Burned Area Emergency Response (BAER) Team Report
Waterfall Fire Summary
July 29, 2004
 The Burned Area Emergency Response
Team (BAER) was composed of technical
experts from the U.S. Forest Service, Nevada
Division of Forestry, and Carson City.
Additional experts were consulted who represented
the Nevada Cooperative Extension,
Natural Resource Conservation Service,
Nevada State Parks, Carson Colony or the
Washoe Tribe of Nevada and California,
Bureau of Land Management, Nevada
Department of Transportation Cartography
Services, and the Nevada Fire Safe Council.
The team was asked to complete the emergency
assessment following the U.S Forest
Service BAER process and complete the
assessment within one week of fire containment.
This article contains a summary of the
information that was collected and considered
in making recommendations for emergency
and long term restoration activities. This
report is intended to be used by a variety of
landowners and agencies to pursue funding
opportunities. We have attempted to identify
emergency treatments by land ownership, as
this will help determine funding sources and
grants to pursue funding which may be available
through the Forest Service, Natural
Resources conservation Service or through
special congressional allocations for private,
state or city lands.
Due to the short timeframe the team had in
putting this assessment together, the report
should be updated as more information is collected
or as conditions change on the landscape.
Questions regarding this assessment
should be directed to Erick Walker (775) 884-8120 at U.S. Forest Service, Carson Ranger
District; Jenny Scanland at Nevada Division
of Forestry (775) 684-2514; or Linda Ritter,
City Manager (775) 887-2100.
Description of Watershed Emergency
The Waterfall Fire is located west of U.S.
Highway 395 directly above Carson City,
Nevada. The burned area includes areas within
eleven watersheds including Kings
Canyons, Ash Canyon, Coombs and Vicee Canyons. The headwaters on the burn area
follow the watershed divide on the Carson
Range of the Sierra Nevada. The canyons
affected are headwater tributaries to the
Carson River to the east. This area is prone to
summer thunderstorms often resulting in
flash flooding.
Land ownership within the fire includes:
USFS, Washoe Tribe of CA and NV, Carson
City, State of Nevada, Private, Nevada State
Board of Regents, and Tahoe State Park. In
addition to being the scenic backdrop for the
Capital City, the area generates most of the
city’s municipal water supply. Initial assessments
indicate that post fire impacts may
include excessive water run off, debris flows,
mud slides and other threats to Carson City’s
municipal water supply and water quality,
infrastructure of the municipal water system,
human life and property. Also at risk are down
slope subdivision drain systems, sewer systems,
and roadways.
Threats to life and property: Over 516
homes ranging from $250,000 to $750,000 in
value are at risk from increased run-off directly
downstream of the Waterfall Fire within Carson City. Areas where the fire burned
directly above and into subdivisions are at
risk of rock falls, flooding and debris flows,
especially in the Ash, and Kings Canyon
areas.
Geologic instability and landside potential: The combination of vegetation loss from
the wildfire with rainfall may result in landsliding.
Computer models were used to derive
hazard ratings for management decision-making.
These include predicting initiation sites
of landslides and estimating runout distances
of debris flows. Results from the computer
modeling indicate that a moderate-high to a
high probability of landsliding occurrence
will take place within the fire area during the
next ten years until re-vegetation takes place.
The probability increases from a moderate to
a high hazard rating in response to rainfall
specifically rainfall events that have a frequency
of 60 minutes or greater for return
intervals of 2 to 25 years. Lesser rainfall frequencies
are unlikely to result in landsliding.
The highest hazard runoff areas are the
existing alluvial fans/aprons located in the
North King Canyon Creek, Premier Mine,
and Ash Canyon Creek areas. The Ash
Canyon Creek area has the greatest risk
because of the likelihood of debris flow
reaching housing developments. High hazard
areas have also been identified in the Vicee
and Coombs Canyon areas but the runout
areas are not as significant because the number
of buildings and houses are much less
prevalent than in the other high hazard areas.
Public safety and closures: The fire area
is easily accessible all along the eastern
perimeter. This area receives very high use
from city residents and visitors. There is an
existing and continuing public safety and hazard
situation on the fire. The public can gain
access to the steep terrain and unstable
canyons in several areas. Carson City has
closed the fire to all public access at this time.
USFS and the private landowners will need to
work together to control use of the area for
the sake of public safety. Signage, public
information kiosks, media releases and barriers
will be needed to meet the public safety
needs for at least the next year and a half.
