Fox 26 Finds San Jacinto West Fork Still Flowing White; Source of Pollution Still Not Identified

Last Monday I photographed white water in the West Fork. Alarmed by what I saw, I sent photos to the TCEQ and SJRA. Then I posted about it last night. Fox 26 saw the post and decided to do some of its own investigating.

San Jacinto River running white has the Hallett sand mine on the West Fork. Photo taken on 11/4/2019.

Fox News Investigates Further

Today, Fox called for an interview. The reporter, Ivory Hecker, also called the TCEQ, the San Jacinto River Authority and Houston Public Works Department. Everybody, it seems is now investigating. Chuck Gilman of the SJRA says he has never seen anything like it.

Meanwhile, the river is still running white. Not AS white, but nothing like its normal color. Fox sent its own helicopter up today and documented a definite discoloration.

Here’s a link to Ms. Hecker’s segment on Fox. I include it here not because it contains an interview with me, but because it contains the results of her own investigation and interviews with others. It also has helicopter footage taken this afternoon showing that the river is still running white, albeit a dirtier white.

So far this week, the TCEQ, SJRA, and City of Houston have all launched investigations. None has reported results yet.

What Causes Color in Water

China has a Yellow River. Wyoming and Utah have a Green River. Colorado has a Blue River. And of course, Texas and Oklahoma share a Red River. Here’s an article about what makes water different colors. They include runoff, chemical spills, reflected light, color temperature, suspended particles, dissolved minerals, you name it. But the article never once mentions WHITE.

In happier times – Pre-Harvey – I drove to the Arctic Circle and photographed spectacular scenery along the way. In Alberta, Canada, I photographed some of the most intensely blue water I have ever seen anywhere. Given the pristine alpine location, you might think the lake in the photo below was naturally blue.

It’s not. Water is a clear colorless liquid. Things IN it give it color. The intense blue in the water below comes from the way suspended “rock flour” from the glaciers refracts light. Still, I’ll take it over San Jacinto white water any day.

In the mountains above Canmore, Alberta.

Best Theory so Far

According to Fox, Houston Public Works suspects the color is caused by suspended sediment from a sand mine. Although both of the mines I flew by on Monday were discharging water from their pits directly into the river, we just need to wait and see what water tests show and whether the discharges I witnessed had been permitted by the TCEQ.

The water was also white upstream from the two mines I photographed – just not as white. So it’s possible those two mines were not even involved. We should not jump to conclusions.

Better Ways to Monitor

Several things are certain at this point, however. Flyovers once every two years by the TCEQ are insufficient to catch issues like this. LandSat flies over Houston 18 times a day. It’s hard for taxpayers to understand why the TCEQ doesn’t use the satellite imagery that the federal government is already collecting anyway. It could provide a higher level of protection at a lower cost. I posed the same question last November to the TCEQ and never received a satisfactory answer.

Second, I have been told that there are ways to monitor the Total Suspended Solid (TSS) concentration in water above and below sand mines. Such gages would make a great way to narrow down the source of pollution and stop it quickly. The SJRA could and should demand such monitoring as part of the price of mining sand near its river banks.

Parting Thought

It’s also hard for people who pay sky-high, City-of-Houston water bills to understand why we allow people to dump things in the drinking water of two million people that raise our treatment costs. It just doesn’t seem right regardless of your politics.

Posted by Bob Rehak on 11.8.19

801 Days since Hurricane Harvey

The thoughts expressed in this post are my 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.

The Day That the San Jacinto West Fork Turned White

On Monday, November 4, I flew up the San Jacinto West Fork in a helicopter and was shocked by what I saw. The West Fork had turned milky white. Here are a series of shots starting at the confluence of the West Fork and Spring Creek and heading upstream. Spring Creek angles off to the top of the frame; the West Fork goes right.

Starting at the 59 Bridge…

Note the difference in color between Spring Creek and the West Fork, angling off the right side of the frame. Also note for contrast the normal looking browning water going into the West Fork from the woods at the bottom.
As we turned up the West Fork, I took this shot. Note the color of the pond at the top of the frame for comparison.
This is the first sand mine going upstream. Note the difference in the water heights between the pit (top) and the river bottom. Also note the pipe sending mine wastewater into the West Fork.

Moving North Past the First Mine

A little farther upstream, though, the water was still white.
I debated on adjectives: chalky or milky?

