5/30/25 – The Northpark Enclave detention basin may be undersized and the developer plans to dump overflow stormwater during extreme events into the only all-weather evacuation route for 78,000 people. That’s according to construction documents and drainage plans obtained from Montgomery County under the Freedom of Information Act.
The last thing you need during a mass evacuation is street flooding.
EHRA, the developer’s engineering company, told Ralph De Leon, project manager for the Northpark expansion project, that all drainage for the new subdivision would be routed south to the Kings Mill Stormwater Detention Basin and then via an outfall channel to the Kingwood Diversion Ditch near the County Line. But the construction drawing above indicates otherwise.
Technically a part of Kings Mill, this 11-acre strip bordering Northpark is just now being developed for single-family residential. Most of Kings Mill was built in phases between 2004 and 2018. And therein lies a huge problem.
Old Plans Use Antiquated Rainfall Statistics
Some of the drainage analyses/plans for the Enclave detention basin date back to 2002 – almost 25 years ago.
Back then, assumptions about “probable maximum rainfall” were very different from today’s. Montgomery County defined a 100-year rainfall then as 12.1 inches in 24 hours.
However, today, MoCo defines a 100-year/24-hour rainfall as 16.1 inches – a 33% increase. But for this development’s location, NOAA defines one as 17.1 inches – a 41% increase. Why the difference?
MoCo adopted Atlas 14 rainfall statistics in 2019. But NOAA fine-tunes its statistics for individual locations. And MoCo regulations use Conroe’s statistics for the entire county. Rainfall decreases as you go farther inland and Conroe is 40 miles north of this location. But that’s not all.
Confusing Documents Don’t Match
It’s not clear how engineers have updated the old drainage analyses in the new plans. MoCo did not provide an updated drainage analysis in response to my FOIA request.
Yet within the construction plans, it appears that EHRA may have tried to mitigate for higher rainfall standards in the development of this tract within Kings Mill.
Calculations on page 9 of Construction Plans Part 2 reference 2023 City of Houston Regulations for detention volume. They show the size (line 3 below) as 11 acres.
Plans do not provide a narrative explaining how all the pieces of this jigsaw puzzle fit together. And trying to track the pieces back through documents dating back almost 20 years is confusing.
15.6 acres in 2012 magically became 11 acres in 2025.
At the very least, it’s safe to say that unexplained differences like these make one question the quality and consistency of calculations in the plans.
55% Impervious Cover?
And they never do explain how they can put 100 homes on 10 acres (minus one acre for the detention basin) and get only 55% impervious cover. Experience suggests that more realistic estimates for that much density would range from 65% to 85% depending on the size of homes and garages.
Only two things became clear after struggling to understand these documents:
There should be a statute of limitations on “grandfathering” permits based on when someone first applied for them.
Someone should have required a new drainage analysis for this project.
More news to follow.
Posted by Bob Rehak on 5/30/25
2831 Days since 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.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/05/20250530-Detention-Overflow-copy.jpg?fit=1100%2C694&ssl=16941100adminadmin2025-05-30 22:13:292025-05-31 20:22:02Enclave Detention Basin Will Overflow into Kingwood Evacuation Route
5/29/25 – On 5/16/25, Harris County Flood Control District (HCFCD) announced a series of maintenance repairs in Kingwood. One was on a tributary of Bens Branch that runs down the west side of West Lake Houston Parkway toward Kingwood Town Center. Yesterday, I received a report from Chris Bloch, a flood activist in Kingwood, that they had started.
HCFCD is making repairs to a ditch romantically named G103-33-01-X007. See #10 in the center of the map below.
Photos Taken on 5/29/25
Below are several pictures taken today at the start of the project. I’m sure it will look better when they finish.
Bens Branch Tributary Repairs near Rustic Woods in Kingwood Town CenterCloser shot shows extent of slide slope and back slope repairs.
Swales behind the side slopes intercept water draining toward the ditch. In the lower right above, you can see a cement structure that helps convey water through a pipe from that swale to the bottom of the ditch. That helps prevent erosion to the side slopes.
Closer shot of same general area.Looking S toward Kingwood Drive at top of frame behind the old HEB shopping center Looking N from Rustic Woods at current extent of repairs. Note the difference in the width of the ditch above and below where the pipe enters near the center of the frame.
More News to Follow
I’ll post more pictures as the project progresses. It’s important to maintain the conveyance of ditches as the flooded merchants in the shopping center above can attest. It still hasn’t completely recovered from Harvey flooding almost eight years ago. This should be very welcome news for them.
Maintenance is a never-ending challenge for HCFCD. They have more than 2500 miles of ditches to maintain. If you see them working near you, please give me a heads up through the contact page of this website.
Posted by Bob Rehak on 5/29/25
2830 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/05/20250529-DJI_20250529184404_0546_D.jpg?fit=1100%2C619&ssl=16191100adminadmin2025-05-29 20:48:352025-05-29 20:50:39HCFCD Begins Repairs to Bens Branch Tributary
“My first thought after I saw this passed was that it was a victory for Kingwood,” said Representative Charles Cunningham who pushed the idea of a dredging district relentlessly for years.
