On 7/23/2020, consultants for the San Jacinto River Basin Master Drainage Plan gave the SJRA Board and the public a first look at a draft of the plan. The final report is due out at the end of August. The draft shows the broad outline of the team’s efforts.
Draft Shows Broad Outline of Recommendations
It shows the types of recommendations they will make. However, this draft does not yet include specific recommendations as to prioritization of projects. Those will change before the final report. For instance, much of the draft focuses on upstream detention. But specific detention site recommendations have not yet been finalized.
Funding and Partners
Below are the key slides and a brief explanation of the main point behind each. This drainage study is 75% funded by a FEMA Hazard Mitigation Grant and 25% by four local partners: the SJRA, City of Houston, Harris County Flood Control, and Montgomery County.
Scope of Study
The study area covers almost 3,000 square miles and the tributaries listed on the left.The SJRA primarily has responsibility for the portion of the watershed in Montgomery County. However, the scope of the drainage study extends to other counties including Waller, Grimes, Walker, Liberty, and San Jacinto.
Heat Map Shows Where Most Damage Occurs
The team started by looking at where flooding has occurred historically. The tan areas aboveshow where the most damage has occurred.
Goals and Methodology
The partners started by looking at vulnerabilities and identifying mitigation possibilities. Their main goals are in red. The final report will make specific recommendations for detention, buy-outs and improving conveyance. Recommendations will also improve flood warning and communication.The team started by integrating and updating all existing hydraulic and hydrologic models in the watershed as reflected on the latest 2018 lidar terrain data. They now take into account new construction, growth, additions to impervious cover, and Atlas-14 rainfall probabilities (which vary by sub-watershed within the larger watershed).To calibrate and verify its H&H models, the drainage study team examined four historical storms that, together, impacted the entire study area. They then adjusted the models using radar rainfall data, and USGS high water marks and peak flow data. The objective: to make the models reflect “ground truth.”The team is also looking at strategies to reduce sedimentation. However, this is not a major focus of this study. Their purpose is not to evaluate the relationship between sediment and flooding. Other studies will do that.
Three Main Areas of Focus
This slide shows the three major thrusts of drainage study effort over the last 1.5 years. The primary focus has been on: a) identifying the best locations for upstream detention that can reduce the volume of water coming downstream to populated areas during floods, b) where to install additional gages to improve flood predictions and warning times, and c) improving communication during emergencies.This shows the steps the drainage team went through to evaluate and rank-order potential sites for detention.
Areas of Highest Potential for Mitigation
Here’s where they found the highest and lowest potential for mitigation. The box explains the watersheds that see the most effective solutions within the SJMDP study area, as explained in the list to the left of the slide.Some drainage projects recommended in previous plans are no longer possible today because of upstream development. However, areas that once held potential for a single large project still hold potential for several smaller projects that add up to significant flood reduction.
Mitigation Project Funding
The cost all the drainage projects identified adds up to about $3 billion. They only reduce flooding of structures worth about $756 million dollars. Because costs exceed benefits, FEMA will not likely fund all of these.However, many of the projects are in areas with low to moderate income (brown and tan areas). See the large concentration in the eastern watershed. That opens up other sources of funding, such as the Department of Housing and Urban Development where the benefit/cost ratio may not be as important.
Harmonizing Regulations Throughout Region
The team will also make recommendations to harmonize floodplain development regs throughout the region. Continuing to allow unmitigated upstream development in floodplains could destroy any new investment made to protect highly populated downstream areas.
Some Problems May Only Be Solved Through Buyouts
Buyouts usually have a high benefit-to-cost ratio relative to construction projects such as detention ponds. Buyout strategies can target the most vulnerable properties, such as those in the 2- and 5-year floodplains. None of the detention projects recommended by the team will likely remove those from danger.
Steps Still Not Completed
The team has finished the steps in red. They in the process of prioritizing projects and developing a phasing plan. The last bullet point is not part of this study.
More Upstream Gages Needed to Eliminate Blind Spots
The team has also identified locations for additional upstream gages and local partners who can help maintain those gages. Think of these like a “distant early warning” system. They give river forecasters visibility into “blind spots.” Forecasters will be able to add up the rainfall on various tributaries and predict the impact and timing of flooding downstream.That could give people more time to evacuate.
Ways to Improve Communication
The team is also looking at ways to communicate better during flood emergencies. They are looking at inundation mapping, evacuation routes, and improved communication protocols.