At the Hallett Mine North of Northpark Drive

The Hallett pond on the west side of the river was emptying into the West Fork. Hallett is north of Northpark Road off Sorters.
On the northern side of the Hallett Mine, we spotted this giant breach that had also been open in October. Notice the eroded shoreline opposite the breach. Water must have shot out of that pit with some force.
This was as far north as we went: the northernmost part of the Hallett Mine. Note the color of the pond on the right for contrast. The water looked less white than farther downstream, but still far from its normal brownish color that you see in the pond.

TCEQ Investigating White West Fork

I don’t think we ever found the source of the whitish discoloration although we found several mines contributing to it. When we got to the northern part of the Hallett Mine, time, fuel and air traffic restrictions dictated that we break off the exploration. So…

These photos were sent to the TCEQ and SJRA for investigation. This is the major source of Houston’s drinking water, folks!

Posted by Bob Rehak on 11/7/2019

800 Days since Hurricane Harvey

The thoughts expressed in this post represent my opinions on 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.

New Union Pacific Railroad Bridge over San Jacinto Will Have Wider Spans

Many readers have asked what the Union Pacific Railroad (UP) is doing to its bridge over the San Jacinto near US59. According to the Houston Chronicle, UP is widening the spans to reduce the potential for catastrophic damage in the event of another storm like Harvey.

If you have children or grandchildren that love trains, cranes and building things, you’ll want to share this post with them. It’s a real life example of a massive (re)construction project in the middle of difficult circumstances and a testament to the kind of brainpower and brawn that built this country.

A New Bridge Rises from the Old

These photos taken on Monday of this week (11.4.2019) illustrate how a new Union Pacific bridge is rising in the same place as the old one. With wider spans, the bridge will now also require different construction.

Wider concrete supports and a steel bed will replace the old tubular supports. UP constructed a temporary bridge next to the new bridge to hold the construction cranes.
This wide shot taken on 11/4/2019 shows how much wider the new spans are compared to the old.

Problems with Old Union Pacific Bridge

Back in 2017, the supports of the old bridge caught many trees swept downstream by Harvey. As you can see in these photos, the old bridge had two or three times the number of supports. David Seitzinger, a Kingwood resident, identified the supports and the trees they caught as a contributor to flooding in this analysis of water levels, flows and timing during Hurricane Harvey.

Photo from September 14, 2017. Harvey knocked out the old bridge. It took weeks to repair and shut down northbound rail traffic.
During Harvey, those old supports caught debris floating downstream that partially dammed the river and destroyed the railroad. Photo from UP report on flood.

A Marvel of Engineering Ingenuity

Current photo shows how the narrow spacing of supports for the temporary bridge are still catching debris floating downstream.
When complete, the bridge will border Harris County Precinct 4’s new Edgewater Park (lower right).
The wider spans should help protect the commercial areas south of the river from flooding.

This presentation explains the importance of railroads to the region’s economy and damage that Harvey did to UP.

The progress of this construction is another encouraging sign of recovery from Harvey.

Posted by Bob Rehak on 11/6/2019 with thanks to the Union Pacific Railroad

799 Days after Hurricane Harvey

Triple PG Sand Mine Finally Starts Plugging Breach on White Oak Creek

In September, Imelda caused the Triple PG sand mine dikes to breach in multiple locations. As a result, the mine’s process water flushed into the drinking water for millions of people. When the owners left the breaches open for weeks, the Texas Commission on Environmental Quality (TCEQ) filed a harsh report with the Texas Attorney General. The AG then sued the mine on October 11.

While the Triple PG owners immediately rushed to seal off the most visible breach into Caney Creek on October 12, other breaches still remain open.

On Tuesday of this week, 46 days after the flood, the Triple PG mine was finally attempting to seal off the main breach into White Oak Creek, another tributary of Lake Houston. I took all of the photos below during the afternoon of November 4, 2019.

The TCEQ had fined Triple PG in 2015. TCEQ again fined the mine in May of this year for allowing process water to escape into the City’s drinking water for weeks. That fine totaled more than $18,000. But when it happened again in September, the Texas Attorney General sued the owners for more a million dollars.

Triple PG White Oak Creek Breach Still Open on 11.4.19

After the AG suit, I thought repairs to all breaches would follow quickly. So I rented a helicopter on 11.4.2019 to check their status. That’s when I took all the photos below. What I saw should have shocked me, but sadly, it did not.

