10/24/24 – It may seem counterintuitive, but there is a well-recognized relationship between wildfires and floods. What is it?
Simple. Wildfires create conditions that increase the risk of future flooding. Specifically, they affect infiltration; runoff volume and speed; erosion; sedimentation; and more.
How Wildfires Increase Future Flood Risk
Here’s an outline of the the relationship between wildfires and floods:
Loss of Vegetation: Forest fires burn vegetation, which normally helps to hold soil in place and absorb rainfall. Fires leave soil exposed and unprotected.
Water-Repellent Soil: Intense fires can cause soil to repel water. This increases the amount of water running off the surface during rainstorms, rather than soaking into the ground.
Increased Runoff: Without vegetation, rainwater flows more quickly and in greater volumes over the landscape. This runoff can lead to flash flooding, particularly after heavy rains in areas recently affected by wildfires.
Erosion and Sediment: Post-fire floods tend to carry a lot of sediment and debris since the soil is no longer stabilized by plant roots. This sediment can settle downstream, reduce the carrying capacity of streams and worsen flooding.
In short, forest fires can create conditions that increase the likelihood of flooding and make flood events more severe in the affected areas. This relationship is particularly common in the period immediately following a wildfire when the landscape is most vulnerable to erosion and rapid runoff.
What the Experts Says
According to FEMA, “While some floods develop over time, flash floods—particularly common after wildfires—can occur within minutes after the onset of a rainstorm. Even areas that are not traditionally flood-prone are at risk, due to changes to the landscape caused by fire. … Flood risk remains significantly higher until vegetation is restored – up to 5 years after a wildfire.”
The National Weather Service says, “Locations that are downhill and downstream from burned areas are highly susceptible to Flash Flooding and Debris Flows.”
The Army Corps of Engineers also warns of the relationship between vegetation loss and flash flooding. They say the risk of debris flows lasts two to five years.
The Corps, FEMA and Weather Service all recommend purchasing flood insurance within their discussions of wildfires.
Current Conditions in Southeast Texas: Growing Fire Risk
So how bad are current conditions?
I already have received an email from one reader who was seriously injured fighting a pasture fire in Liberty County.
No weather monitoring site in southeast Texas has recorded ANY rainfall for the month of October. “That’s impressive because October is usually our second wettest month behind May,” says Jeff Lindner, Harris County’s meteorologist.
October 2024 Rainfall and Departures from Normal
You can see the lack of recent rain in the statistics below:
College Station: 0.00, -3.49
BUSH IAH: 0.00, -3.82
Hobby: 0.00, -4.12
Galveston: 0.00, -3.66
Conroe: 0.00, -3.67
Sugarland: 0.00, -3.29
Drought Worsening
Moderate drought now covers more than half of Texas and severe drought covers more than a quarter of the state. All of Harris and surrounding counties are in moderate or severe drought, except for those along the coast.
Says Lindner, “While the recent dryness has been relatively short thus far compared to other dry spells, it has been intense – accompanied by much warmer than normal late summer and early fall temperatures. This has quickly resulted in drought degradation across the entire region and vegetation health quickly declining.”
Fire Activity Increasing
“The result has also been an increase in wildland fire activity in recent weeks – especially when drier air masses move over the region along with gusty winds,” Lindner continued.
“As the area moves deeper into the fall and winter months, more frequent and stronger cold fronts will bring stronger winds and much drier air masses across the area. Without any significant wetting rainfall, fire-weather conditions will quickly elevate,” he said.
Wildfire Risk Soaring
The Keetch-Byram Drought Index (KDBI) values indicate wildland fire risk. Currently, they show significant risk across the area. The scale is from 0 (completely saturated) to 800 (completely void of moisture to 8 inches deep). Values above 650 indicate an increased risk of wildland fire and values over 700 indicate a significant risk.
Current average KBDI values are:
Austin: 735
Brazoria: 630
Brazos: 744
Chambers: 693
Colorado: 705
Fort Bend: 706
Galveston: 620
Grimes: 730
Harris: 727
Liberty: 739
Matagorda: 615
Montgomery: 715
San Jacinto: 717
Walker: 691
Washington: 738
Wharton: 689
Looking Ahead: Higher than Average Temps/Lower Than Normal Rainfall
We are currently heading into La Niña conditions. “Such global oscillations tend to support southern plains drought,” says Lindner.
