11/14/25 – Both Harris County Commissioners Court and the San Jacinto Regional Flood Planning Group agreed yesterday to keep new, updated Harris County floodplain maps secret from the public. They accepted Harris County Flood Control District’s (HCFCD) explanation that they couldn’t release the maps until FEMA finished vetting them…a process that has gone years longer than scheduled and could drag on for years more. Neither group:
Asked for an explanation of what was taking FEMA so long
Asked how withholding the maps could negatively impact Harris County residents
Pointed to any FEMA regulations requiring that FEMA must release information first
Agreed to pressure FEMA to speed up the vetting process
Addressed why local authorities elsewhere are releasing updated maps before FEMA.
However, a spokesperson for HCFCD insisted after the meetings that HCFCD had a contract with FEMA that prohibited HCFCD from releasing maps paid for with taxpayer money. However, she could not immediately produce the contract for this post.
Other Areas in Texas Released Updated Maps Ahead of FEMA
Other authorities elsewhere seem to have no trouble releasing their updated maps based on Atlas 14. Take the San Antonio River Authority (SARA), for instance. They have posted a DRAFT floodplain viewer since 2022 with disclaimers, even though FEMA has not yet released its versions of the maps.
Screen capture on 11/14/25. Site also contains disclaimer.
The SARA maps even show the 30-year chance-of-flooding to help mortgage applicants understand their flood risk.
San Antonio River Authority Draft Floodplain Viewer showing 30-year flood risk.
Williamson County (Georgetown/Round Rock) also has released its Atlas-14-based floodplain maps ahead of FEMA. The maps feature a slider that lets you compare the extent of old and new floodplains.
11/14/25 Screen capture of old/new floodplain comparison in Williamson County’s draft viewer.
So, it is possible to release new maps ahead of FEMA. No regulations that I can find prohibit it. If Harris County’s contract prohibits it, I will do a followup post when HCFCD produces the contract.
San Jacinto River Flood Planning Group Decides Not to Press Map Update Issue
The San Jacinto River Flood Planning Group (RFPG) met yesterday. Among other things, they voted on a progress report for the Texas Water Development Board that showed their work to date on the next iteration of the state flood plan.
Their interim report identified floodplain expansion everywhere in the river basin except Harris County.
That’s because maps for Harris County were redacted at the request of HCFCD. And that generated a lot of discussion.
One member of the committee said, “We have omitted mapping within Harris County as part of this tech memo deliverable, since that’s posted to the public.” [Emphasis added.] That same member later added, “Not incorporating that maybe oversimplifies or otherwise misleads the general audience.” That member proposed updating the maps before submitting the report to TWDB.
However, instead, the committee decided to simply edit text to remove FEMA’s delivery date for the new maps which HCFCD claims FEMA has repeatedly missed.
“It’s not a change to technical content or substantive content, it’s just going to be how it narrates,” another member said.
The committee also discussed applying political pressure on FEMA to release the maps, but decided not to.
Harris County Commissioners Court Takes No Action on Map Updates
Harris County Commissioners Court on 11/13/25 also included a discussion of the status of flood map updates. (See Item 325 on the agenda.)
Commissioner Tom Ramsey kicked off the discussion by saying, “We have known that FEMA is going to, at some point, issue new floodplain maps for Harris County. And we sit here waiting for FEMA to release these.” Later, he said there would be a significant difference in the extent of floodplains. “The existing 500-year floodplain is now going to be the 100.”
Commissioner Adrian Garcia then said, “This is not my first rodeo related to maps.” He continued. “It’s going to be tough enough when FEMA releases the maps on us, because…
“We’re going to find … developers holding properties that now are going to potentially be un-developable.”
Precinct 2 Commissioner Adrian Garcia
Garcia suggested that perhaps the National Association of Counties (NACo) “move this item along because it is in limbo.” Then he added, “The federal government needs to own this. They need to do their part. And then we can work it at the local level.”
Tina Petersen, executive director of HCFCD claimed, “The responsibilities of FEMA have always been clear. They are responsible for releasing the flood insurance rate maps.” While that’s a true statement, FEMA is moving away from basing NFIP insurance rates strictly on flood zones. However, the maps will remain critical for mandatory flood-insurance purchase requirements for federally backed mortgages.
