Tag Archive for: bens branch

Tree Lane Bridge over Bens Branch Still Standing

The recent drought has reduced the rate of erosion under the Tree Lane/Bens Branch Bridge for now. But with wetter weather expected, we need to accelerate the repair effort. Recent pictures show the desperate need for repairs to the bridge. It’s next to Bear Branch Elementary School where more than 600 students attend grades K-5.

Power of Moving Water

The current state of this bridge and the area around it is a testament to the power of moving water … more than engineers designed the bridge to handle.

Water jetting under the bridge during storms has ripped away great slabs of concrete, eroded side walls, and partially blocked a storm drain outfall.

Condition of Tree Lane Bridge over Bens Branch on 11/24/23

It has also eroded the channel. Rip rap has done little to halt the erosion.

11/24/23. Condition of Tree Lane Bridge over Bens Branch.

Downcutting has exposed utility lines. And stormwater has carried chunks of concrete downstream like toothpicks.

11/24/23. Bens Branch downstream of Tree Lane Bridge.

Before Hurricane Harvey, the tree canopy in this area was so dense, one could barely see Bens Branch from the air. Now, there’s a gaping hole in the landscape caused by the “jetting.”

11/24/23. Downstream erosion of greenbelt caused by jetting water from under bridge.

As more and more water builds up behind the bridge during storms, it causes water to shoot under the bridge with greater pressure and accelerate erosion.

One can’t help but wonder whether the random and cumulative impact of several large storms caused this damage. Whether insufficiently mitigated upstream development helped nature along. Or whether the bridge simply reached the end of its normal life.

The City of Houston attempted to repair this bridge in March 2020. By January of 2023, it was worse than ever. And in June of 2023, I wrote about damage accelerating.

But a prolonged, intense drought last summer put an end to the acceleration. A close comparison of recent photos with those taken six months ago shows that the bridge now looks much like it did last June.

When Will Bridge Be Fixed?

I have learned that both the City of Houston and Harris County Flood Control District (HCFCD) are studying the bridge. In August, the City even allocated money to fix it. However, HCFCD worried about the impact to its Bens Branch channel. The two entities are now trying to reach a mutually agreeable solution.

Having lived near here for 40 years, one thing is clear to me. We can’t count on drought to prevent more erosion forever.

During El Niño years (like now), much of Texas is cooler and wetter than average. Northern storms generally track farther south, producing more clouds, rain and severe weather, according to the NWS.  

Perhaps we’ll get some good news on Tree Lane bridge repairs or replacement by Christmas. I’ll let you know when we get the engineering report.

Posted by Bob Rehak on 11/28/24

2282 Days since Hurricane Harvey

Guefen Clears 17 Acres Between KPHS, St. Martha for 131 High-Density Homes. Will Detention Pond Be Enough?

Guefen Development Partners has announced that it will build a “luxury single family build to rent multifamily community” [sic] on 17 acres between Kingwood Park High School and the St. Martha Church on Woodridge Parkway.

Future site of Preserve At Woodridge. Looking W toward St. Martha Church across a drainage ditch that empties into Bens Branch.

Nine Homes Per Acre with 65% Impervious Cover

Guefen will build 131 units on 14.65 acres. The rest of the 17 acres will contain a detention pond. That works out to nine homes per acre. RG Miller, the firm that engineered the “Preserve at Woodridge” estimates the development will have 65% impervious cover. See the Plans here. (Caution: large file, 21 mb download.)

Grass will definitely be in the minority. I’m not sure what the Preserve is preserving. The site certainly preserves no trees.

Pictures Taken This Week

Here’s what Guefen’s land looks like as of this week.

Looking E. Cleared area between St. Martha and Kingwood Park High School baseball fields will hold 131 homes and a detention pond.
Guefen’s detention pond will border the drainage ditch that empties into Bens Branch about a block south.

Basis of Detention-Basin Calculations

The technically inclined reader may appreciate the detention calculations below. The basis for the calculations is a 16.1 inch rain in 24-hours which is the Atlas-14 amount used throughout Montgomery County. MoCo specifies an average to keep things simple for developers. Their average is slightly less than the 17.3 inches specified by NOAA for the Kingwood area.

