HCFCD Recommends More Study for $30 Billion Flood Tunnels

(Update: Since posting this story, HCFCD has provided a link to the entire 1860-page flood tunnel study online.)

On June 16, 2022, Harris County Flood Control District (HCFCD) held a virtual meeting to present the results of Phase 2 of its flood-tunnels study. Phase 2 recommended eight tunnels estimated to cost $30 billion for further study. The purpose of Phase 3: to advance the design far enough to quantify the benefits and validate cost assumptions in order to apply for grants that would help offset costs.

The secondary purpose of the meeting: to gage public support for tunnels, none of which would benefit the Lake Houston Area.

Below, see a brief summary of the one hour and twenty minute meeting.

Watersheds Where Tunnels Being Considered

Phase 2 recommended additional study for tunnels in the following watersheds:

  • Brays Bayou
  • Buffalo Bayou
  • Clear Creek, Berry and Vince Bayous
  • Halls and Hunting Bayous
  • Little Cypress and Cypress Creeks
  • Sims Bayou
  • White Oak Bayou
From Page 34 of presentation delivered by Scott Elmer, Asst. Director of Operations, HCFCD

The conveyance of all eight projects would TOTAL approximately 75,000 cubic feet per second (CFS). To put that in perspective, that’s approximately 4,000 CFS less than the SJRA released from Lake Conroe during Harvey.

Potential Advantages of Tunnel System

Scott Elmer, P.E. CFM and Assistant Director of Operations for HCFCD, gave most of the presentation. A large part of it focused on the benefits of a flood tunnel system. The hour and twenty minute presentation contained more information than the presentation online. So, I will try to fill in some blanks for you.

Mr. Elmer talked extensively about “inherited flooding.” Much of Harris County, he says, developed before we fully understood flood risk and developed regulations to reduce it. For instance, he showed a series of three images around Halls Bayou and I-45.

  • #1 showed rural farmland.
  • #2 showed development starting near the bayou.
  • #3 showed development so dense that it would require buyouts before mitigation by conventional means.

Mr. Elmer then discussed the time, cost, and disruption of buying out enough properties to construct basins and widen channels. I posted about this last year in regard to the detention basins that straddle Halls at US59. Entire subdivisions had to be bought out before construction could begin. Each of those two basins took approximately a decade to finish, with most of the time consumed by buyouts.

Example of Ideal Location

Here’s an example of another location, farther up Halls between I-45 and Airline Drive.

One of the areas of heavy, repetitive flood damage in Harris County. Image from 1978. Area was farmland in the 1950s.

Many homes in this flat area are no more than a foot or two above the bayou banks. Some even sit below street level.

Same area seen in FEMA’s national flood hazard layer viewer. Cross hatch = floodway. Aqua = 100-year floodplain. Brown = 500-year.

The entire area lies within some kind of flood hazard. And keep in mind, that this flood map was developed after Tropical Storm Allison in 2001. It does not even represent the risk under Atlas 14, the new flood probabilities developed after Harvey.

Harris County’s Flood Warning System shows Halls has come out of its banks at Airline Drive at least 12 times since 1984. Yet there is very little room to widen the channel or build detention basins.

Best Locations for Tunnels

Tunnels represent an ideal complement to traditional solutions in such cases. They:

  • Expand options for flood damage reduction
  • Make the county’s stormwater network more robust
  • Reduce community disruption and increase resiliency

They make the most sense in areas where:

  • Land for traditional solutions is unavailable
  • Residential property acquisition would disrupt neighborhoods
  • Surface solutions would result in environmental impacts

Elmer presented a hypothetical situation to demonstrate equivalent risk reductions. Thirty-four acres required for tunnel construction could offset 3,145 acres of land needed for channel improvements and stormwater basins.

How Tunnel Locations Chosen

In describing how HCFCD chose the eight watersheds for further study, Elmer focused on:

  • Population density
  • Damage centers with high risk
  • Safety of lives
  • Strategic locations for intakes and outfalls
  • Identifying opportunities to integrate tunnels with other flood damage reduction measures
  • Avoiding geologic and man-made hazards, such as oil and water wells; or geologic faults.
Page 33 of Tunnel Presentation

As for the absence of tunnel recommendations on the eastern side of the county, Elmer simply said, other solutions would be more cost effective. He did not provide additional explanation.

For Elmer’s full presentation, click here.

To see a YouTube Video of this entire presentation including the Q&A that followed, click here. The meat of the presentation starts at about 8 minutes and 30 seconds into the video.

  • Elmer’s presentation lasts a little more than half an hour.
  • A moderator describes the need for public comment before September 30 at 41:26.
  • Q&A begins 42:30.
  • The video ends at 1:18:00.

Items Not Covered

HCFCD gave no specific rationales for:

  • Locations of each of the eight tunnels.
  • Excluding large areas of the county.

I, for one, want to read the entire report before submitting my comments. But HCFCD has not made the report available online.

