1 Trinity County Collaborative Group - From Fire Kill to Fuelbreaks - Mad River Complex Fire Salvage Project Geology Summary - prepared by: Fred S. Levitan, Six Rivers National Forest Geologist May 20, 2016 Mad River Complex Fires The fires of the Mad River Complex were ignited by lightning storms on July 30-31, 2015, and burned until contained in late August and early September, 2015. In general, the most intense burning occurred during the first few days of the fires, largely on ridgetops, with lower fire intensities occurring as the fires spread downslope, with some exceptions in later active burning periods. Fire spread from the crest of South Fork Mountain (Pickett Fire), Mad River Ridge (Gobbler Fire), and the Lassics (Lassic Fire), making up in the Mad River Complex fires. The fires as they spread affected watersheds including the South Fork Trinity River, the Mad River and Ruth Lake, and the Van Duzen River and many tributary streams. The Pickett Fire burned portions of both the Six Rivers and Shasta-Trinity National Forests and adjacent private lands; the other fires in the complexes were restricted to the Six Rivers National Forest and adjacent private lands. The current project addresses portions of the burned areas of the Pickett and Lassics Fires on the Six Rivers National Forest (SRNF). Project Background and Proposed Action The project described and analyzed here is a collaborative project between the SRNF and a group of stakeholders known as the Trinity County Collaborative Group (TCCG). Its objective is cost-effective removal of roadside, post-fire standing dead tree fuel concentrations that impede roadside safety corridor objectives, as a first step toward a larger network of roadside fuelbreaks creating safety corridors for community and resource protection. It has been agreed that the present project will avoid sensitive resource areas prone to additional post-fire damage. Specific to geologic resources and potential impacts to water quality, this includes avoidance of project activities on unstable and potentially unstable hillslopes. The proposed project addresses salvage of dead timber only, on up to 205 acres adjacent to roads in the Pickett Fire on the crest of South Fork Mountain and the Lassics Fire east of the Mount Lassic Wilderness and south of the high Lassics peaks. Dead trees would be felled and yarded by ground-based means within a maximum 300-foot wide roadside corridor, as described in the Decision Memo (DM). No new roads would be constructed, and any new temporary roads and landings would be rehabilitated post- project. A robust suite of design features, best management practices and monitoring provisions would be followed to ensure erosion control and to prevent on- and off-site effects to sensitive resources, including geologically unstable areas and water quality, as detailed below. Geologic and Geomorphic Setting The burned area includes bedrock of a variety of lithologies of the Coast Range geologic and geomorphic province of northern California. The Pickett Fire burned area is underlain by the South Fork Mountain Schist and Franciscan assemblage rocks, while the Lassics Fire area consists of Franciscan rocks and an outlier of the Coast Range ophiolite associated with the Great Valley Formation, the bulk of which is located in the easternmost Coast Ranges and westernmost Sacramento Valley (McLaughlin et al, 2000). All of these formations are susceptible to slope instability, with a variety of dormant and active deep-
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Trinity County Collaborative Group - From Fire Kill to Fuelbreaks - Mad River Complex Fire Salvage Project
Geology Summary - prepared by: Fred S. Levitan, Six Rivers National Forest Geologist
May 20, 2016
Mad River Complex Fires
The fires of the Mad River Complex were ignited by lightning storms on July 30-31, 2015, and burned
until contained in late August and early September, 2015. In general, the most intense burning occurred
during the first few days of the fires, largely on ridgetops, with lower fire intensities occurring as the
fires spread downslope, with some exceptions in later active burning periods. Fire spread from the crest
of South Fork Mountain (Pickett Fire), Mad River Ridge (Gobbler Fire), and the Lassics (Lassic Fire),
making up in the Mad River Complex fires. The fires as they spread affected watersheds including the
South Fork Trinity River, the Mad River and Ruth Lake, and the Van Duzen River and many tributary
streams. The Pickett Fire burned portions of both the Six Rivers and Shasta-Trinity National Forests and
adjacent private lands; the other fires in the complexes were restricted to the Six Rivers National Forest
and adjacent private lands. The current project addresses portions of the burned areas of the Pickett
and Lassics Fires on the Six Rivers National Forest (SRNF).