Timetable for Remainder of Project
This chart outlines the project workflow. It shows completed steps in red, and incomplete steps in yellow.The final report with specific recommendations should be released at the end of August or in early September.
Every Little Bit Helps
I can’t wait to see this report in its final form. During the presentation, the presenter talked about reducing flooding downstream at the West Fork and I-45 by up to six feet if all upstream projects are implemented.
One thing to keep in mind: there is no single silver bullet that can solve the regions flood problems. All of these steps are additive. In my personal opinion, a foot here and a foot there can help offset future releases from Lake Conroe. People in the Lake Houston Area benefit from any and all upstream improvements.
Posted by Bob Rehak with thanks to SJRA and HCFCD
1064 Days since Hurricane Harvey and 313 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/07/Screen-Shot-2020-07-23-at-10.27.52-AM.jpg?fit=1500%2C1141&ssl=111411500adminadmin2020-07-28 16:33:252020-08-03 15:02:43San Jacinto River Master Drainage Plan Draft Provides First Look at Final Report Due Out in August
Harris County Flood Control District’s (HCFCD) work on Ben’s Branch has been one of the bright spots in flood mitigation since Hurricane Harvey. The channel is now wide open, bulldozers are neatening up the banks, and crews are hydromulching this morning.
What Is Hydromulch?
Hydromulch (or hydraulic mulch seeding, hydro-mulching, hydraseeding) is a planting process that uses a slurry of seed, mulch, and fertilizer. It is often used as an erosion control technique on construction sites, as an alternative to dry seed. The “gel” accelerates the growth of grass by providing enough moisture and nutrients for the seeds to germinate even in dry weather.
Progress Photos
Paul Campbell of Towncenter Apartments caught this shot outside his apartment this morning.
Hydromulching the banks of Ben’s Branch on 4/25/2020. Photo courtesy of Paul Campbell.Looking northwest over Ben’s Branch toward YMCA soccer fields (upper left). This and photos below taken 4/21/2020.Looking west up Ben’s Branch toward Kingwood Greens and Kingwood Country Club Forest Course across West Lake Houston Parkway.YMCA soccer fields in upper left.Reverse shot of the wide-open Ben’s Branch Channel looking east toward YMCA across West Lake Houston Parkway.
Hydromulching is usually the last step in channel repairs. Planting grass reduces erosion. Without it, rain would simply carry silt back into the channel.
Like New Again
Many thanks to the hard-working folks of the Harris County Flood Control district and their contractors.
In the last year, they have removed approximately 80,000 cubic yards of silt from the area between Kingwood Drive and the YMCA. Despite setbacks during Tropical Storm Imelda. Conveyance should now be restored to what it was in the mid-1990s.
Ben’s Branch hasn’t looked this good in decades. And residents will be much safer from flooding in future storms.
Posted by Bob Rehak on 4/25/2020 with thanks to Paul Campbelland HCFCD
Starting tonight at 11:59 P.M. and lasting through April 3, 2020, “this Order requires all individuals anywhere in Harris County, to stay at home – except for certain Essential Activities and work to provide Essential Business and Essential Government services or perform essential infrastructure construction, including housing.”
Rustling Elms Bridge over Taylor Gully during peak of May 7, 2019 flood.
Non-essential and prohibited:
All exercise facilities including gyms, swimming pools and martial arts studios must close.
A broad range of retail shops must close including barbers, hair salons, tattoo parlors, bowling alleys, game rooms, massage parlors, malls, flea markets, movie theaters, concert halls and more.
All public and private gatherings occurring outside a single household or living unit are prohibited.
Nursing homes, retirement, and long-term care facilities must prohibit non-essential visitors except for end-of-life visitation or critical assistance.
Restaurants will remain closed except for drive-through and carry-out orders.
Churches may only provide services via video or teleconference.
Essential and still exempt:
Grocery stores
Pharmacies
Gas stations
Convenience stores
Liquor stores
Car dealers and repair facilities
Professional services, such as legal, accounting, insurance, etc.
Flood Control Not On List
The corona virus prohibited and exempted lists stretch for 20 pages. They are too numerous to summarize here. However, as I read through the list, nowhere did I see “flood control” or “flood mitigation” work. That made me wonder whether we had potentially traded one type of crisis for another.
So I reached out to county officials and asked how today’s corona virus order would affect the activities of the Flood Control District. Said another way, were they considered “essential activities.”
Flood Control Deemed Essential, Will Continue
The answer: Yes, Flood Control is considered essential under the infrastructure and construction provisions of the order. No, Harris County Flood Control District (HCFCD) will not shut down mitigation projects.