The presenters did not mention current flood risk in the respective locations. Nor did they say whether their recommendations accounted for recent flood mitigation investments.

Since 2000, the watersheds benefitting from the eight tunnels have already received 64 percent of all flood mitigation investments in Harris County. That includes partner spending. For instance:

  • Brays Bayou has received $575.3 million.
  • White Oak has received $526.3 million.
  • Sims Bayou has received $460 million.
  • Cypress and Little Cypress have received $442.5 million.
  • Greens has received $440 million.
  • Hunting and Halls have received $293.7 million.

Full Study Not Released

Before I vote on flood tunnels for these areas, I want to know how much flood risk remains compared to other areas that received less investment.

However, HCFCD has not yet released a study on the level of service (flood frequency likelihood) for every channel in the county.

The Phase 2 study just completed indicates we could spend $30 billion more on 132 miles of tunnels. That works out to almost a quarter billion dollars per mile.

Before I invest that much, I want to know how engineers arrived at these recommendations. Specifically, how much did politics enter into these decisions? The write up on HCFCD’s tunnel page makes it clear that “equity considerations” including the social vulnerability index weighed heavily.

I also want to know how the Cypress tunnel emptying into the San Jacinto West Fork between US59 and West Lake Houston Parkway would affect flooding in the heavily populated Humble/Kingwood Area.

Public Comment Period Lasts Through September 30

If you wish to submit public comments on the flood tunnels, you have until September 30, 2022. Submit comments at Public Input.com/tunnels. I intend to request the entire engineering study and will post more when I learn how HCFCD made the recommendations.

Posted by Bob Rehak

1755 Days since Hurricane Harvey

Demolition Dates Set for Forest Cove Townhomes

Harris County Flood Control District (HCFCD) has set the demolition dates for two of the three remaining Forest Cove Townhome complexes. The two farthest from the river will be torn down on 7/5/22 and 7/14/22. See image below.

On 6/17/22, HCFCD also deposited the check for the buyout of the last unit in the last complex. So, according to HCFCD spokesperson, Amy Stone, “The final demolition should be scheduled soon!”

Demolition dates for the three remaining Forest Cove Townhome complexes. San Jacinto West Fork at top of frame. Forest Cove Community Center and swimming pool on right.

Reason for Delays

Buying out close to 100 units destroyed by Harvey has been a tortuous and time-consuming process. Several of the owners, unable to live in the townhomes, reportedly walked away from their properties, leaving them in limbo. In the process, they created a blight on the community that became a magnet for drug dealing, illegal dumping, vandalism, arson, and graffiti.

I talked to an angry Forest Cove resident this morning who can’t wait for the last remaining units to be demolished.

Photos Taken on 6/18/22

Here are some photos taken this morning from ground and air showing the condition of the last units still standing.

Two complexes scheduled for demolition on 7/5 and 7/14.
Same complexes from the ground.
Last complex, not yet scheduled for demolition
Same complex from ground level.

Back to Green Space

HCFCD usually lets such buyout areas return to green space and has announced its intention to do the same here. However, it’s not yet clear exactly what that means. Flood Control has not yet responded to a request for specific plans.

Nevertheless, the Houston Parks Board has already begun a trail along the West Fork. It currently reaches from the Kingwood trail system at River Grove Park to Marina Drive in Forest Cove, shown below. It now terminates behind the two complexes already scheduled for demolition in July.

Terminus of Houston Parks Board San Jacinto Greenway at Marina Drive, approximately 2.6 miles from River Grove Park as the crow flies.

The Parks Board has plans to take this trail all the way to US59 eventually.

Planned route of trail connecting Woodland Hills Drive to 59 and Spring Creek Trail. Green = completed. Purple = planned.

Someday soon, this area could become a huge asset to the Kingwood/Forest Cove/Lakewood Cove community again.

Posted by Bob Rehak on 6/18/22

1754 Days since Hurricane Harvey

Why Worry about Flooding in a Drought?

This morning, Harris County Meteorologist Jeff Lindner sent me an email that caused me to worry. It wasn’t about flooding. It was about our dismal rain chances for the next two weeks.

His email also contained a map of all the outdoor burn bans in effect across the state. Of 254 counties in Texas, 133 currently ban burns.

According to the Texas A&M Forest Service, more than half of Texas counties have burn bans in effect.

Texas’ drought monitor website shows that as of 6/15/22:

  • 91.4% of the state is abnormally dry.
  • 80% is in moderate drought.
  • 64% is in severe drought.
  • 42.5% is in extreme drought.
  • 16.8% is in exceptional drought.
  • Drought affects 19.3 million people in Texas.
  • We’ve had the 8th driest year to date in the last 128 years.

So why worry about flooding now? Here are my top three reasons. You may have others.