Miners had not yet sealed the White Oak breach. And a white substance was floating out of the mine through it.

Triple PG attempts to repair breach to White Oak Creek on 11/4/2019. The narrow, washed out section of the road on the right looks like it might have been a previous attempt at a repair that failed already.

Meanwhile, Repairs to Triple PG Caney Creek Breach Failing Already

Meanwhile, the breach repair (below), first photographed on October 12, appeared to be slumping into Caney Creek already. Notice how the road is collapsing near the trees at the bottom of the frame in this photo. Glad I’m not driving heavy equipment over that road! Quick call the MSHA! Notice also the difference in the water elevation on either side.

The repair to the Caney Creek breach completed last month appears to be failing already.
Looking west over Caney Creek in the foreground. Erosion is already visible in this side shot of the same repair from a different angle.

Water appears to be piping through the dirt in the repaired breach. Note the wet appearance in several places that also exhibit erosion near the bottom of the dike. Piping is one of the major causes of dike failure. Water seeps under the dike creating channels which undermine it.

Trapped Stormwater: A Problem for Mines in Floodways

A high and constant level of the water in a such a mine creates outward pressure on dikes that invites failure. A spokesman for the Mine Safety and Health Administration said that typically mines must find ways to get rid of excess water after heavy rains or risk breaches. Some try engineered solutions such as spillways. However, Triple PG mine also faces environmental constraints. Specifically, Triple PG cannot flush its process water into the City’s drinking water. Especially when the Attorney General is looking over their shoulder.

My conclusion. Floodways are just dangerous places to build sand mines and this mine sits in two floodways.

Six More Breaches

Here’s a second breach into Caney Creek that they haven’t even started repairing. It appears that water overflowed the pit and started traversing down the side on a diagonal. Note the tree leaning into the creek in the sandy area at the bottom.
And a third breach into Caney Creek. But at least they repaired the road above this one.
And a fourth breach into Caney Creek.
And a second breach into White Oak Creek behind the mine’s stockpile.
And the start of an exit breach along the mine’s southern perimeter where so many homes in Walden Woods flooded. To my eye, it appears that there is little or no elevation difference between the mine road and surrounding homes. So I am not even sure that this qualifies as a dike, or is just the edge of a pond.
And the mother of all breaches on the north side of the mine.

Tick Tock Tick Tock

The suit filed by the Texas Attorney General seeks monetary relief of “not more than $1 million.” But here’s where it gets interesting. The Texas Water Code section 7.102 states that penalties can range up to $25,000 per day for EACH day of EACH violation. It also specifies that “Each day of a CONTINUING violation is a SEPARATE violation.”

With all of these other breaches (that the TCEQ investigators could not see when they first inspected the mine because of washed out roads), these violations could add up quickly. Let’s see. 48 days x $25,000 = $1,200,000 for each breach. If the AG amended the lawsuit, that could add up to some serious bank.

Posted by Bob Rehak on 11.6.2019

799 Days since Hurricane Harvey and 48 since Imelda

The thoughts expressed in this post represent my 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.

SJRA Peak Flow Map from Imelda Shows 1500X Difference Between East/West Sides of Watershed

Here’s a science lesson for the entire family. The SJRA’s peak streamflow and rainfall map for Imelda demonstrated how rain can fall heavily over one part of a watershed and barely touch another. There are huge implications for flooding.

For a high resolution PDF suitable for printing, click here.

Peak Streamflows West to East Vary by 1500X

Note how the gage at Spring Creek in Tomball recorded a peak flow of 22.7 cubic feet per second. The East Fork gage in New Caney registered 34,600 cubic feet per second. That’s a difference of more than 1500X in the peak flow rates!

Rainfall Totals Range from 0 to 30 Inches in 24 miles

The blue figures represent precipitation. That same gage in Tomball recorded none. But a little further east, they picked up more than 5 inches; almost 10 at I-45; more than 15 at I-69, and almost 30 in New Caney.

This is why you need to look at gages upstream on YOUR tributary when flooding is possible! Someday, textbooks will use this map to dramatize that lesson.

Posted by Bob Rehak on 11/5/2019

798 days since Hurricane Harvey and 47 since Imelda

Why You Need to Vote for Mayor Tuesday if You Haven’t Already

This will be the most important mayoral election in Kingwood’s history, but the turnout in early voting was dismal. You would think people don’t care about flooding or that it’s been fixed already. Well, they should care. It hasn’t been fixed.

