On December 6, 2022, The Washington Post ran an article titled “America Underwater: Extreme floods expose the flaws in FEMA’s risk maps.” The lengthy story by Samuel Oakford, John Muyskens, Sarah Cahlan and Joyce Sohyun Lee cross-referenced photos and videos with FEMA flood maps from areas around the country that flooded last summer.
The basic premise: FEMA’s flood maps “are failing to warn Americans about flood risk.” The authors then claim, “The resulting picture leaves homeowners, prospective buyers, renters and cities in the dark about the potential dangers they face, which insurance they should buy and what kinds of development should be restricted.”
There’s certainly room for improvement in FEMA flood maps.
However, the authors blame climate change for the inaccuracy far more than other contributing factors which are far more obvious.
FEMA is supposed to update flood maps every 5-10 years. It’s hard to imagine climate change invalidating them in that time period.
Climate is an average of weather occurring over much longer time periods. Depending on whether you talk to a meteorologist or a geologist, the time period could range from 30 to millions of years.
At least five major ice ages have occurred throughout Earth’s history: the earliest was over 2 billion years ago, and the most recent one began approximately 3 million years ago and continues today (yes, we live in an ice age!). Currently, we are in a warm interglacial that began about 11,000 years ago. The last period of glaciation, often called the “Ice Age,” peaked about 20,000 years ago. At that time, the world was on average probably about 10°F colder than today.
Interestingly, one day after The Post article, the New York Times ran a story about the DNA of animals found frozen in the permafrost of northern Greenland, just a few hundred miles from the North Pole. The 135 different species scientists found there paint a picture of an arctic once lush with life typical of warmer climates today.
And to what degree can climate change explain flood map inaccuracy? Many more obvious reasons exist that are less of a stretch for any inaccuracies.
Reasons Listed in Post Article for Inaccuracy of Maps
Here’s a list of the references in The Washington Post story used to explain inaccuracies found within FEMA maps. I’ve broken them into two groups so you can see the weight they gave to climate change.
Climate-Change References:
“As climate change accelerates, it is increasing types of flooding that the maps aren’t built to include.”
“Extreme precipitation events are growing increasingly common.”
“A warming climate allows storms to carry more moisture, producing greater rain or snow in a short period of time.”
“Climate has changed so much that the maps aren’t going to keep up.”
Maps are out of date, some decades-old “in a changing climate.”
“The effects of a changing climate.”
Climate change impacts are getting worse.
Climate change is “pushing FEMA’s maps beyond their limits.”
A gap exists between the data that goes into FEMA maps and current climate conditions.
Climate change baseline is changing.
“Climate change velocities are high.”
“Maps do not take climate change into account.”
“Overestimating the rarity of some events even before climate change…”
Other Possible Explanations Mentioned by The Post:
“Communities may resist expanding designated flood zones because it adds costs and can hamper development.”
Not all areas that flooded are mapped yet.
“Local communities often resist the expansion of federal flood zones”
“Maps do not forecast flooding. Maps only reflect past flooding…”
“Local governments have been opposed to any maps that show an increasing risk.”
Relatively high imperviousness of gentrifying areas.
Maps don’t reflect intense bursts of rainfall in a short period and the resulting street flooding.
Impervious surface is replacing porous surface.
Maps cover mainly coastal and riverine flooding.
“Rain combining with melted snowpack.”
FEMA flood maps don’t even attempt to model urban flooding
“City neglected drainage problems.”
Local opposition to expanding the floodplain.
No sense of urgency to update maps.
“Multiple compounding factors contribute to the flooding”
Floods Can Also Be Explained Without Climate Change
The second group of references in The Post article seems far more immediate, compelling and easily provable when explaining any inaccuracy found in flood maps. They’re certainly typical of what I have found in the Houston area.
For the past five years I have been researching instances of flooding in and around Harris County. I published more than 250 articles on different aspects of the 2019 Elm Grove floods alone. And I don’t recall one person ever blaming those on climate change.