Project Background and Proposed Action
The project described and analyzed here is a collaborative project between the SRNF and a group of
stakeholders known as the Trinity County Collaborative Group (TCCG). Its objective is cost-effective
removal of roadside, post-fire standing dead tree fuel concentrations that impede roadside safety
corridor objectives, as a first step toward a larger network of roadside fuelbreaks creating safety
corridors for community and resource protection. It has been agreed that the present project will avoid
sensitive resource areas prone to additional post-fire damage. Specific to geologic resources and
potential impacts to water quality, this includes avoidance of project activities on unstable and
potentially unstable hillslopes.
The proposed project addresses salvage of dead timber only, on up to 205 acres adjacent to roads in the
Pickett Fire on the crest of South Fork Mountain and the Lassics Fire east of the Mount Lassic Wilderness
and south of the high Lassics peaks. Dead trees would be felled and yarded by ground-based means
within a maximum 300-foot wide roadside corridor, as described in the Decision Memo (DM). No new
roads would be constructed, and any new temporary roads and landings would be rehabilitated post-
project. A robust suite of design features, best management practices and monitoring provisions would
be followed to ensure erosion control and to prevent on- and off-site effects to sensitive resources,
including geologically unstable areas and water quality, as detailed below.
Geologic and Geomorphic Setting
The burned area includes bedrock of a variety of lithologies of the Coast Range geologic and geomorphic
province of northern California. The Pickett Fire burned area is underlain by the South Fork Mountain
Schist and Franciscan assemblage rocks, while the Lassics Fire area consists of Franciscan rocks and an
outlier of the Coast Range ophiolite associated with the Great Valley Formation, the bulk of which is
located in the easternmost Coast Ranges and westernmost Sacramento Valley (McLaughlin et al, 2000).
All of these formations are susceptible to slope instability, with a variety of dormant and active deep-
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seated and shallow landslide features present. The Franciscan formation is pervasively sheared and
stratigraphically incoherent; with basic lithologies of sandstone and argillaceous materials
predominating. The South Fork Mountain Schist is highly foliated quartz mica schist, with structure
dipping parallel to the eastern slope of the mountain, supporting ubiquitous deep-seated landslide
complexes and perched groundwater. The schist is the tectonic sole of the Farallon Plate that was
subducted and sutured to North America in an accretionary event that began in the late Jurassic; the
Franciscan represents the subduction complex associated with that event (Dumitru et al, 2010). The
Lassics contain numerous outcrops of ultramafic rocks of the ophiolite sequence, and support unique
and rare plant communities adapted to harsh serpentine environments.
A number of large landslide features as well as many smaller features are present on the landscape.
Notably, the Mule Slide is a very large debris slide complex that occupies the eastern slope of the ridge
crest traversed by Roads 1S07 and 1S11, in the immediate vicinity of the proposed Lassics units.
Numerous smaller debris slides are present below the crest slope breaks of the major Lassics ridgelines
as well. Large deep-seated landslide complexes are prevalent in the Pickett Fire area and occupy much
of the western slope downslope of the proposed Pickett units. These and other features are discussed
further in the Field Observations section below.
Fire Effects and Slope Stability Concerns
The unstable geomorphology of the area is susceptible to accelerated slope instability, erosion and
sediment delivery as a consequence of fire effects to soil and vegetation. Possible mechanisms of
increased erosion and landsliding include: 1) increased surface erosion and delivery of sediment as well
as increased channel scour due to loss of soil strength and increased post-fire peak flows from burned
watersheds; 2) increased probability of shallow debris sliding along channels and inner gorges where
banks and toe slopes are susceptible to erosion from higher flood flows; 3) channelized debris flows
from burned areas with loss of soil cover and structure, reduced root strength and increased sediment
delivery to channels; and 4) reactivation of deep-seated landslides, potentially related to loss of
evapotranspiration and associated elevated groundwater following tree mortality from fire (Mikulovsky
et al, 2012; Levitan 2014).
During the Burned Area Emergency Response (BAER) assessment of the Mad River Complex (USDA
Forest Service BAER Team, 2015), a distributed debris flow model developed (Cannon et al 2010) and
run by the USGS was used to help evaluate the risk of post-fire debris flows. Debris flows are shallow
rapid failures that occur when sediment or unconsolidated geologic materials become saturated and fail
in a channelized system, presenting threats of impact and inundation to downstream resources. Debris
flows often initiate in denuded post-fire landscapes, although their prevalence in post-fire environments
of the Pacific Northwest is less evident than in more arid areas of the Intermountain West where intense
summer thunderstorms often initiate debris flow events. Notwithstanding that, the model was run to
assess whether there was increased debris flow potential in fire-affected drainages within the Mad River
Complex. A number of watersheds and channel segments with potentially elevated debris flow risk were
identified and described in the BAER reports. To date, despite the wet winter of 2015-2016, no debris
flows have been reported in the burned areas. There has been considerable small-scale erosion and
sedimentation in the burned areas, including slumping and sliding of road cutslopes and rilling of
hydrophobic soils. Significant landsliding has not been observed to date, but remains a concern as
burned areas and vegetation slowly recover from fire effects.