Repetitive Cycles

Previously, Lindner sent a separate email comparing 2022 with 2011, the start of our last major drought. Within it, he said, “While it is easy to compare heat and drought to other instances in the past, our current heat and drought is far from what this region and state went through in 2011. Rainfall has been much more plentiful this spring than in 2011, and while some of the temperatures may be similar, the intensity of the heat thus far this year is not to the level of 2011. There are some similar comparisons to drought and heat of the summers of 1998, 1988, and 1980.”

The drought years caught my eye. I asked him if there was a reason for the relative regularity.

He replied, “Generally speaking … a lot of our heat/drought and floods correlate with El Niño and La Niña in the central and eastern Pacific. La Niña years tend to favor heat and drought in the southern plains, though not always. 2011 was one of the strongest La Niñas on record since 1950. On the other hand, El Niño tends to favor cooler and wetter periods. Many of our big floods have happened in El Nino years.”

Knowing that floods follow droughts in regular cycles (and that floods could happen at any time from a stray tropical storm), you never want to be lulled into a false sense of security about flooding.

Complacency

Droughts can create complacency about flooding. People forget the pain. Political pressure and attention shift to more pressing problems, such as crime or Covid. And after two years of lockdown, people are ready for vacation, even with $5/gallon gasoline! But like the parable of the Three Little Pigs, people who live in SE Texas can never become complacent about flood threats. Flooding is our #1 natural disaster.

After Harvey, flooding floated to the top of Houstonians’ concerns. We launched massive mitigation efforts. But do you know where they stand today?

Apathy when we’re not flooding could sow the seeds of the next big flood. Vigilance is the price of freedom…from flooding, too.

Unintended Consequences

Most research on hydrological risks focuses either on flood risk or drought risk. However, floods and droughts are two extremes of the same hydrological cycle. They are inextricably linked. One follows the other like night follows day.

Strategies targeted at one may create unintended consequences for the other. So, it is important to consider interactions between these closely linked phenomena.

For instance, drought can decrease groundwater, kill ground cover, and increase erosion. Erosion can create sediment dams that contribute to flooding. We knew giant sand bars like the one below were likely to form in the headwaters of Lake Houston since the 1990s. But our mayors at the time refused to dredge. Even though there was no imminent threat, that turned out to be a costly decision.

The West Fork San Jacinto mouth bar in the headwaters of Lake Houston in 2018. Before/after measurements show that as much as ten feet was deposited in this area during Harvey (five below water/five above). This and other bars have since been dredged, but the Army Corps said they blocked the river 90%.

I could list more examples. But you get the idea. Even though another Harvey is not lingering offshore at the moment, how much have we really learned? How much have actually improved conditions that increased flood risk during Harvey?

Please stay in the fight to make our homes, businesses and community safer.

Posted by Bob Rehak on 5/17/22

1753 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.

Harris County Flood Facts – Did You Know?

While digging for some flood facts on the Harris County Flood Control District website, I came across a media guide written in October 2016. That may be why it was buried in the archives. The headliner – Harvey – happened just 10 months later!

Photo courtesy of HCFCD

Therefore, it contains some obviously dated references. Regardless, it also contains a gold mine of useful information about flooding. In fact, it’s a condensed, crash course in flooding – all in 16 pages. Below: some nuggets of information I pulled from it combined with some updated information.

Did You Know?

  • Harris County Flood Control District maintains more than 2,500 miles of bayous and creeks. That’s the distance from Los Angeles to New York City. Imagine mowing that three times each year during the growing season!
  • Stormwater detention basins near Brays Bayou have a combined capacity equivalent to seven “Astrodomes” — about 3.5 billion gallons!
  • Harris County’s slope toward Galveston Bay is the equivalent of putting dimes under two legs of a 6-foot long pool table. (For every mile toward Galveston Bay, our elevation drops roughly 1 foot.)
  • We receive an average of more than 4 feet of rain every year. (51.84 inches at IAH as of this writing.)
  • Before the 2018 Flood Bond, Harris County Flood Control District and its funding partners spent an average of $150 million each year for the previous 10 years to build projects that reduced flooding risks and damages. Since the flood bond, we have spent almost $23 million per month. That works out to almost twice as much per year and we haven’t even gotten into the expensive right-of-way-acquisition and construction phases of most projects yet.
  • Floodplains show areas at risk for flooding only from bayous and creeks overflowing. There are many areas at risk for flooding from storm sewers and roadside ditches exceeding their capacity that are not located in mapped floodplains.
    HCFCD only has jurisdiction over bayous and major creeks in Harris County. Generally speaking, Flood Control does not have jurisdiction over drainage for highways and streets, including roadside ditches and storm sewers. TxDOT, cities, and precincts manage those issues.

Purpose and Outline of Guide

The purpose of the Guide is to serve as a quick reference guide for reporters who cover flooding. However, it’s also written to a level that the general public will find informative easy to understand.

It provides useful information about the Flood Control District, including its purpose, history, governing body, funding sources, jurisdiction and many projects near bayous and creeks.