Elm Grove did not flood during Harvey, but did flood on two much smaller rains in 2019. The difference? Clearcutting and insufficiently mitigated upstream development. Contractors clearcut approximately 270 acres immediately north of Elm Grove without building sufficient detention capacity before the rains fell.
Regardless of your position on climate change, this discussion dramatizes the needs to:
Understand your local flood risk and the factors that affect it
Buy flood insurance.
Hopefully, Harris County Flood Control District’s MAAPnext project will address data deficiencies discussed in The Post article. But it will be years before those maps become official. And when they do, the landscape will have already changed.
Posted by Bob Rehak on 12/12/22
1931 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.
The smell of ripe grass. The blinding purples, yellows, and whites of fall wildflowers. The buzz of pollinators deciding which stop to make next on the buffet. These are all elements of a strategic approach to flood mitigation across the Milwaukee, Wisconsin metropolitan area.
Photo Courtesy of Matt Berg. Restored wet prairie in MMSD’s Greenseams program.
US Water Alliance’s One Water Summit Explores Greenseams Program
I was asked to join the Texas delegation at the US Water Alliance’s annual conference earlier this fall. The One Water Summit brings together a wide swath of the water sector in the name of planning and managing all water resources (drinking water, wastewater, and stormwater) as part of an integrated process. Since every single drop has value, it’s only logical to treat it that way.
The week included plenty of time thinking and planning with municipal water departments from Dallas, Austin, San Antonio, and Houston, but day one of the conference featured a number of field trips to different examples of the Milwaukee area’s water infrastructure. I chose to spend my afternoon learning about the Milwaukee Metropolitan Sewerage District’s (MMSD) Greenseams program.
Conservation of Parcels with Low and High Infiltration Rates Help Manage Flood Peaks
There are two broad approaches at the heart of the program: 1) conserve land parcels that are wet under normal conditions or that hold water after a rain event and 2) conserve land parcels with high infiltration rates to get water in the ground quickly. In certain areas, wetlands and prairies also undergo restoration efforts to improve performance even further.
Working together, these approaches mean strategic locations slow and hold water upstream to reduce flood peaks downstream and release it gradually over time at a more manageable rate. This results in reduced flood risk for private property and public infrastructure. A natural approach to flood mitigation!
Financing Programs in Surrounding Counties
Milwaukee County’s location means it lies at the end of multiple rivers flowing together just before they enter Lake Michigan. That also means Milwaukee County and the City of Milwaukee are at the receiving end of every interaction between rainfall and land use upstream, including areas far outside their respective jurisdictions.
For the field trip, our group visited a handful of adjacent former farm fields within the City of Franklin. Over the last couple decades, these have been restored to reintroduce prairie vegetation, reconnect historical hydrological features, and reduce erosion.
Photo Courtesy of Matt Berg. Restored prairie in MMSD’s Greenseams program.
As it so happened, our site visit took place just a day after one of the heaviest rainfalls in the region’s recorded history. Despite the downpour, the site was damp but entirely walkable, assuming you’re wearing something like hiking boots and not dress shoes! This site has moderately high infiltration rates, so water drains downward in a hurry. We saw photos from other sites that took the other approach and held substantial water on the surface before slowly releasing it downstream. We very much saw the action in real time.
Beyond Flood Mitigation to Water Quality Improvements, Too
It doesn’t end with flood mitigation, either. Depending on the characteristics of each site in the program and its conservation agreement, there are additional big benefits via ensuring clean drinking water, preserving wildlife habitat, and providing recreation opportunities for residents and visitors.
At the City of Franklin site we visited, it was obvious the rapidly developing surrounding area was already planning for additional trails to connect new neighborhoods to the site’s open space.
How Ideas Could Translate to Houston
You may be thinking that sounds all well and good for Milwaukee, but how about the Southeast Texas?