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Field Observations
Geologic reconnaissance of the project area was conducted several times between November 2015 and
April 2016 as the project was developed. The focus of the field effort was to identify active and
potentially unstable areas and exclude them from the units. As described below in the Regulatory
Framework section, unstable and potentially unstable areas area are defined as Riparian Reserves under
the Northwest Forest Plan (NWFP) and the SRNF Land and Resource Management Plan (LRMP). Among
the collaborative zones of agreement underlying the project, as outlined in the DM, is avoidance of
Riparian Reserves and geologically unstable areas. Furthermore, as described below in the Project
Design Features and Monitoring sections, project planning and implementation are focused on
minimizing to the greatest extent possible damaging effects to fire-affected resources including soil and
water quality. Consequently, field identification of unstable areas included assessment of potential
offsite effects to adjacent landslide-prone hillslopes, and suggestions to project planners to adjust unit
boundaries and prescriptions to avoid promoting slope failures. Following is a unit-by-unit description of
field observations, concerns, and any adjustments made pursuant to field review.
Lassics Units (counterclockwise, east to west) The Lassics units are located in ridgetop positions
in a roughly circular arc encompassing the headwaters of the West Fork Van Duzen River,
following roads 1S11, 1S07, and 2S08 and spur roads that intersect those arterial roads. Bedrock
geology is Franciscan Formation (Central Belt and Yolla Bolly terrane), with a mix of sedimentary
rock types dominated by graywacke sandstone and lesser proportions of argillite and shale. Few
areas of highly sheared mélange are present, and no areas of serpentinite or other ultramafic
lithologies occur within the project units.
Unit 3 - Roads 1S11, 1S11G - 8 acres - The unit is located on either side of Road 1S11 and
extends east across Road 1S11G at its southeast corner. It occupies a broad, gentle ridge crest
with rocky, apparently colluvial soils dominant. The margins of the units are steeper and show
signs of soil creep (pistol-butted trees). A minor landslide area was excluded on the northeast
side of the unit – interpretation is based on a <2 foot high active scarp and an apparent deposit
lobe in a swale. The northwest portion of the unit west of Road 1S11 sits above a large grassy
earthflow, and the unit boundary appears to cross the uppermost portion of the earthflow
scarp. There are is no evidence of recent activity on the scarp, so it was not designated as active
or unstable. The unit appears to present no threats to slope stability, but should be monitored
post-treatment, and any unfavorable project-created drainage issues corrected at that time.
Unit 91A - Road 1S11 - 39 acres - The unit is located on either side of Road 1S11, just north of
Unit 3, on the eastern slopes of Green Mountain. Steep slopes at the head of landslide
complexes are present east (downslope) of the road. The unit is dissected by a number of
drainages descending the east slopes of Green Mountain.
An area at the head of a landslide, with nested benches and scarps, was flagged out at the
northeast corner of the unit. This unit is for future (2017) harvest, following additional post-
fire tree mortality. Consequently, it was not fully evaluated in 2016. Prior to future entry and
unit designation, the unit will be assessed for slope stability concerns, and any unstable areas
will be excluded.
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Unit 91 - Road 1S11 - 1 acre - This small unit is located immediately northeast of Road 1S11 on
the northeast slopes of Green Mountain. It occupies mostly gentle topography, with a steeper
pitch toward the northeast corner. No immediate slope stability concerns were noted. This unit
is for future (2017) harvest, following additional post-fire tree mortality. Consequently, it was
not fully evaluated in 2016. Prior to future entry and unit designation, the unit will be
assessed for slope stability concerns, and any unstable areas will be excluded.
Unit 92 - Road 1S11 - 10 acres - This unit is mostly below (north of) Road 1S11 on the northern
slopes of Green Mountain, west of Unit 91. It is similar to Unit 91a in that it is dissected by a
number of stream channels. Portions below the road are steep, but no immediate slope stability
concerns were noted. This unit is for future (2017) harvest, following additional post-fire tree
mortality. Consequently, it was not fully evaluated in 2016. Prior to future entry and unit
designation, the unit will be assessed for slope stability concerns, and any unstable areas will
be excluded.