Matt Zeve, Deputy Executive Director of HCFCD had this to say. “Everyone who can will work from home. We had already been phasing that in before today. All construction and field work will continue as normal…with appropriate social distancing and hygiene procedures of course.”
Moving Into High-Risk Season for Flooding
As we move into April and May, the rainiest months of Spring, that’s comforting. A reader asked me today, “What would happen if we got a flood on top of the corona virus?” My first inclination was to tell her she needs to write the screenplay and go to Hollywood. But then I said, “That’s actually pretty plausible.”
People mucking out houses in unsanitary conditions and tight, crowded spaces could accelerate the spread of the virus. Crowded rescue boats and choppers would make a first responders nightmare, especially when rescuing people with the corona virus. Thousands of evacuees in churches, schools and convention centers. Evacuating high-risk populations like the elderly from nursing homes. These are not pleasant thoughts.
That’s why I’m glad that the work of flood control will continue as normal. Hurricane season is only nine weeks away.
Posted by Bob Rehak on 3/25/2020
939 Days since Hurricane Harvey and 188 since Imelda
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Mayor Pro Tem Dave Martin shocked a meeting of Kingwood residents at a town hall meeting on February 25, 2020. He he said the City would not participate in a much-rumored buyout of the Perry Homes’ Woodridge Village property that contributed to the flooding of Elm Grove Village twice last year. The rumors first went public in a Houston Chronicle story on January 27th this year. In that story the Chronicle characterized the plan as a bailout, not a buyout, but later retracted that in an editorial board statement.
The plan was to purchase all or part of the land and build a giant detention pond on it that would prevent Elm Grove from flooding again.
Silence After Executive Session in Commissioner’s Court Meeting
The Chronicle story appeared one day before a Harris County Commissioner’s Court meeting. Commissioners were to consider the purchase of the property at that meeting in executive session. But there was no public announcement after the meeting of what they decided. We later learned the reason why.
County Asked City to Pay for Half of Purchase
Harris County, according to Martin at the town hall meeting, decided to ask the City to put up half the money for the purchase of the land. Martin initially supported the purchase “at the right price,” according to the Chronicle story.
However, something happened between the Commissioner’s Court Meeting and the Town Hall Meeting to make Martin change his mind about participating in the deal. At the Town Hall meeting, Martin never mentioned the purchase price as an objection.
Martin Claims We Pay Taxes to County So County Should Pay 100%
Instead, Martin launched into a discussion of his tax bill. He said that out of his total tax bill he paid:
56.4% to Humble ISD
18.8% to the City of Houston (of course, that didn’t include fees, such as those for drainage)
14.4% to Harris County.
That adds up to 89.6%, but Mr. Martin did not explain what happened to the missing 10.4%.
Who Is Doing What
He simply said that dramatized the need to get “… Harris County to do more work in Kingwood.” (Editor’s note: at a previous town hall meeting Martin explained that the county was already taking over all work on ditches and streams in Kingwood, but then he quickly added that if the County purchased the Woodridge property, it would let the CITY do more work on ditches and streams. Martin never addressed that apparent contradiction).
Why City Refuses to Participate
Martin then explained that Kingwood overwhelmingly supported the $2.5 billion Harris County Flood Bond in 2018. He also pointed out that the language in the flood bond lets Harris County purchase land in other upstream counties for the purpose of floodwater detention – exactly like the proposal for Perry Homes’ Woodridge Village property.
According to Martin, County Precinct 4 Commissioner Jack Cagle wants the City of Houston to contribute half of the money.
“Quite frankly,” said Martin, “I’m not going to ask the Mayor to contribute half. Because they (Harris County) should contribute 100% of it because we gave them our tax dollars and they specified what these tax dollars are to be used for. So they need to come up with 100%.”
Martin then talked about berating Harris County Judge Lina Hildago on the subject before urging residents to contact their county officials. He closed by demanding that the County should put up 100% of the money for Perry Homes’ land because “WE are that close to making this happen.” (Emphasis NOT added.) Martin also asserted that if the County took sole responsibility for the deal, it would somehow help flooding problems in other unrelated areas such as North Woodland Hills.
Listen to Audio Clip of Discussion at Town Hall
To listen to a four-minute audio recording of this segment of the meeting, click the key frame of Mayor Pro Tem Dave Martin below.