Houston locals spend a lot of time talking about the impermeable soils of our region. Yet according to the U.S. Department of Agriculture’s Natural Resources Conservation Service, the soil infiltration rates (how fast water moves down through the soil) of Harris County and Milwaukee County are actually quite comparable.
Granted, data from the National Weather Service’s Atlas 14 makes it clear that the intensity of rain events in Houston is much greater than in Milwaukee.
However, two more things that Houston and Milwaukee do have in common are increasing trends in precipitation intensity and a rapidly growing urban footprint. These two compound each other, with heavier rainfall on ever greater hard surfaces causing more and faster runoff.
Photo Courtesy of Matt Berg. Pickerelweed in Panther Branch watershed in Montgomery County, TX.
MMSD works with local land trusts in its region to make Greenseams a success. In the Houston region, groups like Bayou Land Conservancy, Coastal Prairie Conservancy, Galveston Bay Foundation, and Houston Audubon all play big roles in delivering benefits for flood mitigation and clean water supplies through land conservation from the very top of to the bottom of our region’s watersheds.
Photo Courtesy of Matt Berg. Riparian wetland along Spring Creek on the border between Harris County and Montgomery County.
The need is definitely present, and the pieces are there to make it happen. I guess you could say it sure “seams” like heartily pursuing such a regional strategy would be a great idea for Southeast Texas too.
By Dr. Matthew Berg, CEO & Principal Scientist, Simfero Consultants. Posted on 12/9/22
1928 Days since Hurricane Harvey
Note: Milwaukee is known as Cream City for the distinctive light color of the bricks produced there and widely used in its architecture.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/Wildflower2.jpg?fit=1200%2C800&ssl=18001200adminadmin2022-12-09 12:19:162022-12-09 12:23:16Can Cream City Teach Bayou City about Flood Mitigation?
On Dec. 2, I printed a story about an upcoming virtual community meeting on Taylor Gully. At the time, Harris County Flood Control District (HCFCD) had not yet released details yet on how to attend. They have now. See their press release below. Please share it with family, friends and neighbors if you live anywhere along Taylor Gully. That includes parts of Sherwood Trails, all of Elm Grove, all of North Kingwood Forest, parts of Mills Branch, Woodstream Forest, and even parts of Porter in Montgomery County. Yes, plans will affect Porter also.
Virtual Community Engagement Meeting for the Taylor Gully Flood Risk Reduction Project
HCFCD PROJECT G103-80-03.1-E001
BOND PROJECT F-14
The Harris County Flood Control District will hold a community engagement meeting for the Taylor Gully Flood Risk Reduction Project. The purpose of this meeting is to inform residents about the project’s status, share project information and gather important community input on this effort.
The Taylor Gully Flood Risk Reduction Project focuses on improvements to Taylor Gully and the mitigation required to build the project. This project will be partly funded through the 2018 Bond Program, which was approved by Harris County voters on August 25, 2018. Community engagement is a foundational component of the Bond Program, and we invite your participation and input as projects are implemented.
Register Now
The virtual community engagement meeting will be held on:
Or by phone* at 855-925-2801 with Meeting Code: 3364
The meeting will begin with a brief presentation to share project updates, followed by a moderated Q&A session with Flood Control District team members. Residents will be able to submit questions, comments and input before, during and after the meeting, which will be considered during project development. Any comments not addressed during the Q&A session will receive a response at the conclusion of the public comment period.
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. Meeting accommodations can be made for those with disabilities. If needed, please contact 346-286-4040 at least three business days prior to the meeting. For questions, please contact the Flood Control District at 346-286-4000, or fill out the comment form online at hcfcd.org/taylor.
Esta reunión de participación comunitaria se llevará a cabo en inglés; sin embargo, el Flood Control District proporcionará intérpretes de idiomas y materiales traducidos a pedido. En caso de necesidad, comuníquese al 346-286-4040 al menos tres días hábiles antes de la reunión.
