NWS cautions that wildfires can leave lasting effects on the landscape and create a heightened risk of flooding for years.
Locations downhill and downstream from burned areas are highly susceptible to Flash Flooding and Debris Flows, especially in and near steep terrain.
In some areas, where the fire burned hot enough or long enough, soils develop a layer that actually repels water, like rain on pavement. Rainfall normally absorbed by the forest canopy and vegetative debris on the ground will instead quickly run off.
Because of this, much less rainfall is required to produce a flash flood, and the potential for debris flows increases with the loss of plant material that holds the soil in place.
A good rule of thumb is: “If you can look uphill from where you are and see a burnt-out area, you are at risk.”
Debris flows are fast-moving, deadly landslides. They are powerful mixtures of mud, rocks, boulders, entire trees – and sometimes, homes or vehicles. You’ll often hear “debris flows” called “mudslides” or “mudflows”. Many people use the terms interchangeably, but to scientists, each is a different kind of landslide and debris flows are the most powerful and dangerous of the three.
What Causes Debris Flow?
Debris flows occur most commonly during intense rain after wildfires. A debris flow doesn’t need a long rain or a saturated slope. It can start on a dry slope after only a few minutes of intense rain.
“Intense” rain means a burst of rain at a fast rate, about half an inch in an hour. With debris flows, the rainfall rate matters more than total rainfall.
Why are Debris Flows so Dangerous?
Debris flows are fast and unpredictable. They can travel faster than you can run – and they can catch up to your car! Also, no one can say precisely where a debris flow will start or where it will go. It may begin in a stream channel, then jump out and spread through a neighborhood. A debris flow may happen where others have occurred, or in a place that has never seen one before.
Relationship to Drought
Droughts often create fuel for fires. Not long ago, SE Texas was in an extreme drought. Moderate rains recently may make it feel as though the drought is over, but in reality, we are still officially in a severe drought.
FEMA warns that it can take up to FIVE years after a fire for the landscape to restore itself enough to reduce flood risk.
Still skeptical? Check out this BBC story about rainfall triggering flood warnings FOUR years after wildfires devastated parts of New South Wales and Victoria in Australia.
All the more reason to be cautious when camping or burning brush.
Posted by Bob Rehak on 10/25/2023
2248 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/10/20231025-Screenshot-2023-10-25-at-5.07.04%E2%80%AFPM.jpg?fit=1100%2C645&ssl=16451100adminadmin2023-10-25 18:02:002023-10-26 06:49:35Why Floods Often Follow Fires
In fact, there seemed to be twice as many machines as they had then. And there were no lines! Gee, I wonder where all those machines came from and why they actually worked. But I guess we will never know. The county is still fighting to keep those records secret.
The lack of major malfunctions seemed to have everyone in courteous and pleasant moods.
I like the new system – which is actually the old system – where elected officials are in charge of elections instead of appointed screwups with no experience.
Let’s hope our luck holds and the next ten days are like today.
For More Information
A wide variety of information about the election can be found at HarrisVotes.com. For instance:
Remember, we have county-wide voting now. So if by chance, you encounter a long line, you can vote at another location.
And remember to breathe when you check in. In the last election, a number of dead people voted. So, breathing is one of the screening tools now.
Posted by Bob Rehak on 10/24/2023
2247 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/2023/10/Early-Voting-Locations.jpg?fit=1100%2C636&ssl=16361100adminadmin2023-10-24 17:10:162023-10-24 17:37:19Vote: Doors are Unlocked, They Still Have Paper and Machines are Working
FEMA has published two flood-mitigation guides on nature-based solutions showing how communities can develop projects with multiple benefits.
Both are titled “Building Community Resilience with Nature-Based Solutions.” But one focuses on “Strategies for Success.” The other focuses on “A Guide for Local Communities.” Together, they build a case for integrating green and gray solutions to improve resilience.
While geared toward policy makers, planners and flood-mitigation professionals, they will also help community leaders, activists, students and anyone interested in weaving green solutions into flood mitigation, whether on the watershed, community or household level.
These are not technical guides. They focus on high-level benefits and are packed with helpful examples and case studies. The writing is clear, compelling and easy to understand.
“Strategies for Success” Summarized
Strategies for Success is organized around five major themes.
Building strong partnerships
Engaging the whole community
Matching project size with desired goals and benefits.
Maximizing benefits.
Designing for the future.
If you wonder what the term “nature-based solutions” includes, see pages 17-22. They complement gray (engineered) solutions in many ways in many environments.
