Posts Tagged: Wildfire

Urban wildfire impacts water, soil and wildlife

UC experts offer tips on testing drinking water, rehabilitating gardens

As residents start to clean up after the Los Angeles County wildfires, the aftermath will continue to impact water and natural resources in and beyond the fire areas, according to water experts at University of California Agriculture and Natural Resources.

Urban wildfires have grown more frequent and intense in the past decade. Record dryness and high winds created conditions capable of enormous heat and destruction; in these types of wildfire events, infrastructure systems – including water supply and electricity – may be affected.

For example, high heat created in urban wildfires can damage or destroy parts of a water distribution system, which disrupts supplies and introduces risks.

“Volatile organics and carcinogens can enter drinking water through compromised parts of the system that get melted by fire,” said Erik Porse, director of the California Institute for Water Resources. He added, “When distribution systems are damaged or face heavy demands, pipes can lose pressure, allowing bacterial growth.”

Water agencies in affected parts of Los Angeles County responded to these risks by monitoring water quality and releasing “do not drink” advisories in affected areas. Such notices are not unusual following disasters, but are jarring for residents who are accustomed to reliable household water. 

Ash, runoff can contaminate supply of drinking water 

If wildfires occur in watersheds that supply cities with water, ash and polluted runoff may contaminate water bodies in fire zones.

“Water treatment systems may be unable to treat incoming water if that water has high levels of solids or contaminants,” Porse said. 

These risks arose with the Hughes Fire near Castaic Lake, which supplies drinking water to parts of northern Los Angeles County. As the fire spread last week, water agencies in Los Angeles were monitoring the situation closely.

Many areas of Los Angeles also rely on groundwater. Future rains can cause contaminants to infiltrate into groundwater basins and create similar treatment challenges for water agencies.

Local water agencies are the best source of information to find out if drinking water is safe. During times of both routine operations and disasters, water utilities are subject to stringent standards and they monitor water quality in their systems as required by law.

“If a water utility publishes ‘do not drink' or ‘boil' advisories in your area, follow directions in the notice and stay up-to-date through website and social media updates,” Porse advised.

Edith de Guzman, UC Cooperative Extension specialist in water equity and adaptation policy at UCLA, added, “Residents who are not in such advisory areas should feel confident that their utility is monitoring the situation and that their water is meeting regulatory standards and is safe.”

Anyone who has concerns about the quality of the water in their home or office can get their water tested. “Water testing can always provide residents or business owners more information and it's important to understand how to interpret results,” said Porse.

Researchers at UC ANR and the Food-Energy-Water Systems for the Underserved lab at UC Merced published a fact sheet with resources on how to test water and understand the results.

Mudslides, degraded waterways other possible effects of wildfires

While rain would reduce overall wildfire risk, as little as a half-inch of rain in a short period of time could also trigger mudslides or debris flows because intense fires alter the ecosystem.

“Mudslides are a danger in areas burned by wildfires because the fires can destroy vegetation that would usually do two things – soak up some of the water and help keep the soil in place,” said Hope Hauptman, assistant project scientist with California Institute for Water Resources. “So, without that stabilizing plant cover, rain can run off quickly, and the exposed soil – particularly on steep slopes – can turn into dangerous mudflows.”

In addition to removing soil-stabilizing plants, intense fires can change soil characteristics, causing it to repel rather than absorb water, said Monica Palta, UC Cooperative Extension specialist in urban water quality, health and justice at UC Irvine.

“A wildfire with high heat can cause sandy soils in particular to become hydrophobic, or repel water,”Palta said. “A hotter fire creates a waxy substance, formed from burned plant material, that coats the soil and inhibits its ability to infiltrate water and elevates surface runoff.”

Elevated surface runoff increases erosion and causes toxic soils and ash to wash into rivers and the ocean.

“Ash from wildfires can contain heavy metals that are toxic to fish and other animals,” Palta said. “Ash from urban wildfires can have additional types of toxins from melted plastics and other materials in human-built structures like houses.”