*If you attend by phone only, maps and other exhibits will not be visible. However, information will be available after the meeting on the project webpage at hcfcd.org/taylor.
Posted by Bob Rehak on 12/8/2022based on a press release from HCFCD
1927 Days since Hurricane Harvey and 1176 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2022/12/20221206-Taylor-Gully.jpg?fit=1200%2C1200&ssl=112001200adminadmin2022-12-08 07:25:162022-12-08 07:36:21Save the Date: HCFCD Releases Details of Taylor Gully Meeting
Flood Map Accuracy
On December 6, 2022, The Washington Post ran an article titled “America Underwater: Extreme floods expose the flaws in FEMA’s risk maps.” The lengthy story by Samuel Oakford, John Muyskens, Sarah Cahlan and Joyce Sohyun Lee cross-referenced photos and videos with FEMA flood maps from areas around the country that flooded last summer.
The basic premise: FEMA’s flood maps “are failing to warn Americans about flood risk.” The authors then claim, “The resulting picture leaves homeowners, prospective buyers, renters and cities in the dark about the potential dangers they face, which insurance they should buy and what kinds of development should be restricted.”
There’s certainly room for improvement in FEMA flood maps.
But is Climate Change the Reason for Inaccuracy?
However, the authors blame climate change for the inaccuracy far more than other contributing factors which are far more obvious.
Climate is an average of weather occurring over much longer time periods. Depending on whether you talk to a meteorologist or a geologist, the time period could range from 30 to millions of years.
At least five major ice ages have occurred throughout Earth’s history: the earliest was over 2 billion years ago, and the most recent one began approximately 3 million years ago and continues today (yes, we live in an ice age!). Currently, we are in a warm interglacial that began about 11,000 years ago. The last period of glaciation, often called the “Ice Age,” peaked about 20,000 years ago. At that time, the world was on average probably about 10°F colder than today.
Interestingly, one day after The Post article, the New York Times ran a story about the DNA of animals found frozen in the permafrost of northern Greenland, just a few hundred miles from the North Pole. The 135 different species scientists found there paint a picture of an arctic once lush with life typical of warmer climates today.
But another thing puzzles me. I see climate change often mentioned as the reason for drought. The US Geological Survey states, “Climate change has further altered the natural pattern of droughts, making them more frequent, longer, and more severe.” But The Post uses almost identical language to blame climate change for frequent flooding in many of the same general areas at the same time. Which is it?
And to what degree can climate change explain flood map inaccuracy? Many more obvious reasons exist that are less of a stretch for any inaccuracies.
Reasons Listed in Post Article for Inaccuracy of Maps
Here’s a list of the references in The Washington Post story used to explain inaccuracies found within FEMA maps. I’ve broken them into two groups so you can see the weight they gave to climate change.
Climate-Change References:
Other Possible Explanations Mentioned by The Post:
However, the article makes no mention of the mathematical limitations of Extreme Value Analysis, the key to understanding the uncertainties associated with rainfall probabilities.
Floods Can Also Be Explained Without Climate Change
The second group of references in The Post article seems far more immediate, compelling and easily provable when explaining any inaccuracy found in flood maps. They’re certainly typical of what I have found in the Houston area.
For the past five years I have been researching instances of flooding in and around Harris County. I published more than 250 articles on different aspects of the 2019 Elm Grove floods alone. And I don’t recall one person ever blaming those on climate change.
Elm Grove did not flood during Harvey, but did flood on two much smaller rains in 2019. The difference? Clearcutting and insufficiently mitigated upstream development. Contractors clearcut approximately 270 acres immediately north of Elm Grove without building sufficient detention capacity before the rains fell.
Similar stories – with variations – have played out over and over again throughout the Houston region. For instance, we see developers filling in wetlands. Exaggerating the infiltration rates of soils. Underestimating impermeable cover. Building in floodplains. Building to outdated codes and floodplain regulations. Being grandfathered under old regulations. Various jurisdictions refusing to update regulations. And more.