Unit 2A - Road 1S11 - 3 acres – This unit is mostly above (south of) Road 1S11, straddling the
ridgeline, with a smaller area north of (below) the road. Colluvial slopes are prevalent, with
steep road-cuts and through-cuts subject to ravel and rilling. Landslide hazard is low, but care
will need to be taken not to destabilize cutslopes during yarding.
Unit 2 - Road 1S11 -12 acres - This unit is on both sides of Road 1S11, north of the Mule Slide
and immediately east of the junction with Road 1S07. The southern portion of the unit, above
the road, approached the ridge that defines the drainage divide at the head of the Mule Slide,
but does not cross the ridgeline to the landslide area. A portion of the unit that had been
proposed on benched slopes above the slide was eliminated based on the geologist’s
recommendation. The head of an unstable area in a swale downslope (north) of the road at the
west end of the unit was also flagged by the geologist and excluded from the unit. The
remaining unit area occupies colluvial slopes, which are moderate above the road and very
steep (70-80%) below the road (to the north). These steep slopes are very rocky, and show no
signs of instability. Steep road-cuts and through-cuts are subject to ravel and rilling. Landslide
hazard is low, but care will need to be taken not to destabilize cutslopes during yarding.
Unit 1c - Road 1S07 - 6 acres - This unit is mostly west of Road 1S07, south of the junction with
Road 1S11. It occupies a gently rolling ridgetop knoll. The ground is hummocky but shows no
signs of slope instability. A portion of the unit that had been proposed east of the road was
judged unstable and eliminated during early project planning based on the geologist’s
recommendation. A few hundred feet west of the unit, below a steep slope break, there is a
substantial debris slide complex. Unit treatments should have no effect on this feature;
however, it may experience increased activity related to post-fire conditions.
Unit 6 - Road 2S34 - 9 acres – This unit is on either side of Road 2S34, just southeast of Road
1S07 and south of Unit 1c. It is similar to Unit 1C in occupying a gentle rolling ridge crest, with no
slope stability concerns. A gate near the north end of the unit marks a transition to steeper,
concave slopes with debris slide potential – these were excluded from the unit. Steep road-cuts
are subject to ravel and rilling. Landslide hazard is low, but care will need to be taken not to
destabilize cutslopes during yarding.
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Unit 4 - Road 1S07 - 5 acres - This unit is east of Road 1S07 and about 0.5 miles south of Unit 6.
It mostly occupies a flat to gently convex ridge crest area with no slope stability concerns,
although there is a small steeper area in the axis of a swale at the southeast corner of the unit.
This is the only area of concern with this unit. The unit boundary at the southeast corner is
immediately upslope of an active slide scarp, associated with a landslide feature that occupies
the swale downslope of the unit. Care will need to be exercised in assuring that log skidding
does not create additional drainage onto the slide. Recontouring of any gouges or trenches
created by yarding will be necessary to mitigate this concern.
Unit F80 - Road 1S07 - 12 acres - This unit is located east (downslope) of Road 1S07, north of the
junction with Road 2S08. This unit is designated a commercial firewood unit (not saw logs). The
firewood purchaser would be bound to the same project design features and mitigations that
the timber sale contractor would be, including avoiding operations in Riparian Reserves,
following all BMPs, and mitigating/repairing damage that might contribute to slope instability.
The unit is very steep. The northern portion appears colluvial but stable. The southern portion,
south of the junction with Road 2S33 and due north of the junction with Road 2S08, includes
concave slopes in stream headwaters that appear to have some risk of instability. As the stream
corridor Riparian Reserves are excluded from harvest per the project guidelines, these concerns
should be mitigated.
Unit 1B - Road 2S36 - 11 acres – This unit is located above southeast) of Road 2S36, immediately
southeast of Unit F80 and the junction of Road 1S07 and 2S08. The western portion of the unit is
gently convex, while the eastern portion occupies moderately steep, very rocky slopes. No
landslide activity is evident.
Unit 1A – Road 2S36 – 5 acres – This unit is located approximately 1,000 feet northeast of Unit
1B on Road 2S36, above (south of) the road. The unit occupies a convex, moderately sloping
ridge spur. No landslide activity was observed.
