Tag Archive for: Taylor Gully

Preliminary Engineering Contracts Approved for Two Kingwood Drainage Improvements

On June 29, 2021, Harris County Commissioners approved two contracts for preliminary engineering on Taylor Gully and the Kingwood Diversion Ditch. The Taylor Gully project includes looking at Woodridge Village in Montgomery County to possibly expand detention-pond capacity there. See more below.

Taylor Gully Project

Harris County Flood Control District (HCFCD) awarded Idcus, Inc. a $180,555 preliminary engineering contract to develop up to five conceptual alternative scenarios for modifying Taylor Gully. HCFCD and Idcus will then select three scenarios for more detailed analysis. Idcus must perform the work within 300 days of the Notice to Proceed.

The alternative modeling scenarios may include:

  1. Preferred Channel Alternative: This would look at improving the slope, width and lining of channel in conjunction with the existing detention on the Woodridge Village site. This purpose: to determine if the existing detention and proposed channel improvements suffice to mitigate flooding.
  2. Expanded Detention: This would look at expanding the existing stormwater detention on the Woodridge Village site so that no channel improvements are necessary.
  3. Alternative Channel/Detention: This would look at a combination of the two scenarios above. It would determine the amount of additional detention and channel improvements necessary to ensure no adverse impact all the way to Lake Houston.
  4. Optimization Alternative: Building on the alternatives above, this effort would examine additional alternatives to produce a no-adverse-impact solution while maximizing the flood mitigation and minimizing construction costs.
Deliverables for the alternatives include:
  • Channel and basin layouts
  • Estimates of benefits for various levels of storms (100-year, etc.)
  • Right-of-way requirements
  • Cost estimates for right-of-way acquisition, engineering and construction management.
  • Performance metrics, i.e., estimated acreage of land inundation, number of structures in floodplain, number of structures flooded and miles of inundated roadway.
  • A scoring matrix to rank the alternatives.

The scope also includes, when necessary:

  • Hydrologic and hydraulic analysis
  • Surveying
  • Soil sampling
  • Environmental site assessment
  • Subsurface utility exploration
  • Landscape architecture

Finally, Idcus will hold two public engagement meetings near the beginning and end of the project and consult with community groups such as KSA.

Geographic scope includes the Woodridge Village property in MoCo plus the Taylor Gully channel in Harris County.

Kingwood Diversion Ditch

HCFCD entered into a contract with Neel-Schaffer, Inc. for $437,685 for preliminary engineering on the Kingwood Diversion Ditch. Within 300 days,Neel-Schaffer must:

  • Evaluate existing site conditions, previous studies, other projects that could affect this one, topography, rights-of-way, utilities, and soil surveys.
  • Evaluate existing bridges
  • Conduct and H&H analysis to assess existing and proposed conditions (from 2-year to 500-year storms).
  • Analyze Channel Improvements including the:
    • Impact of TIRZ #10’s latest design to replace the Northpark Bridge
    • Diversion structure at the confluence of Bens Branch and the Diversion Channel
    • Drop structures in lieu of a concrete lined channel to minimize high velocities due to the steep grade between
      Walnut Lane and Deer Ridge Estates Blvd.
  • Develop phased construction plans based on available funding, potential impacts and benefits.
  • Conduct two public engagement meetings and coordinate with community groups.

HCFCD may also require Neel-Schaffer to provide addition services when necessary, such as:

  • Surveys
  • Geotechnical investigations, i.e., bridge borings
  • Environmental assessment
  • “Jurisdictional” determination. Does this channel fall under the jurisdiction of the Army Corps? If so, channel design may need to be altered.
  • Determination of detention pond requirements
  • Exploration for subsurface utilities
  • Obtaining permits from the Corps
  • Providing Landscape Architect services
Extent of Kingwood Diversion Ditch. It runs from the new St. Martha Catholic Church north of Northpark to the fire station on Kingwood Drive. Then it runs down to Deer Ridge Park where it makes a turn and enters the West Fork at River Grove Park.

For Complete Text of Contracts…

The first half of each link below contains contract details such as compensation. The second half contains the scope of work.

They were items 146 and 147 respectively on the agenda for the 6/29/21 Commissioner’s Court meeting.

Next Steps

In general, the critical path for each of these projects will follow the project-lifecycle pattern of all HCFCD projects.

Typical steps for new projects constructed under the 2018 bond program.

HCFCD will:

  • Conduct public meeting
  • Develop, review and prioritize alternative designs
  • Commissioner’s court reviews and votes on recommendation
  • Move to final design of selected alternative with same company
  • Engineering company develops construction specs
  • Bid
  • Award
  • Build

These were two of many such contracts approved in the last Commissioners Court meeting.

