Engineering Diagrams for Woodridge Development Reveal Crucial Detention Not Installed Before Elm Grove Flood

Late yesterday, I received engineering and drainage plans for the new development north of Elm Grove called Woodridge Village. They show that the developer had planned detention that was not yet installed when last week’s heavy rains hit. This helps explain why water overflowed into the streets of Elm Grove and North Kingwood Forest instead of staying on the developer’s land – where it should have been – until it could be released at a controlled rate into Taylor Gully.

Figure Four Partners, LTD, a subsidiary of PSWA Inc. and Perry Homes, is the developer of approximately 262 acres. Rebel Contractors completely clear cut the entire area before building required – and as it turns out, crucial – stormwater detention.

Plans Differ from Execution

Plans clearly show a huge detention/retention pond that should have been in the southeast part of the property near Elm Grove and North Kingwood Forest. Its purpose: to capture runoff from the north and west. The plans also show a diversion of water from the existing ditch that borders the eastern side of the property into the non-existent detention pond.

This isn’t the only detention missing on the property. The northwest pond is also non-existent at this writing.

Photographs taken last week after the rains show that the southwest ditch overflowed where it narrowed down into a two foot pipe. Water then rushed overland into North Kingwood Forest on the east side and Elm Grove on the west. Where the detention pond should have been, one could see large erosion channels approximately one to four feet deep.

Here’s how the drainage works for the entire development.

Note that the direction of flow is generally from north to south and west to east.

Here’s a close-up of the area where a large concrete detention pond should have been. See red circle.

Not-yet-constructed detention pond was designed to capture water from the north and release it through a culvert into Taylor Gully. Approximate area for detention pond was 2 acres. Plans show pond was intended to be 15 feet deep. Thus, this one pond could have and should have retained approximately 30-acre feet of runoff, much of which wound up in the streets of Elm Grove.

Storm Hits Approximately Six Months after Clearcutting

Here’s what the area of the not-yet-constructed detention pond looked like after the storm.

Looking southwest toward the culvert. Abel Vera’s home is just beyond the tallest tree on the left. He and his neighbors up and down Village Springs suffered extensive damage from the water that was not retained on this site.

Below is what it looks like from the opposite direction, when you stand with your back to Elm Grove and Vera’s home.

According to the plans, almost everything between the camera position and the telephone poles in the background should be a 15-foot deep detention pond.

This discovery raises a question. Why did developers wait so long to install the proper detention? Satellite images from Google Earth show that this portion of the site was cleared sometime between 10/28/17 and 12/22/18. Residents say it was substantially cleared by November of 2018.

Developer’s Own Plans Contradict Its Statements

That means it sat clearcut without the required detention for about six months.

Figure Four Partners, LTD said in a statement released after the flood that their detention was installed AND that it functioned as planned. Figure Four’s own plans and these photos tell a different story.

Figure Four’s statement also said the rainfall was as so intense that it should be called an Act of God. Harris County Flood Control later released a statement saying the rainfall was between a two and 50-year event.

Posted by Bob Rehak on 5/15/2019, with a heads-up from Jeff Miller

524 Days since Hurricane Harvey

Thoughts and conclusions expressed in this post of my opinions on matters of public policy and safety. They are protected by the First Amendment of the U.S. Constitution and the Anti-SLAPP statutes of the Great State of Texas.

Engineering Plans for Figure Four Development Near Elm Grove

Below are several links that allow you to download the engineering plans for Woodridge Village, sections one and two. I haven’t had time to read them yet. Frankly they make my eyeballs bleed. But maybe some younger eyes can help.

I’m posting these because Kingwood is full of engineers who are more qualified to evaluate them than I. All of us are smarter than one of us.

Cover page of first doc showing detention plans.

Woodridge Village, Sections One and Two, comprise those huge clearcut areas north of Elm Grove. During heavy rains last week, video shows water pouring out of the newly clearcut section into Elm Grove. Something appears to have gone wrong. Texas law prohibits flooding your neighbors.

Please Help Review Engineering Plans

The first talks about their constructions plans for Waterline Relocation and Detention Ponds.

The second talks about their Water, Sanitary Sewer and Drainage Facilities & Paving and Appurtenances for Section 1 of the development.

The third talks about their Water, Sanitary Sewer and Drainage Facilities & Paving and Appurtenances for Section 2 of the development.