See pages 17-24 for the drainage portion of the subdivision plans.

Will the Detention Pond Be Enough?

With other high-density developments going in upstream along Bens Branch, I hope Guefen’s detention pond capacity will suffice. Brooklyn Trails, several blocks upstream on another tributary of Bens Branch, lacks about 30% of the capacity needed to meet Atlas-14 requirements according to my calculations.

Montgomery County’s Subdivision Rules and Regulations specify that outfall ditches, such as the one in the first photo above only need to carry a 25 year rain. (See page 9.) With that in mind, it seems like Guefen’s detention pond so near a ditch would fill up quickly from ditch overflow in a 25-year rain and provide little detention benefit for anything heavier, for instance, 50-100 year rains.

If that ditch ever needs to be widened, like Hall’s Bayou, the fact that so many homes are built so close to it will severely limit mitigation options.

You can’t build mitigation projects if you don’t have the land.

668 SF Homes with “Interior Garages” and “Luxury Vinyl” Flooring

The 131 single-family detached homes will range in size from 668 square feet to 1,255 square feet and feature “luxury vinyl” flooring. The press release boasts of an “amenity suite” including interior garages. It’s hard to imagine how much living space would be left in 668-SF homes with “interior garages.”

So I checked the plans. I found 29 parking spots labeled “garage spcs.” Many more exterior parking spaces exist. But no one, it appears, will be unloading groceries from his/her car directly into a kitchen. Your “interior garage” could be several homes away.

Nor do all the homes front on a street. That’s going to make moving day hard for your college buddies. You know who your real friends are when they’ll go the distance for you.

Speaking of going the distance, in case of an emergency, that firetruck may be parking 250 feet away from some homes. That’s almost the length of a football field.

Build-to-Rent

According to Guefen’s website and press release, the company sees a niche market for this type of housing in the Kingwood area. They are building these homes to rent them, not sell them. The company normally specializes in multifamily and student housing.

While plans show detached homes, they also show five to six feet of separation. That should be enough to dampen most stereos. So party on, Wayne!

Posted by Bob Rehak on 11/10/2021

1534 Days since Hurricane Harvey

High Chance of Thunderstorms Every Day into Next Week

After a few drier days during the Memorial Day weekend, wet weather is returning and will last into next week. We should see a high chance (50% or greater) of thunderstorms every day for the next week.

Pattern Similar to Last Month Setting Up

According to Harris County Meteorologist Jeff Lindner, the upcoming pattern will resemble the heavy rains of early last week and similar patterns in 2015 and 2016. Slow moving low-pressure systems over the southwest US will send multiple disturbances across Texas starting today and lasting into early next week.

Harris County Flood Control inspects damage from heavy rains in May to recently repaired Ben’s Branch. Photo courtesy of Chris Bloch.

Onshore winds will ensure a steady influx of Gulf moisture, high humidity and rainfall production. Disturbances will emerge from northeast Mexico into central and south central Texas nearly every day. Clusters and complexes of thunderstorms will develop and move east into the Houston region.

Difficult to Precisely Predict Heavy Downpours

“When exactly each disturbance will rotate out of Mexico is uncertain. And what state the local air mass will be ahead of each disturbance will also be hard to determine,” said Lindner.

But this pattern, he continued, “will support complexes and clusters of thunderstorms from Tuesday onward – with both a heavy rainfall and marginal severe weather threat. Some days will likely have higher threats of both.”

Widespread rainfall of 3-5 inches is likely over the next several days.

Jeff Lindner, Harris County meteorologist

While our minds may be inclined to spread such totals out evenly over the course of 5-7 days, “that is usually not how it works,” warns Lindner. “At this time of year, we could see 1-3 inches fall in a few hours or less as clusters and complexes move across the region.”

Grounds are still wet from the 10-15 inches of rainfall in May. It will not take much rainfall to trigger run-off and renewed rises on area watersheds, especially as rainfall totals accumulate over time.

Posted by Bob Rehak on 6/1/2021, based on information provided by HCFCD

1372 Days since Hurricane Harvey

City Repairing Storm Sewer Outfalls

One of the most often overlooked points of failure in drainage systems is the lowly storm sewer outfall. When rain flows into the storm sewer on your street, it travels through pipes underground until it reaches the “outfall” at a stream or drainage ditch. If the outfall becomes blocked or damaged, it can back water up and contribute to street flooding.

