New Kings River Development Drainage Analysis, Plans Raise Questions

Harris County Engineering has released preliminary drainage plans and a drainage analysis in response to a FOIA Request for a new Kings River Development located along Kings Park Way and Pinehurst Trail Drive. The drainage analysis claims “no adverse impact” on surrounding neighborhoods because of the three detention ponds they plan to build.

But the analysis by R.G. Miller Engineers, which is now under review by Harris County Engineering:

  • Omits data
  • Contains misstatements
  • Leaves out related reports
  • Includes alarming assumptions.

Together, these issues call into question the conclusion of no adverse impact.

In the meantime, the clearing of the Phase-1 site, owned by Meritage Homes, continues, even though Harris County disapproved construction plans for its detention basin.

Looking W. Mertitage Kings River Phase I construction site was about 80% cleared as of 1/29/24 at noon.

Let’s look at each of the issues above.

Data Omitted

Typically, engineers justify “no adverse impact” by comparing pre- and post-development peak-discharge rates. If the post- rate does not exceed the pre- rate, then they claim “no adverse impact.”

But the drainage analysis does not show the pre-/post comparison in a simple table. Why?

Take Tables 7 and 8A, for instance. They address calculations involving Pond 1 on the first section of land now being cleared (see above).

Table 7 from R.G. Miller Drainage Analysis, Page 7. Note blank boxes top left after Existing Peak Discharge.

The data is missing. They omitted the data again in another series of tables later in the analysis.

Drainage Analysis Table 8a, Page 13. Note missing data after “Maximum Allowable Outflow,” line 6.

A third table (1-D, page 8) includes pre-development runoff for all three ponds. Together, they seem to justify the claim.

But I can’t find the peak runoff for Pond 1 by itself in any one of the pre/post comparisons. Keep in mind that the second two ponds won’t be built for years. In the meantime, Pond 1 will be the sole source of mitigation.

Soil Analysis and Environmental Reports Not Completed

Discharge rates also depend on soil types. That’s because the soil on a site affects the rate of infiltration.

But Section 10 on Page 15 of the drainage analysis talks about how a geotechnical report (which would determine infiltration rates) has not yet been produced. It says, “…a geotechnical investigation is required to characterize potential soil conditions.”

The drainage analysis also never mentions the wetlands on the property. Those would normally be addressed in an “Environmental Issues” section. But that section says only, “Environmental investigation has not been completed in this study.”

This is kind of like your jet taking off without a full load of fuel. You might get to your destination, but…

Misstatement?

The report also contains a huge misstatement.

For instance, Section 2.2.3 (Results) begins with, “The detention storage volume required for the proposed 41.5 acres residential development is 26.98 acre-feet per acre.” That would mean they require 11,196.7 acre-feet of detention. But they’re providing only 39.8 acre-feet of storage volume.

I’m sure this is a typo. Another section of the analysis later states that the 26.98 figure is computed by using Harris County’s minimum requirement of .65 acre-feet per acre.

Such misstatements and poor proofing call into question other calculations in the analysis.

Alarming Assumption

Section 2.1 (Existing Conditions) states, “Since the proposed detention ponds outfall to an existing 30-in RCP and 36-inch RCP at Pinehurst Trail Drive, the maximum allowable discharge in this study will be the maximum capacity of the 30-inch RCP and 36-inch RCP.”

That sounds to me as though they feel they can use 100% of the existing storm sewer capacity…without regard to the needs of surrounding neighborhoods. For instance, assume that surrounding neighborhoods already use 75% of existing capacity. If the new development uses 100%, that means the drains would be 75% over capacity.

No Clear Support for Claim of “No Adverse Impact”

Although, they claim “no adverse impact,” it’s not clear to a lay person how they arrived at that assumption.

In fairness this report is still under review by Harris County Engineering.

The development also sits in the City of Houston’s extra territorial jurisdiction.

I hope both entities make the engineers clarify the basis for their claims and produce a final report that the public can understand. I stared at these 47 pages all day and still don’t understand how they can justify “No adverse impacts.”

Is it too much to ask for clarity when the safety of people and their homes is at stake?

Construction Plan of Detention Basins “Disapproved”

Evidently Harris County Engineering had some concerns with this development, too.

On 2/9/24, Engineering disapproved the R.G. Miller construction plans for Detention Basin #1. Engineering kicked the plans back for housekeeping-type issues.

For instance, the plans didn’t contain:

  • ID of the channel the ponds drained into
  • A Project name
  • A Project number
  • The signature and seal of a registered Texas professional engineer (PE).

Harris County used to refuse to review plans that weren’t signed and sealed by a PE. I am told that such gratuitous omissions make reviewers angry.