Below are some photos that show the difference pre- and post-dredging in the mouth bar area of the West Fork.

Match photos of the mouth bar taken after Harvey and Monday 11.4.2019.

Before Dredging: August 2019

This is an Atascocita Point resident walking out to the dredging operation in August.

After Dredging: November 2019

The 500,000 cubic yards that the Corps removed from the West Fork mouth bar barely scratched the surface. Think that’s an exaggeration? RD Kissling took this photo Sunday, 11.3.19, 700 yards south of the mouth bar as he stood in water just a little more than one foot deep. The channel at this point should be at least 400 feet wide and 30 feet deep to match the depth near Kings Harbor.

Photo taken Sunday November 3, 2019 approximately 700 yards south of the mouth bar by RD Kissling. That’s almost half a mile. Like icebergs, the majority of sandbars exists belong the surface.
Where Kissling took the shot in knee-deep water.

The Two-Year Old Controversy that Started Twenty Years Ago

So what does all this have to do with the contest for Mayor? The current mayor has been arguing with FEMA and the Corps for 798 days over how much Harvey deposited in the mouth bar. We’ve had dueling studies. Endless meetings. Countless stories. And still nothing has changed significantly in this most important region of the river.

The City has neglected its obligation to maintain this area for more than 20 years. Engineers warned for decades of the danger and not a penny of the City’s money was spent on dredging.

The City wants FEMA to remove 1.4 million cubic yards, but FEMA claims it would be funding “deferred maintenance” by the City.

Lest we forget, the mouth bar forms a sediment dam behind the dam that contributed to the flooding of more than 4,000 homes behind it and approximately half the businesses in the Lake Houston Chamber.

Bill King’s Plan to Get it Done

Today, Bill King held a press conference in Kings Point to lay out his plan for dealing with the mouth bar. It includes a $10 million contribution from the City to increase the funds already allocated by the State and County. The money would be used to establish a permanent maintenance dredging program.

According to a television reporter and the press conference, Mayor Sylvester Turner accused King of campaign rhetoric on the mouth bar issue.

This isn’t about rhetoric. It’s about survival.

If you care about Kingwood, if you care about your home, if you’re tired of waiting…please go to the polls tomorrow and vote. I voted for King. He’s the only candidate with a workable plan to address flooding in my opinion. But please just vote for the candidate of your choice. Not voting sends a message to the Mayor that we’re happy.

After 798 days of argument, letter writing, and meetings, it’s time for results. If re-elected, Sylvester Turner will be term-limited. Without another election hanging over his head, I just don’t see much improvement in the current situation.

For More Information

To learn more about the flood plans of the three leading candidates, read this post.

To learn more about Kings plan to address the mouth bar, see this newsletter.

If you would like more background about the mouth bar itself, please review this presentation about the Mouth Bar by Tim Garfield, RD Kissling, and me. Garfield and Kissling were both senior level geologists for one of the world’s largest oil companies before retiring. They provided the content. I just helped them shape their thoughts.

Kissling also wrote this open letter to the City of Houston that spells out problems with the Tetra Tech study that the City commissioned at the Corps’ request.

Please Also Vote FOR Prop 8

Among other items on the ballot, one of the most important from a flood mitigation perspective is Prop 8. Prop 8 would make money available from the Texas Rainy Day Fund to help provide low interest loans and grants to cities and counties. The money could be used to qualify for matching funds from the federal government. The lack of local matching funds has delayed many worthy flood mitigation projects identified after Harvey. Prop 8 should help fund many mitigation projects, bring more of our federal tax dollars back to Texas, and reduce flood risk by accelerating both grant applications and construction. Vote FOR.

Posted by Bob Rehak on November 5, 2019, election day

798 Days after Hurricane Harvey

Rape of the West Fork: A Photo Essay

Thirteen years ago, American Rivers named the West Fork of the San Jacinto one of the ten most endangered rivers in America. It’s only gotten worse since then. Sand mines now form long strips along both shores of the river between I-45 and I-69. You can’t see them from the ground. They’re hidden by “beauty strips” of trees, berms, and “keep out” signs. So here’s a look from a helicopter I rented on 10.2.19.

I use the word “rape” in a metaphorical context. I am not alleging any illegal acts by mining companies, though I suspect there may be some going on here in terms of illegal discharges. Can you count the leaks?

