Tag Archive for: flood damage

Flood Damage Revealed as Waters Recede, Please Report It

5/6/2024 Part II – Flood damage to an unknown number of homes and businesses is being revealed around Lake Houston as waters recede. Most of the serious flood damage seems confined to low-lying homes around rivers and streams.

As I drove around the headwaters of Lake Houston this afternoon from Kingwood to Huffman to Porter and back, I saw plenty of those.

In this post, I will first show some of those photos.

Then I will make a special request that could help this area receive federal assistance. Filling out a simple survey for the Texas Division of Emergency Management (TDEM) could help neighbors without flood insurance. But first the photos.

Photos From Harris and Montgomery County Taken on 5/6/24

Dunnam Road, Kingwood

Submitted by Sharai Poteet.

Northwood Country Estates in Huffman

Submitted by Max Kidd.

Northwood Country Estates, Huffman. By Max Kidd.
River Club Estates, Porter
Lakeside, Kingwood
Lakeside, Kingwood. Flood swept through nursery business.

Sadly, many of the homes I photographed today had been flooded before. And they hadn’t unflooded yet. As I write this on Monday May 6 at 9 PM, the gage at US59 still records a flood level of 53 feet – 10.5 feet above the normal river level for this area. So, some homes remain underwater and inaccessible.

The worst of the flooding may be over. But the West Fork is still at the major flood stage! It should go down to the moderate flood stage on Tuesday and the minor flood stage on Wednesday.

Lakeside, Kingwood

Request from Officials to Report Flood Damage

Elected officials called me today to request assistance. They’re not certain whether there will be enough damage from this storm to qualify for a disaster declaration and Federal assistance.

So please follow these instructions to report damage if you have it.

  • Go online to the Texas Division of Emergency Management.
  • You should be at a page that says, “Individual State of Texas Assessment Tool (iSTAT) Damage Surveys.”
  • Click on the “Spring Storms” link.

Why It’s Important

The objective of this survey is to help state and local emergency management officials across Texas identify and gain an understanding of flood damage that has occurred. If there are enough qualifying damaged structures in your county, residents of your county could qualify for Federal assistance.

Only one survey per family. And the surveys can only be filled out online. They are very simple and you should be able to do them from a phone if your laptop or desktop was destroyed. It should take no longer than five minutes if you have damage photos ready.

They give this guidance for photos.

\✅Take multiple photos from different angles including close-up photos of specific points of damage and photos of the entire structure.
Make sure your photos aren’t blurry or obscured.
Double-check your address as well as the location pin on the in-survey map.
Don’t submit reports of non-residential structures or outbuildings (barns, carports, fences, or cars).
Don’t submit multiple iSTAT entries for the same residence.
Don’t put yourself in a dangerous situation in order to take photos or submit an iSTAT entry.

Reporting damages to TDEM is a voluntary activity. It is not a substitute for reporting damage to your insurance agency, and does not guarantee disaster relief assistance.

Why You Should Take Survey Even if You Have Flood Insurance

Since Harvey, people who are uninsured and not required to have insurance may qualify for FEMA benefits. However, 500 people per county must qualify before anyone in the county gets anything.

Individuals may qualify for SBA loans, housing assistance, etc. It just depends on whether the thresholds are met. This survey is the first step in assessing needs.

As I drove around the headwaters of Lake Houston today, I saw several pockets of damage, usually close to the rivers. And I am sure more exist.

So please share this post with everyone you know to make sure all residents with qualifying damages report them to TDEM. Even if you have insurance, your neighbor may not. Beating that 500 minimum per county could help them and help your neighborhood recover faster.

Posted by Bob Rehak on 5/6/2024

2442 Days since Hurricane Harvey

Why So Much Flood Damage?

Part 1 of a three part series – We can’t stop flooding because we can’t control rainfall. But we can control flood damage – by regulating where and how we build. So, why do we experience so much flood damage?

If our scientific and regulatory systems always worked, homes would never flood. But they do flood. Why? Root causes include:

  1. Inaccurate predictions of future rainfall
  2. Conflicting standards and building codes
  3. Building too close to threats
  4. Upstream changes that undermine downstream assumptions
  5. Difficulty of adapting to those changes downstream
  6. Historical unwillingness to fund flood mitigation at meaningful levels

To keep this post from getting too long, I’ll consider the first three today, the second three tomorrow, and what we can do about them after that.

