base flood elevation Archives

Is It Safe to Build 7,000 Homes on Ryko Land?

5/7/25 – A developer named Ryko has announced plans to build 7000 homes on floodplain land that could be inundated with 7 to 25 feet of floodwater in the next 0.2% annual chance storm. The Houston area has had four such storms in the last 10 years.

From a public policy perspective, that raises three questions:

Could homeowners on Ryko land survive a major flood?
Would evacuating them put first responders at risk?
Is there a better use for the land?

Developer’s Entire Property Likely Under Water During Harvey

Benders Landing Estates (BLE) is currently the southern extent of development in the triangle bounded by Spring Creek, the San Jacinto West Fork and the Grand Parkway. Several of the southernmost homes in BLE flooded during Harvey.

From there, the Ryko land drops 30 feet in elevation to the confluence of Spring Creek and the West Fork. So, it stands to reason that virtually everything on Ryko’s land flooded, too.

FEMA’s Base Flood Elevation Viewer shows that in a 500-year flood, land at the southern end of Ryko’s property near the confluence of Spring Creek and the West Fork would be under 25 feet of water. And at the northern end, higher land would be under 7 feet.

*Flood height above land near confluence of Spring Creek and West Fork. From FEMA Base Flood Elevation Viewer.*

Would Such Flooding Be Survivable?

At the deeper end of Ryko’s property, such a flood might not be survivable. Look at what that much water did to the townhomes in Forest Cove a little more than a mile downstream from Ryko.

Forest Cove Townhomes — *Townhomes cut in half by Harvey’s floodwaters. Photo: September 14, 2017.*

Close up, the damage looked like this.

Riverview townhome — *Forest Cove Townhome destroyed by Harvey.*

Of course, damage at the higher elevations on Ryko’s land would not be as severe. Whether Ryko’s residents could survive would depend on how deep in the floodplain they lived and whether they could evacuate before floodwaters rose.

One resident of Benders Landing Estates told me of helicopter rescues during Harvey.

*Comments on this social media post during Harvey went on for five pages.*

If BLE residents had to be rescued by helicopter, imagine the logistics of rescuing thousands more deeper in the floodplain.

Assuming an average population density of about 2.5 people per household, Ryko’s 7,000 homes could hold 17,500 people.

Rescuing that many residents by helicopter would be an air traffic control nightmare…especially in heavy weather with limited visibility.

Putting First Responders at Risk

Harvey’s floodwaters rose at night as people were sleeping…without warning or time to evacuate. A few miles downstream, a dozen people died as a result of injuries sustained during evacuation by boat. A first responder told me that HFD estimated the West Fork water speed at 22 MPH. That’s dangerous!

Clearly, there are no good ways to rescue that many people when floodwaters rise that high next time.

Is There a Better Use for the Land?

Yes. This land would make an ideal park. And we already have an ideal model in the nearby Lake Houston Wilderness Park. Both areas:

Are roughly similar in size.
Lie between major streams
Are unsafe to develop.
Flood regularly.
Host a variety of wildlife including bald eagles.

*The natural solution to flooding: park land.*

If wilderness floods, it won’t endanger people or property. When water recedes, life goes back to normal without:

Presidential disaster declarations
Congressional appropriations
Bankrupting the national flood insurance program
Decades of flood-mitigation grants and rebuilding efforts.

To end on a positive note, parks enhance home values for humans. Multiple studies have shown that proximity to parks enhances the value of homes.

Perhaps it’s time for Ryko to recognize that developing this land is too risky. Doing so would open themselves up to multi-million dollar lawsuits if people died in a flood…especially after they were warned by Montgomery County that developing the land was unsafe.

In my opinion, Ryko should put a reasonable price on the property that lets the State, County and/or City turn the land into a park. Then everyone could win and walk away whole.

Posted by Bob Rehak on 5/7/25

2808 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.

Far More Proposals in State Flood Plan Than Funds For Them

4/20/25 – There are far more flood-risk-reduction proposals (studies, projects and strategies) in Texas’ first state flood plan than funds to finance them.

Tressa Olsen, Assistant Director of Flood Planning for the Texas Water Development Board, spoke about the plan at a meeting of the Society of American Military Engineers on 4/14/25.