Both came out of the Kingwood Drainage analysis. More on projects affecting other parts of the Lake Houston Area in future posts.

Posted by Bob Rehak on 7/3/2021

1404 Days after Hurricane Harvey

TWDB To Vote on Financial Assistance for Improving Taylor Gully Level of Service from 10 to 100 Years

In its May 6 board meeting tomorrow, the Texas Water Development Board will vote on whether to approve financial assistance from the Texas Flood Infrastructure Fund to widen and deepen Taylor Gully. That would increase the “level of service” from 10 to 100 years.

The channel would then be able to handle a 100-year rain without flooding instead of just a 10-year rain as it does now. And that would benefit more than 400 homes.

To put a ten-year rainfall into perspective, the eight inches received in two days last week by areas northwest of Lake Houston qualified as a ten-year year event. Luckily, the rain that fell over the Taylor Gully watershed only qualified as a 1- to 2-year rain.

Taylor Gully is the channel below Woodridge Village that experienced disastrous flooding twice in 2019 on May 7th and September 19th (during Imelda).

Explanation of Partnerships and Financing

The City of Houston has requested a $10.1 million loan for construction of the Taylor Gully project. The financial assistance that the TWDB will vote on would take the form of a purchase of City of Houston bonds.

Harris County Flood Control District (HCFCD) would lead the project all the way through construction. The Flood Control District (and hopefully, federal money) will provide the balance of project funds up to $20.2 million out of Bond Project ID F-14 and a Community Project Funding request by US Congressman Dan Crenshaw.

The project will require a considerable amount of upfront work that includes engineering, design, surveying, geotechnical work, environmental permitting and more. The project won’t be ready for actual construction for at least a year. And the City cannot tap into a construction loan until construction starts.

Therefore, the Harris County Flood Control District (HCFCD) will use County money to cover those upfront costs, according to Alan Black, Director of Operations for HCFCD. Some land acquisition may also be necessary, though that has not been fully investigated yet.

Congressman Dan Crenshaw has requested federal dollars to help supplement HCFCD funds for the Taylor Gully and Kingwood Diversion Ditch improvements identified in the Kingwood Area Drainage Analysis. Federal dollars could help stretch local dollars to help develop more projects. (See below about Cypress Creek projects.)

Crucial TWDB to Vote Tomorrow

But everything hinges on the City’s application for a loan from the Texas Flood Infrastructure fund. The City’s request will be #6 on the TWDB meeting agenda. Here is the packet for the board that explains the proposal. It includes cost breakdowns and a timetable, which will likely be accelerated according to project insiders.

The TWDB staff has recommended that the board approve the project.

TWDB

The Taylor Gully watershed currently has a 10-year level of service because the area upstream has undergone significant development with limited flood mitigation or detention.

Elm Grove debris pile from Imelda flood. This is one of hundreds of homes that flooded near Taylor Gully.

The proposed project includes improvements along the Taylor Gully channel to upgrade the conveyance capacity to provide a 100-year level of service. The improvements include channel widening, deepening, and lining. The project will benefit more than 400 structures. 387 will see direct benefit during 100-year inundations. An additional 62 structures benefit indirectly.

How to Attend the TWDB Meeting

The Texas Water Development Board (TWDB) meeting to consider approving financial assistance for Flood Infrastructure Fund projects will be held on Thursday, May 6, at 9:30 a.m. There are two ways that the public and interested stakeholders may attend the Board meeting:  

  1. Via GoToWebinar 
  2. Via AdminMonitor.

A recording of the meeting will also be available.

If you wish to address the Board, please fill out the visitor registration form and send it to Cheryl.Arredondo@twdb.texas.gov no later than 8:00 a.m. on May 6. For more information, please visit the TWDB’s website.

This link explains how the TWDB closing process works on loans.

Credits

State Senator Brandon Creighton sponsored the bill that created the state’s Flood Infrastructure Fund in the 2019 legislature. This link tracks expenditures from the Flood Infrastructure Fund. To date, the TWDB has committed almost $200 million from the fund.

The TWDB has recognized the importance of the project. The City of Houston is putting up the lion’s share of the money for the project. HCFCD is fronting the upfront costs and half of construction dollars. And Congressman Dan Crenshaw is helping to stretch local dollars by supplementing them with federal funds.