Inaccurate Predictions of Future Rainfall

Drainage studies start with worst-case rainfall estimates. When engineers design a community, these estimates form the design basis for:

  • Channels
  • Detention basins
  • Subdivisions
  • Building codes
  • Drainage
  • Roads

How much rain you predict determines how wide the channels need to be, how high buildings should be elevated, etc.

100% of the businesses in Kingwood’s Town Center flooded during Hurricane Harvey. Oops!

Worst-case estimates are based on a branch of mathematics called Extreme Value Analysis (EVA).

By definition, EVA uses extremely small data sets. That limits their reliability.

EVA has one other huge limitation. It assumes stationary, underlying processes. And many believe climate is changing.

atlas 14 rainfall probabilities
From Atlas 14 – NOAA’s most current rainfall probability estimates for the north Houston area as of 2023. NOAA is already working on Atlas 15 which will incorporate the results of climate change. These estimates vary by zip code.

So, estimates get updated periodically – especially after major storms such as Tropical Storm Allison in 2001 or Hurricane Harvey in 2017. A 1,000-year storm before Harvey is now considered a 100-year storm! But some areas still use estimates from the 1980s. As a result…

The margin of safety you thought you had when you bought your home may not exist today.

To add to the confusion, different areas within a watershed may use different rainfall probabilities. Right now, engineers throughout the region are designing subdivisions that appear to be outside of floodplains but actually are inside of them.

That’s because of inconsistent adoption of new rainfall probabilities. Some areas use lower standards as a way to attract new development. It’s a competitive tool that reduces developer’s costs.

As if the hodgepodge of standards weren’t complex enough for elected officials, regulators, engineers and residents to understand, the environment around us is constantly changing. The population of the Houston region grew 75% since 2000.

Our drainage systems are designed, built and maintained in pieces. At different times. By different people. Using different assumptions, rules, budgets and goals.

Conflicting Standards, Building Codes and Enforcement

That makes it difficult for engineers designing a new subdivision to know what to do.

But a standard has evolved in the industry called “no adverse impact.” The idea: a new development should not cause flood peaks to rise higher or faster downstream.

Engineers estimate adverse impacts by comparing pre- and post-development runoff rates, and recommending flood-mitigation measures such as stormwater detention basins to compensate for any increase in runoff caused by developments. They don’t always get it right.

In addition to the uncertainty discussed above:

  • Local officials may not want to adopt new higher standards because it could make them less attractive to developers and reducing tax revenue.
  • Contractors may not always build what engineers designed or regulations specify.
  • Local regulators may not have the staff to monitor compliance with regulations.
  • Business people rarely go beyond the minimum that regulations specify because it raises their costs.
  • A few may cut corners by falsifying drainage studies to reduce their costs.

Whatever the reason(s), consequences can be devastating.

During Harvey, excess stormwater from the Colony Ridge development in Liberty County blew out FM1010, a major evacuation route for tens of thousands of people. As of this writing, it still has not been fixed.

Even when regulations agree between different jurisdictions, outcomes may differ radically. Harris and Liberty Counties, for instance, have virtually identical regulations for the construction of drainage ditches. The regulations are designed to reduce erosion that can, in turn, reduce the conveyance of rivers downstream.

Regs in both counties call for ditches to have backslope interceptor swales and grass on side slopes to reduce erosion. You’re looking at the results of inconsistent enforcement.

In the example above, the 3-mile long ditch on the right has expanded almost 80 feet between 2017 and 2023.

Google Earth Pro shows ditch was 122 feet wide in 2017 shortly after construction.
By 2023, erosion had widened same ditch to 198 feet.

All that erosion contributed to the formation of a 4,000-foot sand bar where the San Jacinto East Fork meets Lake Houston. Sediment drops out of suspension where water slows down as it meets a standing body of water.

East Fork Mouth Bar cost $18 million to dredge.
East Fork Mouth Bar in 2019

We frequently see similar runoff from sand mines and developments in Montgomery County.

Confluence of Spring Creek and San Jacinto West Fork. Spring forms the dividing line between Harris and Montgomery Counties. Photo taken 11/11/23.

Such sedimentation reduces conveyance at unnatural (accelerated) rates and creates blockages in the river.