Wildfire ash also contains large quantities of nutrients like phosphorus and nitrogen. When those nutrients enter coastal waterways, they can trigger harmful algal blooms, which is bad for swimmers, surfers and wildlife. “Algal blooms can produce their own toxins, and the large amount of decomposing algae in an algal bloom consumes oxygen that fish and other aquatic wildlife need to breathe,” Palta explained.

These water quality issues can persist for years after a fire.

“When contaminated water infiltrates soil or is taken up by plants, the contaminants have a good chance of being bound and stored there,” Palta says. “As wildfire destroys plant communities and causes soils to repel water, it causes not only the release of contaminants into the environment, but reduces the ability of an environment to capture and store those contaminants before they reach a river or the ocean.”

Cleanup crucial in rehabilitating garden after fire 

To remove the harmful substances in soil and improve infiltration, Palta recommends taking off the top 6 to 12 inches of soil in gardens, disposing of the soil in plastic bags placed in a trash bin (do not discard in a green bin or compost pile), and then adding new, clean soil to garden beds. 

Mixing in compost also will improve infiltration and bind contaminants like heavy metals. 

“I would advise engaging a professional to remove the soil because you need to wear correct protective equipment to avoid exposure,” she added. “You can wash ash off of garden plants with water from a hose, but be aware that the contaminants will then go into the soil, so wash your plants before removing soil from the yard. Scorched plant material should be removed from the garden, as it may contain contaminants.” 

She also recommends replanting vegetation in the “clean” soil as soon as possible, and taking steps to control erosion. 

“To stabilize slopes and hillsides, you can lay logs or branches perpendicular to the slope to block water and erosion down the slope,” Palta said. 

UC Master Gardeners of Butte County also have a list of tips on how to mitigate damage on a landscape burned by wildfire when heavy rains begin.

The Los Angeles County Department of Public Health encourages testing soil and water (if not done by your local water provider) prior to starting a garden. On page 16 of the agency's Soil and Water Testing Guidelines for Home and Community Gardens is a list of soil-testing labs. 

UCCE report: Local forest restoration teams effective at rapid response

Quickly planting trees after wildfires crucial for communities, ecosystems, carbon goals

As the climate crisis fuels more high-severity wildfires, many forests – adapted to bounce back from frequent but less-intense fires – are struggling to recover quickly.

“In a lot of locations, forests in the Sierra Nevada that burn at high severity are not regenerating on their own,” said Susie Kocher, University of California Cooperative Extension forestry and natural resources advisor for the Central Sierra. “They need to have living trees to drop seeds; if everything dies in an intense fire, then there's a high likelihood in those locations that trees might not return for a while.”

According to Kocher, a forest may take multiple decades to grow back on its own, seeding in very slowly from the edges of a burn. To speed up that regeneration process, a pilot program of local “Emergency Forest Restoration Teams,” or EFRTs, have been helping forest landowners rapidly remove dead trees, plant new seedlings and expedite other vital tasks after wildfires.

Kocher is a co-author of a recently released report evaluating the EFRTs, which appear to be effective in assisting often-overwhelmed private landowners navigate competitive funding programs and complicated permitting pathways after wildfire. Small private landowners in California own 7 million acres, comprising 22% of forested land across the state.

“None of our current assistance programs were really designed to rapidly respond to high-severity fire disasters,” Kocher said. “And we're just getting so much more high-severity fire now that there needed to be a different way of helping people, besides business as usual.”

Lead agencies improve coordination of restoration efforts

Drawing from a successful model in Washington, Kocher and other members of the Governor's Forest Management Task Force recommended the formation of EFRTs in 2019 and this recommendation made it into the California Wildfire and Forest Resilience Action Plan of 2021.

Following the Caldor, Dixie and Tamarack fires during that year, disaster relief funds from CAL FIRE and the U.S. Forest Service enabled the establishment of pilot EFRTs in each of the affected regions. A key innovation was designating a local lead agency to coordinate restoration efforts: the El Dorado Resource Conservation District (Caldor), the Feather River Resource Conservation District (Dixie) and Alpine County (Tamarack).

