USGS maps the hazard.
We show what's downstream.

How a burn scar becomes a debris flow

1. 01 / 04

   Fire leaves a scar

   Burned slopes shed rain instead of soaking it up.

   Nov 13 → Dec 28, 2017

   The same slopes, six weeks apart. Drag the line to compare.

   Runout Labs · Screen

   We measure burn severity on every slope from satellite images.

2. 02 / 04

   Rain hits bare soil

   A short burst of intense rain is enough to start it.

   33 → 50 dBZ in 17 minutes

   Radar over the Montecito front, 3:09–3:48 AM, Jan 9, 2018. Higher dBZ means heavier rain.

   Runout Labs · Watch

   We track the storms forecast over your top-ranked canyons.

3. 03 / 04

   Channels gather the flow

   Runoff picks up soil and rock as it funnels into the canyons.

   36 canyons · 70% steeper than 23°

   1. 01Cold Spring
   2. 02San Ysidro
   3. 03Romero

   Share of the canyon area above the slope USGS uses for debris-flow likelihood. 10 m USGS 3DEP.

   Runout Labs · Rank

   We order the canyons below the scar, first to last.

4. 04 / 04

   It reaches the canyon mouth

   Where the canyon opens, the flow spreads onto roads, pipes and homes.

   162 structures destroyed

   Of 558 inspected in CAL FIRE's damage survey after Jan 9, 2018. USGS mapped 3.5 km² of debris-flow inundation.

   Runout Labs · Brief

   We name the roads, pipes and buildings below the worst canyons.

Nov 13, 2017Dec 28, 2017

Sentinel-2 true color · 10 m · Nov 13 and Dec 28, 2017

For whoever owns what's downhill.

• 
  Counties + emergency managers

  Which drainages to plan around, and which storms to watch.
• 
  Water + irrigation districts

  Which burned canyons drain to your intakes, canals and reservoirs.
• 
  Utilities + co-ops

  Which burned canyons sit above your lines, poles and roads.
• 
  Risk pools + insurers

  Which insured and member assets sit below a scar's worst canyons.