West Fork mouth bar in headwaters of Lake Houston. Army Corps found conveyance of West Fork reduced by 90% because of this and similar blockages upstream.

Sixteen thousand homes and 3,300 businesses flooded in the Lake Houston Area, according to the Lake Houston Chamber.

Sedimentation is a maintenance issue everywhere at every scale. The montage below shows representative images of roadside ditches in Harris County that have filled in. During storms, blocked storm pipes trap water in neighborhoods.

Roadside ditches blocked by sediment keep water from reaching bayous and back water up into homes.

In 2009, Harris County revised its floodplain development standards. The new code affected things such as:

  • Elevation above the 100-year floodplain
  • Acceptable foundation types in flood- hazard areas
  • Building in floodways including width, depth, bracing and other requirements for piers
  • Where fill can and cannot be used
  • Detention pond requirements
  • Wind resistance
  • Elevation above street level

After Harvey, Harris County Engineering compared damage found in subdivisions built before and after the new standards.

Subdivisions built with the updated standards experienced one twentieth the amount of damage.

However, “grandfathering” of new developments under older regulations often contributes to insufficient mitigation that can affect property owners downstream. For instance, one recently completed 77-acre RV park in the Kingwood area has a detention basin that holds half the stormwater required by new regulations, even though it was built after they went into effect.

Building, Buying Too Close to Threats

The goal of many engineering studies is to build “safely” near water. What do you have to do to protect a family from a hundred-year flood?

These scientific-looking studies are incomprehensible to most people. Yet the engineering seals on them create a sense of security. So does the availability of nationally subsidized flood insurance.

Given those reassurances and given that some people will pay a premium to live near water despite the threats, some developers push the envelope into areas prone to flooding. That’s how we get high-density development in floodplains.

Apartments crowd Brays Bayou at Kirby. HCFCD and its partners have spent more than a half-billion dollars since 2000 to mitigate flooding along Brays.

Similarly, some developers pave over wetlands and ponds that are nature’s stormwater detention systems.

Magera Wetlands
Site of Madera development in Montgomery County at FM1314 (north/south) and SH242 (east/west).
Madera will eliminate wetlands but claims it will have no adverse impact.
Same intersection but looking SW. Looking at what used to be wetlands on the NE side of SH242/FM1314.

Loss of these wetlands reduces floodwater storage. Before development, this area was a 10-year flood zone.

It’s sometimes possible to fix flood threats after the fact. But building on properties like you see here leaves little room for mitigation.

More to Follow

Come back tomorrow when I’ll elaborate on three more root causes of flood damage.

  • Upstream changes that undermine downstream assumptions
  • Difficulty of adapting to those changes downstream
  • Historical unwillingness to fund flood mitigation at meaningful levels

Posted by Bob Rehak on 11/19/23

2273 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.

Texas Ranks #2 in States with Most Flood Damage

It’s easy to forget flooding in the middle of a drought. But we should never forget that Texas ranks #2 in states with the most flood damage. This and other statistics below demonstrate why we shouldn’t become complacent.

Debris pile from Imelda flood in Elm Grove Village (Kingwood).

Different Measures, Similar Rankings

Many ways exist to rank flood-prone areas and Texas ranks high on most of them.

  • National Flood Insurance Plan (NFIP) payouts? Texas ranks #2 after Louisiana between 1978-2021.
  • Most hurricanes? Out of the 300 hurricanes that made landfall in the US since 1851, Texas ranks #2 after Florida with 66 hitting the Lone Star state – 22% of the U.S. total.
  • Percentage of state’s total population living in floodplains? Texas ties for 10th according to a 2017 study. But a 2023 TWDB study shows that 20% of Texans now live in floodplains; that would tie us for 3rd if nothing else changed.
  • Most disaster declarations? Texas ranks #2 when considering all types.
  • Flood deaths? Texas ranks #1. Two hundred people died between 2010 and 2022. Over a longer period of time, 1959-2014, the state had over 850 flood deaths.
  • More Texans live in floodplains (one in five) than the entire populations of 30 other states.

Harris County Ranking

As bad as the Texas statistics are, Harris County’s are even worse.

Between 1978 and 2021, Harris County led all counties in the the entire country for NFIP claims filed (171,300), about 44% of the total claims for all of Texas.

Moreover, 42% of all Texans living in floodplains live in the San Jacinto watershed. The number of floodplain dwellers in the San Jacinto watershed alone exceeds the population of 15 states and the District of Columbia.