The guide also includes sections highlighting the flooding history of Harris County, a glossary of flood-related terms, interesting flood facts, and a section dispelling common flooding myths. More on those in a later post.

To review the entire media guide, click here.

Posted on 6/16/2022 by Bob Rehak based on information and photos in the HCFCD Media Guide

1752 Days since Hurricane Harvey.

General Land Office Launches Disaster Preparedness Campaign

The Texas General Land Office (GLO) has launched a disaster preparedness campaign called “Don’t Ignore Your Risk.” GLO developed the new outreach initiative to encourage Texans to prepare for hurricane season and stay prepared. The season began Wednesday, June 1, and runs through November 30, 2022.

“Don’t Ignore Your Risk”

The disaster preparedness campaign includes a series of video advertisements in English and Spanish. They urge Texans to take time now to:

  • Know their risk
  • Purchase flood insurance
  • Protect their home
  • Safeguard documents
  • Prepare emergency supplies
  • Map an evacuation route.

Most Homeowner Insurance Policies Don’t Cover Flooding

GLO produced a series of twelve short videos that you can watch and share on YouTube from this page. They’re powerful, poignant and compelling. Each makes a simple point about the value of preparedness. And each underscores the value of flood insurance.

Kickoff commercial in English or Spanish.

“Be prepared and have a solid plan in place prior to severe weather,” said Commissioner George P. Bush. “Knowing your risks, having an evacuation plan, gathering supplies, securing documents, and protecting your property with flood and wind insurance are key steps to being prepared for storms or wildfires.

Texans can follow the GLO on social media and find disaster preparedness information for family and pets at recovery.texas.gov/preparedness.”

Aid No Match for Flood Insurance

According to a report by the Risk Management and Decision Processes Center at The Wharton School, homeowners received an average of $8,900 in individual housing assistance from Federal Emergency Management Agency (FEMA) following Hurricane Harvey. Meanwhile, the average of flood insurance claims was $115,104.

And almost five years after Harvey, the City of Houston’s Housing and Community Development Department still has hundreds of millions of dollars left to distribute. Counting on aid, as opposed to insurance, could mean years of living in subpar conditions.

According to FEMA, just one inch of flood water can cause more than $25,000 in damage.

Five Essential Steps

The GLO encourages all Texans to prepare for hurricane season by doing the following:

Know Your Risk

Sign up for your community’s emergency warning system. The Emergency Alert System (EAS) and National Oceanic and Atmospheric Administration (NOAA) Weather Radio also provide emergency alerts.

Make Your Evacuation Plan

Check with local officials about updated evacuation shelters for this year. Know where your family will meet up if you are separated and where you will stay. Pack a “go bag” including items you need to take with you if you evacuate. A “go bag” should be easy to carry and kept in a place where you can grab it quickly. Check with drivetexas.org to find routes near you. To find a shelter near you, download the FEMA app at fema.gov/mobile-app.

Gather Supplies

Plan for your entire household including children, people with disabilities or access/functional needs, and pets. Don’t forget medications.

Secure Documents

Remember to secure copies of important personal documents. Filing for government assistance requires documentation. Be sure to keep documents in a secure location and take them with you if you need to evacuate. Place these documents in a waterproof bag and back them up on cloud storage or a thumb drive.

Protect Your Property

Shutter your home as needed. Review your flood insurance policy (or sign up for one). And declutter drains and gutters. Most homeowner and renter insurance policies do not cover flood damage. And a flood insurance policy generally does not take effect until 30 days after purchase. So, be sure to maintain your policy or get one now. Take a video “tour” of your home to document all items and the home’s current condition.

Remember, just because you may be outside of the 100-year flood plain doesn’t mean you won’t flood. Sixty-four percent of Harris County homes that flooded during Harvey were outside of the 100-year flood plain.

For more information, visit recovery.texas.gov/preparedness.

Credits

The campaign will run for the next three months. It includes social media, digital display, cable, broadcast and streaming platforms. Inspired by Senate Bill 285. It was signed into law during the 86th Session of the Legislature.

The GLO helps educate Texans about the benefits of protecting their homes and finances through flood insurance and being prepared for storms and other natural disasters.

Credit for the commercials goes to 1820 Productions for production and editing.

Posted by Bob Rehak on 6/15/22 based on a GLO press release

1751 Days since Hurricane Harvey

Demolition of Old Kingwood Middle School Beginning

Contractors have fenced off the old Kingwood Middle School and started demolishing the driveways and parking lots, including the area where the school’s new permanent detention pond will go. Meanwhile, the new Kingwood Middle School building is nearing completion behind the old one. Largely invisible from the ground behind construction fencing, the aerial photos below show the progress of construction.

Pictures Taken on 6/12/22

Main entrance to old Kingwood Middle School now fenced off and being torn up. Plans show permanent detention pond going here.

One significant difference between the old facility and the new one: a detention pond that should help reduce the risk of local flooding in an era of higher, post-Harvey Atlas-14 rainfall probabilities.