Wind erosion and public safety: The
Waterfall Fire lies adjacent to U.S. Highway
395 and directly adjacent to Carson City. The
local winds are consistent in the afternoon
along the mountain front in Carson City. The
dust and ash from this fire could cause public
safety problems related to decreased visibility
and health problems. Blowing ash could also
impact the municipal water supply, as the City uses surface water supplies that lie within
the burned area.
Carson City and Virginia City municipal
water supplies: The Waterfall Fire
occurred in a designated municipal watershed.
It is the sole municipal watershed for
Carson City. Potential impacts of the
Waterfall Fire to surface water supplies to
Carson City include increases in sediment
load and turbidity in the creeks that supply
surface water to Carson City, and a possible
increase in pH. The increased sediment load
to the surface water treatment plant will likely
cause temporary shutdown of the plant during
precipitation events and heavy runoff
periods. Landslides and/or mudslides would
likely create the same effects, but may have
the potential for longer-term disruption of
operations if they occur in the stream bottoms.
Hydrologists have confirmed that there
is a high risk of debris flows and very high
probability of increased ash and silt in the
streams and just above the water quality treatment
plant. The highest potential comes with
the first moderate to high storm event. This
would cause damage to the buildings and system
infrastructure associated with the water
quality treatment plant.
Sedimentation caused by the fire will also
reduce the infiltration capacity of the Vicee
Canyon recharge infiltration basins by plugging
the bottom substrates with fine-grained
material. Other debris carried downstream
during major precipitation events may also
interrupt recharge capabilities.
Also at immediate risk are the pipelines in
Lakeview, Timberline, Vicee and Ash
Canyons that supply water from
Marlette/Hobart Water System to Virginia
City and Carson City. These pipelines are
vulnerable in several places where they cross
streams. There are two pipelines, one that
supplies water to the historic inverted siphon
to Virginia City (which is their only source of
municipal water) and another to the Ash
Canyon Water Treatment Plant in Carson
City. The access road to the Marlette Lake
pump was within the fire and was burned. The
Marlette Lake pump operates on diesel fuel
and must be trucked in three times a week.
The road is at risk of damage from increased
flows and is not to a high enough standard to accommodate those flows. Loss of access on
this road to the Marlette/Hobart Water System
would inhibit system adjustments and the
delivery of diesel fuel to the Marlette Lake
pump, which would reduce and stop the flow
to Virginia City and Carson City within a few
days.
Threat to soil loss and loss of productivity: High severity burn occurred on 1,261
(14%) acres, and moderate severity burn
occurred on 3,990 acres (45%). Acres of low
severity burned areas are 2,860 (33%). (The
remaining 8% not burned but was disrupted
by fire suppression operations.) This level of
severity has created localized hydrophobic
soil conditions, removed over story vegetation
and organic duff cover. The majority of
the high burn severity area is in the Kings
Canyon and Ash Canyon sub-watersheds. The
majority of the high burn severity areas are on
very steep slopes, and have a mixed moderate
to fine sandy loam surface. There is as much
as three inches of burnt ash on the high severity
burn areas and no natural mulch on the soil
surface. These soils are perched above the
perennial streams in the Kings and Ash
canyons. High and moderate burn severity
areas have very high erosion potentials. This
situation places high risks upon water quality
as well as threatening long-term site productivity
and quality, and could contribute to
debris flow during larger watershed events,
posing a potential threat to life and property.
Threat to stream and Carson River
water quality: Sediment yield is expected to
increase from moderate and high severity
burn areas as discussed previously. Key
streams considered to be at extremely high
risk from increased sediment yields are Ash
Canyon and Kings Canyon Creek. These
creeks flow through the City’s drainage system
and into the Carson River. These channels
and pipes are not sized to compensate for
this increase in expected waterflows or filter
the sediment load. Therefore the Carson River
can expect an increase in ash, storm flow,
sediment and debris with the first substantial
thunderstorm event and with spring runoff.
Threat to aquatic ecosystem integrity: Many of the riparian zones and aspen stands
were burned at moderate and high intensities.
These habitats are particularly important as
they provide for high biodiversity, travel corridors,
and local microclimates. In addition, Kings and Ash Canyon Creeks are recreational
fisheries, with brook and rainbow trout.
The lack of overhead shading vegetation due
to the fire, and the resulting increased sedimentation
into the creeks threaten aquatic
environments. Preliminary assessments by
Nevada Department of Wildlife found a total
loss of the recreational fisheries. The threat of
overland flow, debris flows and slope failure
above the actual stream beds in steep areas
will overwhelm these systems with sediment
and threaten the natural restoration of the
woody vegetation.