Commissioner Rodney Ellis tried to pin Petersen down by asking if other places were releasing updated flood maps and adding disclaimers like “draft” or “preliminary.”
Petersen dodged the question. Her 55-second response boiled down to, “We believe we are close. We believe it is prudent to wait.”
Petersen also dodged Ellis questions relating to FOIA requests and how much the new maps cost the county.
Commissioner Leslie Briones asked for an update on what FEMA has accomplished in the second half of the year. Petersen replied, “Really, where FEMA is at now is all of the data that has been submitted from the flood control district has been reviewed, and they are currently working to develop the draft flood insurance rate maps.”
Briones concluded the discussion. “We are all in and making sure we’re supporting you so that we can get the information out and work in support as strongly as possible,” she said.
That concluded the discussion. Commissioners took no action. They just moved to the next agenda item.
No Good Answers
In the end, the recognition of higher flood risk could increase flood insurance premiums and make floodplain properties more difficult to develop.
Kicking the can down the road and pointing fingers at FEMA, an agency undergoing radical change, avoids difficult conversations now. But it also exposes Harris County residents to higher flood risk.
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/2025/11/San-Antonio-River-Authority-30-year-map-scaled.png?fit=2560%2C1340&ssl=113402560adminadmin2025-11-14 12:46:272025-11-15 18:30:52New Floodplain Maps Remain Secret For Now – At Least in Harris County
11/12/25 – My weird nephew Izzy called this morning. He was all excited about what he thought would be a tax refund check from Harris County. He had just finished scanning through the San Jacinto Regional Flood Planning Group’s latest report and had convinced himself that the check was in the mail.
The Holiday Miracle
“Uncle Bob! Uncle Bob! Did you see what happened?”
“No Izzy. Calm down. What happened?”
“Harris County solved all its flooding problems and they didn’t even have to spend half the money in the flood bond!”
“Whoa there, Izzy. That sounds a little too good to be true. What makes you think that?”
(Flipping through a loose-leaf binder with hundreds of pages): “Lookee here, Uncle Bob. Every map in the book is like this. Yessiree.”
“Yep, Uncle Bob. Every county in the river basin has flooding problems ‘cept Harris County. We done solved all our problems! I’m going to get me a new motorcycle with my refund check.”
“What’s wrong with your old motorcycle, Izzy?”
“It got flooded out.”
“And why do you think the county would give you a refund, Izzy?”
“They solved all our problems but only spent half the money. They geniuses.”
Izzy Gets an Education
“But that’s not how bonds work, Izzy. They don’t borrow the money until they need it.”
(Suddenly deflated) “You got to be kidding me.”
“Sorry Iz. I could use a refund check, too.”
“Oh, man. I was going to splurge and get me some nacho cheese Doritos with the change.”
“I’ll treat you to Doritos, Izzy, but I want to figure out what’s going on here.”
Uncle Bob’s Shocking Discovery
(Flipping through the report) “See, Uncle Bob. Harris County has NO flooding problems anymore, anywhere, nohow. I’m going to drop my flood insurance. That’ll save me some serious bank.”
“I wouldn’t drop it just yet, Izzy.”
“Why not?”
“Did you read this explanation on page 14, Izzy?”
“Read? Who reads anymore, Uncle Bob? That’s so old school.”
“It says the flooding in Harris County is still bad. They just aren’t saying how bad.”
“Why?”
“They claim they’ve been trying to figure out how to dish up the bad news…for four years.”
“Damn straight. I just can’t believe they’d try to trick me like this. They ‘da govmint. They ain’t supposed to trick people. Lives depend on this.”
“What do you say we drown our sorrows in some nacho cheese Doritos while I explain about government, Izzy?”
Posted by Bob Rehak on 11/12/25
2997 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.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2025/11/No-Flooding-in-Harris-e1762992703859.png?fit=1100%2C809&ssl=18091100adminadmin2025-11-12 17:53:122025-11-12 20:27:29Izzy Finds Harris County Magically Solved All Its Flooding Problems Overnight
11/11/25 – The San Jacinto Regional Flood Planning Group will consider adopting a set of proposed minimum floodplain management practices for the entire river basin at its meeting on November 13. The standards are part of a requirement by the Texas Water Development Board for the 2028 update of the state’s next flood plan.
