of total flood-mitigation funding since 2000.

Funding now correlates more highly with LMI population than damage!

Data also calls into question why some feel compelled to tweak the equity prioritization framework endlessly.

Improved Basis for Reporting

Before I dive into the data, though, let me point out that between the 3Q21 and the end of last year, the county changed the way it compiles historical data. Instead of using the start/stop dates in project management software and reporting only completed projects, the county is now using invoice dates. This produces much higher accuracy. Dollars do not spill over from one period into another. The new data also reflects spending on projects that are ongoing, but still open.

In response to my FOIA Request, the county provided spending using both the old and new methods. They differ by roughly $615 million. Of that, approximately $215 million reflects actual fourth-quarter spending and $400 million reflects the change in when expenses are recognized.

Spending by Watershed

The rank order of spending by watershed has not changed much since last year. Several watersheds moved up or down by a place or two.

The top four are still the top four in the same order. But some of the amounts changed radically, mostly due to the change accounting. For instance, White Oak increased from $387 million to $521 million. But out of the $134 million difference, $102 million comes from when expenses are recognized.

Because this gets so confusing, and because the rank order did not change much, I will use only the new totals compiled by invoice date from now on. I will not compare old and new totals based on the different accounting methods.

*Spending by watershed between 1/1/2000 and 12/31/2121 broken down by county and partner contributions, and LMI/Other watersheds.*

Graphs of Spending

Here’s a graph of total funding by watershed since 2000, arranged from highest to lowest.

*Watersheds rank ordered by amount of flood-mitigation funding received between 1/1/2000 and 12/31/2121.*

Funding correlates with population. But you can see notable exceptions below. Some watersheds get far more funding than their proportion of the population, i.e., White Oak, Sims and Greens. Others get far less.

*Spending is not allocated proportionately to population in all cases. Six out of eight LMI watersheds received more funding than their population alone would justify.*

But population alone does not tell the whole story. Some watersheds are huge and some small. So I also looked at population density per square mile. The curves correlated even less.

Graphing population density vs. total spending shows more variance. Of the eight LMI watersheds, four (Brays, White Oak, Sims, and Greens) get far more than their population density alone would dictate.

As we saw last year, funding flows primarily to damage. The chart below plots funding versus the total number of structures in each watershed damaged in five major storms (Allison, Tax Day, Memorial Day, Harvey, and Imelda). The slope of the curves closely match. But several major exceptions exist.

Historical Discrimination?

Many community groups from LMI neighborhoods have alleged historical discrimination in the distribution of flood-mitigation funding. I just don’t see it. All of the pie charts below take into account all funding between 1/1/2000 and 12/31/2021 based on invoice dates.

*The county itself sent almost 60% of its flood-mitigation funding to one third of the watersheds* *with majority LMI populations.*

*An even larger percentage came from partner funding.*

*Whether you look only at county funding, partner-funding, or the total, the picture is still roughly the same.* *One third of the watersheds get almost two thirds of the funding.*

*Top 4 include Brays, White Oak, Sims and Greens. All have an LMI percentage higher than 50%.*

LMI Population Now Correlates Higher with Funding than Damage

A coefficient of correlation of 1.0 is considered perfect. A good example: between gallons of gas in your car and the distance they will take you.

As a result of the constant tweaking of the equity funding formula, “Population” and “LMI Population” now correlate more highly with “Funding” than “Damage.” The correlation between “Funding since 2000” and:

Population Density = .54
Damage = .85
Population = .87
LMI Population = .89

Statisticians consider all of the last three very high.

With all the rhetoric flying around these days, it’s more important than ever to have facts to base your decisions on. To see all the original data from my FOIA Request, click here.

Posted by Bob Rehak on 2/26/2022

1642 Days since Hurricane Harvey

Life Out of Balance

In addition to monitoring sand mining legislation, I have spent the last several days drafting and redrafting my own letter to the Army Corps and TCEQ about the proposed new high-rise development for Kingwood.

I’m not done with my letter yet. I keep discovering alarming facts. They raise questions about the wisdom of such a development in a fragile, wetlands environment.

