News - Reduce Flooding

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

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.

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

Where The Water Came From: May Flood Dissected

May 6, 2024, Monday 2 AM – Flooding in the Houston area during the first week of May 2024 caused quite a stir. It made national headlines most days last week. Twenty percent of the region’s annual rainfall fell in two or three days in several places upstream from Lake Houston.

Water rose quickly along the West and East Forks of the San Jacinto. Several homes flooded in Kingwood. But thousands more were on the verge of flooding when water finally started to recede yesterday.

Thankfully, rainfall Sunday in most places was on the low side of predictions. And at this hour, all gages continue to head downward with the exception of one or two far upstream to the northwest.

As last week wore on, people rode an emotional roller coaster from uncertainty to anxiety, fear, relief and, for some, anger. If lives weren’t destroyed, they were certainly upended. Many are searching for someone to blame for sleepless nights.

So let’s try to dissect what happened during this event. Then, let’s try to draw some conclusions and identify questions that remain to be answered.

How Much Rain Fell Where

Fortunately, the Harris County Flood Warning System, USGS National Water Dashboard, and SJRA have put a lot of tools at our disposal.

The first thing to check is how much rain fell where. HarrisCountyFWS.org makes that easy.

Go to the home page.
Under Site Selection/Sites by Agency, select All.
Under Rainfall Data, select Last 7 days.
Click the Watersheds option in the View tab (top left)

You should get a map that looks like this.

*From Harris County Flood Warning System, 5/5/24 at 10PM*

Note the extreme figures:

18.16″ and 17.8 inches that fell above Lake Conroe’s Dam
16.52 inches south of the Lake Conroe Dam
17″ in the Peach and Caney Creek Watersheds,
16″ in the East Fork Watershed
15.4″ in the Luce Bayou Watershed.

How Runoff Converged

To get a better feeling for how these watersheds connect, consult the map below without all the visual interruptions. I’ve circled the area that drains into Lake Houston in red.

From this you can see that the upper San Jacinto watershed draining into Lake Houston is immense.

The Texas Water Development Board provides some statistics. The size of the:

Entire river basin is 3976 square miles.
Area circled in red is 2828 square miles.
Area draining into Lake Conroe is 445 square miles.

So…

71% of the entire river basin drains through Lake Houston. Only 15.7% of the area draining into Lake Houston comes from above the Lake Conroe Dam.
Calculations based on TWDB data.

There are no other dams in the watershed. So, 84.3% of the area is beyond the control of the SJRA including everything on the East Fork.

But still, did SJRA save the water up too long and then release it in a giant pulse that swamped Humble, Kingwood and Atascocita? That’s a little harder to tell. We’ll come back to that later.

But USGS gives you a fast, simple way to learn where and when water peaked.

Peak Flows Compared from Different Tributaries

Go to the USGS National Water Dashboard. It’s a central repository for all gages that measure discharge rates.

Note: the term “discharge” applies not only to water released from a dam. Hydrologists also use the term to describe water flowing under a bridge. Discharge is measured in Cubic Feet Per Second (CFS).

Let’s look at how major streams in the watershed compared.

East Fork and Tributaries Above Lake Houston

*East Fork at FM1485 in New Caney peaked at 68,000 CFS on Friday, May 3, 2024 *6:45 PM* .*

*Luce Bayou peaked on Friday May 3 at 4PM at 12,100 CFS.*

*Caney Creek peaked at 18,900 CFS Friday May 3 at 12:15AM.*

*Peach Creek in Splendora peaked at 10,300 CFS on May 3 at 9:30 AM.*

Peak discharges are not directly additive because the peaks occurred at different times.

West Fork

I won’t post graphs for every tributary on the West Fork. But let’s look at two key points: below the Lake Conroe Dam and at US59.

That’s the only portion of the river system that SJRA controls. All other West Fork watersheds, such as Spring, Cypress, Little Cypress, Willow and Lake Creeks, enter the river below there. They all peaked at different times.

But by the time water got to US59, the combined peak was slightly higher – 82,700 CFS.

*West Fork at 59. Peak discharge of 82,700 CFS occurred on May 4 at 10AM.*

Main Stem of San Jacinto Below Lake Houston

And by the time all the water from the East and West Forks went over the Lake Houston dam, the San Jacinto downstream in Sheldon peaked at 157,000 CFS.