Other than that, a majority of the state legislature actually encourages what you see below. So does Montgomery County. MoCo gives most of these mines tax breaks in the form of timber exemptions, which the State Comptroller says they should not get; they should be taxed as depleting assets.

Is the West Fork naturally sandy? Yes. That’s a true statement. Is it unnaturally sandy, too? Is sand mining contributing to the loss of Lake Houston capacity? Does it contribute to flooding though massive sediment plugs such as the mouth bar? You be the judge.

From I-69 to I-45 in 72 Photos

The sequence of images below starts at I-69 and goes northwest just past I-45. The first image is at the confluence of the West Fork and Spring Creek. Note the difference between the color of the two. The West Fork splits off to the left. It’s the Lake Houston tributary with virtually all the mines. Below, a small sampling of the destruction that occurs every day in the name of construction…out of sight and out of mind.

I apologize in advance if some of the photos seem repetitive. It’s important to understand how much of the West Fork that mines consume.

Warning: this post contains many photos. WIFI connection, patience, and large screen advised.

Posted by Bob Rehak on 11/3/2019

796 Days since Hurricane Harvey

The thoughts expressed in this post represent my opinions on matters of public policy. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the state of Texas.

Pit Capture on Caney Creek: What Happens When A Sand Mine Builds Flimsy Dikes in Floodways

This story illustrates on of the dangers of pit capture in sand mining. During the peak of Imelda, 42,000 cubic feet of floodwater per second came down Caney Creek. However, early the morning of September 19th, residents south of the Triple PG Sand Mine on Hueni Road in Porter started seeing water coming from the mine before it came up from the creek.

Escaping with Only a Minute to Spare

They started evacuating their families and animals. One Walden Woods resident told me that the water came up so fast, it covered an entire SUV within an hour. Another told me that had she waited one more minute to evacuate, she and her family would have had no way out. The force of the rushing water undermined the house and garage of a third. Farther south of the mine, residents of Dogwood Lane, Woodstream Village, Dunnam Road, and Riverchase felt the same panic.

Caney Creek Captures Triple PG Sand Pits

So what happened? A review of aerial photographs below taken on 10.2.19, almost two weeks after Imelda, showed a massive breach in the northern dike of the mine. Erosion patterns suggest the water then rushed through the mine in a north to south direction.

  • Trees laid down in a southerly direction at the entry point
  • Sand waves orient along the north-to-south direction of flow
  • East/west roads separating the ponds were blown out, by water flowing north to south
  • The mines main stockpile shows massive erosion along its western edge in a north-to-south direction
  • Sand is piled up against the mine’s main building along the northern side only (where the water came from)

Photo Tour of the Aftermath

All the photographic evidence suggests a classic case of pit capture. Peach Creek joins Caney Creek just north of this entry point.

Where water entered the mine from the north. Looking northwest from inside the mine and past the northern dike. Note the trees pushed into the mine by the force of the water, indicated the direction of flow.
Reverse shot. Looking south into the Triple PG Sand Mine.
A closer view of the same scene shows clear evidence of erosion within the mine from rushing floodwaters. The water came from directly behind the camera position. The road in the middle was blown out, but reconstructed by the time I shot this photo two weeks after Imelda. The TCEQ said they could not safely reach this part of the mine because of damaged roads.

You can see from the shot above that water barreled through this mine as if shot from a water cannon.

Close up of repairs to damaged road. Looking southwest. Sand patterns show water moving north to south.
Note the sand pushed up against the north-facing back of this building.
The eastern side of this stockpile was eroded from the bottom by water side-swiping it from a north-to-south direction.

No Effective Dike at Southern End of Mine

There really is no dike at the southern end of the pit, just a road around the perimeter. The ground level in the neighborhood to the south is virtually even with the level of the road. After water flowed through the pit, it flowed through neighborhood(s) to the south and damaged homes. It’s easy to see the damage immediately south of the pit and imagine the pit capture as the cause of the damage. The damage faces the mine, not Caney Creek to the east.

Floodwaters from the Triple PG mine partially knocked this home off its foundation. The owner had to jack it up and re-level it. The back of the house faces the mine and is not more than a hundred feet from it.
The same homeowner’s garage. Floodwaters from the mine scoured under it. Again, the back of the garage faces the mine and is not more than a 100 feet from it.