The recommendations start on page 22 of the technical document. However, the document is 634 pages long and 214 megabytes in size. So, I’ve extracted them for easy reference.
They are targeted to floodplain managers in cities and counties in the San Jacinto River Basin. But they affect everyone from developers, homebuilders, and home buyers to home owners, insurers and first responders. So, I will add some explanatory comments below the proposed regs for those who may not understand their logic or language.
Proposed Minimum Floodplain Management Practices
Participation in the National Flood Insurance Program (NFIP)
All regulatory entities to implement ordinances that meet minimum requirements per the NFIP
All regulatory entities to remain active NFIP participants in good standing
All regulatory entities to participate in the Community Rating System (CRS) Program to reduce flood insurance rate premiums across the region.
Development of “No Adverse Impact” Policies
All regulatory entities to define a no adverse impact policy.
The no adverse impact policy should be focused on preventing negative impacts. Evaluation of impacts should be completed using best available hydrologic and hydraulic modeling, where appropriate.
Establish Minimum Finished Floor Elevations
All new habitable structures shall have a finished floor elevation established at or above or waterproofed to the FEMA effective 0.2% Annual Chance of Exceedance (ACE) flood elevation as shown on effective FIRMs except in areas designated as coastal flood zones.
Where regulatory mapping has been updated using Atlas 14 or newer rainfall data, all new habitable structures shall have a finished floor elevation established at or above or waterproofed to the FEMA effective 1.0% ACE flood elevation as shown on effective FIRMs except in areas designated as coastal flood zones.
In areas designated as coastal flood zones, all new habitable structures shall have a finished floor elevation established at or above or waterproofed to the FEMA effective 1.0% ACE flood elevation as shown on effective FIRMS plus 1 foot of freeboard.
All new critical facilities shall have a finished floor elevation established at or above or waterproofed to the FEMA effective 0.2% ACE flood elevation as shown on effective FIRMs plus 2 feet of freeboard except in areas designated as coastal flood zones.
Where regulatory mapping has been updated using Atlas 14 or newer rainfall data, all new critical facilities shall have a finished floor elevation established at or above or waterproofed to the FEMA effective 1.0% ACE flood elevation as shown on effective FIRMs plus 2 feet of freeboard except in areas designated as coastal flood zones.
In areas designated as coastal flood zones, all new critical facilities shall have a finished floor elevation established at or above or waterproofed to the FEMA effective 1.0%ACE flood elevation as shown on effective FIRMS plus 2 feet of freeboard.
Encourage Use of Best Available Data
Utilize the latest rainfall data, NOAA Atlas 14 or newer rainfall data, when conducting new analyses, designing drainage infrastructure, or developing regulations and criteria.
Compensatory Storage Requirements in the 1.0% ACE Floodplain
Any reduction in floodplain storage or conveyance capacity within the 1.0% ACE regulatory floodplain must be offset with a hydraulically equivalent (one-to-one) volume of mitigation sufficient to offset the reduction, except in areas identified as coastal flood zones.
A full hydrologic and hydraulic analysis should be performed to demonstrate that floodplain fill mitigation provided is sufficient.
Compensatory Storage Requirements in the 0.2/% ACE Floodplain
Any reduction in floodplain storage or conveyance capacity within the 0.2% ACE regulatory floodplain must be offset with a hydraulically equivalent (one-to-one) volume of mitigation sufficient to offset the reduction, except in areas identified as coastal flood zones.
A full hydrologic and hydraulic analysis should be performed to demonstrate that floodplain fill mitigation provided is sufficient.
Development of Detailed Hydrologic and Hydraulic Analysis Criteria/Requirements
All regulatory entities to develop hydrologic and hydraulic modeling criteria or requirements.
All regulatory entities to identify features of a proposed development that would warrant a full hydrologic and hydraulic analysis.
Incentivizing the Preservation of the Floodplain
All regulatory entities to explore and develop systems for incentivizing the preservation of the floodplain directly within the regulatory floodplain or within 100 feet of the banks of unstudied streams.
Nature-Based Solutions
All regulatory entities to adopt criteria for design of nature-based solutions for drainage infrastructure and stormwater quality management. TWDB’s nature-based solutions guidance manual should be referenced when adopting criteria.