The National Weather Service indicates drought development and persistence across all of Texas into early 2025. See below:
Source: National Weather Service Climate Prediction Center
Be Careful with Outdoor Burning
Beryl left a lot of dead vegetative debris lying around last summer. It’s now turning into fuel. So be extremely careful with outdoor fires. It’s probably best not to burn those leaves you rake up this fall.
The fire you prevent now could help prevent flooding next spring.
Posted by Bob Rehak on 10/24/24
2613 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/10/Wildland-Fire-Risk.png?fit=769%2C839&ssl=1839769adminadmin2024-10-24 20:29:282024-10-24 20:31:57Relationship Between Wildfires and Floods
10/23/24 – Starting Friday 10/25/24 at 8 PM through Monday 10/28/24 at 5AM, contractors will close the Northpark crossover at Russell Palmer Road to pour new concrete in the median. See location of the X in the diagram below.
That means northbound traffic on Russell Palmer will not be able to turn west (left) toward 59. Nor will westbound traffic on Northpark be able to turn south onto Russell Palmer. In each case, traffic must detour by looping around to another open crossover then doubling back.
Eastbound and westbound traffic on Northpark drive will not be affected.
Only area within boundaries of red box will be closed.Picture taken on 10/11 for previous post.
To minimize inconvenience caused by the crossover closure, crews will place rebar and pour concrete directly on compacted dirt, rather than putting asphalt down first.
Utility Conflicts Almost Eliminated
Elsewhere on Northpark, CenterPoint was working to remove the last of its power poles. That means the last of the utility obstacles should soon be out of the way for road construction crews.
Exact Dates of Total Closure, Bridge Construction Still Not Determined
Work is expected to begin on the frontage roads over the UPRR tacks in January. Motorists can expect a 3-day closure of Northpark Drive in either January or February as UPRR crews remove and replace more than 200 feet of railroad tracks.
The exact date of the closure depends on how quickly the railroad crew completes other work. They will also be reconstructing the crossing farther north on the tracks at Knox road. Union Pacific is trying to schedule both projects back to back.
Construction on the bridge structure itself is still a year away.
Phase-2 Preparations Underway
TxDOT approved the proposed schematics for Phase 2 earlier this year. Phase 2 will:
Expand Northpark Drive from Russell Palmer Road to east of Woodland Hills Drive from four to six lanes
Replace both bridges at the Kingwood Diversion Ditch
Replace the roadway crossing at Ben’s Branch.
Add a 90-acre foot detention basin for more stormwater mitigation and to control flow into the Diversion Ditch.
Now, that TxDOT has approved schematics for Phase 2, LHRA is conducting land surveys, obtaining rights of entry, and preparing documents needed to acquire roadway right-of-way and drainage easements.
Ralph De Leon, TIRZ manager, explained the primary reason for extending the extra lanes east past Woodland Hills. It has to do with drainage, specifically eliminating a huge depression in the roadbed. The road dips from west of the Diversion Ditch almost to Woodland Hills. He said engineers want to establish a consistent elevation between high points.
The purpose of the expansion project is to accommodate growth and create an all-weather evacuation route for 78,000 Kingwood residents.
“All the work we’re doing in Phase 1 would do no good in an evacuation if people couldn’t get to it,” he said.
Red X on left at Bens Branch corresponds to X in elevation profile on right. Source: USGS National Map Viewer.
Construction of Phase 2, however, is still several years away.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/10/20241011-DJI_20241011100947_0985_D.jpg?fit=1100%2C619&ssl=16191100adminadmin2024-10-23 21:12:572024-10-24 10:22:22Northpark Crossover at Russell Palmer Closed Friday through Sunday
10/22/24 – The New York Times ran a story today about a radical English experiment to reduce flooding. The gist: giving land back to the sea by turning farm land into salt marsh.