Surprising Discoveries

A marina to hold 640 yachts could fill the the entire West Fork. Lined up bow to stern, they would stretch at least 16,000 feet – the entire distance from the marina to the mouth bar. Talk about traffic jams and impacts on navigation! (Hint: Navigation is one of the things that the Corps considers.)

Then I started to think about the population increase and the water supply. Five thousand condos at 2.71 people per household (Kingwood average) PLUS a 50 story hotel, would add about 15,000 people to Kingwood’s population – about a 20 percent increase.

Kingwood is on well water drawn from the Evangeline Aquifer. USGS shows that the water level in the aquifer is decreasing at the rate of 1.7 feet per year, but only recharging at one-tenth of one inch per year, We’re using up the aquifer 200 times faster than the recharge rate! A twenty percent increase would kick that rate up to 240X. (Hint: the Corps also considers impacts on the water supply.)

*Depletion rate of the Evangeline aquifer near the site of the proposed high-rise development in Kingwood is unsustainable.*

Think maybe this could have to do with increasing rates of subsidence and your foundation problems? Check out this AP article that shows what subsidence is doing in Tehran. (Hint: the Corps considers environmental impacts, safety, economics, and the welfare of the public, too.)

Wrong Number and a Hang Up

With that pleasant thought, I decided to call the developer to see if we could talk about some of my concerns. Surprise! The developer does not answer the phone number listed in the Public Notice. The people who answer the phone tell me I have the “Wrong number” and hang up. So I sent a certified letter requesting a public meeting to discuss these issues. We shall see if he responds. Many of the phone numbers for the developers’ other companies are not live. It kind of makes you wonder who you’re dealing with.

Putting it All into Perspective

The deeper I dig, the more concerned I become about connections between the high-rise development, sand mining and legislation. Are we encouraging unsustainable practices? Stay with me for a second.

It all reminds me of a classic 1952 science fiction book called The Space Merchants by Pohl and Kornbluth. I read it decades ago.

In a vastly overpopulated near-future world, businesses have taken the place of governments and now hold all political power. The public is constantly deluded into thinking that all the products on the market improve quality of life.

The book illustrates how production/consumption cycles thrive. On a small scale, think about movie theaters putting more salt on popcorn, so you’ll buy a $5 soft drink that costs a penny to make.

On a grander scale think about sand mining in the flood plain to get cheap sand. So that these developers can build high rises in the flood plain. And sell them thanks to below-cost government flood insurance. That you and I pay for with our taxes. When all we really wanted to do was take a walk by the river and enjoy the serenity … that’s being destroyed.

*Nesting pair of great egrets seconds after their first egg hatched. I call this shot, “Proud Parents.” By Bob Rehak.*

It also reminded me of a movie called Koyaanisqatsi released in 1982. Francis Ford Coppola executive-produced it. It’s 90 minutes of world-class cinematography. The visual tempo increases from languid when we see nature photography in the beginning – to frenetic at the end when we see nature being overpowered by man and technology. Imagine time-lapse photography applied to evolution that accelerates at a dizzying pace.

The title, a Navajo phrase meaning “life out of balance”, is revealed at the end. The movie makes its point without speaking a word. It created an impression that’s still vivid after 35 years. I highly recommend it if you want to feel what’s happening to the San Jacinto in your bones.

You can buy or rent the movie through the iTunes Store or Amazon Prime Video. It’s a classic in the documentary genre.

Connecting the Dots

The book, the movie, the high-rise development and the sand mines make you want to scream “Enough already.” We need to restore balance. Live life in harmony with nature. Isn’t that what we wanted for our children when we decided to buy homes in Kingwood?

I’m sure that someone will say, “But we need the tax revenues.” To which I will say, “If we weren’t destroying our own environment maybe we wouldn’t need such high taxes.

A couple hundred million tax dollars to dredge!? Maybe that sand isn’t so cheap after all. I know emotion won’t sway the Corps and TCEQ, but dammit, “Enough already!”

Posted by Bob Rehak on January 25, 2019

514 Days since Hurricane Harvey

As always, these represent my opinions on matters of public police. They are protected by the First Amendment of the United States Constitution and the Anti-SLAPP statute of the Great State of Texas.

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