Side parking lot and temporary detention pond in foreground. Old and new buildings in background. Looking NW.
New vs. old: Three stories compared to one.
Looking SW at entire complex. Athletic fields will replace the old building in background.
New building now completely dried in. Contractors focusing on finishing the interior work.
Old building in foreground will soon be demolished leaving a vast expanse of green in front of this gorgeous community showcase.

Out with Old, In With New

All along, the plan has been to tear down the old school when the new one is ready for students. Athletic facilities, formerly behind the old building will move in front of the new building.

It’s a delicate ballet. Dozens of cars were parked along Cedar Knolls today as workers scramble to get the facility ready for the next school year.

Humble ISD’s web page for this project contains artists renderings that will help you visualize the result. Humble ISD did not return phone calls today to discuss more details about the construction, old-building demolition and a completion date. But I will keep you posted as I get more information.

To see the progress of construction, visit these pages on ReduceFlooding.com.

Posted by Bob Rehak on 6/13/22

1750 Days since Hurricane Harvey

Western Caribbean Could Get Active This Week

(Updated at 1:30p.m. 6/13/14 to reflect increased risk) According to Harris County Meteorologist Jeff Lindner, a tropical system may form over the western Caribbean Sea this week. The National Hurricane Center has increased the probability of formation from 20% to 30% to 40% so far today.

NHC gives the yellow area a 30% chance of formation as of 8am EDT on 6/13/22.
Upgraded to 40% chance of formation as of 1PM Houston time, 6/13/22.

Converging Systems

Currently, a trough of low pressure extends from the eastern Pacific Ocean (south of Mexico) across central America into the far western Caribbean Sea. It is producing numerous clusters of showers and thunderstorms. Additionally, a westward moving tropical wave is starting to interact with the eastern part of that trough. See below.

Satellite image of Atlantic Basin as of 9:50 Houston time on 6/13/22. Note the area starting to curve around Central America and the westward moving storm off the cost of South America.

Thunderstorm clusters over the eastern Pacific are in the formative stages of tropical development. Meanwhile, showers and thunderstorms over the western Caribbean remain disorganized and in an environment generally of strong upper level westerly wind shear.

Global forecast models show varying degrees of development over the western Caribbean Sea east of Honduras by mid week.

Jeff Lindner, Harris County Meteorologist

Most models indicate development very near the eastern coast of central America. And it is possible that no development happens due to the close proximity to land and/or wind shear.

Should this surface low actually develop, the sprawling ridge of high pressure over the southern plains responsible for our current heat wave will affect forecasts.

Without any sort of defined center for the Caribbean system, confidence is low on where anything may form and eventually move. However, the majority of the global models keeps this disturbed area close to central America and then potentially in the Bay of Campeche.

National Hurricane Center Forecast

The National Hurricane Center agrees. It currently gives the feature a 40% chance of formation over the next 5 days. That’s up from 20% yesterday and 30% this morning.

At a minimum, the NHC predicts that an area of low pressure will develop by the middle part of this week over the southwestern Caribbean Sea. Forecasters add: “Some slow development of this system is possible thereafter while it drifts generally northwestward off the coasts of Nicaragua and Honduras.”

 Check National Hurricane Center Daily During Season

This should serve as a reminder that we are in hurricane season. And it is a good idea to check the tropical weather outlook at least once per day.

The best place to do that is the National Hurricane Center website. While the statistical peak of hurricane season is still three months away (September 11), life threatening tropical systems do strike in early in the season. Here’s an interesting article about devastating June storms.

Many people in the Houston area will remember Tropical Storm Allison in 2001. It killed 22 people and dumped almost as much rain as Harvey. It caused all the flood maps to be revised at the time.

Posted by Bob Rehak on 6/13/2022

1749 Days since Hurricane Harvey

Virtual Meeting on Flood Tunnels Thursday Night

The Harris County Flood Control District (HCFCD) will hold a community engagement meeting to share Phase 2 results for the Feasibility Study of Stormwater Conveyance Tunnels. The meeting’s purpose: to inform residents about the status of the Tunnels study and share study information.

At the highest level, the study looks at the potential to reduce flooding risks in Harris County via large-diameter, deep underground tunnels that convey stormwater.

The study includes three phases:

  • Phase 1 examined the feasibility of tunnels in this area.
  • Phase 2 looked at potential routes and alignment concepts for areas with unmet needs.
  • Phase 3, if needed, will include a preliminary design to validate assumptions.
Stock photo from Phase 1 report shows tunneling machinery (cutterhead and shield) being lowered into a launch shaft.

Tunnel Tradeoffs

The primary benefit of tunnels: they add stormwater conveyance without disturbing development on the surface. In highly developed or environmentally sensitive areas, this is important. But tunnels also come with technical and financial challenges. For instance, you must route them around oil wells, water wells, and geologic faults. And the cost can be considerable: up to $150 million per mile for a 40-foot-wide tunnel.