Segment of 2/25/2020 Kingwood Town Hall Meeting in which Houston Mayor Pro Tem Dave Martin discusses the buyout of Perry Homes’ Woodridge Village land to construct a detention pond and why Harris County Should Pay for 100% of the deal.
Mr. Martin never explained why the taxing entity we pay the least to should assume exclusive responsibility for the entire project. Nor did he address why drainage fees paid to the City, could not be used for the project.
Meanwhile, the county has been silent on whether it will pick up 100% of the tab for the detention work. And Elm Grove residents still spend sleepless nights every time it rains.
Posted by Bob Rehak on 3/1/2020
915 Days after Hurricane Harvey and 164 after Imelda
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.
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When we think about flooding, most of us don’t think beyond the repair costs of homes. But there are more costs to communities that can remain hidden for years. Erosion, for instance, is one of the hidden costs of flooding that we rarely talk about.
You’ve heard me talk about the eroded sediment from sand mines that winds up downstream in the mouth bars of the East and West Forks of the San Jacinto.
The City, County, State and Federal Government have already spent more than $100 million to remove eroded sediment that is blocking the West Fork of the San Jacinto and much more remains.
Ben’s Branch became virtually blocked with sand after Harvey. Harris County Flood Control is now removing the excess sediment to restore conveyance of the channel.
We’ve all seen how such eroded sediment can back water up and raise flood levels. And we’ve all seen how much that can cost. Not just from the initial flood, but in terms of remediation.
Look At the Cost of Erosion From the Upstream Side, Too
Ditch erosion can affect homeowners in other ways, too. By threatening their property and community property. Lost property is yet another one of the hidden costs of flooding.
Ditch erosion in Commons on Lake Houston.Photo from January 2019.
In Deer Ridge Estates, ditch erosion is creeping inexorably toward back yard fences.
Kingwood diversion ditch where it crosses past Deer Ridge Estates just north of Deer Springs Drive.Photo from Jan. 2019.
On a recent flight down the San Jacinto West Fork, I spotted erosion threatening the back yards of homes still under construction in the new Northpark Woods subdivision.
Erosion can threaten pipelines, too.
Pipelines undermined by erosion at Liberty Materials Mine near Conroe.
Let’s Play Hot Potato
Who is responsible for repairing the upstream erosion when it happens? In Harris County, we’re lucky, we have a flood control district that has assumed responsibility for that. But the ditch two photos above is in Montgomery County. So are the pipelines in the photo above.
Who is responsibly for repairing erosion in these cases? The County? The homeowners? The homeowner association? The developer? The sand mine? The pipelines? A flood control or drainage district? Everyone wants to assume it’s someone else’s problem. No one wants to assume responsibility.
But without someone stepping up, these homes will eventually be threatened. And with the exception noted above, few people or groups are stepping up.
Paul Crowson, a Montgomery County flood activist has posted about this subject on Facebook. Says Crowson, “The county, the flood control district, the neighborhood HOA, the POA, the City, the State, the developers, the engineers … all are passing the blame and responsibility around to each other.”
“These poor people (in the court case) have lost most of their yard, and are in danger of losing their home to the ravages of the drainage easement nightmares,” says Crowson. “Those nightmares are growing every day and will eventually swallow them and their home. Why does it matter to you? I’m thinking right now of Roman Forest, Tavola, New Caney, and Montgomery County.”
It’s Easier to Keep Up Than Catch Up
I would argue that it’s cheaper to prevent a disaster in the making than to remediate a disaster after the fact. Remember those homely homilies your parents and grandparents tried to instill in you? An ounce of prevention is worth a pound of cure. A stitch in time save nine.
Congressman Dan Crenshaw says the Navy Seals have a similar saying for those who fall behind on those long training runs they take. “It’s easier to keep up than catch up.” They’re all true! And the same holds true for deferred maintenance.
When Deferred Maintenance Turns into a Disaster Area
Montgomery County does not have a flood control district. Nor does it seem especially eager to address problems, such as those in the photo above.
As we saw with the mouth bar on the West Fork that had been building up under water for decades, maintenance can be deferred for only so long.
Then a monster flood comes along like Harvey. It finds the weak points in systems…and boom. Deferred maintenance turns into a disaster area.
Posted by Bob Rehak on 2/28/2020 with input from Paul Crowson
913 Days after Hurricane Harvey
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Good news! Jason Krahn with the Harris County Flood Control District (HCFCD) has announced that the District will start restoring conveyance capacity to Bens Branch beginning August 19, 2019. The contractor’s official start date is that Monday, but it will take several days to move equipment to the site. “So the citizens of Kingwood should see the contractor on site by midweek,” said Krahn.