I would love to hear from civil engineers who know about these things. Reply in confidence through the contact form on this web site.

A shout-out to Houston City Council Member Dave Martin and his staff for supplying these documents. And another to Montgomery County for supplying them to him.

Posted by Bob Rehak on 5/15/2019

624 Days since Hurricane Harvey

Webster, Spurlock Law Firms File Suit on Behalf of More Than 100 Flood Victims

The Webster and Spurlock law firms today jointly filed a lawsuit on behalf of more than one hundred flooded home owners in the Elm Grove area. Webster and Spurlock list Figure Four Partners, LTD., PSWA, Inc., and Rebel Contractors, Inc. as the defendants.

Details of Suit

The lawyers say they may amend the suit to add Perry Homes and LJA Engineers. In addition, they say more homeowners could soon join the suit. Elm Grove Homeowners Association reportedly held another meeting with the lawyers at Good Shepherd Episcopal Church tonight.

The suit alleges negligence, negligence per se, gross negligence, nuisance, and violation of Section 11.086 of the Texas Water Code. Plaintiffs see exemplary damages and a permanent injunction among other things.

Read the text of the their legal filing here.

A statement by Figure Four Partners, LTD, claims the flood was an act of God. However, 93% of all the homes that flooded in Kingwood and Forest Cove were within a few flocks of the land that Figure Four clearcut.

Background

Also, videos and photographs that have surfaced since the flood show water pouring out of their new development into the streets of Elm Grove that already were retaining rain. Elsewhere in Kingwood, there was little street flooding that entered homes. So it appears that the combination of sheet flow from Figure Fours’ development with street flooding made the difference.

One resident sent me these pictures last night via the submissions page on this web site. They show water in the streets that appears to be higher than water in Taylor Gully.

Taylor Gulley just before the flood peaked, according to the photographer. Image taken at Rustling Elms shows that ditch was mostly within its banks at this point, though certainly, some overflow can be seen.
Water over bumper of school bus.
Never park your car in the street during a flash flood.
Same scene from lower angle a little later in the flood.

Posted by Bob Rehak on 5/14/2019

623 Days since Hurricane Harvey

93% of Flood-Damaged Homes in Kingwood and Forest Cove Are Near Area Clearcut by Figure Four Partners

I spent four hours driving around Kingwood and Forest Cove this afternoon counting flood-damaged homes from the heavy rains last week. I counted a total of 211. Of those, 196 were in Elm Grove and North Kingwood Forest. That means 93% were near the 262 acres that Figure Four Partners clearcut for its new development in Montgomery County.

Approximate area where vast majority of damage occurs. Arrow represents direction of drainage from lower third of Figure Four Partners’ new development.

The remaining 15 homes appeared to be isolated, low-lying homes or homes with blocked drains. Only four of those in Woodland Hills and Bear Branch appeared related to creek or ditch flooding. The rest were scattered around Kingwood and Forest Cove.

Breakdown by Location

Here’s the breakdown of what I could find … in descending order.

  • Elm Grove – 175
  • North Kingwood Forest – 21
  • Bear Branch – 5
  • Forest Cove – 4
  • Woodland Hills – 3
  • Trailwood – 2
  • Kings Forest – 1

Most damaged homes outside of Elm Grove and North Kingwood Forest appeared to be isolated instances in low-lying areas. In two places, I saw two damaged homes next to each other.

I could only find four homes (plus the St. Martha school and Kids in Action) that flooded near Bens Branch. Bens Branch is another stream about the size of Taylor Gully and not far from it.

I expected to find many more flooded homes near Bens Branch. But after going down dozens of cul-de-sacs and finding no damage, I abandoned that search.

Massive Concentration Raises Legal Questions

The concentration of damage within a few blocks of Figure Four Partners’ 262 clearcut acres will certainly raise legal issues for the developer and its contractors. So does the fact that all the other creeks in the Kingwood and Forest Cove area put together did not flood more than six homes/businesses that I could see. Several law firms are already reportedly filing law suits on behalf of flood victims. More on that later.

Figures Understated

These numbers may be understated because I may have missed some homes where trash had already been picked up. I was looking for the tell-tale wallboard residue in grass where people had piled sheetrock, but trash crews were doing a pretty good job.