At the watershed scale, they can include:
Land conservation
Greenways
Wetland restoration and protection
Stormwater parks
Floodplain restoration
Fire management
Bike trails
Setback levees
Habitate management
At the neighborhood or site scale, they include:
Rain gardens
Vegetated swales
Green roofs
Rainwater harvesting
Permeable pavement
Tree canopy
Tree trenches
Green streets
Urban greenspace
In coastal areas, they include:
Wetlands
Oyster reefs
Dunes
Waterfront parks
Living shorelines
Coral reef
Sand trapping
The section about maximizing benefits will help leaders sell such projects to their communities. It contains helpful tips that improve value and case studies that dramatize it.
The guides also come with links to additional resources.
“Guide for Local Communities” Summarized
This guide begins by reprising many of the same solutions mentioned above. Then it quickly moves into three main sections:
Building the business case for nature-based solutions summaries their potential cost savings and non-monetary benefits. They include:
Hazard mitigation benefits in a variety of situations/locations
Community co-benefits, such as ecosystem services, economic benefits, and social benefits
Community cost savings, such as avoided flood losses, reduced stormwater management costs, reduced drinking water treatment costs.
Planning and Policy Making covers:
Land-use planning
Hazard mitigation planning
Stormwater management
Transportation planning
Open-space planning
Implementation includes:
Boosting public investment
Financing through grants and low interest loans
How to incentivize private investment
Federal funding opportunities
Key takeaways include:
Communities that invest in nature-based approaches can save money, lives, and property in the long-term AND improve quality of life in the short term. Other key takeaways are:
The biggest selling point for nature-based solutions is the many ways they can improve a community’s quality of life and make it more attractive to new residents and businesses.
Diverse partners must collaborate.
Scaling up will require communities to align public and private investments.
Many types of grant programs can be leveraged for funding.
I’ll add one more: It’s easier to build these into communities as they are developing rather than retrofit them after the fact.
Local Examples
Regardless, the right combination of green solutions can make a valuable supplement to flood mitigation in every community.
The 5,000 acre Lake Houston Park provides recreational amenities and flood protection to surrounding areas.
Many great examples of a nature-based solutions surround us locally. Look at Lake Houston Park; Kingwood and The Woodlands which have greenbelts and bike trails along creeks; the Spring Creek Greenway; and the Bayou Land Conservancy’s Arrowwood Preserve.
Recreational asset and flood-mitigation project.
Parks like Kingwood’s East End make more great examples. East End preserves wetlands, accommodates tens of thousands of visitors each year, and provides valuable habitat for wildlife.
Interested in getting more projects like this started near you? As a starting point, please share these brochures with leaders in your community. And support local groups seeking to preserve green spaces such as the Bayou Land Conservancy.
Why Floods Often Follow Fires
FEMA, USGS, and the National Weather Service (NWS) all have posted stories about floods that often follow fires. But WHY do they?
This NWS graphic tells the story.
About the Danger
NWS cautions that wildfires can leave lasting effects on the landscape and create a heightened risk of flooding for years.
Locations downhill and downstream from burned areas are highly susceptible to Flash Flooding and Debris Flows, especially in and near steep terrain.
In some areas, where the fire burned hot enough or long enough, soils develop a layer that actually repels water, like rain on pavement. Rainfall normally absorbed by the forest canopy and vegetative debris on the ground will instead quickly run off.
Because of this, much less rainfall is required to produce a flash flood, and the potential for debris flows increases with the loss of plant material that holds the soil in place.
What Is a Debris Flow?
Debris flows are fast-moving, deadly landslides. They are powerful mixtures of mud, rocks, boulders, entire trees – and sometimes, homes or vehicles. You’ll often hear “debris flows” called “mudslides” or “mudflows”. Many people use the terms interchangeably, but to scientists, each is a different kind of landslide and debris flows are the most powerful and dangerous of the three.
What Causes Debris Flow?
Debris flows occur most commonly during intense rain after wildfires. A debris flow doesn’t need a long rain or a saturated slope. It can start on a dry slope after only a few minutes of intense rain.
“Intense” rain means a burst of rain at a fast rate, about half an inch in an hour. With debris flows, the rainfall rate matters more than total rainfall.
Why are Debris Flows so Dangerous?
Debris flows are fast and unpredictable. They can travel faster than you can run – and they can catch up to your car! Also, no one can say precisely where a debris flow will start or where it will go. It may begin in a stream channel, then jump out and spread through a neighborhood. A debris flow may happen where others have occurred, or in a place that has never seen one before.