*TWDB’s Assistant Director of Flood Planning, Tressa Olsen.*

Altogether, the 15 regional flood planning groups in the state identified approximately 5,000 proposals with a combined price tag of $54.5 billion. But, she says, the legislature has allocated only approximately $1.4 billion since 2019 for them.

Of the $54.5 billion, more than $34 billion are in the San Jacinto river basin.

*Page 13 from Olsen’s presentation on state flood plan. To see her entire presentation, click here.*

That underscores the need for better floodplain management practices that can prevent rather than correct flooding problems – especially in the San Jacinto watershed. After more flood issues become apparent in the next big storm, it may take generations and billions of dollars to remediate them.

Right now, 14 bills pending in the state legislature mention the state’s Flood Infrastructure Fund. But most of those bills focus on prioritizing projects. Not one bill establishes a steady income stream for the Fund which helps finance mitigation projects in the State Flood Plan.

Proposed Ryko Development Makes Case For Intensive Scrutiny

Regardless, every month, it seems more and more developments are moving into floodplains and closer to rivers. Major storms can turn those rivers and streams into raging torrents that destroy homes and lives.

Last week, I focused on the proposed Ryko development immediately west of Kingwood in Montgomery County.

The company hopes to build 7,000 homes on 5,500 flood-prone acres near the confluence of Spring Creek and the San Jacinto West Fork.

*Ryko’s land lies within the area bounded by Spring Creek (left) and the San Jacinto West Fork (right).*

North of Ryko’s land, about halfway to the Grand Parkway and on property 30 feet higher than the confluence, is an existing subdivision called Bender’s Landing Estates. (See top of map below.) One resident told me that 53 homes there flooded during Harvey.

So, Ryko’s property below Benders Landing has even higher flood risk. See red outline superimposed over FEMA’s map below.

Ryko Flood risk — *Ryko property bounded by red. Cross-hatched = floodway. Aqua = 1% annual chance. Brown = .2% annual chance.* *The Houston area has had four .2% annual chance floods in the last 10 years.*

As the Federal government scales back disaster relief and flood mitigation assistance, and as the State doesn’t step in to provide steady funding for mitigation efforts in the State Flood Plan, the responsibility to prevent flooding will increasingly fall onto the shoulders of local officials.

But that will require local officials to update and integrate data on their own. FEMA is already years behind schedule in releasing new flood maps for the Houston region.

Elevation Data Acquired in 1988

“Base Flood Elevation” in engineer-speak is the expected height of a 1% annual-chance (100-year) flood. FEMA provides a Base-Flood-Elevation Viewer that estimates the height above ground for both 1% and .2% Annual Chance (500-year) Floods.

However, FEMA uses elevation data acquired in 1988 to estimate the height of base floods above ground level.

Near the confluence of Spring Creek and the West Fork, Ryko land would be under more than 25 feet of floodwater in a .2% annual chance flood. A point near Benders Landing Estates on much higher Ryko ground would be under 7.3 feet of water in the same flood.

A whole page in FEMA’s Base-Flood-Elevation estimates discusses disclaimers. “Everyone is at risk,” it says. “The chances of experiencing a flood can vary due to unevaluated conditions, such as the unstudied effects of community growth and development or intense storms uncharacteristic to historical trends.”

Extreme Risk Requires Extreme Caution

FEMA’s reports even suggest actions homeowners can take to reduce their flood risk and insurance premiums, such as elevating slabs. But by how much? FEMA doesn’t say. And elevation can be a shifting target.

One of the “unevaluated conditions and unstudied effects of community growth” is subsidence.

Harris-Galveston Subsidence District says subsidence at a gage next to Ryko’s property averages .73 inches per year due to groundwater withdrawal. Adding 7000 new homes would accelerate subsidence.

0.73 inches per year translates to approximately two feet of sinking during a 30-year mortgage. And that’s twice as much as the freeboard factor (safety margin) used to establish the elevation of foundations above expected floods in Montgomery County.

MoCo only requires foundations of new homes to be one foot above the base flood elevation (100-year floodplain), And we’ve had four 500-year floods in the area in the last 10-years. The image below shows what one of those floods did to townhomes in Forest Cove about a mile downstream from Ryko’s property.