Social media reported damage in Hunters Ridge, Sherwood Trails, Kings Mill and Kings Point. But I did not see the damage. If someone flooded in these areas, please send me your address through the contact form on this web site and I will update the count.

Also, I have not yet ventured to Atascocita, Huffman, or Porter. More on those areas in a subsequent post.

People on ten streets in Porter reported damage; all streets appear to be close to the new development, but I have not verified the proximity of damaged homes on those streets to the clearcut area. That 93% figure could rise or fall depending on what I find in Porter.

Posted by Bob Rehak on 5/14/2019, with thanks to Regan McMahon-Cohen for compiling a list of streets and neighborhoods from social media

623 Days since Hurricane Harvey

All conclusions expressed in this post are opinions on matters of public policy. They are protected by the Anti-SLAPP statute of the Great State of Texas and the First Amendment of the US Constitution.

Simple Demonstration Underscores How Clearcutting Contributes to Flooding

We all understand intellectually that vegetation helps reduce runoff. But I never fully appreciated how MUCH runoff it could prevent until I saw this video. Michael Jrab sent the link to me this morning. It shows a brilliantly simple, table-top experiment in a science class. The experiment dramatizes the value of vegetation and how clearcutting can contribute to flooding by accelerating the rate of runoff.

It takes only a minute or so to watch. Notice both the volume AND THE CLARITY of the water coming out.

Now contrast that with this shot of erosion in the clearcut area just north of Elm Grove. One can only wonder how fast the water moved through here.

Part of the 262 acres clearcut by Figure Four Partners, LTD, a subsidiary of PSWA and Perry Homes.

Posted by Bob Rehak on 5/13/2019

622 Days since Hurricane Harvey

Cogdill Video Shows Overland Sheet Flow From Clear-Cut Area Pouring into Elm Grove; HCFCD Issues Report on Flood

Edy and Ricky Cogdill live across the street from Abel Vera on Village Springs Drive. Both the Veras and the Cogdills live at the end of the street. Their properties butts up against the new development on the other side of the Montgomery County line seen in the background of this video. Edy Cogdill shot the video on May 7, 2019. It shows what hydrologists call “overland sheet flow.”

A small part of the 262-acre development that drains toward Elm Grove. Sheet flow from this clear-cut area ran off into Elm Grove. On top of street flooding, it caused house flooding.

Edy Cogdill shot this video will standing on her front porch with an umbrella. As the floodwaters came out of the clear-cut area to their north, the water hit the Cogdill house and started moving sideways. Toward the end of this short video, Edy pans right. You can see the the flow coming out of the new development and rushing down Village Springs Drive past the dead-end barrier.

The water from the development added to street flooding in progress. As a result, homes flooded.

Video courtesy of Edy and Ricky Cogdill on Village Springs Drive in Elm Grove. Shot on May 7, 2019.

Harris County Flood Control Issues Report on Storm

Jeff Lindner of Harris County Flood Control issued a report this morning on last weeks two flash flooding events.

The report says: “130 structures were flooded in the Elm Groove Village subdivision in the northern portions of Kingwood on Tuesday evening. HCFCD staff investigated this area on Wednesday, May 8th and determined that the flooding was potentially caused by development upstream in Montgomery County that sent large volumes of sheetflow into the subdivision and Taylor Gully (G103-80-03.1). The isolated nature of the heavy rainfall on Tuesday afternoon prevented more widespread flooding impacts.”

Lindner also cautioned that the number of affected structures may change; the City of Houston is still verifying the number. Earlier media reports of 400 homes flooding may have overstated the problem.

2- to 50-Year Official Rainfall Rates

The Harris County Flood Control Report on the storm also states that on May 7: “Heavy rainfall rates developed due to slow storm motions over northeast Harris County including the Humble and Kingwood areas. A 30-min rate of 2.9 inches was recorded at US 59 and the West Fork of the San Jacinto River and a 1 hour rate of 4.0 inches. A 6-hr rainfall rate of 7.9 inches was recorded at the East Fork of the San Jacinto River and FM 1485. Rainfall rates between the 15-min and 6- hr time periods on Tuesday afternoon and evening averaged between a 2-yr and 50-yr frequency over the extreme northeast portions of Harris into southeast Montgomery Counties. This rainfall was relatively isolated in the far northeast portions of Harris County and the Kingwood area.” 