Reasons for Pit Capture

What is pit capture? It’s when a river or stream cuts through the pit of a nearby sand/gravel mine instead of following its normal course.

How does it happen? Water starts to overtop or penetrate the dike. It creates a fissure that rapidly widens and opens a hole. Pretty soon the dike collapses and the water rushes in. The water moves from areas of high pressure and elevation to areas of low pressure and elevation. After the water moves into into the pit, it fills the pit up and needs to find a way out on the other end. Like a water ballon attached to a faucet, sooner or later dikes on the other side burst.

Why does this happen?

  • The mine was built in the floodway of Caney Creek on a point bar
  • Dikes made out of sand could not withstand the force of the water
  • Dikes had previously failed in the same places and left “weak points”
  • When the water came up, it took the path of least resistance
  • Texas has no minimum setbacks from rivers for mines
  • Texas enforces no best management practices for mines

What Next for the Triple PG Mine?

The Texas Attorney General is currently suing the mine for allowing its process water to pollute Lake Houston. The mine left its dikes open for weeks after multiple breaches in multiple storms. The TCEQ also found that the mine was breached from east to west between White Oak and Caney Creeks.

Potential fines could reach well past a million dollars. That raises the question, “What can be done with this mine to protect residents below the mine and to protect the City of Houston’s water supply?”

Over the years, Triple PG’s owners have removed 800 acres of forest and an unknown volume of sand from the mine. The risk of pit capture is greatest were mines are deeper than the adjacent river bed and close to the river/stream. Both conditions apply in this case.

The dike between Caney Creek and the Triple PG pit is a narrow strip of unvegetated dirt, just wide enough to support a vehicle…and not compacted very well as you can see below.

This shows repairs to an exit breach to Caney Creek farther south. No geotextile fabrics or rip rap are holding the repair together. Photo courtesy of Josh Alberson. Taken 11.2.2019.
This closer shot shows the same breach filled with sand and clay. You can see how flimsy the repair is. The uncompacted and unprotected soil is already eroding after two inches of rain last week. Photo courtesy of Josh Alberson. Taken on 11.2.2019.

It will be interesting to see whether a professional engineer will certify this repair, as a restraining order demands.

If the courts should shut this mine down, sealing it off permanently will be difficult and costly.

Posted by Bob Rehak on 11.3.2019 with images from Josh Alberson

796 Days since Hurricane Harvey and 45 since Imelda

The thoughts in this post reflect my 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.

Woodridge Village Detention Calculations Off by More Than 40% According to New Standard

Developers in Montgomery County try to avoid building detention ponds by beating the peak. They also have attempted to minimize the amount of detention ponds they must build by beating the clock.

Woodridge Plans Approved One Month Before NOAA Updates Flood Data

A year to the day after the peak of Hurricane Harvey on August 28, LJA Engineering submitted a hydrology report to Montgomery County. A table buried on page 32 of the PDF shows that they based their analysis on a 100-year storm that dropped 12.17 inches of rain in 24 hours.

From Page 2.1 of LJA Hydrology Report Addendum, 8/28/2018 (page 32 of pdf.)

Two weeks earlier, USGS had issued its report on peak streamflows and high water marks for Hurricane Harvey.

At this point, the world knew that flood maps would soon change radically. But the LJA report contains no mention of Harvey, USGS, or NOAA’s new Atlas 14 data. And in fact…

Less than one month after the LJA Engineering hydrology report, on September 27, NOAA issued new rainfall frequency values for Texas. Called Atlas 14, the NOAA analysis established significantly higher rainfall frequency values for this part of Texas.

New updated NOAA Atlas 14 data shows that a hundred-year rain for the Lake Houston area is now defined as 17.3 inches in 24 hours, up from 12.17 inches by the old standards.

NOAA redefined the amount of rainfall it takes to qualify as a 100-year or 1000-year event. They defined the new 100-year rain as 17.3 inches in 24-hours – a 42% increase. That means that to meet new 100-year standards, Perry would have had to increase its detention capacity by 42%. Instead of 271 acre feet, it would have needed 385.

Using Atlas 14 would have reduced the number of salable lots and the economic projections for the development to a substantial degree.

The one flood map in the 59-page LJA Engineering hydrology report shows flood plains magically stopping at the county line.

The one flood map that the LJA hydrology report does include (page 51 of PDF and above) shows flood zones stopping at the county line (the black diagonal) and the boundary of the Perry property (the maroon-bordered polygons). Pretty odd for a site partially covered by wetlands!