All regulatory entities to establish criteria that would require new construction to incorporate, or minimally consider, nature-based solutions in design of drainage infrastructure and mitigation.
Operations and Maintenance
All flood-related authorities who own and operate drainage infrastructure to create a maintenance plan for those assets to manage and reduce future replacement costs.
All flood-related authorities who own and operate drainage infrastructure to develop and maintain an asset management plan, including GIS dataset of assets, to support maintenance of infrastructure. Datasets to leverage infrastructure toolkit that has been prepared by the TWDB to improve the assessment of drainage infrastructure condition and functionality.
Property Acquisition Program
All regulatory entities to develop property acquisition program for repetitive loss structures.
Flood Warning System
All regulatory entities to develop flood warning system for public awareness.
Hazard Mitigation Plan
All regulatory entities to develop a Hazard Mitigation Plan to help prepare for, respond to, and recover from flood events and maximize funding eligibility for disaster recovery funding.
Explaining the Proposed Minimum Floodplain Regulations
If you’re scratching your head about anything above, the following explanations may help.
NFIP and CRS
The National Flood Insurance Program’s Community Rating System (CRS) encourages counties and municipalities to go beyond minimum floodplain management requirements in exchange for discounts on flood insurance premiums for their residents.
CRS rewards local governments that implement regulations which:
Reduce flood losses
Encourage accurate insurance rating
Promote awareness of flood risk
Depending on the strength of a community’s practices, it could earn its residents anywhere from 0% to 45% discounts on their flood insurance premiums. Currently, Houston and Harris County earn 25% discounts. Montgomery County earns 15%.
So encourage your elected officials. This recommendation hits you in the pocketbook.
No Adverse Impact
Chapter 11.086 of the Texas Water Code says “No person may divert or impound the natural flow of surface waters in this state, or permit a diversion or impounding by him to continue, in a manner that damages the property of another by the overflow of the water diverted or impounded.”
The San Jacinto Flood Groups recommendation encourages local governments to adopt policies and best practices that prevent such adverse impacts.
Finished Floor Elevations
These recommendations encourage cities and counties to establish minimum heights above expected flood levels for buildings. “Finished floor” refers to living space. Sometimes people park cars under the first finished floor. This recommendation does not count garages below living space.
Together these recommendations say that if an area has adopted Atlas 14 (the latest rainfall probability statistics) and flood maps have been updated, the first finished floor can be set at or above the 100-year (1%) flood level. Otherwise, the first finished floor should be elevated at or above the 500-year (.02%) flood level.
Critical facilities, such as hospitals, fire stations, police stations and evacuation centers should always be at least 2 feet above the 500-year flood elevation.
Compensatory Storage Requirements
This recommendation is the same as “no net fill” requirements already in effect for many 100-year floodplains in the region. It has the effect of saying, “You can’t bring dirt into the floodplain, but you can move it around.” For instance, to elevate homes, builders would have to use the dirt excavated from a detention basin. It’s designed to prevent constriction of the floodplain, which could raise flood heights.
Hydrologic and Hydraulic (H&H) Analyses
H&H Studies define where and how flooding occurs, including how fast runoff occurs, how fast it will move and where it will go. They replace flood maps based on outdated or incomplete data. They incorporate Atlas 14 rainfall data and account for new development, impervious cover, and drainage changes, including recent channel improvements or detention basins.
They enable updated floodplain mapping and help build regional consistency in data and methodology. That in turn helps improve local floodplain regulations and insurance accuracy.
Floodplain Preservation and Nature-Based Solutions
The farther homes are from floodplains, the safer they are. Preventing flood damage is vastly cheaper than correcting damage afterwards, often by a factor of 5 to 10 times or more.
Floodplain preservation provides permanent benefits including economic continuity, insurance savings, environmental benefits, and recreational benefits. It also avoids post-flood recovery costs including infrastructure repair, housing assistance, insurance claims, business disruption, and environmental cleanup.
O&M, Property Acquisition, Flood-Warning System, and Hazard Mitigation Plan
The last four floodplain management recommendations emphasize preparation.
Regular maintenance, for instance, can keep channels from becoming clogged with sediment.
Buyouts in areas that flood repeatedly prevent future damage and mitigation costs.
Flood warning systems can tell people when to evacuate or streets to avoid in a flood.