Unit 5 - Road 2S20 - 22 acres - This unit is located on both sides of Road 2S20 where it descends
a series of switchbacks traversing a broad ridge spur to the northeast. Near the gate on 2S20,
approximately 400 feet north of the junction with Road 2S08, colluvium from the fill slope has
blocked the inboard ditch and diverted spring flow onto the road surface in two locations,
saturating the road surface. Immediately downslope of fill slope, an approximately two-foot
high active scarp is present, above a hummocky hillslope that appears unstable. Because of this
unstable slope, it is NOT recommended to dip and drain the spring at the road onto the hillslope
at this location. Rather, because this site needs repair prior to project implementation to
provide a stable road surface, ditch cleaning and spot rock is recommended. This location should
be monitored and evaluated for a long-term solution (Decommissioning? Road reconstruction
with drainage and stabilization measures incorporated into the design?)
The unit itself is generally moderately steep, with slightly hummocky ground in a mix of convex
and concave slopes. Some colluvial activity was observed (pistol-butted trees), but no signs of
more pervasive landsliding or slope instability were observed within the unit. North of the unit is
a steep concave headwall that descends into a drainage – this is outside the unit and below the
road, which is the unit boundary. Proposed activities should not negatively affect slope stability.
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Unit 90 - Road 2S24 - 8 acres - This unit is located above (on the north side of) Road 2S24, in the
Summit Flats area about 0.5 miles northeast of the junction with Road 2S08. The unit occupies
gentle to moderate sideslopes with no signs of slope instability.
Unit 90a - Road 2S24 - 18 acres – This unit overlaps Unit 90, but is on both sides of the road and
extends roughly 1,500 feet further to the northeast. It is located on moderate, slightly concave
sideslopes undissected by drainages. No signs of slope instability were seen. This unit is for
future (2017) harvest, following additional post-fire tree mortality. Consequently, it was not
fully evaluated in 2016. Prior to future entry and unit designation, the unit will be re-assessed
for slope stability concerns, and any unstable areas will be excluded.
Pickett Units - The Pickett units are located on and near the ridgetop of South Fork Mountain off
Road 1S23 south of its junction with Highway 36, and on Road 1S41 on the west slope of South
Fork Mountain. Bedrock is South Fork Mountain Schist, with some massive metavolcanic
outcrops present near the ridgetop. The contact with Franciscan rocks (metasandstone and
metashale) is at the base of unit 37.
Unit 32 - Roads 1S23 and 1S41 - 9 acres - This unit is located on the downslope side (southwest)
of Road 1S23, approximately 2.5 road miles south of the junction with Highway 36. Road 1S41
joins Road 1S23 in the southern half of the unit. The upper portion of the unit occupies the
convex ridge crest of South Fork Mountain, and no slope stability concerns were observed there.
The western portions of the unit quickly drop off to steep, rocky slopes above concave
headwalls. These slopes were evaluated in the field, and suspected landslide-prone portions of
concave headwalls were excluded as the unit was laid out on the geologist’s recommendation.
The remaining steep slopes within the unit are subject to post-fire rill and sheet erosion and dry
ravel on denuded, hydrophobic soils. An especially sensitive area between Roads 1S23 and
1S41, within the unit, will require careful post-project monitoring and erosion control
implementation to reduce the risk of sediment delivery and drainage diversion on Road 1S41.
Immediately downslope of Unit 32, an old non-system road crosses a steep headwall slope and
two swales. The northern of the two sites is immediately upslope of a channel head. Both
crossings are eroding and failing, and are in need of repair (fill removal). If sale area
improvement (K-V) funds are available, this would be a good application for those.
Unit 33 - Road 1S23 - 6 acres - This unit is located on the downslope side (southwest) of Road
1S23, approximately 2,000 south of Unit 32. It also occupies gently convex ridgetop slopes and
steeper slopes on the west side of South Fork Mountain. These steeper slopes are generally very
rocky, with no evident slope stability concerns. Some areas of unconsolidated colluvial soils are
present, and may require care to prevent and control erosion from skid trails, log skidding paths,
etc. Landing access may require disturbing steep cutslopes on road 1S23, which will likewise
require monitoring and erosion control to prevent sediment delivery and progressive cutslope
failure.