The subhead claims, “When a huge tract of land on the Somerset coast was deliberately flooded, the project was slammed as ‘ridiculous’ by a local lawmaker. But the results have been transformative.”
The experiment is ten years old this year. And the area had record rains. Even after they received a month’s worth of rain in a day in September, no one flooded. Experts believe that England’s traditional defenses – seawalls, barriers and sandbanks – will be insufficient to hold back the sea in the face of climate change.
History of Project
The radical English experiment cost about $20 million pounds ($26 million). “Rather than attempting to resist the sea, the land was given back to it,” says author Rory Smith. He claims that, “A decade on, its results might offer a blueprint for how some parts of Britain — and the rest of the world — might adapt to the reality of climate change.”
“The idea was to turn what had been farmland into salt marsh, an ancient ecosystem that soaks up water as the tide comes in and releases it as the sea retreats.”
The project encountered considerable pushback from displaced farmers. One called it “environmental vandalism.” And a member of parliament called it an “extravagant, ridiculous scheme.”
The NYT points out that since 1860, Britain has lost 85 percent of its salt marshes, according to the U.K. Center for Ecology and Hydrology, a research institute. The article continues, “Returning Steart [the area where the experiment took place] to swampy wilderness was, in part, an acknowledgment that the overdevelopment of coastal land had made flooding more likely, not less.”
Benefits of Experiment
The return to nature began in 2014. After digging a series of canals that look like the veins of a leaf, they let water flow in. It wasn’t pretty at first. But ten years later, “The marsh acts as a natural and hugely effective bulwark against flooding, absorbing and slowing tides before they can encroach inland,” says the leader of a local conservation group.
The man-made swamp has become a haven for wildlife and birdwatching. It is now a source of immense local pride. Cows can even graze within it, eating natural grasses, which allows farmers to sell their leaner beef at a premium. Scientists have even documented the ability of the swamp to act as a carbon sink.
The alliance between the conservationists and the local population has helped to overcome initial objections to the project, which some describe as “rewilding.”
Could It Work Here?
The conservationists in charge of the radical English experiment believe it has great applicability for America and Australia.
Hurricane Ike devastated developed areas along the Bolivar Peninsula in 2008 that still haven’t fully recovered today. But the swamps behind them recovered immediately. Areas still flooded, but flood damage was greatly reduced.
The Times story reminded me of exploring salt marshes near High Island and Anahuac with my Nikon. I’m constantly reminded of the beauty of nature and how the marshes buffer us from flooding. Even more, I’m dazzled by the abundant wildlife.
I took the shot below in December several years ago during the fall migration near Anahuac National Wildlife Refuge. The geese were so thick you could barely see the ground. Or the sky!
Tens of thousands of snow geese taking wing over salt marsh near Anahuac National Wildlife Refuge.
Sometimes the solution may not be to fight nature, but to enjoy it more.
Posted by Bob Rehak on 10/22/24
2611 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2024/10/20081214-Snow-Geese-2972.jpg?fit=1100%2C731&ssl=17311100adminadmin2024-10-22 21:25:512024-10-22 21:45:33Radical English Experiment Reduces Flooding
Relationship Between Wildfires and Floods
10/24/24 – It may seem counterintuitive, but there is a well-recognized relationship between wildfires and floods. What is it?
Simple. Wildfires create conditions that increase the risk of future flooding. Specifically, they affect infiltration; runoff volume and speed; erosion; sedimentation; and more.
How Wildfires Increase Future Flood Risk
Here’s an outline of the the relationship between wildfires and floods:
In short, forest fires can create conditions that increase the likelihood of flooding and make flood events more severe in the affected areas. This relationship is particularly common in the period immediately following a wildfire when the landscape is most vulnerable to erosion and rapid runoff.
What the Experts Says
According to FEMA, “While some floods develop over time, flash floods—particularly common after wildfires—can occur within minutes after the onset of a rainstorm. Even areas that are not traditionally flood-prone are at risk, due to changes to the landscape caused by fire. … Flood risk remains significantly higher until vegetation is restored – up to 5 years after a wildfire.”