A hazard mitigation plan helps identify natural hazards, assess risks and vulnerabilities, and outline long-term strategies to deal with them.
New Floodplain Maps Remain Secret For Now – At Least in Harris County
11/14/25 – Both Harris County Commissioners Court and the San Jacinto Regional Flood Planning Group agreed yesterday to keep new, updated Harris County floodplain maps secret from the public. They accepted Harris County Flood Control District’s (HCFCD) explanation that they couldn’t release the maps until FEMA finished vetting them…a process that has gone years longer than scheduled and could drag on for years more. Neither group:
However, a spokesperson for HCFCD insisted after the meetings that HCFCD had a contract with FEMA that prohibited HCFCD from releasing maps paid for with taxpayer money. However, she could not immediately produce the contract for this post.
Other Areas in Texas Released Updated Maps Ahead of FEMA
Other authorities elsewhere seem to have no trouble releasing their updated maps based on Atlas 14. Take the San Antonio River Authority (SARA), for instance. They have posted a DRAFT floodplain viewer since 2022 with disclaimers, even though FEMA has not yet released its versions of the maps.
The SARA maps even show the 30-year chance-of-flooding to help mortgage applicants understand their flood risk.
Williamson County (Georgetown/Round Rock) also has released its Atlas-14-based floodplain maps ahead of FEMA. The maps feature a slider that lets you compare the extent of old and new floodplains.
So, it is possible to release new maps ahead of FEMA. No regulations that I can find prohibit it. If Harris County’s contract prohibits it, I will do a followup post when HCFCD produces the contract.
San Jacinto River Flood Planning Group Decides Not to Press Map Update Issue
The San Jacinto River Flood Planning Group (RFPG) met yesterday. Among other things, they voted on a progress report for the Texas Water Development Board that showed their work to date on the next iteration of the state flood plan.
Their interim report identified floodplain expansion everywhere in the river basin except Harris County.
That’s because maps for Harris County were redacted at the request of HCFCD. And that generated a lot of discussion.
One member of the committee said, “We have omitted mapping within Harris County as part of this tech memo deliverable, since that’s posted to the public.” [Emphasis added.] That same member later added, “Not incorporating that maybe oversimplifies or otherwise misleads the general audience.” That member proposed updating the maps before submitting the report to TWDB.
However, instead, the committee decided to simply edit text to remove FEMA’s delivery date for the new maps which HCFCD claims FEMA has repeatedly missed.
“It’s not a change to technical content or substantive content, it’s just going to be how it narrates,” another member said.
The committee also discussed applying political pressure on FEMA to release the maps, but decided not to.
Harris County Commissioners Court Takes No Action on Map Updates
Harris County Commissioners Court on 11/13/25 also included a discussion of the status of flood map updates. (See Item 325 on the agenda.)
Commissioner Tom Ramsey kicked off the discussion by saying, “We have known that FEMA is going to, at some point, issue new floodplain maps for Harris County. And we sit here waiting for FEMA to release these.” Later, he said there would be a significant difference in the extent of floodplains. “The existing 500-year floodplain is now going to be the 100.”
Commissioner Adrian Garcia then said, “This is not my first rodeo related to maps.” He continued. “It’s going to be tough enough when FEMA releases the maps on us, because…
Garcia suggested that perhaps the National Association of Counties (NACo) “move this item along because it is in limbo.” Then he added, “The federal government needs to own this. They need to do their part. And then we can work it at the local level.”
Tina Petersen, executive director of HCFCD claimed, “The responsibilities of FEMA have always been clear. They are responsible for releasing the flood insurance rate maps.” While that’s a true statement, FEMA is moving away from basing NFIP insurance rates strictly on flood zones. However, the maps will remain critical for mandatory flood-insurance purchase requirements for federally backed mortgages.
Commissioner Rodney Ellis tried to pin Petersen down by asking if other places were releasing updated flood maps and adding disclaimers like “draft” or “preliminary.”
Petersen dodged the question. Her 55-second response boiled down to, “We believe we are close. We believe it is prudent to wait.”
Petersen also dodged Ellis questions relating to FOIA requests and how much the new maps cost the county.