More about Phase 2

In Spring 2022, HCFCD completed Phase 2 of its feasibility investigation. The purpose of Phase 2 was to identify unmet flood mitigation needs in Harris County’s watersheds. Phase 2 also developed distinct tunnel concepts to meet those needs. 

This phase of the study focused on identifying:

  • Watersheds that met the criteria for a tunnel 
  • Flood damage centers that presented the highest risk and determining whether the tunnels would be more cost-effective over traditional flood control measures (e.g. stormwater detention, channelization, or buyouts)
  • Potential strategic locations for intakes and outfalls
  • Opportunities to integrate tunnels with existing and proposed flood damage reduction systems
  • Geologic and man-made hazards.

Phase 2 found that a tunnel SYSTEM, rather than one or more individual tunnel alignments, should be the focus of further study. Thus, we would need additional study before a final decision on whether to move forward with tunnels. 

Phase 2 received funding from the U.S. Department of Housing and Urban Development’s Community Development Block Grant Disaster Recovery program.

Meeting Details: How to Register

Community engagement is an important component of this study. So, HCFCD invites your participation.


The Virtual Community Engagement Meeting will be held on: 
Thursday, June 16, 2022
6:30 p.m. – 7:30 p.m.
Join online at: PublicInput.com/Tunnels
Or by phone* at 855-925-2801 with Meeting Code: 9622

*If you attend by phone only, maps and other exhibits will not be visible. However, information will be available after the meeting on the project webpage at hcfcd.org/tunnels.

The meeting will begin with a brief presentation to share project updates. A moderated Q&A session will follow. You can submit questions, comments and input before, during and after the meeting. Any comments not addressed during the Q&A session will receive a response after the conclusion of the public comment period.  

Even if you can’t attend the live meeting, still register to receive project updates. Video of the meeting will be available on the Flood Control District’s website and YouTube channel after the event.

Accommodations can be made for those with disabilities. If needed, please contact 346-286-4040 at least three business days prior to the meeting. For questions, please contact the Flood Control District at 346-286-4000, or fill out the comment form online at hcfcd.org/tunnels.

Overview of Other Phases

For a brief history of the tunnel investigation, visit this page on the HCFCD website.

Phase 1 took a high-level look into the feasibility of constructing large-diameter deep tunnels to help move stormwater out of Harris County. It considered soil types, geotechnical challenges, hydraulic capacity, impacts, scheduling, and cost projections. Phase 1 was not watershed specific. Nor did it focus on any particular alignment/location.

Phase 1 findings include:

  • Geotechnical conditions do not appear to present any remarkable, nor non-negotiable concerns.
  • Geologic faults may require special design and construction considerations if crossed by the tunnel; not considered fatal flaws.
  • Tunnels can move a significant rate of stormwater operating by gravity as an inverted siphon.
  • Tunnel cost, including a 50 percent contingency, for a representative 10-mile long, 25- and 40-foot diameter tunnel is approximately $1 billion and $1.5 billion respectively.

For the complete 1700-page, 300-megabyte final report, click here.

Phase 3 will include preliminary design. The purpose:

  • Prove project benefits and costs
  • Select locations
  • Investigate geologic faults
  • Validate assumptions made during Phase 1 and 2
  • Identify internal and external sources of funding.

This post will give you more background about flood tunnels.

Posted by Bob Rehak on 6/12/2022

1748 Days since Hurricane Harvey

Upstream Addicks-Barker Trial Concludes, But No Ruling Yet on Damages

The damages phase of the Upstream Addicks-Barker class-action lawsuit over Hurricane Harvey flooding concluded Friday, 6/11/2022. Earlier, Judge Charles F. Lettow ruled that the Army Corps was liable for damages. The question being decided now is “How much will they get?” We don’t yet have that answer, but should before the end of the year.

Flooded homes inside Addicks Reservoir during Harvey but still outside even today’s 100-year floodplain.

Basis for Claims

After Hurricane Harvey, people and businesses both upstream and downstream of the Addicks and Barker Reservoirs on Houston’s west side sued the Army Corps. Plaintiffs in both cases alleged that the Army Corps’ operation of the dams flooded their homes and constituted a taking of their property without compensation. The Fifth Amendment of the U.S. Constitution prohibits that.

“No person shall be … deprived of … property, without due process of law; nor shall private property be taken for public use, without just compensation.”

From Fifth Amendment of U.S. Constitution

Difference Between Upstream, Downstream Cases

However, the Upstream and Downstream cases also have important differences. Upstream, the Corps did not own all the land inside the U-shaped reservoirs. Worse, the Corps permitted developers to build homes and businesses inside the reservoirs on land that remained in private hands. The Corps did not anticipate it all flooding based on storms they had studied going back to the 1890s. Yet the Corps still built the walls taller and longer than it needed to hold anticipated floods.

When Harvey came along, the water in the reservoir backed up onto that private property and flooded hundreds of homes.