Today is the last day of the legislative session that the Senate considers bills. So it was do-or-die time. And Senator Brandon Creighton teed the bill up perfectly with the help of Senator Paul Bettencourt who shepherded the bill through his Local Government Committee.
Now, it’s on to the Governor’s desk. The good news: shortly after Harvey, Governor Abbott visited Kingwood. He flew up and down the West Fork. He personally saw the mouth bar and other sediment buildups in our rivers and streams.
Thank you to all those who wrote letters, testified in Austin, and never gave up hope for a dredging district. It was a true team effort between residents who never forgot the pain of flooding and leaders who never forgot those they represented. Together, we will make a difference for future generations and the future of the area.
I would be remiss if I didn’t also thank former State Rep. Dan Huberty; former Mayor Pro Tem Dave Martin; City Council Members Fred Flickinger and Twila Carter; and the Army Corps of Engineers. They started this ball rolling years ago. \
And thank you, too, Houston Mayor John Whitmire. Former City Flood Czar Stephen Costello. The architects of the 2018 Flood Bond. Congressman Dan Crenshaw. Harris County Commissioner Tom Ramsey. And Bill McCabe and Dianne Lansden, who kept the Lake Houston Area Flood Prevention Initiation going for years.
My apologies to anyone I overlooked. So many contributed! They all had one thing in common. They put the safety of each other above partisan politics. And it showed in tonight’s unanimous vote.
Beating the Odds
Between “dream” and “done” in the Texas legislature, there’s a lot of hard work.
I came across this table today on the Texas Legislature Online website. It shows the success rate of various types of legislation to date.
Of all the bills introduced in both the House and Senate to date, only about 1 in 12 made it this far.
These numbers will change tomorrow because of additional bills passed today in both the House and Senate.
Here’s what each of those acronyms above stands for:
HB – House Bill
A proposed law originating in the House of Representatives.
If passed by both chambers and signed by the Governor (or allowed to become law), it becomes part of Texas statute.
Used for substantive changes to law (e.g., criminal statutes, environmental rules, etc.).
SB – Senate Bill
A proposed law originating in the Senate.
Same process and purpose as an HB, just introduced in the Senate instead of the House.
HJR – House Joint Resolution
Proposes an amendment to the Texas Constitution or requests Congress to call a constitutional convention.
Does not require the Governor’s signature.
If it’s a proposed constitutional amendment, it must be approved by voters in a statewide election.
Originates in the House.
SJR – Senate Joint Resolution
Same as HJR, but introduced in the Senate.
HCR – House Concurrent Resolution
Expresses the will of the House and Senate together but does not have the force of law.
Often used to make requests of federal government, authorize ceremonial recognitions, or approve internal legislative matters (e.g., adjournment).
Requires approval by both chambers, but not the Governor’s signature.
SCR – Senate Concurrent Resolution
Same as HCR, but introduced in the Senate.
HR – House Resolution
Used for internal House matters or to express one chamber’s opinion or recognition.
Examples: honoring a constituent, changing House rules.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2018/07/Mouth-Bar-Cropped.jpg?fit=2000%2C859&ssl=18592000adminadmin2025-05-28 22:34:562025-05-30 08:46:01Dredging District Bill Passes Unanimously in Senate
Enclave Detention Basin Will Overflow into Kingwood Evacuation Route
5/30/25 – The Northpark Enclave detention basin may be undersized and the developer plans to dump overflow stormwater during extreme events into the only all-weather evacuation route for 78,000 people. That’s according to construction documents and drainage plans obtained from Montgomery County under the Freedom of Information Act.
EHRA, the developer’s engineering company, told Ralph De Leon, project manager for the Northpark expansion project, that all drainage for the new subdivision would be routed south to the Kings Mill Stormwater Detention Basin and then via an outfall channel to the Kingwood Diversion Ditch near the County Line. But the construction drawing above indicates otherwise.
Technically a part of Kings Mill, this 11-acre strip bordering Northpark is just now being developed for single-family residential. Most of Kings Mill was built in phases between 2004 and 2018. And therein lies a huge problem.
Old Plans Use Antiquated Rainfall Statistics
Some of the drainage analyses/plans for the Enclave detention basin date back to 2002 – almost 25 years ago.
Back then, assumptions about “probable maximum rainfall” were very different from today’s. Montgomery County defined a 100-year rainfall then as 12.1 inches in 24 hours.
However, today, MoCo defines a 100-year/24-hour rainfall as 16.1 inches – a 33% increase. But for this development’s location, NOAA defines one as 17.1 inches – a 41% increase. Why the difference?
MoCo adopted Atlas 14 rainfall statistics in 2019. But NOAA fine-tunes its statistics for individual locations. And MoCo regulations use Conroe’s statistics for the entire county. Rainfall decreases as you go farther inland and Conroe is 40 miles north of this location. But that’s not all.
Confusing Documents Don’t Match
It’s not clear how engineers have updated the old drainage analyses in the new plans. MoCo did not provide an updated drainage analysis in response to my FOIA request.