Commissioner Leslie Briones asked for an update on what FEMA has accomplished in the second half of the year. Petersen replied, “Really, where FEMA is at now is all of the data that has been submitted from the flood control district has been reviewed, and they are currently working to develop the draft flood insurance rate maps.”
Briones concluded the discussion. “We are all in and making sure we’re supporting you so that we can get the information out and work in support as strongly as possible,” she said.
That concluded the discussion. Commissioners took no action. They just moved to the next agenda item.
No Good Answers
In the end, the recognition of higher flood risk could increase flood insurance premiums and make floodplain properties more difficult to develop.
Kicking the can down the road and pointing fingers at FEMA, an agency undergoing radical change, avoids difficult conversations now. But it also exposes Harris County residents to higher flood risk.
See the Harris County Commissioners Court discussion of flood maps at 3:13:36 of this video. The San Jacinto River Flood Planning Group does not publish video of its meetings.
FEMA’s Region 6 Map Division would not confirm when they will release new flood maps for Harris County. They referred me back to HCFCD.
HCFCD has refused to share flood risk information with the County’s own Community Flood Resilience Task Force despite repeated requests since 2021.
And partially as a result, people are building and buying tens of thousands of homes in Harris County floodplains that could flood in the next big storm.
Posted by Bob Rehak on 11/14/25
2999 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.
Izzy Finds Harris County Magically Solved All Its Flooding Problems Overnight
11/12/25 – My weird nephew Izzy called this morning. He was all excited about what he thought would be a tax refund check from Harris County. He had just finished scanning through the San Jacinto Regional Flood Planning Group’s latest report and had convinced himself that the check was in the mail.
The Holiday Miracle
“Uncle Bob! Uncle Bob! Did you see what happened?”
“No Izzy. Calm down. What happened?”
“Harris County solved all its flooding problems and they didn’t even have to spend half the money in the flood bond!”
“Whoa there, Izzy. That sounds a little too good to be true. What makes you think that?”
(Flipping through a loose-leaf binder with hundreds of pages): “Lookee here, Uncle Bob. Every map in the book is like this. Yessiree.”
“Yep, Uncle Bob. Every county in the river basin has flooding problems ‘cept Harris County. We done solved all our problems! I’m going to get me a new motorcycle with my refund check.”
“What’s wrong with your old motorcycle, Izzy?”
“It got flooded out.”
“And why do you think the county would give you a refund, Izzy?”
“They solved all our problems but only spent half the money. They geniuses.”
Izzy Gets an Education
“But that’s not how bonds work, Izzy. They don’t borrow the money until they need it.”
(Suddenly deflated) “You got to be kidding me.”
“Sorry Iz. I could use a refund check, too.”
“Oh, man. I was going to splurge and get me some nacho cheese Doritos with the change.”
“I’ll treat you to Doritos, Izzy, but I want to figure out what’s going on here.”
Uncle Bob’s Shocking Discovery
(Flipping through the report) “See, Uncle Bob. Harris County has NO flooding problems anymore, anywhere, nohow. I’m going to drop my flood insurance. That’ll save me some serious bank.”
“I wouldn’t drop it just yet, Izzy.”
“Why not?”
“Did you read this explanation on page 14, Izzy?”
“Read? Who reads anymore, Uncle Bob? That’s so old school.”
“It says the flooding in Harris County is still bad. They just aren’t saying how bad.”
“Why?”
“They claim they’ve been trying to figure out how to dish up the bad news…for four years.”
“Seriously?”
“I’m sorry, Izzy. They shoulda hired you to run Flood Control.”
“I got me a calculator that goes to 15 digits.”
“I’m sure you could have helped, Izzy.”
“Damn straight. I just can’t believe they’d try to trick me like this. They ‘da govmint. They ain’t supposed to trick people. Lives depend on this.”
“What do you say we drown our sorrows in some nacho cheese Doritos while I explain about government, Izzy?”
Posted by Bob Rehak on 11/12/25
2997 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.
San Jacinto Flood Planning Group’s Proposed Minimum Floodplain Management Practices
11/11/25 – The San Jacinto Regional Flood Planning Group will consider adopting a set of proposed minimum floodplain management practices for the entire river basin at its meeting on November 13. The standards are part of a requirement by the Texas Water Development Board for the 2028 update of the state’s next flood plan.