National Wetlands Inventory Map shows both sections of Woodridge Village contain wetlands.

Woodridge Plans Approved Even Before LJA Submitted Hydrology Report

Now here’s where it gets even more interesting. City of Houston approved the detention plans on 8/12/18 – two weeks BEFORE the LJA hydrology report on 8/28/18 and only a month BEFORE NOAA released the new Atlas 14 data. Hmmmm! Think they were in a hurry to get these approved? (Note: The approval date for MoCo is unreadable).

Signature block for City of Houston from Woodridge Village detention plans.

Perry Homes played a game of beat the clock and was winning … until May 7, 2019.

Future Flood Risk Remains Even with Planned Detention Ponds

Until now, I have been posting about the lack of detention ponds. Closer analysis reveals that this is only part of the problem. Even if Perry builds the remainder of the detention ponds as planned, they will be insufficient to meet the new NOAA standards and will pose a flood risk to people downstream.

After contributing to two floods in Elm Grove and North Kingwood Forest, the engineers and owners of Woodridge Village surely must realize how dangerous trying to Beat the Clock was.

Forty-two percent of a 100-year flood as defined by the new Atlas-14 data will overflow the banks of the detention ponds and add to the load on Taylor Gully or go into the streets of Elm Grove and North Kingwood Forest.

Facing west. This panoramic drone image by Chris Betz takes in most of the Woodridge Village constructions site. Note the ponding water 3.5 days after a two-inch rain.

This image taken Friday night at Sunset shows how impervious the Woodridge soil is. Water is still ponding three and a half days after a two-inch rain (October 28, 2019).

I wonder if the LJA engineers calculated the runoff coefficient accurately. Given some of the other problems in this report, perhaps an engineer would care to comment on their calculations.

Posted by Bob Rehak on 11/2/2019

795 Days after Hurricane Harvey and 45 after Imelda

The thoughts expressed in this post represent my opinions on 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.

Q&A with HCFCD on Ben’s Branch Flooding Issues

After St. Martha’s Catholic School and Kids in Action almost flooded on a two inch rain earlier this week, I asked Harris County Flood Control a series of questions about Ben’s Branch. The questions covered a variety of topics. They included the Kingwood Drainage Assessment; flood mitigation alternatives along the creek; preservation of natural amenities; a maintenance agreement with Friendswood and Bear Branch Trail Association; timing for all of the above; and more.

St. Martha’s school on Tuesday after two inches of rain

Harris County Flood Control District continues to be a paragon of openness and transparency. Below: detailed answers to the questions people have been asking.

Q. Ben’s Branch is included in the Kingwood Drainage Assessment. When will that study be complete?

A. Our consultant is scheduled to submit the Draft Feasibility Report for HCFCD review in May 2020. We plan to hold a public meeting by early 2020 to present preliminary results and then a second meeting to present final results and recommendations for future actions.

Q. Will the consultant report findings on creeks “as they go” (one by one) or deliver one summary report at the end? (The concern: that they could sit on recommendations for months that might prevent flooding in the interim.)

A. We do not envision the alternative analysis to be completed on a creek by creek basis, but we are working to identify some initial projects that could be recommended for implementation prior to completion of the report.

This assessment is to determine level of service and make recommendations for projects to move into preliminary engineering once this assessment has concluded. Some projects might require partnerships to implement.

Q. I understand that you are close to reaching a maintenance agreement with Friendswood for the natural portion of Ben’s Branch between North Park and Kingwood Drive. Can you send me a copy of the proposed maintenance agreement or, as a backup, summarize the key features?

We are seeking an easement from the Bear Branch Trail Association, with a waiver from Friendswood Development Company, to perform desnag activities for stormwater conveyance purposes on the portion of Bens Branch between Woodland Hills and Kingwood Drive where we currently have no property rights; that is, from approximately 1,500 feet downstream of Woodland Hills to approximately 3,000 feet upstream of Kingwood Drive. Please go to the Interactive Maps of Kingwood Assessment Area on our website and look at the fuchsia line along Bens Branch on the “Channel Right-of-Way in the Kingwood Area” map.

We will share the easement language once it has been finalized.

Q. How long have you been working on this easement?

Since October 24, 2018.