HCFCD, Crenshaw Also Working on Cypress Creek Improvements

Crenshaw’s funding request would also help fund the Westador and TC Jester Detention Basins on Cypress Creek. Those are two large basins being planned by HCFCD. Together they would hold about 1,600 acre-feet of stormwater.

To put that in perspective, 1,600 acre feet is enough to contain a foot of rain falling over 2.4 square miles. That could provide benefits both upstream and down. More news to follow on those projects.

Posted by Bob Rehak on May 5, 2021

1345 Days since Hurricane Harvey and 594 since Imelda

What Next for Woodridge Village, Taylor Gully

When Harris County and the City of Houston closed on the purchase of Woodridge Village, flood victims in Elm Grove, North Kingwood Forest and along Taylor Gully were elated. Harris County purchased the land to create a regional floodwater detention basin. That immediately raised questions about what comes next and when?

Public Input

Although an exact date has not yet been announced, the Harris Count Flood Control District (HCFCD) plans to hold community engagement meetings in the near future.

The first will occur early in the development of the Preliminary Engineering Report (PER). The goals: to inform the community of each project’s purpose and receive community input during preliminary engineering.  

A second meeting will occur once the final draft of the preliminary engineering report is complete. Its purpose: to present the results to community.

HCFCD will also communicate with local groups such as homeowner associations and the Kingwood Service Association in regularly scheduled virtual meetings as needed. Those will provide project updates and information about other Flood Control District efforts (e.g., buyouts, maintenance projects, smaller capital projects) in the Kingwood area throughout the PER process.

The Flood Control District will also identify opportunities to participate in regularly scheduled meetings and develop project-specific presentations to convey project information and proposed project features.

First Engineering Firm Already Selected

The engineering firm elected to develop the Preliminary Engineering Report for Taylor Gully improvements, IDCUS, will also consider Woodridge Village within its scope of work. IDCUS will consider what detention volume can be achieved on the Woodridge Village property and how that would affect the Taylor Gully project. 

The Flood Control District plans to set up a separate project with a different consultant team to provide the detailed design services for the proposed detention basin. 

Role of Rustling Elms Bridge in Flooding to Be Examined

Many residents have observed that the bridge over Taylor Gully at Rustling Elms seems to be a choke point that backs water up into surrounding homes. HCFCD will examine the role of the bridge in flooding. But, said Matt Zeve, Deputy Executive Director of HCFCD, “I cannot guarantee that the recommended plan will include any modifications to Rustling Elms.”

Looking downstream at the Rustling Elms Bridge over Taylor Gully during peak of May 7, 2019 flood. Note how water downstream from the bridge is within banks, but water upstream is overflowing.

The different heights of water above and below the bridge relate its design. See below.

Looking upstream at same bridge at later date, you can see how the twin-culvert design severely restricts flow.

However, retaining more water upstream might eliminate the need to make any costly changes to the bridge. Everything works together. It’s just too early to tell.

Other Changes Being Considered

The Flood Control District is considering a regional stormwater detention basin for the Woodridge Village site. A portion of the property will be owned by the City of Houston for a future wastewater treatment plant. 

Looking south across the main portion of Woodridge Village toward homes that flooded twice in 2019. HCFCD will have the southern two thirds of this property (toward the top of the photo) to use for a regional detention basin.

Other amenities could be considered for the site, but would require a partner to construct and maintain those amenities. “The Flood Control District does not design, construct, or maintain amenities such as dog parks, trails, playgrounds, or sports fields,” said Zeve. However, HCFCD expressed a willingness to meet and work with community groups to discuss potential partnerships and make sure that input is included in design considerations.

Atlas 14 Will Form Basis of Design

Perry Homes sized detention ponds currently on the site to meet pre-Atlas-14 requirements. That means their detention capacity will fall about 30-40% short of Atlas-14 requirements. Montgomery County’s Atlas-14 requirements are lower than Harris County’s. When asked about this, Zeve responded, “HCFCD will use Atlas 14 rainfall rates for our designs even if the watershed area is not in Harris County.” That should provide some extra capacity that provides a buffer against additional upstream growth in the watershed.

Could Excavation Start Before Hurricane Season?

The Flood Control District will sometimes starts excavation on sites before final design plans are completed.  HCFCD uses this program frequently to get a head start on excavation for large stormwater detention basins.  “The District may not have enough time to get that program up and running by June 1, 2021, but we can certainly provide updates on this effort via our website,” said Zeve.