Posted by Bob Rehak on 5/13/2019

622 Days since Hurricane Harvey

Law on “Overflow Caused by Diversion of Water” and Photographic Analysis of Recent Elm Grove Flood

As I interviewed flood victims in Elm Grove last week, I constantly heard different versions of the same story. “We never flooded before. Then they changed the drainage on that land to the north of us and we flooded.” Another common theme: “Water was flowing right out of the new subdivision through our street.”

“You Can’t Flood Neighbors”

An acquaintance at Harris County Flood Control told me that its a basic tenet of Texas law that you can’t flood your neighbors. I asked him for a legal reference. He said, “Check the Texas State Water Code.” I did. It’s more than 2200 pages long. Just as I was falling asleep reading the requirements for inter-basin transfers, I stumbled on Sec. 11.086. Quite interesting, that section! It reads (in part):

“OVERFLOW CAUSED BY DIVERSION OF WATER”

(a) No person may divert or impound the natural flow of surface waters in this state, or permit a diversion or impounding by him to continue, in a manner that damages the property of another by the overflow of the water diverted or impounded.

(b) A person whose property is injured by an overflow of water caused by an unlawful diversion or impounding has remedies at law and in equity and may recover damages occasioned by the overflow.

(c) The prohibition of Subsection (a) of this section does not in any way affect the construction and maintenance of levees and other improvements to control floods, overflows, and freshets in rivers, creeks, and streams or the construction of canals for conveying water for irrigation or other purposes authorized by this code. However, this subsection does not authorize any person to construct a canal, lateral canal, or ditch that obstructs a river, creek, bayou, gully, slough, ditch, or other well-defined natural drainage.

(d) (Not applicable to Elm Grove)

Amended by Acts 1977, 65th Leg., p. 2207, ch. 870, Sec. 1, eff. Sept. 1, 1977.

In Plain Language

I’m not a lawyer and I don’t offer legal advice, but it sounds to me as if the law says:

(a) You can’t divert water in a way that damages others.

(b) Someone whose property is harmed by an overflow may recover damages.

(c) People (such as developers) can make improvements in drainage to control flooding. However, they can’t make improvements that obstruct well-defined natural drainage features such as creeks, gullies or ditches.

That last point is crucial because the developer north of Elm Grove (Figure Four Partners, LTD), reportedly filled in natural ditches or streams that worked well for generations. The replacements? Those didn’t work out so well in heavy rains last week.

A Photographic Examination of Flood Pathways

Abel Vera, the resident closest to the new development on Village Springs Drive was flooded from the street, not Taylor Gully. How can you be sure? Compare these two pictures on the inside and outside of the fence between his house and Taylor Gully.

Inside back yard fence, facing Village Springs Drive. Taylor Gully is on the other side. Photo taken on 4/8/19, two days after flood.
Outside of same fence facing gully shows no debris line. Grass is standing tall, not matted down by flood waters. These two photos in combination suggest that the primary direction of flow came from the street, not the drainage ditch.
Warning sign at end of Village Springs Drive caught flood debris rushing down the street from developer’s property. This was not just a case of water backing up from storm drains.
Vera’s vehicle was parked high on his driveway. This side faced water flowing out of the new development. The side facing away from the new development did not trap any debris. This indicates flow came from the new development. The flood was not simply from water rising in the street. It was from water flowing from the developer’s property where changes to drainage had been made.
Vera’s house is behind the trees on the right. Notice how much higher the developer’s new culvert is compared to the land around it. The height and the constriction diverted water toward Vera’s house on the right behind the trees and down Village Springs Drive.

Where Did The Water Come From?

I believe the floodwater came from rainfall on approximately 267 acres being clear cut by the developer. Had a foot of rain fallen on Vera’s property, with none coming from anywhere else, the water level would not have risen past the bottom of his driveway. His home would likely be whole today.

However, clear cutting, filling in old channels, constricting new channels and changing the slope of the land on those 267 acres all appear to have diverted water. Below is a satellite image showing the outlines of the developer’s property.

Approximate outline of land owned by Figure Four Partners LTD. This satellite image is dated 2/23/19. More land has been clear cut since then.

Let’s zoom in on the area above the culvert where the drainage ditch coming down the east side of the property makes a 120-degree turn, just above Same Way and Right Way.