I would link to all the construction plans here. But the file sizes are massive and the construction plans moot for now. More later when/if they’re approved. For now, to review the entire 45-page, 16 meg drainage analysis, click here .

Posted by Bob Rehak on 2/26/24

2372 Days since Hurricane Harvey

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

Construction Begins on Mercer Stormwater Detention Basin

Harris County Flood Control District (HCFCD) has begun construction of a 512 acre-foot stormwater detention basin upstream from Lake Houston on Cypress Creek near Mercer Arboretum. HCFCD hopes to complete the project in 2024.

The Mercer Project is located on the northeast corner of Hardy Tollroad and FM1960. It stretches north to Cypress Creek. A residential neighborhood borders it on the east.

Clearing the wooded site in Commissioner Rodney Ellis’ Precinct 1 began in January and continues. Meanwhile, it appears that excavation has begun in the portion of the site closest to Cypress Creek.

The projects includes two connected basins. Construction of the north basin appears further along than the south basin.

Mercer Stormwater Detention Basin

Photos of Construction Progress

I took the photos above on Sunday afternoon, 2/25/24. Surprisingly, contractors were hard at work.

Looking NW from over FM1960 toward Cypress Creek and Hardy Tollroad. North Basin will be on right. Start of South Basin is on left. Lower right area contains wetlands.
Mercer Stormwater Detention Basin
Reverse angle looking S toward downtown Houston on horizon. Cypress Creek in foreground. Wooded area on left is designated for floodplain preservation.
Closer shot shows beginning of excavation of north pond.
Contractor is burning downed trees. I did not notice any piles of mulch.
Looking N at more new clearing for South Basin.

Details and Funding for Mercer Project

Both basins will have dry bottoms. An underground equalizer pipe will balance the water level in the two basins, while avoiding the majority of jurisdictional wetlands and streams on the property.

A 54″ outfall pipe will move water back into the creek from the basins after a storm at a rate consistent with pre-construction runoff. A 30-foot-wide berm will accommodate maintenance and future recreational activities such as hike and bike trails.

This project is listed in the 2018 Bond Program as F-88. HCFCD estimated the cost at the time at $25 million, which included land acquisition, design and construction. Construction alone costs $14.8 million.

Funding comes both from the bond and a grant from the U.S. Department of Housing and Urban Development’s Community Development Block Grant Disaster Recovery program.

Benefits

The Mercer Project will lower the water surface elevation in the area shown below during a 100-year flood by .35 feet.

Mercer Project location and benefit limit per HCFCD.

The Mercer project will remove the 100-year area of inundation from 30 structures and the 500-year area from another 17 structures. The homes benefitted extend from the Hardy downstream approximately to Cypresswood Drive.

Impact on Lake Houston Area

I applaud this project because every little bit counts. But three to four inches of flood-level reduction along Cypress Creek will have a much larger impact along Cypress Creek than in the Humble/Kingwood area. Here’s why.

Cypress Creek is just one of 11 watersheds that feed into Lake Houston. Cypress joins Spring Creek just upstream from the US59 bridge over the West Fork. In a 100-year storm evenly distributed across the region, the total runoff volume for each watershed upstream of Lake Houston is almost 2 million acre feet.

This project provides a hair more than 500 acre feet. So, by itself, it will retain only 0.025% of the water running off upstream of Lake Houston.

However, the Mercer Basin will retain 0.27% of the runoff in the Cypress Creek watershed. See table below provided by the SJRA.

Acre-feet of runoff from watersheds upstream of Lake Houston, assuming a 100-year rain uniformly distributed across the region.

A regional drainage study for the Cypress Creek watershed found that flooding along tributaries is predominately caused by stormwater from a rising Cypress Creek backing up into the tributaries. It’s not a lack of sufficient stormwater conveyance or drainage capacity on the tributaries themselves. HCFCD believes stormwater detention basins could reduce that backwater issue.

HCFCD’s Ultimate Recommendation for Cypress Creek

The regional drainage study described here recommends nearly 25,000 acre-feet of additional stormwater detention in the watershed – 50X more than this project provides. It’s unclear where all that land will come from in a watershed that’s already highly developed.

And that dramatizes the need to preserve land along creeks and bayous before it gets developed. That will be a far more cost-effective strategy in the long run.

Posted by Bob Rehak on 2/25/24

2371 Days since Hurricane Harvey

Save the Dates: Diversion Ditch, Northpark Phase II Meetings

Save two dates: March 6 and 7 for important public meetings. These meetings represent your chance to provide input on plans that will affect the future of Kingwood and your family’s safety.