The National Weather Service says, “Locations that are downhill and downstream from burned areas are highly susceptible to Flash Flooding and Debris Flows.”
The Army Corps of Engineers also warns of the relationship between vegetation loss and flash flooding. They say the risk of debris flows lasts two to five years.
The Corps, FEMA and Weather Service all recommend purchasing flood insurance within their discussions of wildfires.
Current Conditions in Southeast Texas: Growing Fire Risk
So how bad are current conditions?
I already have received an email from one reader who was seriously injured fighting a pasture fire in Liberty County.
No weather monitoring site in southeast Texas has recorded ANY rainfall for the month of October. “That’s impressive because October is usually our second wettest month behind May,” says Jeff Lindner, Harris County’s meteorologist.
October 2024 Rainfall and Departures from Normal
You can see the lack of recent rain in the statistics below:
Drought Worsening
Moderate drought now covers more than half of Texas and severe drought covers more than a quarter of the state. All of Harris and surrounding counties are in moderate or severe drought, except for those along the coast.
Says Lindner, “While the recent dryness has been relatively short thus far compared to other dry spells, it has been intense – accompanied by much warmer than normal late summer and early fall temperatures. This has quickly resulted in drought degradation across the entire region and vegetation health quickly declining.”
Fire Activity Increasing
“The result has also been an increase in wildland fire activity in recent weeks – especially when drier air masses move over the region along with gusty winds,” Lindner continued.
“As the area moves deeper into the fall and winter months, more frequent and stronger cold fronts will bring stronger winds and much drier air masses across the area. Without any significant wetting rainfall, fire-weather conditions will quickly elevate,” he said.
Wildfire Risk Soaring
The Keetch-Byram Drought Index (KDBI) values indicate wildland fire risk. Currently, they show significant risk across the area. The scale is from 0 (completely saturated) to 800 (completely void of moisture to 8 inches deep). Values above 650 indicate an increased risk of wildland fire and values over 700 indicate a significant risk.
Current average KBDI values are:
Looking Ahead: Higher than Average Temps/Lower Than Normal Rainfall
We are currently heading into La Niña conditions. “Such global oscillations tend to support southern plains drought,” says Lindner.
The National Weather Service indicates drought development and persistence across all of Texas into early 2025. See below:
Be Careful with Outdoor Burning
Beryl left a lot of dead vegetative debris lying around last summer. It’s now turning into fuel. So be extremely careful with outdoor fires. It’s probably best not to burn those leaves you rake up this fall.
The fire you prevent now could help prevent flooding next spring.
Posted by Bob Rehak on 10/24/24
2613 Days since Hurricane Harvey
Northpark Crossover at Russell Palmer Closed Friday through Sunday
10/23/24 – Starting Friday 10/25/24 at 8 PM through Monday 10/28/24 at 5AM, contractors will close the Northpark crossover at Russell Palmer Road to pour new concrete in the median. See location of the X in the diagram below.
That means northbound traffic on Russell Palmer will not be able to turn west (left) toward 59. Nor will westbound traffic on Northpark be able to turn south onto Russell Palmer. In each case, traffic must detour by looping around to another open crossover then doubling back.
In my 10/11 post on Northpark expansion, I implied that Northpark traffic would be closed also. That was a mistake. It will remain open in both directions.
To minimize inconvenience caused by the crossover closure, crews will place rebar and pour concrete directly on compacted dirt, rather than putting asphalt down first.
Utility Conflicts Almost Eliminated
Elsewhere on Northpark, CenterPoint was working to remove the last of its power poles. That means the last of the utility obstacles should soon be out of the way for road construction crews.
Exact Dates of Total Closure, Bridge Construction Still Not Determined
Work is expected to begin on the frontage roads over the UPRR tacks in January. Motorists can expect a 3-day closure of Northpark Drive in either January or February as UPRR crews remove and replace more than 200 feet of railroad tracks.
The exact date of the closure depends on how quickly the railroad crew completes other work. They will also be reconstructing the crossing farther north on the tracks at Knox road. Union Pacific is trying to schedule both projects back to back.
Construction on the bridge structure itself is still a year away.