Posted by Bob Rehak on 3/11/2021

1290 Days since Hurricane Harvey

HCFCD Taylor Gully Repair Project Approximately One-Third Complete

On January 19, I posted about Harris County Flood Control District’s (HCFCD) second major repair project on Taylor Gully since 2019. Thirty-nine days later, HCFCD has completed about one third of the project. They have now started on the downstream side of the Maple Bend Bridge in Kingwood’s Woodstream Village.

Pictures of Work to Date

Here are pictures of the Taylor Gully repairs taken today, 2/28/2021.

Looking upstream from Maple Bend Bridge at completed portion. Compare how this looks to a little more than a month ago.
Reverse angle, looking downstream from start of repairs toward Maple Bend Bridge.
Look at the size of that new storm drain. That should get water to the ditch in a hurry.
There’s another new, huge pipe downstream from the bridge. Compare the size of the old one on the opposite side of the creek.

Purpose of Project

The purpose of the project: to repair erosion and side-slope failures; repair or replace outfalls; rectify flowlines; and rehabilitate existing backslope swale systems. 

  • Erosion repairs include the placement of fill material, placement of 3″x5″ granular fill and the placement of grade #1 riprap. 
  • Channel cross sections will be restored to the original design where feasible. 
  • The oldest recorded drawing on file is for the proposed channels from Elm Grove Village to White Oak Creek completed in March 1982. Record drawings typically show a 6-foot wide channel bottom with 3:1 side slopes.

Separate From Preliminary Engineering Study Approved on 2/5

Before HCFCD leaves a project, they will establish grass on the side slopes to prevent erosion and more downstream sedimentation.

This project is separate from a Taylor Gully preliminary engineering study for capital improvements that was approved by Harris County Commissioner’s Court at its last meeting. The capital improvements could include more upstream detention on the Perry Homes Woodridge Village Property, which is still pending purchase 1.5 years after Imelda.

A previous study, the Kingwood Area Drainage Analysis, proposed improvements to Taylor Gully in October 2020.

Posted by Bob Rehak on 2/28/2021

1279 Days since Hurricane Harvey

Woodridge Village Purchase and Two More Kingwood Flood Control Measures APPROVED by Harris County Commissioners Today

Today, at 5:52PM, Harris County Commissioners Court unanimously approved three flood-control measures affecting Kingwood. The measures included approval to negotiate engineering contracts for improvements to the Kingwood Diversion Ditch and Taylor Gully. The third approval involved purchase of Woodridge Village from Perry Homes to build a regional floodwater detention facility in Montgomery County.

Woodridge Village Purchase Finally Approved

The latter has ranked high on the community’s agenda ever since sheet flow from Woodridge Village contributed to flooding hundreds of homes in Elm Grove and North Kingwood Villages twice in 2019.

Woodridge Village photographed one year after Imelda, when sheet flow flooded approximately 600 homes at the top of the frame.

Since then, Perry has completed the planned detention ponds on the property. However, the amount of detention still falls 40% of that needed under the new Atlas-14 standards.

The City of Houston will purchase 77 acres of the property outright for a wastewater treatment facility. The City will then pay for its half of the remaining Woodridge property by trading land that the Flood Control District can use to reduce the cost of flood mitigation projects elsewhere.

Neither the City nor County have yet announced a closing date for the Woodridge purchase.

The City and HCFCD will work with the community as plans for the property and Taylor Gully are developed by IDCUS Inc.

Kudos to County and City

Seventeen months after Imelda, families in Elm Grove and North Kingwood Village will sleep easier tonight, knowing they are one HUGE step closer to safety.

Thanks to all four Harris County Commissioners, especially Precinct 4 Commissioner Jack Cagle, and Harris County Judge Lina Hildaldo. Thanks also to Houston Mayor Pro Tem Dave Martin who helped overcome objections raised at several stages in the Woodridge purchase process.

Posted by Bob Rehak on 2/9/2021

1260 Days since Hurricane Harvey

Three Kingwood Flood-Mitigation Projects on Harris County Commissioners Court Agenda Next Tuesday

Harris County Commissioners posted their agenda for next Tuesday and it has three Kingwood flood-mitigation projects on it.

  • Preliminary engineering and final design services for improvements to:
    • Taylor Gully
    • Kingwood Diversion Ditch
  • Purchase of Woodridge Village to build a stormwater detention basin in Montgomery County.

In case you plan to watch the meeting, all three items fall under Harris County Flood Control District (HCFCD). Unless commissioners take items out of order, HCFCD projects usually come second on the agenda after Engineering. Below: exact text of each agenda item.