Regardless of your position on climate change, this discussion dramatizes the needs to:
Hopefully, Harris County Flood Control District’s MAAPnext project will address data deficiencies discussed in The Post article. But it will be years before those maps become official. And when they do, the landscape will have already changed.
Posted by Bob Rehak on 12/12/22
1931 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.
Can Cream City Teach Bayou City about Flood Mitigation?
The smell of ripe grass. The blinding purples, yellows, and whites of fall wildflowers. The buzz of pollinators deciding which stop to make next on the buffet. These are all elements of a strategic approach to flood mitigation across the Milwaukee, Wisconsin metropolitan area.
US Water Alliance’s One Water Summit Explores Greenseams Program
I was asked to join the Texas delegation at the US Water Alliance’s annual conference earlier this fall. The One Water Summit brings together a wide swath of the water sector in the name of planning and managing all water resources (drinking water, wastewater, and stormwater) as part of an integrated process. Since every single drop has value, it’s only logical to treat it that way.
The week included plenty of time thinking and planning with municipal water departments from Dallas, Austin, San Antonio, and Houston, but day one of the conference featured a number of field trips to different examples of the Milwaukee area’s water infrastructure. I chose to spend my afternoon learning about the Milwaukee Metropolitan Sewerage District’s (MMSD) Greenseams program.
Conservation of Parcels with Low and High Infiltration Rates Help Manage Flood Peaks
There are two broad approaches at the heart of the program: 1) conserve land parcels that are wet under normal conditions or that hold water after a rain event and 2) conserve land parcels with high infiltration rates to get water in the ground quickly. In certain areas, wetlands and prairies also undergo restoration efforts to improve performance even further.
Working together, these approaches mean strategic locations slow and hold water upstream to reduce flood peaks downstream and release it gradually over time at a more manageable rate. This results in reduced flood risk for private property and public infrastructure. A natural approach to flood mitigation!
Financing Programs in Surrounding Counties
Milwaukee County’s location means it lies at the end of multiple rivers flowing together just before they enter Lake Michigan. That also means Milwaukee County and the City of Milwaukee are at the receiving end of every interaction between rainfall and land use upstream, including areas far outside their respective jurisdictions.
As a result, MMSD uses a mix of grants, bond funds, and service fees to strategically implement its program and preserve land not just within its own service area but on upstream portions of watersheds in a handful of surrounding counties. This makes for greater impact in Milwaukee County and also introduces flood mitigation benefits for many more communities throughout a much broader swath of watersheds in the region.
Link Between Restoration and Reduction
For the field trip, our group visited a handful of adjacent former farm fields within the City of Franklin. Over the last couple decades, these have been restored to reintroduce prairie vegetation, reconnect historical hydrological features, and reduce erosion.
As it so happened, our site visit took place just a day after one of the heaviest rainfalls in the region’s recorded history. Despite the downpour, the site was damp but entirely walkable, assuming you’re wearing something like hiking boots and not dress shoes! This site has moderately high infiltration rates, so water drains downward in a hurry. We saw photos from other sites that took the other approach and held substantial water on the surface before slowly releasing it downstream. We very much saw the action in real time.
Beyond Flood Mitigation to Water Quality Improvements, Too
It doesn’t end with flood mitigation, either. Depending on the characteristics of each site in the program and its conservation agreement, there are additional big benefits via ensuring clean drinking water, preserving wildlife habitat, and providing recreation opportunities for residents and visitors.
At the City of Franklin site we visited, it was obvious the rapidly developing surrounding area was already planning for additional trails to connect new neighborhoods to the site’s open space.
How Ideas Could Translate to Houston
You may be thinking that sounds all well and good for Milwaukee, but how about the Southeast Texas?