Use the image below to understand the location of the images that follow.

The photo below compared to the satellite image above shows that the developer appears to have extended the ditch straight up. However, the ditch extension also appears to be clogged with debris from the clear cutting. Whether the developer stacked it there or the storm swept it there is unknown.

Facing north. The main ditch makes a 120-degree turn by the tire. You can see what appears to be a new ditch that helps drain the northern section of land in the upper right.
Here’s a telephoto shot showing the same blockage in the ditch.
Immediately to the left of the shot above, you can see how far clear cutting has progressed toward the ditch.
Turning 180 degrees and looking the other way down the ditch, toward Taylor Gully, you can see that it dead-ends halfway down the eastern boundary of the property.
At the end of the shot above, this is what you find. The entire flow of the ditch must go through what appears to be a 2-foot pipe covered with debris..

Compared to the volume of the ditch, that two-foot pipe will not carry much water in a flood. It may have been adequate when surrounded by woodlands and wetlands to sponge up any overflow. Right now though, it doesn’t feel up to the task of draining hundreds of acres of clear-cut land.

Shot while standing on edge of ditch above the pipe entrance, looking south and a little west. When water came out of the ditch above, it headed back west toward the Vera House on Village Springs Drive to find another way out.
Here you can see the force of large volume of water came out of the ditch above the pipe during the flood.

Consequences

This sequence of pictures suggests that a large volume of water coming down from the clear-cut parcel to the north, wound up being channeled back across the southern parcel and into Elm Grove. A portion of the flood also channeled through the subdivision to the east. Restrictions in both outflow channels forced water into streets and homes.

Here’s what Abel Vera’s home looked like yesterday.

There are 400 more just like it in Elm Grove.

Posted by Bob Rehak on 5/13/2019

622 Days since Hurricane Harvey

All thoughts above are opinions regarding matters of public policy and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP statute of the great State of Texas.

Figure Four Partners Denies All Responsibility for Elm Grove Flooding; Blames God

Figure Four Partners, LTD, a subsidiary of Perry Homes and PSWA, Inc., its sole general partner, issued a statement today regarding the flooding in Elm Grove Village. Elm Grove is a part of Kingwood that borders Figure Four’s development, Woodridge Village, in Montgomery County.

In the statement, Figure Four denied any responsibility for the flooding and blamed it on an act of God. Further, they invoked the shield of government approval, saying their plans were approved by the City of Houston and Montgomery County.

Their unsigned statement, which I have reproduced verbatim below, says:

 FIGURE FOUR STATEMENT 

“While our hearts go out to the homeowners that recently flooded in the Elm Grove Subdivision, the flooding there this week had absolutely nothing to do with the Figure Four and Perry Homes project nearby.” 

“As virtually every media outlet in the region has reported this week, and Harris County Flood Control meteorologist Jeff Lindner confirmed, Tuesday’s rainfalls at times matched the intensity of Hurricane Harvey. The Houston Chronicle reported that “The rainfall was particularly severe in suburban areas such as Kingwood …” 

“Though our project is still in the land clearing stage, many of the detention ponds are complete – providing improved drainage to the area that did not previously exist. Additionally, the drainage study and construction plans for the Figure Four project were completed by LJA Engineering, an experienced and highly respected firm and approved by the County. All City and County permits were obtained and all applicable building codes have been followed. 

“Several questions have been asked about a concrete structure on the project. This structure is the outfall control device and part of the permitted and approved drainage plan. The outfall control device functioned as designed on Tuesday night. Similar to the detention ponds, the outflow control structure improved drainage in the area.” 

– End of Statement –

Concrete structure referred to in statement above.

Flaws in Argument

At the risk of clarifying the obvious, I would point out that:

  • Elm Grove didn’t flood during Harvey.
  • The improved drainage did not work as well as the previous natural drainage, which the developer filled in.
  • The “highly respected” LJA Engineering, Inc. was sued by almost 500 homeowners in the Woodlands for flooding there (see below).
  • The “many” completed detention ponds, none of which I could see in drone footage, were not up to the task.
  • If the outflow control structure “improved drainage,” why did 400 homes flood that didn’t flood before?