Often, the damage to the outfall is so remote and difficult to find, that unless someone makes it his or her specific mission, it can go undetected.

Chris Bloch Takes on the Mission

Luckily for Kingwood residents, retired engineer Chris Bloch has made it his mission to identify damaged outfalls and bring them to the attention of the City of Houston. In his quest to help the Kingwood community, Bloch has trudged through mud, muck, brambles and underbrush for years. But his persistence has finally started paying dividends.

Recently the City repaired four outfalls that empty into Bens Branch. The repairs coincided with Harris County Flood Control District’s project to restore conveyance of the channel between Rocky Woods and Kingwood Drive. The result: reduced flood risk to surrounding neighborhoods.

Locations of four outfalls recently repaired by City of Houston in conjunction with HCFCD restoration of Bens Branch

Below: pictures before and after the repairs.

Outfall #1: Cedar Knolls At Woods Estates

Outfall #1 before repairs. Severe erosion exposed then partially severed pipe. The erosion resulted from churning water behind a logjam in the natural section of Bens Branch.
The logjam that created the erosion has since been removed by HCFCD.
Outfall #1 drained approximately 10.7 acres.
The outfall repaired by the City was upstream of HCFCD’s Ben’s Branch restoration project. Of the two other outfalls in this photo, HCFCD repaired the one in the foreground and the City repaired the one in the middle. See Outfall #4 for more info on that one.

Outfall #2: Laurel Garden and Bens Branch

At point #2, drain pipe had cracked and was pushed upward, causing water to back up.
How the same outfall looks today.

A sinkhole also developed along this line. That usually results from part of the pipe collapsing in on itself. Dirt above the hole then erodes into the pipe. The City plans to address the sinkhole now that Flood Control has finished its work.

Outfall #3: Wildwood Ridge Near Deerbrook

According to Bloch, this area originally had 22 feet of corrugated metal pipe and another 50 feet of concrete pipe sections that failed. Erosion undercut the pipe and washed it away.

Outfall #3 before repairs.
Outfall #3 before repairs.

As erosion widened and deepened the area around the destroyed pipe and a manhole, trees fell into the widening “ditch.” The blockages caused the water to churn, creating even more erosion.

Below is the “after” shot. Instead of replacing all the pipe, the City created a wider ditch that will greatly improve street drainage in this watershed.

The area eroded by the damage to outfall #3 has been replaced by a side ditch. It will provide more than enough conveyance to handle water exiting the 36″ pipe.

In the picture above, the rocks surrounding the outfall are called riprap. Riprap is a permanent layer of large, angular stone, cobbles, or boulders typically. Riprap armors, stabilizes, and protects the soil surface against erosion and scour in areas of concentrated flow, such as at outfalls.

The storm sewer outfall #3 services a drainage area of 28.6 acres.

Outfall #4: East Side of Bens Branch at Rocky Woods and Wildwood Ridge

During a storm, the cover on this manhole blew off. Later, young people threw wood into the open manhole and started fires while they drank beer.

Before repairs. The manhole acted as a chimney that made it easy to have a roaring fire.
People also threw beer cans and other debris into the manhole.

Eventually the sewer line became completely blocked according to the City. As a result, storm water backed further up the line. Increased pressure lifted covers off of all upstream manholes. In addition, the pressure forced storm water out between the concrete pipe joints and created a number of sinkholes.

Due to all of this damage approximately 580 feet of 24-inch sewer line and three manholes had to be replaced by the City. This is probably one of the most expensive cases of vandalism Kingwood has experienced.

Chris Bloch

With the line completely blocked, it was of no use and storm water runoff from this area would flow further down Wildwood Ridge where several homes suffered flood damage.

The old outfall.
Outfall #4 after repairs. Note also replacement of the manhole. Not shown: the 580 feet of other repairs including more manholes.
The drainage area serviced by this sewer is only 5.6 acres, the 24-inch line was more than adequate for this acreage.

Kudos to the City and Bloch

These are just four of several repairs underway. More news to follow.