“The idea is that one well-established local agency gets the funds to carry out all the reforestation work,” Kocher said. “They find contractors for the landowners and plan and carry out all the work needed, including dead tree removal, site preparation and replanting; this helps it be more coordinated across the landscape and reduces competition for contractors.”

“Also, for most of that work, there's no cost to the landowner – which is a huge benefit to them, because these things can get really expensive, like many thousands of dollars an acre,” Kocher added.

Although there was an initial steep learning curve for the local lead agencies on the complexities of reforestation and the maze of required permits, they quickly executed a significant number of forest restoration treatments. Within two years, the three pilot teams had collectively completed over 2,500 acres of dead tree removal and 1,400 acres of conifer planting.

“The overwhelming benefit of the pilots was that a lot of work got done on the ground, that otherwise would not have been done – at least not in the timeframe that was made possible by the EFRTs,” said Daylin Wade, a UCCE staff research associate and co-author of the recent report, who synthesized feedback from interviews of professionals involved in the program.

Rapid reforestation better financially, ecologically

Both Wade and Kocher underscored how the EFRTs were crucial in completing restoration tasks in a timely manner. Removal of dead wood becomes trickier and more expensive over time, as the trees decay and are dangerous to cut down.

“A major accomplishment was getting trees out of there while it was both safe and economically viable to remove those trees – and getting trees in the ground before shrubs dominate the site,” Wade explained.

It's also imperative to quickly remove the dead trees to reduce the fuel load and minimize the chances of re-burn in the area.

“If you're not doing this work, then you're actually endangering the investment that you're putting into rebuilding communities that burned, because they're in danger of burning again if you have huge piles of dead trees everywhere,” Kocher said.

Furthermore, expediting those tasks helps restore the forest cover that is crucial for sequestering carbon and achieving the goals of California's sweeping climate action plan – such as attaining carbon neutrality by 2045.

“We have very ambitious carbon goals for our forests in California, and so reestablishing them – even on private lands – is a public benefit,” Kocher said.

Evaluation of EFRTs by UC Cooperative Extension continues

In addition to enumerating the progress of the three EFRT case studies, the evaluation report also lists recommendations to further enhance the program, such as securing rapid and flexible funding for future EFRTs, improving guidance for local lead agencies and streamlining permitting processes.

The authors also stressed the need to expand opportunities for the commercial sale of woody material in the aftermath of a wildfire event. Selling logs and wood chips reduces the volume of material that would need to processed onsite by the EFRTs and their contractors, thereby defraying some of the costs for that work.

But there simply hasn't been a sufficient market for that woody biomass.

“It's a big barrier,” Kocher said. “If we had a healthier timber market, it would be easier to make this stuff pay its own way and be less of a subsidized endeavor.”

UC Cooperative Extension's EFRT evaluation work – made possible by funding from the U.S. Forest Service State, Private and Tribal Forestry, Region 5 – will continue for the next couple years. On the heels of this first report, Wade will next gather and summarize feedback from private landowners on whether the EFRTs are meeting their goals.

And, later this summer and fall, researchers will begin assessing the ecological success of the plantings in the restoration areas, surveying seedling survival and gauging the volume of competing vegetation.

“It's hugely encouraging that we've gotten all these trees in the ground, but it's not the end of the process – it's just the beginning,” Kocher said. “Trees and forests need to be maintained over time, so this next step will let us see how successful that has been, and if there are additional steps needed to actually ensure that these trees succeed and thrive.”

The full report, dedicated to the memory of report co-author and UCCE advisor Ryan Tompkins, can be found at https://ucanr.edu/efrt.

Report: Making homes more resistant to wildfire can be affordable

Priorities include removing objects within five feet of a house, upgrading vents

Wildfire losses cost taxpayers and communities hundreds of billions of dollars each year, and preparing communities before a disaster occurs is the best way to avoid damage to homes and neighborhoods. Retrofitting existing homes can make communities safer while avoiding billions in disaster costs.

As Californians learn to live with wildfire, scientists encourage improving the structure and design of houses and other buildings to help them survive wildfire. A new report shows that even inexpensive changes can increase wildfire resistance.