Threat to terrestrial ecosystem integrity: There are no Federally listed plants or animals
known to exist in the watershed. No critical
habitat exists in the watershed. There are
no state listed plants or habitat known to exist
in the burn area.
The Waterfall Fire burned approximately
2,767 acres of forested stands. These areas
were important to species such as black bear,
goshawk, flamulated owl, bats, and many
other types of cavity nesting birds. The long
period in which it will take for this habitat to
reestablish will have an adverse effect to forest
dependent species. The Waterfall Fire
burned nearly all of the winter range and significantly
impacted the summer range for the
Carson River mule deer herd. Damage to the
winter range amounted to the loss of important
bitterbrush, sagebrush, sagebrush/perennial
grass, and Sierra mountain shrub foraging
habitats. Loss of these vegetation types
has created a forage deficit on the winter
range. Damage to summer range amounted to
the loss of over story cover, hiding cover, and
forage with the removal of almost all brush
and shrubs and a substantial portion of the
over story trees. There is long-term loss of
deer winter range and other wildlife habitats
in the Waterfall Fire area through type conversion
to a non-native cheatgrass and/or
other noxious weed dominated vegetation
type. This can alter the fire cycle such that
some shrub/brush habitats may not return.
Invasive weed threat: There are several
non-native undesirable and noxious weed
species that were present pre-fire. Many of
these have a high post-fire expansion and
colonization probability. Seeding will be
important to aid in the control of these
species as well as using herbicide treatment
where needed.
Species Postfire Threat Potential
Cheatgrass - Bromus tectorum . . . . . . . . . . . . very high
Medusahead Taeniatherum caput-medusae . . . . . .high
Hoary cress Cardaria draba . . . . . . . . . . . . . . . . . . .high
Canada thistle - Cirsium arvense . . . . . . . . . . . moderate
Tall whitetop - Lepidium latifolium . . . . . . . . . . .moderate
Russian-thistle - Salsola kali . . . . . . . . . . . . . . . . . . . high
Yellow starthistle -Centaurea solstitialis . . . . . . . . . . high
Annual ragweed -Ambrosia artemisiifolia . . . . . . . . .high
The location of the noxious weeds are both on
Forest System Lands and City and Private.
They are almost all along travel routes leading
to the National Forest. Cheatgrass is present
in varying amounts on all lands. Return
and expansion of cheat grass into much of the
burned area is expected to occur from 6300 ft.
and below into the urban interface. This
threat is real, known, and apparent, not speculative.
Mountain big sage habitats throughout
the west have experienced a significant
impact from this invasion. Prior to human settlement,
the typical fire regime was 12-25
years, with the advance of cheatgrass, the
potential of increased fire intervals is eminent.
Due to the change in plant structure and
fuel loads, fires often burn much hotter. These
more intense fires can promote the invasion
of exotics, most commonly cheat grass. In
turn, the fire regime shortens to every few
years which places this urban interface at
great risk.
Because cheatgrass has very weak root
systems, erosion potential will remain high if
not reseeded with other species, and in some
cases, a non-native such as crested wheat has
been recommended. At elevations below
6300 feet, cheat grass can begin to out-compete
native shrubs and perennial grasses.
Following fire, soil nutrient conditions are
more favorable towards noxious weeds and
invasive species thus promoting their introduction over native plant species. Therefore,
in the case of sagebrush and bitterbrush habitats,
fire has increased these areas susceptibility
to invasion by cheat grass and other noxious
weeds.
Fuels: The Waterfall Fire destroyed a
significant amount of the forest cover. Rarely
was the fire intense enough to consume significant
amounts of the woody portions of
killed trees. If not removed from the watersheds
these trees will add a large volume of
dead fuel to the landscape over the next 5 to10 years. This issue is most critical around
the urban interface, but will be watershedwide
as well. Selected fire-killed trees that
should be removed around the burned
perimeters of the Lakeview and Timberline
subdivisions, and on the west side of those
homes located at the mouth of North Kings
Canyon.
This information was submitted by the BEAR Team and Genny
Wilson, U.S. Forest Service Team Leader,
and has been summarized by Juan F. Guzman,
Carson City Open Space Manager.
For a complete copy of this report on CD, please contact the City Manager's Office at 887-2100.
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