Lawyers for the flooded property owners asserted that the federal government cannot use private property to store federal floodwaters without providing compensation. The judge agreed.

Second of Two Phases Nearing Completion

In the first phase of the upstream case, the court found the Corps liable. In the second phase, the court considered damages, i.e., how much compensation property owners should receive.

Although the trial portion of the damage phase just concluded, the case is not yet over. McGhee, Chang, Landgraf & Feiler, one of the law firms representing plaintiffs in the class-action suit, said they must still submit post-trial legal briefings. Then they will make final closing arguments in Washington D.C. in a few months. “We expect a decision to be rendered by the Court thereafter – probably sometime in late fall/winter,” said a press release by the firm.

Exponential Growth, Larger Storms, But No Mitigation

After reading the 46-page decision, I gained a better grasp of the history of the dams and the nature of the claims.

The Corps built the dams much higher than they needed to hold a 100-year flood based on what they knew at the time.

But the Corps did not purchase all land inside the reservoirs. They left private property outside the area expected to flood. At the time the dams were constructed, that land was used for ranching and rice farming.

If the land flooded, reasoned the Corps, not much damage would result. But then came Houston’s exponential growth in the 1950s. Those ranchers and rice farmers sold their land to developers. And developers started to build inside the reservoir.

Then the Corps realized that the storms on which it based the reservoirs’ designs (including a storm from the 1890s) were smaller than storms hitting the Houston area in the modern era. But by then, it was too late.

When the Corps realized future floods would likely invade homes, it launched an awareness program and held some public meetings. But the judge felt that information didn’t filter down to most homebuyers.

Also, the Corps took no concrete steps to reduce flood risk when it realized the severity of the problem. Worse, the Corps continued to issue permits and authorizations for more developments.

To sum up 46 pages in a sentence, “The Corps knew it had a problem and did nothing to fix it.” (That’s my takeaway, not the judge’s language.) The Corps remained focused on its primary objective – preventing downstream flooding.

Downstream Focus Looms Large in Upstream Decision

Said Judge Lettow, “Equipped with the knowledge that storms of the design-storm magnitude were probable, the Corps did not stray from its primary objective to prevent downstream flooding (indeed, it probably could not), even when it knew that could well mean impounding water on private property.”

Lettow cites a 2012 Water Control Manual which the Corps followed during Harvey. It instructs the Corps to operate the dams in a manner consistent with their original purpose: to protect downstream property by impounding water in upstream reservoirs. It states “…operate the reservoirs in a manner that will utilize to the maximum extent possible [Emphasis added] the available storage to prevent the occurrence of damaging stages on Buffalo Bayou.”

Knew Larger Floods Probable

According to the judge, the Corps continued to follow that policy even though it understood that rainfall events – larger than ones they designed the dams around – were “probable, rather than merely possible.”

Lettow also found it “undisputed that plaintiffs did not know their properties were located within the reservoirs and subject to attendant government-induced flooding.”

Government Planned for Years to Impound Floodwater on Private Property

Said one hydrologist who reviewed a detailed history of the Corps’ decision making, “The Corps of Engineers did NOT buy the entire area they knew would be inundated if Addicks and Barker reservoirs were at peak storage capacity.”

Judge Lettow said, “The government had made a calculated decision to allow for flooding these lands years before Harvey, when it designed, modified, and maintained the dams in such a way that would flood private properties during severe storms. Defendant cannot now claim that this harm was unavoidable when it planned for years to impound floodwaters onto plaintiffs’ properties.”

The Corps made the best decisions it could with the information AVAILABLE at the time.  But as we all know, things change! And that’s what worries me most about this case.

Right now, developers are building projects all around the region based on flood maps that will soon be replaced.

To read the original complaint by one of the law firms (Irvine $ Conner), click here.

For the complete text of the liability ruling, click here.

Posted by Bob Rehak on 6/11/2022

1747 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.

 

 

Different Factors Affect Hurricane Strength, Rainfall

The factors that create hurricane strength may not be the same factors that create intense tropical rainfall. According to NOAA, warm sea surface temperatures can increase storm intensity. Meanwhile, the absence of steering currents and wind sheer can cause even weak storms to stall over an area and dump huge amounts of rainfall.

Two things happened this week to bring these factors into focus.

First, sea surface temperatures in June have already reached those not usually observed until late July or August in Galveston.

Second, this week marks the anniversary of Tropical Storm Allison, which set rainfall records for its era and caused all the flood maps to be redrawn (until Harvey). That prompted more research into meteorological factors that affect hurricanes, their formation, and their destructiveness.

Record Heat Tied to Higher than Usual Sea Surface Temperatures

Jeff Lindner, Harris County’s meteorologist, released a report this morning that said, recently all along the Texas coast, the nighttime lows have reached near record highs. Galveston, for instance, has failed to fall below 83 degrees for the last 72 hours and the low yesterday was only 84 degrees which is 1 degree shy of the all-time high “record low” of 85 from last summer.