“Retrofitting a Home for Wildfire Resistance” suggests that some of the most effective strategies to reduce the vulnerability of homes and neighborhoods to wildfire can be done affordably.

“This report is a practical tool that helps evaluate the relative costs and benefits of fire-hardening retrofits,” said Yana Valachovic, a University of California Cooperative Extension forest advisor, who reviewed the study. “These retrofits can substantially improve the odds that a home or building will withstand wildfire exposures to embers, radiant heat or flame contact.”

The report is co-authored by Kimiko Barrett, wildfire research and policy analyst for Headwaters Economics, a non-partisan research organization based in Bozeman, Montana, and Stephen L. Quarles, UC Cooperative Extension advisor emeritus, who has studied the vulnerability of the built environment to wildfire exposures and potential mitigation strategies.

In partnership with California's Department of Forestry and Fire Protection, or CAL FIRE, Barrett and Quarles examined the costs for improving the structure and design of existing homes to increase their wildfire resistance.

“This tool can also help homeowners build a budget and prioritize tasks that often feel overwhelming,” Valachovic said. “Everyone should prioritize removing combustible vegetation, mulch, and stored materials within the first five feet of a structure and upgrading vents to resist embers.”

Simple actions can reduce a home's vulnerability to wildfire

The report's conclusions are derived from a detailed examination of the latest available science on mitigation strategies and construction costs. The authors identified costs for retrofitting structures to meet and exceed California's building code (Chapter 7A) for wildfire resistance, but the general principles and conclusions can be applied in other states, adjusting for local economic and supply conditions.

For a typical 2,000-square-foot home in California, retrofitting costs can range from $2,000 to upwards of $100,000 for the highest level of protection.

“When we looked at the latest building techniques and cost data, we found some effective retrofitting strategies can be done for between $2,000 to $10,000,” said Barrett. “While the highest level of protection can cost more, it is often not necessary. Simple actions such as removing flammable materials from near the home and removing debris from the roof can be done at little to no cost.”

The authors also incorporated effective mitigation strategies that could reduce risk without requiring costly upgrades over the entire home, such as replacing siding only on the side of a home that is close to another building, such as neighbor's home or a detached garage, or replacing combustible deck boards next to the home with a noncombustible deck board or metal grate.

They also incorporated a systems approach, where the vulnerability of adjacent components are considered, and recommend steps such as placing noncombustible surfaces at the intersection between two components.

For example, Quarles said: “Adding a gutter cover and ensuring the adjacent edge of roof is not vulnerable by incorporating a metal drip edge and, if necessary, a noncombustible bird stop at the edge of the roof. Or, replacing a combustible deck board next to the house and, if necessary, adding metal flashing at the base of the exterior wall.”

Cost estimates in the report include those for upgrading a home's exterior walls, roof, deck, windows, doors, eaves, gutters and near-home landscaping – all areas likely to be exposed to embers, direct flames and radiant heat.

“The graphics detailing specific elements of the retrofitting process are very useful,” Valachovic said.

Charts, architectural renderings and a detailed appendix of cost estimates provide a basis for a general understanding of the methods and budgets that homeowners might consider when retrofitting their home for wildfire resistance.

Retrofitting for wildfire can make communities safer

Contractors and others seeking information about building wildfire-resistant homes can gain valuable insights from this analysis, along with retrofit costs generated by the California Wildfire Mitigation Program.

“This analysis demonstrates that investing in wildfire-resistant retrofitting for homes is a cost-effective strategy to protect communities that could save billions in disaster costs,” said Barrett. “As more people live in fire-prone areas, we must also take a closer look at retrofitting homes to be stronger and more durable.”

While the authors hope Californians use the information to protect their homes, people who work in construction, development, design and policy also can use the information to show that retrofitting homes for wildfire resistance is an effective way to protect communities.

This 58-page report received funding from CAL FIRE and the U.S. Forest Service and can be downloaded for free at https://headwaterseconomics.org/wp-content/uploads/2024/06/Wildfire_Retrofit_Report_20240624.pdf.