Montgomery County Commissioners beware!

Posted by Bob Rehak on 4/21/25

2792 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.

New Website Makes It Easier to Accurately Assess Flood Risk, Potential Damage

A new web site, MyFloodRisk.org, gathers and presents information in a way that makes it easier than ever to accurately assess flood risks and costs.

One of the nation’s largest insurance companies developed the site after years of watching people fall victim to outdated and inaccurate flood maps. Therefore, the site analyzes data from many other sources to gain a much more complete understanding of risk.

Assesses Flood Risk for Every Property in U.S.

The site collects relevant flood-related information on every property in the United States and organizes it in a powerful way that makes it easy to visualize your flood risk. Just put in an address and boom. You’re scrolling through screen after screen that shows:

Your base flood elevation
Slab elevation
Proximity to flood zones
Total FEMA insurance claims in your county
Total recorded flood events in your county
FEMA disaster assistance grants in your state to date
Potential for storm surge (not really a factor in the Lake Houston area, but important in you have a vacation home further south)
Frequency of tropical storms, and more.

See a few of the screen shots below.

*Quickly see what flood zone you are in and the percent of FEMA payouts in that zone.* *I was shocked to learn that even though I am in an X zone, 20% of all NFIP claims and one-third of all federal disaster assistance comes from an X zone.*

*Based on your address, the site calculates the difference between your slab elevation and the base flood elevation.*

Note, even though I’m more than 13 feet above the base flood elevation, during Harvey, the flood came up to my driveway, where first responders were launching rescue boats!

*Total FEMA Insurance Claims in Harris County. County will change depending on address.*

*A composite score pops up as last screen in series and lets you download a PDF of entire sequence.*

Flood Damage Calculator Estimates Cost Per Inch of Floodwater

Not only is there a flood RISK calculator. The site also contains a flood LOSS calculator. For the latter, you plug in the value of your home and its contents. Then you set the flood height – from one inch to 48″. It calculates how much you could typically expect to lose with a flood of that height.

*Potential Flood Loss Calculator. Input values for property and possessions, then use slider on right to see potential losses based on different flood heights.*

The scary thing is how much you could lose even you get just an inch of water in your home! Play with it. You will see what I mean.

Free Service, No Purchase Necessary

The web site is affiliated with an insurance company, National Flood Insurance, LLC, which is licensed in all 50 states. I’m sure they will be happy to provide you with a flood insurance quote if you want one, but it’s not necessary to get a quote or talk to an agent to use this free risk and damage assessment service.

Professional Version Available

The site’s manager, Jennifer Scherff, says, “We have a professional version of the website as well that we offer to realtors and lenders. This version is free as well. For professionals we offer liability waivers on our flood risk reports, to bring awareness of true flood risk to the groups of people who are selling homes to unknowing individuals, especially in states where flood disclosure laws do not exist.

“At the end of our wizard tool where you are given a final flood risk score we have a new section that allows the user to answer a few questions and recieve a flood insurance indication quote in seconds. These quotes are the most accurate you’ll find,” claims Scherff.

Without recommending this, or any other broker/agent, I would just say this. If you live in the Lake Houston Area, you should have flood insurance. As we saw last year, river flooding is not the only threat. With the high intensity rains we get here, street flooding is a constant threat, too.

Delivers “The Right Five”

In the information technology business, they have a maxim called “The Right Five.” Success is all about presenting the Right Information to the Right People in the Right Format at the Right Time in the Right Place. This web site scores a check mark on all five.

Re: the Right Time, hurricane season starts June 1. Remember, it takes 30 days for flood insurance to go into effect. So if you think you MIGHT want it, the time to start thinking about it is NOW.

You could find all the information they present by yourself if you were willing to crawl the web for hours. They aggregate everything in seconds and present it in an easy-to-understand, graphically appealing format.

The site also contains tips on flood mitigation, flood restoration, a blog, a reference library and a link to get a quote.

Once again, the site is MyFloodRisk.org. I plan to list it on my links page and refer to it often.

Posted by Bob Rehak on 3/5/2020

919 Days since Hurricane Harvey and 168 since Imelda

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