Phase-2 Preparations Underway
TxDOT approved the proposed schematics for Phase 2 earlier this year. Phase 2 will:
Now, that TxDOT has approved schematics for Phase 2, LHRA is conducting land surveys, obtaining rights of entry, and preparing documents needed to acquire roadway right-of-way and drainage easements.
Ralph De Leon, TIRZ manager, explained the primary reason for extending the extra lanes east past Woodland Hills. It has to do with drainage, specifically eliminating a huge depression in the roadbed. The road dips from west of the Diversion Ditch almost to Woodland Hills. He said engineers want to establish a consistent elevation between high points.
The purpose of the expansion project is to accommodate growth and create an all-weather evacuation route for 78,000 Kingwood residents.
“All the work we’re doing in Phase 1 would do no good in an evacuation if people couldn’t get to it,” he said.
Construction of Phase 2, however, is still several years away.
For More Information
Consult the Lake Houston Redevelopment Authority project pages. Or see these ReduceFlooding posts:
Posted by Bob Rehak on 10/23/24
2612 Days since Hurricane Harvey
Radical English Experiment Reduces Flooding
10/22/24 – The New York Times ran a story today about a radical English experiment to reduce flooding. The gist: giving land back to the sea by turning farm land into salt marsh.
The subhead claims, “When a huge tract of land on the Somerset coast was deliberately flooded, the project was slammed as ‘ridiculous’ by a local lawmaker. But the results have been transformative.”
The experiment is ten years old this year. And the area had record rains. Even after they received a month’s worth of rain in a day in September, no one flooded. Experts believe that England’s traditional defenses – seawalls, barriers and sandbanks – will be insufficient to hold back the sea in the face of climate change.
History of Project
The radical English experiment cost about $20 million pounds ($26 million). “Rather than attempting to resist the sea, the land was given back to it,” says author Rory Smith. He claims that, “A decade on, its results might offer a blueprint for how some parts of Britain — and the rest of the world — might adapt to the reality of climate change.”
“The idea was to turn what had been farmland into salt marsh, an ancient ecosystem that soaks up water as the tide comes in and releases it as the sea retreats.”
The project encountered considerable pushback from displaced farmers. One called it “environmental vandalism.” And a member of parliament called it an “extravagant, ridiculous scheme.”
The NYT points out that since 1860, Britain has lost 85 percent of its salt marshes, according to the U.K. Center for Ecology and Hydrology, a research institute. The article continues, “Returning Steart [the area where the experiment took place] to swampy wilderness was, in part, an acknowledgment that the overdevelopment of coastal land had made flooding more likely, not less.”
Benefits of Experiment
The return to nature began in 2014. After digging a series of canals that look like the veins of a leaf, they let water flow in. It wasn’t pretty at first. But ten years later, “The marsh acts as a natural and hugely effective bulwark against flooding, absorbing and slowing tides before they can encroach inland,” says the leader of a local conservation group.
The man-made swamp has become a haven for wildlife and birdwatching. It is now a source of immense local pride. Cows can even graze within it, eating natural grasses, which allows farmers to sell their leaner beef at a premium. Scientists have even documented the ability of the swamp to act as a carbon sink.
The alliance between the conservationists and the local population has helped to overcome initial objections to the project, which some describe as “rewilding.”
Could It Work Here?
The conservationists in charge of the radical English experiment believe it has great applicability for America and Australia.
Hurricane Ike devastated developed areas along the Bolivar Peninsula in 2008 that still haven’t fully recovered today. But the swamps behind them recovered immediately. Areas still flooded, but flood damage was greatly reduced.
The Times story reminded me of exploring salt marshes near High Island and Anahuac with my Nikon. I’m constantly reminded of the beauty of nature and how the marshes buffer us from flooding. Even more, I’m dazzled by the abundant wildlife.
I took the shot below in December several years ago during the fall migration near Anahuac National Wildlife Refuge. The geese were so thick you could barely see the ground. Or the sky!
Sometimes the solution may not be to fight nature, but to enjoy it more.
Posted by Bob Rehak on 10/22/24
2611 Days since Hurricane Harvey