Public invited to observe prescribed fire training in Santa Cruz County

 

First Forester TREX to be held June 3-6

California's first-ever Forester Prescribed Fire Training Exchange event focused on bringing together professional foresters, forest managers and fire practitioners will occur June 3-6 near Watsonville. The four-day event is being hosted by the Central Coast Prescribed Burn Association, which empowers the public to build a culture of good fire and supports private landowners in conducting prescribed burns in Monterey, San Benito and Santa Cruz counties.

There will be one burn conducted during the event, likely on June 4 or 5, which will be open for the public to observe.

Prescribed Fire Training Exchanges (TREXs) first came to Northern California in 2013, and have made a positive cultural shift concerning prescribed fire, within both regional fire services and the general public. These “good fire” TREX events have drawn significant attention, especially in the context of more severe wildfire seasons.

After months of cross-organizational planning, the four-day long training will be focused on exploring the connections between sustainable forest management, wildfire resilience, timber harvesting, prescribed fire, and will include a burn within a commercially harvested redwood forest. The TREX will provide experiential training opportunities to forest managers and planners to advance statewide knowledge of how to conduct prescribed fire in merchantable timber stands.

Along with the prescribed burn, the program will include lectures, local tours, and open discussions on how to incorporate fire into timber management, burn planning and timber harvest planning, pre- and post-fire considerations, and permitting mechanisms for fire and timber harvesting. Presentations will be given by local forestry consultants, University of California Agriculture and Natural Resources, CALFIRE and local fire practitioners.

The burn location will occur near Mount Madonna, on private land with access allowed for accompanied observation only.  Be advised, while the ForesterTREX planning team works closely with theMonterey Bay Air Resources District to assure good smoke dispersal, smoke may be seen and be present in these areas during and after a burn. Please see the Central Coast Prescribed Burn Association webpage at calpba.org/centralcoastpba for updates close to the burn date.

Participants and partners include the Mount Madonna Center, members of the Amah Mutsun Tribal Band and the Esselen Tribe of Monterey County, University of California Agriculture and Natural Resources, Resource Conservation District of Monterey County, CALFIRE, local land trusts, scientists, ranchers, students, researchers, land managers and others. The Central Coast Prescribed Burn Association is currently funded via California Coastal Conservancy grants.

For more information or to join a group of observers, contact Barb Satink Wolfson, UC Cooperative Extension area fire advisor at bsatink@ucanr.edu.

Latest research in fire science focus of free webinar series

Wildfire, cultural and prescribed burns, plant flammability among topics covered

Interested in learning about some of the latest research in fire science and stewardship? Join the UC ANR Fire Network  for a series of free lunchtime webinars to explore fire science topics with colleagues from across the globe.

This four-part webinar series will address fire in land management, plant flammability, fire history and management and forestry and fuel profiles. 

Everyone is welcome to watch the Hot Topics in Fire Science and Stewardship Webinar Series. 

Restoring Fire to Meadows and Other Cultural Landscapes

Presenters: Alice Lincoln-Cook, California Indian Basketweavers Association; Brian Peterson, Fire Forward

• May 29, noon–12:45 p.m. Pacific Time
• Register by May 29: https://bit.ly/3Qksc0J 

How Can We Assess Plant Flammability?

Presenters: Jane Cawson, University of Melbourne; Max Moritz, UC Santa Barbara and UC ANR

• June 5, 3­–3:45 p.m. Pacific Time
• Register by June 4: https://bit.ly/3WetrlA

Nuances in Fire History and Management: Lessons from Oregon Presenters: Andrew Merschel, U.S. Forest Service Pacific Northwest; Chris Dunn, Oregon State University

• June 12, noon–12:45 p.m. Pacific Time
• Register by June 11: https://bit.ly/44fMU7u

Forestry and Fuel Profiles

Presenters: Don Radcliffe, University of Washington; Eric Knapp, U.S. Forest Service Pacific Southwest

• July 17, noon–12:45 p.m. Pacific Time
• Register by July 16: https://bit.ly/4aTqI5Q

For more information, visit https://ucanr.edu/sites/fire/Home_430/Events.  

 

 

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