Thanks to the City of Houston, Mayor Pro Tem and District E Council Member Dave Martin, and his staff for coordinating these repairs with the Public Works Department. Residents will sleep much better in the next big storm.

Thanks also to Chris Bloch for his tireless efforts in reporting these issues. If you find similar problems near your home or business, please report them through the contact page on this web site. I’ll make sure they get to Chris who will make sure they get to the people who can help.

Posted by Bob Rehak on 4/18/2021 based on information and photos collected by Chris Bloch

1328 Days since Hurricane Harvey

HCFCD Completes Removal of Another 10,000 Cubic Yards From Bens Branch

Harris County Flood Control District (HCFCD) contractors have completed removal of virtually another 10,000 cubic yards of sediment that had accumulated in Bens Branch between Rocky Woods Drive and Kingwood Drive. While a little cleanup work and equipment removal remains, we can call this job “well done.”

Scope of Work Completed

HCFCD widened and deepened half mile stretch of the creek/ditch. Flood Control also re-sloped the banks, straightened the flow lines, replaced backslope interceptor drains, restored the original conveyance of the ditch, and replanted grass.

Tens of Millions in Nearby Damages during Harvey

During Harvey, dozens of homes flooded along both sides of this channelized stream. So did Kingwood High School and the old H-E-B shopping center north of Kingwood Drive. The shopping center is still mostly vacant because of flood damage. And the Humble ISD spent $70 million to restore Kingwood High School which flooded to the second floor.

Approximately 1000 Truckloads of Sediment Removed

Given that your average dump truck holds about 10 cubic yards, contractors removed about a 1000 truckloads of sediment during this phase of the Bens Branch project.

While the truck traffic got intense at times, contractors finished months ahead of schedule. They originally scheduled completion for early July.

Before/After Photo Essay

The first photo below was taken in January before the start of the project. I shot the rest on April 16.

Bens Branch at Rocky Woods in January 2021 before start of clean-out project.
Bens Branch at Rocky Woods after completion of project on April 16, 2021. The greenish tinge on the slopes is hydro mulch. Hydro mulch is grass seed embedded in a gelatin which can be sprayed on the slopes. Nutrients in the gelatin help ensure that grass will begin to grow in the least amount of time possible, hopefully before heavy rains can erode the slopes.
In fact, new grass shoots are already poking out of this ground. This new drain at Laurel Garden replaces one that had collapsed and become almost totally blocked. The average service life of galvanized corrugated metal pipe is up to 40 years.
New entrance to drain behind maintenance road on side of ditch.
Note the warning. Waste dumped in these drains blocks them and contributes to neighborhood flooding. Even if waste does not block the drain, it can wind up in Lake Houston or Galveston Bay.
Looking back upstream toward the new drain at Laurel Garden.
This shot dramatizes the proximity of Kingwood High School to the ditch. Looking downstream. Notice Lake Houston in the background in the upper left.
Looking upstream from Town Center
Looking downstream from the middle of the Bens Branch project toward Town Center.
Only removal of the temporary crossing and three pieces of equipment (lower left) remain. Every building in the background flooded during Harvey.

No More Bens Branch Projects Scheduled At This Time

This was the fourth and final phase of Bens Branch restoration. Previous projects addressed Bens Branch from:

HCFCD says it has no plans at this time to address the portion from the Y to the West Fork near Kings Harbor.

No one can guarantee that this work will prevent a future flood, but it will certainly make one less likely.

Thanks to the women and men of HCFCD and their contractors who kept the Bens Branch project moving through the pandemic. And to the US Department of Agriculture’s National Resources Conservation Service which provided partial funding.

Thanks also to the Bear Branch Trail Association, Kingwood Service Association and Kings Forest CA. All helped provide access to the project area across their property.

Onward to other projects such as Woodridge Village Detention, Taylor Gully restoration, and Diversion Ditch expansion. More on those in future posts.

Posted by Bob Rehak on April 17, 2021

1328 Days since Hurricane Harvey

Bens Branch Clean-out North of Kingwood Drive Already 40% Complete

As of this morning, Stuart Consulting Group (a project manager for Harris County Flood Control) estimates that clean-out of Bens Branch between Kingwood Drive and Rocky Woods Drive is 40% complete.