Summary of Woodlands Case and Court Documents

In the lawsuit against LJA Engineering, Inc., plaintiffs alleged that the engineers failed to prepare for, or consciously ignored, a foreseeable weather event, which resulted in the flooding of homes and caused catastrophic losses.

While never really addressing the merits of the allegations, the defendant denied the allegations and responded with 25 reasons why they should not be held accountable. For instance, the defendant responded that the flooding was an act of God. They also claimed the defendants assumed risk when they bought their homes; that the plaintiff’s injuries were caused by unspecified third parties; and that the plaintiffs’ own acts or omissions caused or contributed to their alleged injuries.

Here’s a federal court’s summary of the case, before it was remanded to Harris County District Court.

LJA and co-defendants Woodlands Land Development, L.P. and The Howard Hughes Corporation, pled for abatement of the case, claiming that the plaintiffs failed to provide them with sixty-day advance written notice of the claims. The judge then abated the case on 4/22/19.

Difference Between Woodlands and Elm Grove Cases

The Woodlands and Elm Grove situations are similar in that they both involved extreme weather events and flood damage. However, there are also some major differences. In the Woodlands case, plaintiffs occupied the land developed by the defendants. In Elm Grove, neighboring land owners were damaged during development of adjoining property.

Also, in the Woodlands case, plaintiffs alleged that the property had flooded in 1994, that defendants knew it, and that they failed to raise the property high enough to prevent flooding during Harvey. However, Elm Grove did not flood either in 1994 or during Harvey. It flooded only after clear cutting and the beginning of earthwork on the Figure Four Partner’s property.

It will be interesting to see whether any lawsuits emerge from those damaged in Elm Grove.

In the Figure Four Statement, you can see how the company is already setting up themes for their legal defense if necessary. LJA Engineering invoked the same themes during its defense of the Woodlands allegations.

In Other Developments Saturday…

Yesterday was filled with new developments and discoveries:

  • Elm Grove held a public meeting with a law firm to inform flooded residents of their legal rights.
  • Many residents of Porter came to the meeting to complain of drainage issues on the northern and western sides of the project.
  • It became clear that another 175-acre parcel of land was a part of the project. That parcel has also been clear cut, but no drainage “improvements” were visible.
  • No other precautions were visible to prevent runoff of silt such as berms, sand bags, or silt fences.
  • Water was ponding on neighbors’ property.
  • No stormwater pollution prevention permits were posted at any of the entrances to the job site that I could see. That in itself may be a violation of state regulations.
  • Harris County Judge Lina Hidalgo still had not visited Kingwood or declared a disaster. Such a declaration would make residents available for assistance from government agencies.

Additional Parcel Triples Clear-Cut Acreage

Saturday, Porter residents called to my attention the fact that Figure Four Partners was also developing an even larger tract of land not visible from Kingwood.

Location of Woodridge Village, Section 3. MCAD lists it as 161.74 acres, but plat shows it as 175.

This link shows a plat of the northern 175 acres, which Figure Four Partners called “Woodridge Village Section 3.” For those who are interested in contacting the developer or engineering company, the plat shows their addresses and phone numbers.

Here’s what the area looks like. It’s roughly twice the size of the area to the south that directly borders Kingwood.

Elm Grove is on the right out of frame. Note the slope toward Elm Grove.
Another angle on the northern tract shows clear-cutting in progress and the slope toward Elm Grove.
Looking south, directly toward Elm Grove and the area that flooded so badly. Elm Grove and another giant clear-cut tract belonging to Figure Four Partners are beyond the tree line.
Flooded Porter residence that backs up to Figure Four development. Residents in both Sherwood Trails and Porter who border the development complain of the build up of stagnant, stinking water because of altered drainage.

Meanwhile, Clean-Up Continues in Elm Grove

Debris washed into Elm Grove from developer’s property shows how high water flowed in down Village Springs Drive.
Home after home along Village Springs Drive had debris piled head high as residents mucked out their homes.
Oh, that low, down-in-the-dumpster feeling...
Since the flood on Tuesday, Houston City Council Member Dave Martin has been inspecting the clear cut area adjacent to Elm Grove, coordinating City clean-up efforts, and meeting with affected residents.
Houston Mayoral Candidate Bill King (l) consults with flooded resident Abel Vera (r) about events that unfolded during the flood. Piles of dirt in the background are roughly sitting on top of the original stream on the property that was filled in by the developer. Vera’s home is directly behind him. This is one of at least a half dozen trips King has made to Kingwood in the last year to understand flooding issues in the area.
Flooded Elm Grove and Porter residents attending a meeting at Good Shepherd Episcopal Church to learn about their legal options. Shot shows approximately half of the crowd.