Houston locals spend a lot of time talking about the impermeable soils of our region. Yet according to the U.S. Department of Agriculture’s Natural Resources Conservation Service, the soil infiltration rates (how fast water moves down through the soil) of Harris County and Milwaukee County are actually quite comparable.
Granted, data from the National Weather Service’s Atlas 14 makes it clear that the intensity of rain events in Houston is much greater than in Milwaukee.
However, two more things that Houston and Milwaukee do have in common are increasing trends in precipitation intensity and a rapidly growing urban footprint. These two compound each other, with heavier rainfall on ever greater hard surfaces causing more and faster runoff.
MMSD works with local land trusts in its region to make Greenseams a success. In the Houston region, groups like Bayou Land Conservancy, Coastal Prairie Conservancy, Galveston Bay Foundation, and Houston Audubon all play big roles in delivering benefits for flood mitigation and clean water supplies through land conservation from the very top of to the bottom of our region’s watersheds.
The need is definitely present, and the pieces are there to make it happen. I guess you could say it sure “seams” like heartily pursuing such a regional strategy would be a great idea for Southeast Texas too.
By Dr. Matthew Berg, CEO & Principal Scientist, Simfero Consultants. Posted on 12/9/22
1928 Days since Hurricane Harvey
Note: Milwaukee is known as Cream City for the distinctive light color of the bricks produced there and widely used in its architecture.
Save the Date: HCFCD Releases Details of Taylor Gully Meeting
On Dec. 2, I printed a story about an upcoming virtual community meeting on Taylor Gully. At the time, Harris County Flood Control District (HCFCD) had not yet released details yet on how to attend. They have now. See their press release below. Please share it with family, friends and neighbors if you live anywhere along Taylor Gully. That includes parts of Sherwood Trails, all of Elm Grove, all of North Kingwood Forest, parts of Mills Branch, Woodstream Forest, and even parts of Porter in Montgomery County. Yes, plans will affect Porter also.
Map of Project
Virtual Community Engagement Meeting for the
Taylor Gully Flood Risk Reduction Project
HCFCD PROJECT G103-80-03.1-E001
BOND PROJECT F-14
The Harris County Flood Control District will hold a community engagement meeting for the Taylor Gully Flood Risk Reduction Project. The purpose of this meeting is to inform residents about the project’s status, share project information and gather important community input on this effort.
The Taylor Gully Flood Risk Reduction Project focuses on improvements to Taylor Gully and the mitigation required to build the project. This project will be partly funded through the 2018 Bond Program, which was approved by Harris County voters on August 25, 2018. Community engagement is a foundational component of the Bond Program, and we invite your participation and input as projects are implemented.
Register Now
The virtual community engagement meeting will be held on:
December 14, 2022, 6:30 p.m. – 7:30 p.m.
Join online at: PublicInput.com/taylor
Or by phone* at 855-925-2801 with Meeting Code: 3364
The meeting will begin with a brief presentation to share project updates, followed by a moderated Q&A session with Flood Control District team members. Residents will be able to submit questions, comments and input before, during and after the meeting, which will be considered during project development. Any comments not addressed during the Q&A session will receive a response at the conclusion of the public comment period.
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. Meeting accommodations can be made for those with disabilities. If needed, please contact 346-286-4040 at least three business days prior to the meeting. For questions, please contact the Flood Control District at 346-286-4000, or fill out the comment form online at hcfcd.org/taylor.
Esta reunión de participación comunitaria se llevará a cabo en inglés; sin embargo, el Flood Control District proporcionará intérpretes de idiomas y materiales traducidos a pedido. En caso de necesidad, comuníquese al 346-286-4040 al menos tres días hábiles antes de la reunión.
*If you attend by phone only, maps and other exhibits will not be visible. However, information will be available after the meeting on the project webpage at hcfcd.org/taylor.
Posted by Bob Rehak on 12/8/2022 based on a press release from HCFCD
1927 Days since Hurricane Harvey and 1176 since Imelda