Agenda Item Text

Item 79:

Recommendation that the Harris County Flood Control District be authorized to negotiate an agreement for engineering services with IDCUS Inc. to provide preliminary engineering and final design services for improvements to Taylor Gully on HCFCD Unit G103-80-03.1. (San Jacinto River Watershed, Bond ID F-14, Project ID G103-80-03.1-E001, Precinct 4).

Item 82:

Recommendation that the Harris County Flood Control District be authorized to negotiate an agreement for engineering services with Neel-Schaffer, Inc. to provide preliminary engineering and final design services for improvements to the Kingwood Diversion Channel on HCFCD Unit G103-38-00. (San Jacinto River Watershed, Bond ID F-14, Project ID G103-38-00-E001, Precinct 4).

Item 92:

Recommendation that the Harris County Flood Control (District) be given authorization to decree that this District project serve a public purpose and public necessity require that the Harris County Real Property Division be directed to acquire two (2) fee simple tracts for the public project known as Woodridge Village Stormwater Detention Basin on behalf of the District, for the purpose of stormwater detention, in Montgomery County.

Woodridge Village Plan

If purchased from Perry Homes, HCFCD will swap part of Woodridge Village – the northern 77 acres of the 268 total – with the City of Houston. The City wants to build a wastewater treatment plant there and has negotiated with the County to swap land elsewhere in the City that HCFCD can use to reduce the cost of flood mitigation projects. The land reportedly includes parcels along Halls and Greens Bayous. This swap represents a win/win that helps protect more people throughout the City and County.

Woodridge Village
Looking north, at most of the 268-acre Woodridge Village Property. Road connects to Woodland Hills Drive new Kingwood Park High School out of frame on left. City is interested in portion at top of frame. Flood Control would use the rest for mitigation.

Scope of Engineering Studies Still Unclear

Contracts for the engineering studies have not yet been negotiated. However, we do have clues in the Kingwood Area Drainage Assessment final report about what these projects might include. Last October, HCFCD talked about:

  • Widening and deepening Taylor Gully to increase conveyance and/or building the detention pond in Woodridge Village, which empties into Taylor Gully. So Woodridge and Taylor Gully are related; what happens with one will affect the other.
  • Widening the Kingwood Diversion Ditch all the way from St. Martha’s Catholic Church at the county line to the San Jacinto West Fork. The Diversion Ditch project also included building a detention pond to ensure no adverse downstream impacts. Finally, the Drainage Assessment recommended splitting the ditch near Deer Ridge Park. The split would convey part of the floodwaters straight to the West Fork instead of routing all through River Grove Park via a circuitous route that takes them under Woodland Hills Drive which has washed out in the past.
Red line is Bens Branch. White Line is Kingwood Diversion Ditch. Green line shows where Kingwood Area Drainage Assessment recommended splitting flow as it approached West Fork at bottom of frame. Detention pond location not yet finalized.

No Recommendations Certain Yet

Nothing is certain yet. Commissioners Court deferred the Woodridge Village purchase five times last year – in April, May, July, August and September.

And as for the engineering work, a close reading of the text above shows that HCFCD has not yet negotiated contracts. HCFCD simply wants permission to negotiate the agreements. “Once we receive authorization to negotiate the agreements from Commissioners Court, we can meet with the consultants and develop the scope, schedule, and budget,” said Matt Zeve, Deputy Executive Director of HCFCD.

Regardless, this is good news and welcome progress for flood-weary Kingwood residents still struggling with recovery. These projects put us three steps closer to solutions.

For the full agenda, click here.

Posted by Bob Rehak on 2/5/2021

1256 Days after Hurricane Harvey and 505 After Imelda

HCFCD Starts More Repairs on Taylor Gully

Harris County Flood Control District (HCFCD) has begun a three-month repair project on Taylor Gully near Maple Bend Drive in Kingwood’s Woodstream Forest. The repairs will extend 750 feet upstream and 1500 feet downstream of Maple Bend. The entire length of the project lies within a man-made channel and does NOT extend into the natural area on the northeast. See below.

Orange line indicates approximate extent of repair project. Image courtesy of Google Earth. Water flows toward the upper right.

This work activity will have no effect on wetlands; threatened or endangered species or their habitats; cultural or historic resources; or rookeries.

Looking upstream from Maple Bend. Photo taken 1/19/2021.
Looking downstream across Maple Bend bridge toward next phase of project, which will stop before the woods. Note outfall replacement pipe stored on right bank in distance. Photo taken 1/19/2021.

Purpose of Project

The purpose: to repair erosion and side-slope failures; repair or replace outfalls; rectify flowlines; and rehabilitate existing backslope swale systems.