Posted by Bob Rehak on May 12, 2019

621 Days After Hurricane Harvey

Thoughts expressed in this post represent my opinions on matters of public policy. They are protected by the First Amendment of the U.S. Constitution and the Anti-SLAPP statute of the great state of Texas.

How Unusual Were Recent Storms? New NOAA Data Sheds Light

New Atlas-14 data from the National Oceanographic and Atmospheric Administration (NOAA) sheds some light on the intensity of storms in the last week. How unusual were they?

May 3rd was a 200-year storm. May 7 was a 100-year storm. And we can expect a week that wet about once every 5-10 years. Here’s how to find the probability for any storm, location or interval.

Step One: Find Gage Nearest You

Large variations in rainfall totals exist even within small geographic areas. So finding the gage nearest you is the first step. For instance, in this week’s storms, official gages in New Caney and Humble registered differences of more than 25% for the same event. Harris County Flood Control has a Flood Warning System that shows all gages in Harris County and many in surrounding counties. You can also use your own data if you have a rain gage.

Step Two: Determine Time and Volume

When you’re obtaining the official gage data, try to narrow down the duration as close as possible. That’s because you’re estimating rainfall INTENSITY – a function of both time and volume. A two-inch rain spread out over a day is NOT the same as a two-inch rain in ten minutes.

Step Three: Find Average Recurrence Interval

Once you know how much rain fell in your area in a given amount of time, the next step is to determine the “average recurrence interval (ARI).” That tells you how often you’re likely to experience a storm of that intensity. Here’s where and how to find it.

To determine the ARI for any location, go to this page on the NOAA site.

Example

Once you’re at the NOAA site, click your location on the map. Here, I clicked on the approximate location of Elm Grove in Kingwood.

A chart showing the average recurrence intervals for Kingwood will appear below the map.

From NOAA Atlas-14. NOAA offers both tabular and graphical formats, but the tables seem easier to interpret. Atlas 14 includes the latest data, including Hurricane Harvey.

On Friday, May 3, Kingwood received 5-6 inches in less than an hour. Scrolling down to the 60-minute line and over to the column that shows 5.49 inches, we can see that that was an estimated 200-year rainfall.

On Tuesday, May 7, the Porter/New Caney area received about 8-10 inches of rain in less than six hours. That was an estimated 100-year rain.

For the seven days starting May 3, gages in the Lake Houston area averaged 10-12 inches. We can expect a week that wet about every 5-10 years.

Probabilities Can Be Mind-Benders

But wait! How can that be? How can you get a 200-year rain and 100-year rain four days apart? And how can we get weeks this wet in 2015, 2016, 2017 and 2019 if it’s supposedly a 5-year event? Simple. You’re dealing in probabilities of independent events. If you toss a coin ten times and it comes up heads each time, the chances of it coming up heads on the 11th toss are still 50%.

It’s the same way with weather. Just because you won the lottery last week doesn’t mean you can’t win it again this week. With that happy thought, I’ll wish you pleasant skies today.

Posted by Bob Rehak on 5/11/2019 with help from Diane Cooper

620 Days since Hurricane Harvey

Crenshaw Coordinating Gift Card Drive for Flood Victims, May 11, 10-Noon, at Second Baptist Church

U.S. Congressman Dan Crenshaw is in a new fight now – to help provide flood relief.

Elm Grove had hundreds of flash flood victims this week; other villages had smaller numbers.

Gift Cards Needed

“Few of the victims had flood insurance,” said Crenshaw. “Let’s come together as a community to help our neighbors, just as we did after Hurricane Harvey. Please drop off gift cards that can help people recover. In the parking lot of Building B at Second Baptist on US59 this Saturday from 10 to 12.”

Always appreciated at times like these: gift cards for restaurants, hardware stores, and clothes. No amount is too large or small. Think about what you needed after Harvey. Thank you for helping.

Posted by Bob Rehak on 5/10/19

619 Days after Hurricane Harvey