Q. How will this easement differ from your normal easements?

We are obtaining this easement to perform desnag activities to allow the free flow of stormwater. For information about our desnag operations, please visit our website https://www.hcfcd.org/hurricane-harvey/kingwood-information/hcfcd-vegetation-management-activities/.

When Friendswood Development Company granted fee ownership of this portion of Bens Branch to the Bear Branch Trail Association, they retained certain rights and set specific restrictions on the property that would make it impossible for HCFCD to perform its necessary flood control responsibilities.

This agreement is different because the Friendswood Development Company wants to restrict HCFCD’s rights to “widen, deepen, enlarge, straighten, or smooth the channel in such a way as to increase channel capacity.” 

HCFCD has been working to negotiate the right to enter this property and complete channel maintenance operations for drainage purposes, while still maintaining the aesthetics that are important to both the Friendswood Development Company and the Bear Branch Trail Association. HCFCD will request the right to review plans for future improvements placed within the channel (e.g., bridges and low water crossings).

HCFCD cannot allow activities that could increase the risk of flooding where we spend public dollars.

Q. What were Friendswood’s concerns?

They wanted no alteration of the channel geometry and to retain the ability to add trails, bridges, and other structures without obtaining permits from HCFCD.

Q. Will the maintenance described in the agreement be enough to restore conveyance of Ben’s Branch so that it doesn’t flood surrounding homes and businesses?

We plan to perform desnag operations to remove obstructions so that stormwater can be conveyed efficiently.  HCFCD can’t guarantee that flooding won’t occur in surrounding homes and businesses.  HCFCD can selectively remove vegetation along the banks and other debris in the channel to increase the capacity of the channel to convey stormwater downstream.

Q. What will it take to avoid flooding? Said another way, what obstacles do you face in restoring conveyance?

Before we can perform these activities, we need to have property rights and the ability to safely access the site.

Q. What would Harris County Flood Control prescribe for Ben’s Branch to protect people from flooding?

We have not formally begun our process to identify alternatives; however, we expect to explore these alternatives for the Bens Branch channel:

  • Expanding the Kingwood diversion ditch from 150 feet to approximately 300 to use more of the right of way. Because the Kingwood diversion channel diverts water from the Montgomery County portion of the upper Bens Branch watershed, and there appears to be available capacity in the diversion channel, we will look into whether diverting more flow down the diversion channel would result in reduced flows along Bens Branch. Please note that we anticipate that this option would require a stormwater detention basin along the lower limits of the diversion channel.
  • Effectiveness of building stormwater detention basins in the upper Bens Branch watershed (Montgomery County side). This will only be feasible if large undeveloped tracts are identified for possible future basins.
  • Evaluation of channel conveyance improvement needs along the entirety of Bens Branch. Some improvements may need to be considered on portions of the channel within which HCFCD has no legal authority to work.  If this is the case, HCFCD would coordinate with the property owners to determine what improvements could be completed.

Q. Are there compromises that would provide protection from flooding without destruction of the natural amenities which residents also value? I realize this may involve a discussion of degrees of protection.

As part of this study, HCFCD will be identifying alternatives to provide 100-year level of protection within the channels, using the rainfall rates from the newly adopted Atlas 14. These alternatives will identify the magnitude of improvements necessary to handle approximately 18 inches of rainfall runoff in a 24 hour period.

There are times that flood risk reduction competes with natural and public amenities; when that occurs, HCFCD works to minimize impacts to natural amenities. Once alternatives are identified, Kingwood Area residents will have a chance to voice their opinions and concerns with our alternatives. Please note that at some point it might become necessary for the Kingwood community to decide between higher levels of flood protection and maintenance of existing amenities.

Q. Do you have any idea yet why St. Martha’s and Kids in Action almost flooded on a one year rain? What has changed in your opinion?

We do not have any formal findings as to the potential causes for the excessive ponding along Bens Branch near the Kids in Action / St. Martha’s area. The intensity of the rainfall contributed to the ponding; inlets are typically designed to handle approximately 1” per hour, and when the rainfall intensity exceeds this, there is ponding in streets and parking lots.

It also appears that there may be a downstream blockage since extremely slow velocities were seen in the water in this area and there are much lower water surface elevations in the Bens Branch channel sections further downstream. HCFCD has contacted the Bear Branch Trail Association to ask them to assess their channel and remove any blockages.  

Posted by Bob Rehak on 11/1/2019 with help from Beth Walters of HCFCD

794 Days since Hurricane Harvey and 43 since Imelda