Angeles National Forest
U.S. Forest Service
701 N. Santa Anita Ave.
Arcadia, CA 91006
While many wildfires cause minimal damage to the land and pose few threats to the land or people downstream, some fires cause damage that requires special efforts to manage unacceptable risks afterwards.
Summer thunderstorms and other rain events in the mountains can result in high runoff and flash flooding.
Wildfire increases the potential for post fire flooding, soil erosion, and debris flows that could impact campgrounds, fishing areas, homes, structures, roads, and other infrastructure within, adjacent to, and downstream from the burned areas.
Post-fire, watershed conditions will naturally receive and transport water and sediment differently than during pre-fire conditions.
The public and communities adjacent to and downstream from burned areas should expect increased flooding and debris transport during smaller rain events than would normally cause this.
The potential for increased runoff and debris flows are not just a one-year concern.
We need to recognize the threat potential of flash floods and debris flows may exist for the next 3-5 monsoon and winter seasons, depending on the intensity of these storms.
For life and safety concerns, California National Forest closures may need to be implemented prior to forecast rain events until the burned area fully recovers.
Residents and visitors should remain alert to weather events and plan ahead when travelling along roads downstream from the burned areas of recent wildfires.
Forest Service Burned Area Emergency Response (BAER) teams have been working on California’s National Forests to assess the condition of the watersheds on federal land that burned this summer and fall.
The BAER assessment team identifies potential threats to critical values-at-risk and recommends emergency stabilization response actions that are implemented on federal lands to reduce potential post-fire risks.
BAER critical values that may be considered at-risk on National Forest System (NFS) lands are:
Human life and safety.
Property on Forest Service lands such as buildings, water systems and infrastructure, road and trail prisms.
Natural Resources on Forest Service lands such as water, soil productivity and hydrologic function, areas where invasive species or noxious weeds may impact native or naturalized communities and may include critical habitat or suitable occupied habitat for federally listed threatened or endangered species.
Cultural and Heritage Resources such as pre-historic and historic properties and sites on Forest Service lands.
For values and resources potentially impacted off NFS lands, one of the most effective BAER strategies is interagency coordination with other responsible agencies, entities, and local cooperators who assist affected businesses, homes, and landowners prepare for rain events.
While multi-agency efforts are being taken to reduce the risks to life and safety downstream from the burned area, residents in the area should develop individual plans to protect themselves and their property.
The Forest Service and Natural Resources Conservation Service (NRCS) work together and coordinate with other federal, state and local agencies, and counties that assist private landowners in preparing for increased run-off and potential flooding and debris flows.
NRCS works with local sponsors to prepare damage survey reports for eligible sites on private lands adjacent to and downstream from affected areas. NRCS uses these reports, along with the BAER team’s assessment report, to develop emergency measures to reduce the impacts from potential increased water and debris flows, and assist sponsors to implement recommended emergency measures (www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1045263.pdf).
Many local county offices of emergency management promote preparedness through emergency services programs to assist the public to prepare for, respond appropriately to, and quickly recover from natural emergencies that may impact county residents and visitors. Please check your local county website for emergency preparedness for potential National Weather Service flood warnings.
Homes or businesses that could be impacted by flooding from federal land that resulted from wildfires may be eligible for flood insurance coverage from the National Flood Insurance Program (NFIP). Information about NFIP is available through FEMA at www.floodsmart.gov/, or www.floodsmart.gov/flood-insurance/why. Other flood preparedness information is available at www.ready.gov/floods.
SAFETY MESSAGE: Everyone near and downstream from the burned areas should remain alert and stay updated on weather conditions that may result in heavy rains over the burn scars. Flash flooding may occur quickly during heavy rain events be prepared to take action. Current weather and emergency notifications can be found at the National Weather Service website: www.weather.gov/.