1500 Feet Complete from Upstream Starting Point

According to Jose Pedraza who works for Stuart Consulting, the contractor began work at the upstream/Rocky Woods Drive end of the site and is moving downstream. So far, they have completed about 1500 linear feet of work on both sides of the stream.

At the start of the project, surveyors found that accumulated sediment had severely constricted the conveyance of the channel.

Ben’s Branch at start of project in January. The area between the red lines filled with sediment since Friendswood first constructed the ditch in the 1970s.
Looking south from between Rocky Woods and Valley Way Drive. This is how the section above looks today from a drone. Photo taken 3/13/2021. Note Kingwood High School in upper right.
Farther downstream, looking east toward Kingwood Town Center in background. Contractors have just started working on this reach of the stream.
Looking back upstream toward the west and Kingwood High School, you can see same reach from the opposite direction.

Work to Date Has Included…

So far, the contractor has:

  • Conducted excavation and off-site disposal
  • Installed import fill, 3×5 granular fill, and grade 1 riprap
  • Graded channel side slopes on both sides of the channel for 1500 linear feet.

Expected Completion by July 4 or Earlier

Due to weather and other small delays, projected duration of the job increased from 150 to 168 days. Expected completion was extended to July 4, 2021. However, based on recent on-site inspection reports, work is now moving faster. So, with luck, the finish date may be pushed forward into June once more.

Preserving Property, Tax Dollars

Homes on both sides of this stream flooded during Harvey. So did Kingwood High School. The building flooded to the second floor. It suffered $67 million dollars in damages and lost another $10 million in contents.

Hopefully, this project will reduce flood risk. Conveyance of the channel had been reduced from a 100-year level of service to a 2-year level in some places. A 2-year level of service means that the creek will flood in a 2-year rain. The goal of this project is to restore the channel to its original conveyance capacity. That includes straightening, widening and deepening clogged parts of the channel.

Posted by Bob Rehak on 3/15/2021

1294 Days after Hurricane Harvey

Sneak Peak at Results of Kingwood Area Drainage Analysis; Review Before Meeting Tuesday Night

The Harris County Flood Control District has released a Report Summary of results from the 600-page Kingwood Area Drainage Analysis. HCFCD will hold an online community meeting Tuesday night to discuss the results. It may help to review this summary or HCFCD’s before the meeting.

Objective: Protect Homes/Businesses from Bigger Rains

The objective of the Kingwood Area Drainage Analysis: to provide the knowledge needed to protect homes and businesses from flooding in a 100-year (1% chance) rain as defined by the new, higher Atlas-14 Rainfall Probability Statistics. Said another way, the engineers want to make sure that if you bought a home outside the 100-year flood plain, that you STILL won’t be flooded in a 100-year rain. Engineers call that “the 100-year Level of Service (LOS).”

Steams, ditches and channels evaluated as part of the Kingwood Area Drainage Analysis. Please note ditch numbers for any comments you make as the flood control district identifies them by that number. It will help communication.

What Study Included

To accomplish their objectives, engineers:

  • Evaluated historical floods and mapped flood damage
  • Created hydrologic and hydraulic models to quantify flooding risks along streams, channels and open ditches
  • Identified drainage issues associated with storm sewers and streets
  • Performed an overland flow analysis
  • Used LiDAR, record drawings, previous surveys and data collected in the field
  • Incorporated the impact of potential storm sewer improvements on channel capacity
  • Quantified detention capacity needed to prevent increasing flows into Lake Houston
  • Determined how many structures would benefit from each improvement (or planned future improvement)
  • Researched rights-of-way and flowage easements
  • Recommended channel-capacity improvements
  • Recommended bridge and culvert improvements
  • Developed preliminary cost estimates
  • Recommended construction sequencing

In places where ditches provide less than a 100-year level of service, storm sewers cannot empty into them during a 100-year rain. When that happens, water backs up into streets and can flood homes. So engineers are looking at the performance of the drainage system from end to end in conjunction with the City of Houston.