Yet within the construction plans, it appears that EHRA may have tried to mitigate for higher rainfall standards in the development of this tract within Kings Mill.
Calculations on page 9 of Construction Plans Part 2 reference 2023 City of Houston Regulations for detention volume. They show the size (line 3 below) as 11 acres.
Plans do not provide a narrative explaining how all the pieces of this jigsaw puzzle fit together. And trying to track the pieces back through documents dating back almost 20 years is confusing.
For instance, the same plot that’s 11 acres in 2025 was listed as 15.6 acres in the October 2012 drainage analysis.
At the very least, it’s safe to say that unexplained differences like these make one question the quality and consistency of calculations in the plans.
55% Impervious Cover?
And they never do explain how they can put 100 homes on 10 acres (minus one acre for the detention basin) and get only 55% impervious cover. Experience suggests that more realistic estimates for that much density would range from 65% to 85% depending on the size of homes and garages.
For More Information
Montgomery County Engineering provided:
There Should Be A Law
Only two things became clear after struggling to understand these documents:
More news to follow.
Posted by Bob Rehak on 5/30/25
2831 Days since 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.
HCFCD Begins Repairs to Bens Branch Tributary
5/29/25 – On 5/16/25, Harris County Flood Control District (HCFCD) announced a series of maintenance repairs in Kingwood. One was on a tributary of Bens Branch that runs down the west side of West Lake Houston Parkway toward Kingwood Town Center. Yesterday, I received a report from Chris Bloch, a flood activist in Kingwood, that they had started.
HCFCD is making repairs to a ditch romantically named G103-33-01-X007. See #10 in the center of the map below.
Photos Taken on 5/29/25
Below are several pictures taken today at the start of the project. I’m sure it will look better when they finish.
Swales behind the side slopes intercept water draining toward the ditch. In the lower right above, you can see a cement structure that helps convey water through a pipe from that swale to the bottom of the ditch. That helps prevent erosion to the side slopes.
More News to Follow
I’ll post more pictures as the project progresses. It’s important to maintain the conveyance of ditches as the flooded merchants in the shopping center above can attest. It still hasn’t completely recovered from Harvey flooding almost eight years ago. This should be very welcome news for them.
Maintenance is a never-ending challenge for HCFCD. They have more than 2500 miles of ditches to maintain. If you see them working near you, please give me a heads up through the contact page of this website.
Posted by Bob Rehak on 5/29/25
2830 Days since Hurricane Harvey
Dredging District Bill Passes Unanimously in Senate
5/28/25 – HB1532, the Lake Houston Area Dredging District Bill, passed unanimously in the Texas Senate tonight, 31-0.
“My first thought after I saw this passed was that it was a victory for Kingwood,” said Representative Charles Cunningham who pushed the idea of a dredging district relentlessly for years.
Today is the last day of the legislative session that the Senate considers bills. So it was do-or-die time. And Senator Brandon Creighton teed the bill up perfectly with the help of Senator Paul Bettencourt who shepherded the bill through his Local Government Committee.
Now, it’s on to the Governor’s desk. The good news: shortly after Harvey, Governor Abbott visited Kingwood. He flew up and down the West Fork. He personally saw the mouth bar and other sediment buildups in our rivers and streams.
After his helicopter landed, he issued seven directives designed to reduce flood risk in the Lake Houston Area. And this is a huge step in that direction. So, he should be onboard.
Congratulations
Thank you to all those who wrote letters, testified in Austin, and never gave up hope for a dredging district. It was a true team effort between residents who never forgot the pain of flooding and leaders who never forgot those they represented. Together, we will make a difference for future generations and the future of the area.
I would be remiss if I didn’t also thank former State Rep. Dan Huberty; former Mayor Pro Tem Dave Martin; City Council Members Fred Flickinger and Twila Carter; and the Army Corps of Engineers. They started this ball rolling years ago. \
And thank you, too, Houston Mayor John Whitmire. Former City Flood Czar Stephen Costello. The architects of the 2018 Flood Bond. Congressman Dan Crenshaw. Harris County Commissioner Tom Ramsey. And Bill McCabe and Dianne Lansden, who kept the Lake Houston Area Flood Prevention Initiation going for years.
My apologies to anyone I overlooked. So many contributed! They all had one thing in common. They put the safety of each other above partisan politics. And it showed in tonight’s unanimous vote.
Beating the Odds
Between “dream” and “done” in the Texas legislature, there’s a lot of hard work.
I came across this table today on the Texas Legislature Online website. It shows the success rate of various types of legislation to date.
Here’s what each of those acronyms above stands for:
HB – House Bill
SB – Senate Bill
HJR – House Joint Resolution
SJR – Senate Joint Resolution
HCR – House Concurrent Resolution
SCR – Senate Concurrent Resolution
HR – House Resolution
SR – Senate Resolution
The table below summarizes key differences.
Summary Table
To compare this year’s statistics with previous years’, see Texas Legislature Online.
Posted by Bob Rehak on May 28, 2025
2829 Days since Hurricane Harvey