These extremely high “low temps,” says Lindner, are more typical of August than June and directly tied to the nearshore water temperature which is already 83-86 degrees along the Texas coast.

28-30 degrees Celsius translates to 83-86 degrees Fahrenheit.Source: NOAA.

That raised two questions for me:

  • Are sea surface temperatures warmer than normal?
  • If so, how does that affect hurricane formation?

Sea Surface Temperatures Much Higher than Normal

I first researched sea surface temperature anomalies. You can see from the map below that the entire tropical Atlantic, Caribbean and Gulf of Mexico show higher-than-normal temperatures. How much higher?

Anomalies are departures from normal. This map shows anomalies for today. Source: NOAA.

Most of the upper Gulf Coast is 1-2 degrees Celsius above normal. That translates to about 2-4 degrees Fahrenheit.

Eighty-six degrees Fahrenheit is the normal average for August in Galveston. And we’re already experiencing that in June!

Relationship Between Sea Surface Temps and Hurricanes

So how will that affect hurricanes? The short answer: it will likely make them more intense, according to NOAA. Here’s how.

In order for a hurricane to form, two things must be present: a weather disturbance, such as a thunderstorm, that pulls in warm surface air from all directions and water at the ocean’s surface that is at least 80° Fahrenheit (27° Celsius).

Because warm air and warm seawater spawn these storms, they form over tropical oceans where seawater is hot enough to give the storms strength and the rotation of the Earth makes them spin.

Hurricanes start simply with the evaporation of warm seawater, which pumps water into the lower atmosphere.

NOAA

Converging winds then collide and turn upwards, where water vapor starts to condense. That releases heat that warms the surrounding air, causing it to rise as well. That causes even more warm, moist air to spiral in to replace it.

As long as the base of this weather system remains over warm water and its top is not sheared apart by high-altitude winds, it will strengthen and grow. More and more heat and water will pump into the air. The pressure at its core will drop further and further, sucking in wind at ever-increasing speeds.

Eventually, hurricanes turn toward mid-latitudes, i.e., Texas. When they move over cold water or land, they lose touch with the hot water that powers them. The hurricane then weakens and breaks apart.

Recent studies have shown a link between ocean surface temperatures and tropical storm intensity – warmer waters fuel more energetic storms.

NOAA

Other Factors Correlate with Higher Rainfall

Energy and intensity, however, do not correlate directly with rainfall. Other factors play larger roles in creating monster rainfall rates.

A slow moving storm that meanders or stalls can dump more rain than fast moving storms that blow through areas quickly. Tropical Storm Allison makes an excellent example.

This week is the anniversary of Tropical Storm Allison (June 5-10, 2001). NOAA has a special web page that tells the story of Allison and its destructive rains. Before Harvey, Allison set records for much, but not all, of the Houston Region. Greens Bayou at Mount Houston Parkway, for instance, received 38.78 inches of rain.

Allison lingered around the Houston area for days, went up to Lufkin, and then backtracked over already saturated ground before moving east.

The absence of strong steering currents allowed Allison to stall and dump huge rainfall amounts on Houston.

“The devastating flooding from Allison is a stark reminder that rainfall from tropical cyclones does not depend upon the strength of the system.”

NOAA

The Hydrometeorological Prediction Center found six factors that impact the rainfall potential of landfalling tropical cyclones:

  • Storm track (or movement)
  • Time of day
  • Storm size
  • Topography
  • Wind shear
  • Nearby weather features

Between June 5th and the 9th, the two major factors leading to heavy rainfall over Southeast Texas turned out to be Allison’s slow movement and the time of day. These were aided by an abundance of available Gulf moisture.

Graphic showing rainfall totals for Harris County, Texas for June 5 - 9 2001 during Tropical Storm Allison. The highest recorded rainfall was 38.8 inches. Image courtesy of Tropical Storm Allison Recovery Project.
Tropical Storm Allison 5-day rainfall totals in 2001 related primarily to the storms track and slowness, caused by the absence of steering currents and wind sheer.

Time of day deserves more explanation. On Day 4 of Allison, the sun cleared over much of Houston. That increased daytime heating. And the heat caused feeder bands to intensify over areas that previously flooded. No one died during the first three days of the storm. But 22 died during the last two as rainfall from those bands reformed over areas already badly flooded.

Give Your Kids a Science Assignment for the Summer

Weather is one of nature’s biggest puzzles. I find it endlessly fascinating. If your kids are bored already by the summer’s heat, give them a science assignment. Have them research NOAA’s website to learn more about hurricanes and the heat. Hint: ask them how that bright red area in the northern Pacific (in the SST anomalies map). Then ask them how that’s related to drought, trade winds, wind-sheer, and predictions for an above-average hurricane season.

Posted by Bob Rehak on 6/9/22 based on information from NOAA.

1745 Days since Hurricane Harvey