The recommendations start on page 22 of the technical document. However, the document is 634 pages long and 214 megabytes in size. So, I’ve extracted them for easy reference.
They are targeted to floodplain managers in cities and counties in the San Jacinto River Basin. But they affect everyone from developers, homebuilders, and home buyers to home owners, insurers and first responders. So, I will add some explanatory comments below the proposed regs for those who may not understand their logic or language.
Proposed Minimum Floodplain Management Practices
Participation in the National Flood Insurance Program (NFIP)
Development of “No Adverse Impact” Policies
Establish Minimum Finished Floor Elevations
Encourage Use of Best Available Data
Compensatory Storage Requirements in the 1.0% ACE Floodplain
Compensatory Storage Requirements in the 0.2/% ACE Floodplain
Development of Detailed Hydrologic and Hydraulic Analysis Criteria/Requirements
Incentivizing the Preservation of the Floodplain
Nature-Based Solutions
Operations and Maintenance
Property Acquisition Program
Flood Warning System
Hazard Mitigation Plan
Explaining the Proposed Minimum Floodplain Regulations
If you’re scratching your head about anything above, the following explanations may help.
NFIP and CRS
The National Flood Insurance Program’s Community Rating System (CRS) encourages counties and municipalities to go beyond minimum floodplain management requirements in exchange for discounts on flood insurance premiums for their residents.
CRS rewards local governments that implement regulations which:
Depending on the strength of a community’s practices, it could earn its residents anywhere from 0% to 45% discounts on their flood insurance premiums. Currently, Houston and Harris County earn 25% discounts. Montgomery County earns 15%.
So encourage your elected officials. This recommendation hits you in the pocketbook.
No Adverse Impact
Chapter 11.086 of the Texas Water Code says “No person may divert or impound the natural flow of surface waters in this state, or permit a diversion or impounding by him to continue, in a manner that damages the property of another by the overflow of the water diverted or impounded.”
The San Jacinto Flood Groups recommendation encourages local governments to adopt policies and best practices that prevent such adverse impacts.
Finished Floor Elevations
These recommendations encourage cities and counties to establish minimum heights above expected flood levels for buildings. “Finished floor” refers to living space. Sometimes people park cars under the first finished floor. This recommendation does not count garages below living space.
Together these recommendations say that if an area has adopted Atlas 14 (the latest rainfall probability statistics) and flood maps have been updated, the first finished floor can be set at or above the 100-year (1%) flood level. Otherwise, the first finished floor should be elevated at or above the 500-year (.02%) flood level.
Critical facilities, such as hospitals, fire stations, police stations and evacuation centers should always be at least 2 feet above the 500-year flood elevation.
Compensatory Storage Requirements
This recommendation is the same as “no net fill” requirements already in effect for many 100-year floodplains in the region. It has the effect of saying, “You can’t bring dirt into the floodplain, but you can move it around.” For instance, to elevate homes, builders would have to use the dirt excavated from a detention basin. It’s designed to prevent constriction of the floodplain, which could raise flood heights.
Hydrologic and Hydraulic (H&H) Analyses
H&H Studies define where and how flooding occurs, including how fast runoff occurs, how fast it will move and where it will go. They replace flood maps based on outdated or incomplete data. They incorporate Atlas 14 rainfall data and account for new development, impervious cover, and drainage changes, including recent channel improvements or detention basins.
They enable updated floodplain mapping and help build regional consistency in data and methodology. That in turn helps improve local floodplain regulations and insurance accuracy.
Floodplain Preservation and Nature-Based Solutions
The farther homes are from floodplains, the safer they are. Preventing flood damage is vastly cheaper than correcting damage afterwards, often by a factor of 5 to 10 times or more.
Floodplain preservation provides permanent benefits including economic continuity, insurance savings, environmental benefits, and recreational benefits. It also avoids post-flood recovery costs including infrastructure repair, housing assistance, insurance claims, business disruption, and environmental cleanup.
O&M, Property Acquisition, Flood-Warning System, and Hazard Mitigation Plan
The last four floodplain management recommendations emphasize preparation.
As common-sense as these ideas are, it’s amazing that many areas still have not adopted them. That may be why Texas has more people living in floodplains than the populations of 30 states.
Posted by Bob Rehak on 11/11/25
2996 Days since Hurricane Harvey