Limitations: What Study Does NOT Include

The study does NOT:

  • Include new topographic surveys
  • Evaluate improvements for greater than 100-year events
  • Examine Montgomery County issues except for North Park Drive
  • Identify sites for detention basins
  • Duplicate the San Jacinto River Basin Master Drainage Plan or associated sedimentation and sand trap studies

No construction is included as part of this project. This project will only lay the groundwork for subsequent construction projects.

Study Identified Nine Channels That Need Improvement

Not surprisingly, the Kingwood Area Drainage Analysis found that many channels do not need improvements. Said another way, they already provide the required level of service. However, engineers identified nine channels that DO need improvement to protect homes and businesses.

Six of those nine have rights-of-way controlled by HCFCD. They include:

  1. Bens Branch – G-103-33-00
  2. Kings Crossing Ditch – G103-33-04
  3. Kingwood Diversion Ditch – G103-38-00
  4. No Name – G103-38-01
  5. No Name – G103-38-01.1
  6. Taylor Gully – G-103-80-03.1

Other entities control the rights-of-way for the three remaining ditches/streams that need improvements:

  1. Bear Branch – G103-36–00
  2. No Name – G103-36-03
  3. No Name – G103-46-01

For summary sheets of each recommended Kingwood Area Drainage Analysis project, click on the associated links. The Taylor Gully project will need to be re-analyzed if the Woodridge Village purchase goes through; that area could turn into a regional detention facility.

This table contains a summary of streams, channel types, ownership, current level of service, improvements, rights of way needed, cost estimates and detention estimates for all the projects considered in the Kingwood area.

Two Projects Recommended Immediately

Based on the results of the Kingwood Area Drainage Analysis, HCFCD recommends two projects: G103-38-00 (Kingwood Diversion Ditch) and G103-80-03.1B (Taylor Gully) move to the next phase: engineering design. Additionally, HCFCD recommends the Taylor Gully project be reanalyzed to determine how the use of Woodridge Village for detention could modify the recommended plan.

These two projects were chosen because:

  • They help the largest number of people.
  • HCFCD owns land to expand and deepen the Diversion Ditch.
  • Diversion Ditch enhancement will immediately take pressure off Ben’s Branch, and help flooding there.

Thus, these two projects address the three biggest needs. The remainder will have to wait for Capital Improvement funds.

First Step of Many

The Kingwood Area Drainage Analysis is a feasibility study that helped identify the problem areas. As you can see from the lifecycle diagram below, it represents the first step of several. The Flood Control District included $10 million in the bond fund (See F14) for Kingwood projects. That can be local-match seed money for attracting state and federal grants.

Source: Harris County Flood Control. After completion of the feasibility study comes preliminary engineering.

Online Meeting Details Tuesday Night

HCFCD will hold an online meeting Tuesday night. Engineers will describe the project and recommendations in more detail. You will also have a chance to interact with team members, make suggestions, and ask questions.

Tuesday, October 20, 2020

6:30 p.m. to 7:30 p.m.

 Join online at PublicInput.com/Kingwood

Or by phone at 855-925-2801 with Meeting Code: 9541

Please login a few minutes early. The Flood Control District has a brief survey on the login page that will help them track your concerns.

What the Flood Control District Needs from You

The Flood Control District needs to know about local issues that they may NOT have identified near you.

For example, culverts under Kingwood Drive for a ditch near me are almost totally blocked by sediment. That could have affected their analysis. And the stream may have correctable issues that could easily prevent future flooding.

Another example. The recommendations include taking out the low water crossing near Bear Branch Elementary School. Many kids use that to walk or bicycle to school. Removal without replacement would create a major inconvenience. It might also negatively affect downstream bridges damaged in previous storms.

A final example: the study did not recommend any changes to the bridge over Taylor Gully at Rustling Elms. However, many Elm Grove residents identified that as a major issue in two floods last year.

The Rustling Elms Bridge is a road over twin culverts, not a true open bridge like the one farther downstream in the background.

Please join the meeting Tuesday night and be prepared to discuss such issues. Volunteer your local knowledge. Speak up now or live with the results.

Credits

The Kingwood Area Drainage analysis cost $700,000. Funds from the 2018 Harris County Flood Bond and TIRZ 10 paid for this study.

Posted by Bob Rehak on 10/19/2020

1147 Days since Hurricane Harvey