  • Erosion repairs include the placement of fill material, placement of 3″x5″ granular fill and the placement of grade #1 riprap.
  • Channel cross sections will be restored to the original design where feasible.
  • The oldest recorded drawing on file is for the proposed channels from Elm Grove Village to White Oak Creek completed in March 1982. Record drawings typically show a 6-foot wide channel bottom with 3:1 side slopes.

Several homes in this neighborhood flooded during Imelda when water backed up into streets. While the rainfall amounts exceeded the capacity of storm drains, damaged outfalls could also have contributed to such backups. So restoring damaged outfalls will help reduce flood risk.

The earthwork will consist of installation of granular fill and Grade 1 riprap below the ordinary high-water mark. Sediment will be excavated to contour channel side slopes and bottom dimensions to match previously rectified conditions.

Start of side slope repairs. Photo taken 1/19/2021.

Previous Repair History

HCFCD record drawings show a general repair project on G103-80-03.1 in July 2012. According to HCFCD records, an emergency repair on the baffle structure on G103-80-03.1 was completed in October of 2019.

Baffle previously repaired after Imelda. Photo taken 1/19/2021. The structure required an emergency repair due to significant erosion and a rip-rap dam that had formed, severely blocking flow.

Such baffles slow the flow of stormwater to enable the channel downstream of the structure to drain efficiently, according to Beth Walters, a spokesperson for HCFCD.

Taylor Gully was twice severely damaged by excessive flow from Woodridge Village upstream at the Montgomery County Line in 2019. The new development flooded severely on May 7 and September 19 when sheet flow from heavy rains poured into the gully before Woodridge Village’s detention ponds were completed. This is the second major repair project since then. The first extended from the county line to near West Lake Houston Parkway.

Taylor Gully repairs from Maple Bend Bridge on 1/19/2021

Utility Crossings

Utilities along this reach of Taylor Gully (G103-80-03.1) include natural gas, telecommunication, electric, sanitary sewer and water. The CenterPoint gas line, telephone line, and water line all cross the channel at Maple Bend Drive. A 10” sanitary sewer line crosses the channel at the downstream end of the project.

Posted by Bob Rehak on 1/19/2021 with thanks to Beth Walters, Harris County Flood Control District

1239 Days since Hurricane Harvey and 488 since Imelda

HCFCD Recommends Expanding Diversion Ditch as First Priority in Kingwood

At the Harris County Flood Control District’s (HCFCD) Kingwood Area Drainage Analysis meeting tonight, HCFCD recommended that expansion of the Kingwood Diversion Ditch should be the community’s highest priority.

The Diversion Ditch project would help address several potential problems. Expanding it would remove 62 structures from inundation areas and another 586 structures would benefit from improved local drainage. In addition, the project:

  • Can divert floodwater from Ben’s Branch, which will be a much more complicated project, taking more time.
  • Has a 300-foot right-of-way, of which only half is being used
  • Has bridges that already span the entire 300 feet.
  • Will help carry floodwaters from rapidly growing south Montgomery County.

History of Diversion Ditch

In the early days of Kingwood, Friendswood Development Company built the Diversion Ditch to reduce water flowing into Ben’s Branch. But since then, upstream development and larger rains have stressed the capacity of both Ben’s Branch AND the Diversion Ditch. Engineers estimate that peak flows have doubled since 1985.

Most of Ben’s Branch is Natural Channel

Ben’s Branch cuts diagonally through the heart of Kingwood. See red lines below. More than half its length – between Woodland Hills and Rocky Woods Drive is natural channel. Widening it will be complicated and take much time.

Red Line indicates approximate path of Ben’s Branch through Kingwood.

Ben’s Branch Now at 2-Year Level of Service

However, areas on both sides of Ben’s Branch are threatened by flooding as you can see in the image below from FEMA’s Flood Hazard Viewer.

Ben’s Branch once had a 100-year level of service, meaning it had enough carrying capacity to prevent homes from flooding in everything but a 100-year rain. Models based on new Atlas-14 rainfall probability frequencies indicate that the channel’s capacity is now down to a 2-year level of service. That means it will flood in minor rains, exactly as St. Martha School did last year.

Worse yet, Ben’s Branch has decreased to a 2-year level of service throughout its length.

HCFCD Kingwood Area Drainage Analysis
Source: Fema’s Flood Hazard Layer Viewer. Cross-hatched equals floodway, aqua = 100 year floodplain, brown = 500-year floodplain. Floodplains shown above are based on pre-Atlas-14 rainfall probability statistics. An Atlas-14 hundred-year rain is about 30-40% higher than the old hundred-year rain.