Project Scope
The project will include removing and disposing of approximately 76,285 cubic yards of sediment accumulations. This will be a multi-step process. First, HCFCD’s contractor, Solid Bridge Construction, LLC, must remove the soil from the creek. Then the soil must drain and dry. Finally, dump trucks will remove the excavated material.
Scope of Ben’s Branch project outlined in red.
The project will extend from Kingwood Drive south to the library, then east under West Lake Houston Parkway to the YMCA, then south again to an area adjacent to Deerwood Country Club. It will stop 1800 feet from the river where the the ditch flattens out into a natural stream, near the Y canoe launch.
Sedimentation restricting the conveyance of Ben’s Branch between the library and West Lake Houston Parkway. Looking west from bridge.
The east/west portion of this project above became severely silted during Harvey, contributing to flooding in Kingwood Greens, Town Center, the Enclave, Kingwood Village Estates. A dozen seniors died in Kingwood Village Estates from injuries sustained during the evacuation or from the stress of seeing their homes destroyed when they returned.
City Portion of Ditch South of Y Not Included
The City of Houston reports that it has not yet secured maintenance easements from adjoining property owners south of the Y.
Most of the ditch adjoins property owned by the Clubs of Kingwood. Here’s what it looks like from a drone. My thanks to Jim Zura of Zura Productions for his time and expertise in securing this footage.
Ben’s Branch out of the YMCA looking toward Lake Houston. HCFCD project does NOT include this portion which is controlled by the City of Houston. Note the dredge operation in the distance at the end of this video. Drone footage courtesy of Jim Zura, Zura Productions.
For more information about the project, consult the Kingwood pages of the HCFCD website. The project ID is # G103-33-00-X004 – Bens Branch Conveyance Restoration.
Krahn expects the lower portion of Ben’s Branch to take 9 months. Construction equipment will access the work area via the established access points from Kingwood Drive, Bens View, West Lake Houston Parkway, and Denmere. The contractor will use heavy construction equipment such as dump trucks, excavators and bulldozers. Motorists should stay on high alert for truck traffic when passing near construction access points.
Expect Extra Traffic
The average commercial dump truck holds ten to fourteen cubic yards. So this project could result in 5,500 to more than 7,000 round-trips before its over.
Posted by Bob Rehak on 8/12/2019 with video from Jim Zura of Zura Productions
713 Days since Hurricane Harvey
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Harris County Flood Control District (HCFCD) is nearing completion of its project to clean out Taylor Gully. The project will restore the ditch’s conveyance through Elm Grove. The ditch had become clogged due, in large part, to erosion from months of clear-cutting and construction activities immediately upstream in the new Woodridge Village development.
After the Flood, but Before the Clean-Out
Below, several shots taken shortly after the May 7th flood.
Erosion on Woodridge Village property. Concrete culvert in background is entrance to Taylor Gully on Harris County side of Montgomery County Line. Another shot of erosion leading to culvert, visible in upper right.Looking north at same culvert from Harris County side of county line.Flood debris carried downstream into Elm Grove portion of Taylor GullyShot taken at end of May looking south along Taylor Gully. Three weeks after the May 7 flood.
After the Clean-Out
What a difference some backhoes and bulldozers can make!
Looking south from same area today, but from opposite side of Gully. Photo courtesy of Jeff Miller.
Re-contoured backslope swale with new culvert. Photo courtesy of Jeff Miller.
Newly cleared Taylor Gulley Backslope Swale near the homes that flooded in North Kingwood Forest. Photo courtesy of Jeff Miller.
Brand new backslope interceptor structure and improved swale by HCFCD located just north of Creek Manor where it dead ends into Taylor Gulley.Photo courtesy of Jeff Miller.
These backslope interceptor swales reduce erosion, provide additional floodwater storage, and help prevent floodwaters from impacting structures.
One Month From Statistical Peak of Hurricane Season
Today is one month from the peak of hurricane season – September 11. Hundreds of people in Elm Grove and North Kingwood Forest will have an additional margin of safety thanks to HCFCD’s Taylor Gully project. Despite three months of near-perfect construction weather, Perry Homes’ contractors have only completed two of five planned detention ponds upstream. More on the construction status of Woodridge Village in my next post.
Posted by Bob Rehak on 8/11/2019 with photography from Jeff Miller
712 Days since Hurricane Harvey and 3 months + 4 days since the May 7th flood
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