A Big Target

It’s important to look at many different measures, because no one measure conveys the full picture. For instance:

  • Number of hurricanes also reflects miles of subtropical shoreline.
  • The sheer size and population of Texas make it rank high on many measures. Said another way, we are a big target.
  • The high clay content of our soils discourages infiltration and encourages runoff of rainfall.
  • Dollar losses may depend as much as on affluence or population density in floodplains as the severity of flooding.
  • Dollar losses in Texas also reflect old building codes in many locations.

And then there’s the huge number of mobile homes in Texas. They are notoriously susceptible to high winds, like those often associated with hurricanes.

Their placement also makes them more vulnerable to flooding than other types of housing. A study by Headwaters Economics found that one in seven mobile homes is located in an area with high flood risk, compared to one in 10 for all other housing types.

Texas, a Leader in…

Texas leads the nation in many things: oil, gas, cotton, job creation, economic expansion and more. Unfortunately, we’re also a leader in flooding.

Better land-use and building codes could certainly help reduce the flooding. But will the state’s new flood plan recommend that? The focus seems to be on flood mitigation more than flood prevention.

The San Jacinto Regional Flood Planning Group recommended $46 billion worth of studies and mitigation projects in its regional plan. And the San Jacinto is just one of 15 watersheds in the state!

In sharp contrast to the magnitude of mitigation needs, the legislature voted only approximately $1 billion for flood prevention projects this year.

That’s enough to make a dent in the state’s budget, but not the problem. Perhaps we need to re-examine our priorities.

Posted by Bob Rehak on September 4, 2023, Labor Day

2197 Days since Hurricane Harvey


John Rocco’s Harvey Experience: Death and Destruction in the X-Zone

John Rocco lives in Kingwood Greens where 225 out of 225 homes flooded according to statistics compiled by the Kingwood Service Association. John is a man of few words. He let these images tell the story for him and sketched out a few details (see below). All images were taken after he was able to re-enter his home. I can only imagine his horror. It looks like his whole home was shaken, not stirred. But the home wasn’t the real tragedy.

John Rocco #1
An inch of mud and flood damage up to the door knob.
John Rocco #2
Fine layers of silt cover everything.
John Rocco #3
Large screen TV flipped off its stand
John Rocco #4
Fridge on the fritz
John Rocco #6
Kitchen needs aide!
John Rocco #7
What 240,000 CFS can do to your home
John Rocco #8
His life was turned upside down.
John Rocco #10
Buried treasures.
John Rocco #11
Room no longer fit for living
John Rocco #12
Uncalm after the storm
John Rocco #13
Come right in and sit awhile!

Death and Destruction in the X-Zone

Said Rocco,  “I’m supposedly not in a flood plain (Zone X) and I did the research on the build up of the Greens area after the 1994 flood before buying here in 2015. My house was built in 2005. Before moving here, I lived on Scenic Shore in Kings Point since 2001.”

“My son lost his house in the Enclave as well as his business next to the FEDEX store. We restored both as well as my house. My neighbor and I rescued the 90-year-old next door just as the water was within an inch of covering her bed in her first floor master. She had no idea. Unfortunately, she died about 2 months later.” 

“My wife was suffering with stage 4 cancer. I had to carry her out of the house in waist deep water to a rescue boat that our son arranged to pick us up. She was in shock. She caught pneumonia twice,  spent time in the hospital. She passed away in May, 2018, nine months later. I’m not blaming the flood per se, but it certainly had an effect.”

“I will say this. I will not restore all this again if we don’t get appropriate actions to mitigate flooding problems.”

Directly Impacted by Mouth Bar

Thank you, John, for reminding our political leaders of the pain that thousands of residents suffered. The homes in Kingwood Greens, like those in Foster’s Mill, Kings Point, Kings River and Atascocita Point were directly impacted by the mouth bar.

A year and a half after Harvey, a year after Mayor Turner said the mouth bar would be removed, and six months after “everybody but Trump” met in Austin and agreed in principle to remove it, not one cubic yard has been removed.

Performance, Not Promises

As we head into another election season AND another hurricane season, we need to remind our elected officials that it’s time for performance, not promises.

Posted by Bob Rehak on March 14, 2019

562 Days after Hurricane Harvey