When flood maps are updated based on Atlas-14 statistics, those floodplains will likely expand…unless we do something to handle more floodwater before then.

However, Ben’s Branch will not move to preliminary engineering right away.

How to Protect Against Bigger Rains and More Upstream Development

The Kingwood Area Drainage Analysis sought to understand what we need to do to restore a 100-year level of service to all ditches and streams based on Atlas 14. Of the 19 ditches and streams studied, nine need improvement. The level of service for some, including Ben’s Branch, has been reduced to 2 years.

Expanding the Diversion Ditch is the fastest way to take pressure off of Ben’s Branch.

The Diversion Ditch intersects Ben’s Branch at the new St. Martha Church. It then flows south to Deer Ridge Park and then winds through River Grove Park. See the white line below.

Kingwood Diversion ditch (white line) intersects Ben’s Branch near the new St. Martha Church.

Expansion Capacity Already Built into Diversion Ditch

Engineers foresaw the day when Kingwood would need more drainage capacity due to upstream development in Montgomery County. They built the Kingwood Diversion Ditch to handle the extra stormwater. They also made the bridges over the diversion ditch wider than they needed at the time. Finally, they dedicated a flood easement on both sides of the ditch that was wider than they needed, so they could expand the ditch later without encroaching on neighboring properties. Here’s how it looks from the air.

Looking north across Northpark Drive toward Bens Branch, which cuts diagonally from left to right through the middle of the frame. Note the ample clearance under the bridge and the wide shoulders of the ditch. St. Martha Church is in the upper left.
Looking south toward Kingwood Drive at the Diversion Ditch. King’s Mill is on right in foreground.

Both Kings Mill and Kings Manor now drain into the Diversion Ditch. But they came long AFTER Diversion Ditch construction. Other new upstream developments that drain into the Diversion Ditch and Ben’s Branch include Brooklyn Trails and Woodridge Forest, both in Montgomery County.

As a result, the Diversion Ditch itself has decreased to a 2- to a 25-year level of service in places. However, it still offers a 100-year level of service in others.

Looking NE toward Deer Ridge Park from over Hamblen Road. A corner of Deer Ridge Estates is on the left. The diversion ditch cuts in front of the park (upper left to lower right) and goes into an area largely undeveloped on its way to the river (out of frame to the right).

Impact on River Grove Park

Once the Diversion Ditch passes through the area shown in the photo above, it enters wetlands and winds through River Grove Park. Two questions arise. How do we protect, from additional flow:

  • The park?
  • People downstream on the West Fork?

The first question is simple: split the flow in two. Take part through the undeveloped area west of the park. See the green below.

Green Line represents one possible route for diversion of the diversion ditch.

The second question is more complicated. We need a retention basin to hold the extra stormwater until the peak of any flood passes on the West Fork. But where? The closer you get to the river, the lower the elevation. Because of that, the basin could fill with floodwater from the river before it fills with floodwater from upstream. Fortunately, some large tracts of land exist on higher ground that could be purchased. HCFCD estimates the need at 1248 acre-feet. Preliminary engineering should start soon to address these issues.

Upstream Development Not Addressed by Analysis

Unfortunately the Kingwood Area Drainage Analysis did not address upstream development issues in Montgomery County. That was beyond the scope of work. Regardless, such issues must be addressed somehow, someday soon. Otherwise, even the improvements we invest in today could soon be overwhelmed by additional floodwaters.

In that sense, these channel improvements represent a stopgap measure. The real solution lies in making everyone in the region realize that we are all in this together.

Additional Resources

If you missed the presentation, you can view it on YouTube.

Here is a PDF that contains the District’s summary of the Kingwood Study. It includes a spreadsheet comparing the improvements plus data sheets on the nine recommended projects.

The ten remaining channels/streams already offer a 100-year level of service. Therefore, no improvements are needed. HCFCD felt Taylor Gully should be the next priority after the Diversion Ditch. But the possible purchase of Woodridge Village may require re-thinking project requirements. Specifically, if Woodridge turns into a giant detention basin, the channel may not need as much deepening or widening.

Posted by Bob Rehak on 10/20/2020

1148 Days since 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

Mayor Pro Tem Martin Provides Additional Details on Purchase of Woodridge Village

Houston Mayor Pro Tem Dave Martin issued a press release today that provided additional details about the potential Harris County/City purchase of Woodridge Village.