Relationship to Drought
Droughts often create fuel for fires. Not long ago, SE Texas was in an extreme drought. Moderate rains recently may make it feel as though the drought is over, but in reality, we are still officially in a severe drought.
FEMA warns that it can take up to FIVE years after a fire for the landscape to restore itself enough to reduce flood risk.
Earlier this week, the AP reported a story about three Texans killed in flash flooding that followed a New Mexico wildfire.
Still skeptical? Check out this BBC story about rainfall triggering flood warnings FOUR years after wildfires devastated parts of New South Wales and Victoria in Australia.
All the more reason to be cautious when camping or burning brush.
Posted by Bob Rehak on 10/25/2023
2248 Days since Hurricane Harvey
Vote: Doors are Unlocked, They Still Have Paper and Machines are Working
I just voted in record time. I drove to the polling place, parked, voted, and returned home in 22 minutes – door to door.
The doors to the polling place were actually unlocked when I arrived 4PM. They had plenty of paper. And both the voting machine and scanner worked.
I encountered none of the problems I experienced during the last election.
In fact, there seemed to be twice as many machines as they had then. And there were no lines! Gee, I wonder where all those machines came from and why they actually worked. But I guess we will never know. The county is still fighting to keep those records secret.
The lack of major malfunctions seemed to have everyone in courteous and pleasant moods.
I like the new system – which is actually the old system – where elected officials are in charge of elections instead of appointed screwups with no experience.
Let’s hope our luck holds and the next ten days are like today.
For More Information
A wide variety of information about the election can be found at HarrisVotes.com. For instance:
Here is a map of early voting locations in the northern part of the county.
Remember, we have county-wide voting now. So if by chance, you encounter a long line, you can vote at another location.
And remember to breathe when you check in. In the last election, a number of dead people voted. So, breathing is one of the screening tools now.
Posted by Bob Rehak on 10/24/2023
2247 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.
FEMA Publishes Nature-Based Solution Guides, Advice
FEMA has published two flood-mitigation guides on nature-based solutions showing how communities can develop projects with multiple benefits.
Both are titled “Building Community Resilience with Nature-Based Solutions.” But one focuses on “Strategies for Success.” The other focuses on “A Guide for Local Communities.” Together, they build a case for integrating green and gray solutions to improve resilience.
While geared toward policy makers, planners and flood-mitigation professionals, they will also help community leaders, activists, students and anyone interested in weaving green solutions into flood mitigation, whether on the watershed, community or household level.
These are not technical guides. They focus on high-level benefits and are packed with helpful examples and case studies. The writing is clear, compelling and easy to understand.
“Strategies for Success” Summarized
Strategies for Success is organized around five major themes.
If you wonder what the term “nature-based solutions” includes, see pages 17-22. They complement gray (engineered) solutions in many ways in many environments.
At the watershed scale, they can include:
At the neighborhood or site scale, they include:
In coastal areas, they include:
The section about maximizing benefits will help leaders sell such projects to their communities. It contains helpful tips that improve value and case studies that dramatize it.
The guides also come with links to additional resources.
“Guide for Local Communities” Summarized
This guide begins by reprising many of the same solutions mentioned above. Then it quickly moves into three main sections:
Building the business case for nature-based solutions summaries their potential cost savings and non-monetary benefits. They include:
Planning and Policy Making covers:
Implementation includes:
Key takeaways include:
Communities that invest in nature-based approaches can save money, lives, and property in the long-term AND improve quality of life in the short term. Other key takeaways are:
I’ll add one more: It’s easier to build these into communities as they are developing rather than retrofit them after the fact.
Local Examples
Regardless, the right combination of green solutions can make a valuable supplement to flood mitigation in every community.
Many great examples of a nature-based solutions surround us locally. Look at Lake Houston Park; Kingwood and The Woodlands which have greenbelts and bike trails along creeks; the Spring Creek Greenway; and the Bayou Land Conservancy’s Arrowwood Preserve.
Parks like Kingwood’s East End make more great examples. East End preserves wetlands, accommodates tens of thousands of visitors each year, and provides valuable habitat for wildlife.
Interested in getting more projects like this started near you? As a starting point, please share these brochures with leaders in your community. And support local groups seeking to preserve green spaces such as the Bayou Land Conservancy.
Posted by Bob Rehak on 10/23/23
2046 Days since Hurricane Harvey