Las Conchas Burned Area Report 7-29-11
Incident: Las Conchas Burned Area Emergency Respon Burned Area Emergency Rehabilitation
Released: 8/15/2011
Date of Report: 07/29/2011
BURNED-AREA REPORT
(Reference FSH 2509.13)
PART I - TYPE OF REQUEST
A. Type of Report
[X ] 1. Funding request for estimated emergency stabilization funds
[ ] 2. Accomplishment Report
[ ] 3. No Treatment Recommendation
B. Type of Action
[] 1. Initial Request (Best estimate of funds needed to complete eligible stabilization measures)
[X ] 2. Interim Report # 4 . Changes are noted in blue.
[ ] Updating the initial funding request based on more accurate site data or design analysis
[ ] Status of accomplishments to date
[ ] 3. Final Report (Following completion of work)
PART II - BURNED-AREA DESCRIPTION
A. Fire Name: Las Conchas Fire B. Fire Number: NM-N6S-000451
C. State: NM D. County: Sandoval, Los Alamos, Rio Arriba
E. Region: 3 F. Forest: Santa Fe
G. District: Jemez/Espanola/Coyote RDs H. Fire Incident Job Code: PNF5PS
I. Date Fire Started: June 26, 2011 J. Date Fire Contained: unknown at this time
K. Suppression Cost: $40.9M (as of 7/16/2011)
L. Fire Suppression Damages Repaired with Suppression Funds
1. Fireline waterbarred and slashed (miles): ongoing at this time
2. Fireline seeded (miles): ongoing at this time
3. Other (identify): n/a
M. Watershed Number:
N. Total Acres Burned: 156,590 acres (from 7/20/2011 infrared)
Acres
%
BIA - Jemez
2,842
1.9%
BIA - Santa Clara
16,609
11.0%
BIA - Santo Domingo
63
0.0%
County - Los Alamos
44
0.0%
Dept of Energy
118
0.1%
National Park Service
20,817
13.8%
Private or Other
5,033
3.3%
USFS - SFNF- Coyote
22
0.0%
USFS - SFNF- Espanola
27,220
18.1%
USFS - SFNF- Jemez
50,023
33.2%
Valles Caldera National Preserve
27,837
18.5%
as of 7/15/11
150,628
Total administered by the Santa Fe National Forest - 51%
O. Vegetation Types: Pinyon/Juniper, Ponderosa Pine, Mixed Conifer
P. Dominant Soils: Mollic Eutroboralfs/Andic Ustochrepts/Typic Ustorthents, viltrandic hapludalfs, viltrandic eutrocryepts, pachic argiustolls
Q. Geologic Types: Rhyolite/andesite/pumice/tuff/basalt
R. Miles of Stream Channels by Order or Class: Ephemeral/Intermittent - 272, Perennial - 110
S. Transportation System
Trails (miles): 100
Roads (miles): Level 1 - 117, Level 2 - 154, Level 3 - 56
PART III - WATERSHED CONDITION
A. Burn Severity (acres):
Low - 43,450
Moderate - 39, 910
High - 28,470
Unburned - 17,950
No data - 19,620
B. Water-Repellent Soil (acres): 35,000
C. Soil Erosion Hazard Rating (acres):
Low - 75,080 Moderate - 37, 490 Severe - 33,807
D. Erosion Potential: 14 tons/acre
E. Sediment Potential: 972 cubic yards / square mile
PART IV - HYDROLOGIC DESIGN FACTORS
A. Estimated Vegetative Recovery Period, (years): 5
B. Design Chance of Success, (percent): 20 - 90
C. Equivalent Design Recurrence Interval, (years): 25
D. Design Storm Duration, (hours): 1
E. Design Storm Magnitude, (inches): 1.7"
F. Design Flow, (cubic feet / second/ square mile): 100
G. Estimated Reduction in Infiltration, (percent): 20
H. Adjusted Design Flow, (cfs per square mile): approximately 700
PART V - SUMMARY OF ANALYSIS
A. Describe Critical Values/Resources and Threats (narrative):
The Las Conchas fire began on June 26, 2011 as the result of a windthrown tree striking and shorting out a powerline. The burned area is located southwest, west, north and northwest of the town of Los Alamos, NM. The burned area is on National Forest System lands managed by the Jemez, Espanola, and Coyote Ranger Districts of the Santa Fe National Forest, Jemez Pueblo, Santa Domingo Pueblo, and Santa Clara Pueblo lands, Bandelier National Monument, Valles Caldera National Preserve lands, Department of Energy lands, as well as numerous tracts of private lands.
Slopes within the burned area are predominantly moderately steep-to-steep, with lesser amounts of flat mesas. The tuff and pumice derived soils are productive but have very high erosion potentials due to low bulk density of extrusive volcanic parent material. Many channels have not experienced high flows in many years and consequently have large amounts of stored sediments that could entrain easily under peak flows.
Burn severity mapping for the Las Conchas burned area was done using an initial BARC map obtained from RSAC from a Landsat image on July 3, 2011 and a spot image on July 5, 2011. Field verification and assessment of the BARC image was done.
Please see Appendix A for an executive summary on the resources and threats.
Critical Values Identified
Critical Values identified (FSM 2523.1 Exhibit 01) during the Las Conchas BAER assesment are:
·1. Human Life and Safety,
·2. Property,
·3. Cultural Resources, and
·4. Natural Resources.
The Las Conchas BAER team evaluated the risk to those critical values per FSM 2523.1 Exhibit 02.
The risk matrix (below), Exhibit 2 of Interim Directive 2520-2010-1 was used to evaluate the Risk Level for each value at risk identified during Assessment:
Probability of Damage or Loss
Magnitude of Consequences
Major
Moderate
Minor
Loss of life or injury to humans; substantial property damage; irreversible damage to critical natural or cultural resources.
- Injury or illness to humans; moderate property damage; damage to critical natural or cultural resources resulting in considerable or long term effects
Property damage is limited in economic value and/or to few investments; damage to natural or cultural resources resulting in minimal, recoverable or localized effects
RISK
Very Likely
(>90%)
Very High
Very High
Low
Likely
(>50% to 10% to