  • Wednesday, March 6, 2024, Harris County Flood Control District will hold a virtual meeting to reveal the recommendations for the Kingwood Diversion Ditch Project. That meeting will run from 6:30 PM to 7:30 PM.
  • The following day, TxDOT has announced a meeting from 5-7 PM, Thursday, March 7, 2024, to reveal plans for the next phase of the Northpark Drive Expansion Project. This meeting has both virtual and in-person options.

For more information on each, see below.

Diversion Ditch Meeting

The Kingwood Diversion Ditch runs down the western side of Kingwood from St. Martha’s Catholic Church to Deer Ridge and River Grove Parks. Along the way, it crosses under Northpark Drive, Kingwood Drive, Walnut Lane and Deer Ridge Estates bridges. Affected homeowner and business associations include:

  • Kingwood Place Commercial
  • Northpark Place Commercial
  • North and South Woodland Hills
  • Kings Mill
  • Kings Manor
  • Trailwood
  • Forest Cove
  • Barrington
  • Deer Ridge Estates

Friendswood originally built the Diversion Ditch to take pressure off Bens Branch, hence the Ditch’s name. Ben’s Branch angles diagonally through Kingwood from St. Martha’s Catholic Churches (old and new), past Kingwood High School and Town Center. It reaches the river between Kings Harbor and Fosters Mill.

The Diversion Ditch and Bens Branch are connected, so one affects the other. Together, they affect half of Kingwood.

Bens Branch shown in red. Diversion Ditch is white. Green is proposed outfall into San Jacinto West Fork

The Kingwood Area Drainage Analysis listed improvements to the Kingwood Diversion Ditch as the most important flood-mitigation project in Kingwood. It affects more people than any other drainage project in the area.

HCFCD’s proposed project alternative recommends:

  • Channel conveyance improvements
  • A diversion structure at the intersection of the Kingwood Diversion Ditch and Bens Branch to divert stormwater into the Kingwood Diversion Ditch
  • Bridge replacements at Kingwood Drive, Walnut Lane, Deer Ridge Estates Boulevard and the pedestrian bridge at Lake Village Drive
  • A new outfall to the West Fork San Jacinto River

Here is HCFCD’s press release on the meeting. The virtual community engagement meeting will be held on:

March 6, 2024
6:30 p.m. – 7:30 p.m.
Join online at: PublicInput.com/Kingwood2
Or by phone* at 855-925-2801 with Meeting Code: 6701

Even if you are unable to attend the live meeting, residents are encouraged to register for the meeting to receive future project updates. A recorded version of the meeting will be available on the Flood Control District’s website and YouTube channel after the event.

To provide comments, fill out the comment form online at www.hcfcd.org/F-14.

Northpark Drive Expansion Phase II Meeting

TxDOT, the Lake Houston Redevelopment Authority (LHRA) and the City of Houston Tax Increment Redevelopment Zone (TIRZ) 10 are soliciting public comments for the next phase of the Northpark Drive Expansion Project.

Phase II will run from slightly west of the Kingwood Diversion Ditch to slightly east of Woodland Hills Drive. Part of the mile-long project falls in Montgomery County and part in Harris County.

The purpose of the project is to address current and increasing traffic congestion. Utility and drainage features will also be upgraded.

And to improve safety for bicyclists and pedestrians, the project will include a new pedestrian underpass and 10-foot wide sidewalks that connect to the Kingwood trail system.

The TxDOT announcement provides a few of the details:

  • To improve commute times, the roadway will expand to three lanes in each direction and include turn lanes.
  • To improve safety, lane width will also increase.
  • The proposed reconstruction will include new signals at the Woodland Hills Drive and Hidden Pines Drive.
  • To improve drainage and make Northpark passable in high water events so Kingwood residents have an all-weather evacuation route.

TxDOT does not anticipate impacting any home or business structures at this time. But strips of property that front on the roadway will need to be acquired. For additional details, see this TxDOT page or a schematic drawing on this LHRA page.

Portion of Northpark Phase II through the Northpark Place Commercial Association. Purple represents additional right of way that will need to be acquired.

Don’t miss this meeting, especially if you live, work or go to school in the northern part of Kingwood.

Thursday, March 7, 2024
from 5-7 p.m.
Kingwood Park Community Center
4102 Rustic Woods Dr.
Kingwood, TX 77345

You can provide public comments by mail or email:

All comments on Northpark Phase II must be received or postmarked by Friday, March 22, 2024.

I’ll cover both of these meetings and provide reminders as the dates approach. Your feedback is important. If you have concerns about the plans, these meetings are the time and place to voice them.

Posted by Bob Rehak on 2/24/24

2370 Days since Hurricane Harvey