*San Jacinto River at Sheldon downstream from Lake Houston peaked at 157,000 CFS on Saturday, May 4 at 11:30 AM.*

Conclusions

Several things should be clear at this point.

The SJRA release from Lake Conroe wasn’t responsible for all the water flowing into Lake Houston.
SJRA doesn’t control any water on the East Fork where the worst home flooding apparently occurred. Official damage reports may take weeks.
The broken gate on the Lake Houston Dam (one of four with a combined release rate of 10,000 CFS) made no difference at the peak of the flood. By then, the 3160-foot-wide spillway was discharging a 5+ foot wall of water every second – more than 150,000 CFS, compared to 2,500.

Unanswered Questions

Having said that, I believe we definitely need to do an “after-action report” on this flood. Engineers need to answer questions, such as:

How much sooner should we have started pre-releasing water from Lake Houston to have made a difference?
Did SJRA wait too long to start releasing? Would an earlier release at a lower rate have made a difference?
Did the new SJRA strategy of throttling back releases every 2 hours help downstream? Or harm anyone upstream?
Why is it taking so long (almost 7 years) to figure out how to add more floodgates on Lake Houston?
Why don’t we have more upstream detention yet, one of the basic mitigation strategies identified after Harvey?
What was the role of Colony Ridge in the East Fork flooding? It covers an area 50% bigger than Manhattan and has virtually no detention basins holding water back from the East Fork. How did they pull that off?
When this flood recedes, will we see that sediment has once again reduced conveyance?
Why is the Lake Houston Area, which drains an area bigger than Harris County (and which has the most severe flooding in the county) getting so little help from Harris County? We’ve received only $39 million out of more than $1.9 billion spent since Harvey on flood mitigation. That’s 2%.

We need to start these conversations now.

Posted by Bob Rehak on 5/6/2024

2442 Days since Hurricane Harvey

Worst of Kingwood Flooding May Be Over, But More Heavy Rain On Way

May 4, 2024 Part II – The worst of this week’s Kingwood flooding may be over, but more heavy rain is on the way.

At 2 PM today, flooding on the East Fork and West Fork San Jacinto Rivers was finally receding. Early even. And lower than expected.

But another storm could drop heavy rainfall on the area tonight. As a result: the National Weather Service (NWS) is keeping a flood watch in effect through Sunday night. NWS predicts that we could get another 1-3 inches with locally higher amounts of 4-8 inches possible.

Earlier and Lower Peaks than Previously Expected

The National Weather Service revised its previous estimate for the West Fork downward shortly after the gage indicated water at US59 was receding. The West Fork was not supposed to peak until early tomorrow morning. And then it would have peaked almost 4 feet higher.

*NWS Advanced Hydrologic Prediction Service, Sat. 5.4.24 at 5PM.*

The East Fork started receding last night at FM1485. Water in the Lake Houston Area started trending down late this morning as predicted. That limited Kingwood flooding somewhat.

Even the water level at the dam is going down (though it’s still six feet above normal).

This is welcome news for all Kingwood residents and their manicurists.

But whether Kingwood flooding continues to go down will depend on the amount of new rain we get. Mother Nature can be a tease sometimes.

Little Housing Damage, Rampant Street Flooding

This morning, I journeyed out with a drone and a Nikon. The most housing damage I saw was on Dunnam Road. I heard of other housing damage, i.e., in Woodstream, Atascocita Point, Kingwood Lakes and Kingwood Greens. But it tended to be isolated.

That’s little consolation for the people who got wet. But it’s a great relief for the vast majority of people who didn’t.

The Dunnam Boat Launch’s Self-Serve Bait Shop was under 17 feet of water according to the owner, who intends to rebuild. Much of her equipment was swept downstream.

Street flooding, however, was rampant and widespread from Woodstream down to Royal Shores on the East Fork and all along the West Fork, past US59.

I also saw lots of floodwater creeping toward homes. But most stopped short of entering homes.

As a consequence, this storm may become the future benchmark for Kingwood flooding. It will set the standard for how much floodwater the area can handle without major housing damage. The saving grace was homes elevated above street level.

Kingwood Flooding In Pictures

Here are more than three dozen shots that summarize what Kingwood flooding looked like on the ground today. Some impacted areas were the direct result of the river overflowing. Others were caused by “backflow flooding.” That’s when high water in the river keeps won’t let channels, streams and storm drains empty.

Please note: I couldn’t get everywhere because of blocked streets and the range of my drone.