# Presentation: 541275

## After the Wildfire

- Jerome V. De Graff
- Geologist
- USDA Forest Service

## First of an often dual natural disaster

- Wildfire

**First of an often dual natural disaster**

**2003 Old-Grand Prix Fires**

## When seasonal rainfall comes, debris flows may occur.

- Debris Flows

**When seasonal rainfall comes, debris flows may occur.**

**Santaquin, UT 2001**

**Waterman Canyon, CA 2003**

## The Southern California ‘Fire-Flood’ Sequence

- Relationship between wildfire and flooding in southern California recognized by 1930
- By 1950s, field studies showed that some flood events were actually debris flows
- Now known this takes place in many parts of the western United States

## Burned Area Emergency Response (BAER)

**BAER teams rapidly assess emergency situations based on the effect of vegetation loss in burned watersheds and ‘values-at-risk’ **

**San Bernardino, Calif.**

**Notes:**
Burned Area Emergency Response (BAER) teams assess the potential impacts of wildfires on Federal lands.  This is a rapid assessment carried out in the latter stages of wildfire suppression.  Initial Forest Service BAER assessments including recommendations for mitigation measures must be submitted within 7 days of fire containment, i.e., when the fire is enclosed with firelines keeping it from growing larger.

## Burned Area Emergency Response Objectives 

- Minimize threats to human life and property, onsite and off-site
- Minimize loss of soil and onsite productivity
- Minimize loss of water control and deterioration of water quality

**Notes:**
Efforts to mitigate the impact of identified emergency conditions must be in place before the 1st damaging storm event.  Often, wildfires occurring in the late summer or early fall leave only weeks to design and construct mitigation measures.

## 'Wildland-Urban Interface'

**Urban growth places many more people, homes, and other property next to National Forests.  This is the ‘Wildland-Urban Interface”.**

**From Chourre, M. & Wright, S.,  2006**

**Notes:**
The wildland-urban interface increases the number of people and property at risk from fires on adjacent National Forest and other undeveloped lands.  

## Past Fire Suppression Policies Increased Fuel Loads

**Notes:**
After many decades of suppressing fire, it was recognized that frequent fires played an important and beneficial role in many forest and range ecosystems.  Some tree species need fire to prepare the natural seed bed for successful regeneration or to cause seeds to be released.  In other ecosystems, frequent small fires allow for other species to grow and avoid large disastrous fires.  Many areas now have too much fuel that built up during the period when all fires were suppressed.

## Hayman Fire, 2002

- Mollie Fire, 2001

- Cerro Grande Fire, 2000

- Rodeo-Chedeski, 2002

- Cedar Fire,2003

- Old & Grand Prix Fires, 2003

- Biscuit Complex Fire (OR), 2002

- Waterfall Fire, 2004

- Larger Wildfires

**Notes:**
Larger fires near areas with increased urbanization mean BAER teams need better ‘tools’ to improve prediction of debris flows.  The consequences of inaccurate prediction in past decades was limited mainly to low-value property.  Now peoples lives and significant property loss are at greater risk.

## 2003 Old-Grand Prix Fire

**Notes:**
One valuable tool was utilized for the 2003 Old-Grand Prix Fire near San Bernardino, CA.  Maps developed by Dr. Cannon and her USGS colleagues for the BAER team helped identify the risk for debris flows by various watersheds.  Debris flow probability  (1-33%, 34-67%, 68-100%) for the watersheds was defined for the 2-yr, 1-hour storm (0.52 inches), 10-yr, 1-hr storm (0.9 inch) and 25-yr, 1-hour storm (1.12 inch) recurrence.  This information was used in conjunction with property, road, stream channel and other maps for developing evacuation and notification plans.