Unanimous County Vote For Earnest Money Contract

As reported Tuesday evening, Harris County Commissioner’s Court voted unanimously to authorize the Harris County Real Property Division to negotiate an earnest money contract with Figure Four Partners, LTD. The purchase includes two tracts of land containing 267.35 acres located in Montgomery County, which could become the Woodridge Village Stormwater Basin.

The purchase price of $14,019,316.00 is about $5 million below the appraised value of the land. Martin thanks Harris County Judge Lina Hidalgo, Precinct One Commissioner Rodney Ellis, Precinct 2 Commissioner Adrian Garcia, Precinct 3 Commissioner Steve Radack, and Precinct 4 Commissioner Jack Cagle for their support. 

TWDB Loan Application

Said Martin, “This is the first crucial step in completing an inter-local agreement between the City of Houston and Harris County to purchase Woodridge Village.” This vote, coupled with the upcoming announcement from the Texas Water Development Board of the City’s eligibility to apply for a 0% interest loan to help develop the Woodridge Village project, will help reduce future flooding in Kingwood and the Lake Houston region.” 

During May of 2019, as well as Tropical Storm Imelda almost exactly a year ago, Woodridge Village contributed to flooding and heavy sediment deposited in much of northern Kingwood.  Mayor Pro Tem Martin called for the immediate stoppage of the planned development and sale of this site.

End-of-Year Deadline

Martin says he is happy to see the execution of the earnest money contract. It will lock in the purchase price for 120 days. The purchase of the property is contingent upon Harris County Flood Control District (HCFCD) entering in to an interlocal agreement with the City of Houston within 120 days of signing the earnest money contract. 

Last week, the City of Houston Public Works Director, Carol Haddock, submitted a letter of intent to the HCFCD Executive Director, Russ Poppe. It acknowledges the commitment by both parties, City and County, to execute a binding inter-local agreement no later than December 31, 2020. 

“A binding agreement for the proposed transaction can only be evidenced by HCFCD executing a finalized inter-local agreement which will need the approval of Houston City Council” said Martin. Martin also said he “is committed to working with every council office to gain their support of this interlocal agreement, as mutual support of projects to reduce future flooding citywide are key to a successful resiliency plan.” 

The location of the Figure Four Property is suitable for a sub-regional stormwater detention facility, which will help protect affected residents from future intense rainfall events.

Dave Martin, Houston Mayor Pro tem

Consolidation of Three Wastewater Treatment Plants on Woodridge Property

“Additionally, the City has identified a need for approximately 73 acres of the total site to serve as the location for a regional wastewater treatment plant,” says Martin. “This would facilitate consolidation of three wastewater treatment plants in the Kingwood Area.”

Two of these three plants were significantly impacted by flooding during Hurricane Harvey.  

The City would contribute cash for the portion of the site that would house the new wastewater treatment facility.

Land in Lieu of Cash for Floodwater Detention Portion of Property

For the floodwater-detention portion of the property, the City would contribute land in lieu of cash for Harris County Flood Control District flood-risk-reduction projects. 

Construction Funding Details Still to Be Worked Out

Once purchased, the City and District will work together to find additional funding to construct additional stormwater detention on the site to maximize downstream benefits. The Perry Homes/Figure Four Partners property only contains enough detention capacity at the moment to handle about 60% of Atlas 14 requirements. Atlas 14 is NOAA’s attempt to update rainfall precipitation frequency statistics. The need for the update became apparent after four so-called 500-year rains in five years (Tax Day, Memorial Day, Harvey, Imelda).

Despite the recent completion of three additional detention ponds, the Woodridge Village site currently only has about 60% of the detention capacity needed to handle a true 100-year rain (according to Atlas-14 requirements). Photo 9/11/2020.

The City has recently submitted an abridged application to the Texas Water Development Board (TWDB) for a $30 million grant/loan to fund a flood-damage-reduction project on Taylor Gully.

TWDB manages the capital Flood Infrastructure Fund (FIF) created by the 86th legislature in 2019, thanks to Texas State Senator Brandon Creighton and Texas State Representative Dan Huberty. The legislature mutually seeded the FIF program with approximately $790 M, the state has received applications requesting over $2.3 billion to date. Staff recommendations for applications to advance to the formal comprehensive application submittal phase are pending. 

“Ultimately, approval of this earnest money contract is a huge win for the City of Houston and Kingwood residents,” said Martin. “We hope to have more good news once the city has completed its application to the Texas Water Development Board for improvements to Taylor Gully, which will happen later this year.”

Posted by Bob Rehak on 9/17/2020

1115 Days after Hurricane Harvey and 364 since Imelda