Unit 34 - Road 1S23 - 10 acres - This unit is located on the downslope side (southwest) of Road
1S23, immediately south of Unit 33. It also occupies gently convex ridgetop slopes and steeper
slopes on the west side of South Fork Mountain. In the southern portion of the unit, these
slopes are moderately steep (20-30%) and may be tractor harvestable. The northern portion of
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the unit is located in a steep, rocky concave headwall, with numerous rock outcrops and cliff
bands. No landslide concerns were observed, but colluvial sliding of rock and soil in the steep
headwall is likely. Erosion control will need to be implemented where log skidding occurs on
unconsolidated colluvial slopes.
Unit 37 - Road 1S41 - 11 acres – This unit is located on Road 1S41, between descending
switchbacks, on the west slope of South Fork Mountain, approximately one road mile southwest
of Unit 32. Slopes are moderately steep, with no landslide concerns observed within the unit.
There are some areas of concern for slope stability and sediment delivery immediately adjacent
to the unit, however. At the southeast corner of the unit, there is an unstable swale immediately
upslope of the road which has been designated as a legacy sediment source for repair. The
swale incorporates the toe of an earthflow that appears to be associated with a shear zone.
Unstable drainage, which is not captured in the existing channel and culvert, has eroded a gully
across the road. Due the unpredictable instability of the drainage and the hillslope feature, the
best repair solution would appear to be to disperse drainage with coarse rock across the
roadbed and through the switchback below.
Spur road 1S41A, due north of the diverted swale, is experiencing fill failure directly into a
stream channel. Repair would consist of pulling back the roadfill and disposing of it in a stable
location, either against the cutslope or in a berm to block the road entrance. This would be a
good application of sale area improvement funds (K-V), if they are available.
Regulatory Framework
As described in the DM, the following regulatory authorities apply to the project, specific to slope
stability and geologic concerns:
Six Rivers National Forest Land and Resource Management Plan (LRMP):
Direction from the LRMP will be followed regarding geology and unstable areas, including standards and
guides for 1) Riparian Reserves – through avoidance of all unstable riparian reserves and mitigation of
off-site effects, as described above; 2) General Forest – through design features to maintain site
productivity and to implement all relevant BMPs as agreed to in the Management Agency Agreement
and the Waiver of Waste Discharge with the North Coast Water Board.; and 3) forest-wide standards
and guides as listed below:
1-6 The potential for increased mass movement and soil erosion will be addressed for proposed
timber harvest and road building. Landslide hazard maps and a risk assessment should be
developed for timber harvest planning. Alternate road specifications or road locations should be
evaluated where proposed management would increase the potential for mass movement and
soil erosion. (LRMP IV-71).
1-7 Roads, landings, and timber harvest units will be located and designed to avoid triggering or
accelerating mass movements that would adversely affect a stream or degrade a commercial
growing site by removing a substantial volume of topsoil. (LRMP IV-71).
Aquatic Conservation Strategy (Northwest Forest Plan and Six Rivers NF LRMP): The action was designed
to meet the Aquatic Conservation Strategy including: all activities staying outside the riparian reserves,
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project design features to minimize erosion and best management practices for protecting water
quality. The project meets the aquatic conservation strategy.
Clean Water Act. The project will be conducted in accordance with requirements of the Regional Water
Quality Control Board, North Coast Region, to ensure compliance with the California Water Code and
the Federal Clean Water Act and Porter-Cologne Water Quality Control Act. All streams will be managed
in full compliance with the Aquatic Conservation Strategy and Basin Plan to achieve water quality goals
and objectives. The Forest Service will comply with this Act through the use of BMPs to ensure
protection of soil and water resources, as well as an approved monitoring plan under the terms of the
North Coast Regional Water Quality Control Board (NCRWQCB) the Categorical Waiver for Discharges
Related to Timber Harvest Activities on Federal Lands Managed by the United States Department of
Agriculture, Forest Service (Order No. R1-2015-0021), as described in the DM.
Effects Analysis, No Extraordinary Circumstances
The project was designed to eliminate or minimize to the greatest degree possible, negative effects to
resources, including water quality and erosion concerns associated with slope instability. Units were
reviewed ensure that unstable areas were excluded; project areas that might contribute to off-site
erosion or instability have been designated for intensive monitoring and erosion control measures.
Special consideration has been given to the sensitivity of soils and geologic features to disturbance in
the post-fire environment, and appropriate design features, mitigations and monitoring have been
incorporated in the project to reduce any project effects to the minimum possible. Consequently, there
should be no significant effects, and no extraordinary circumstances, as a consequence of the proposed
project, specific to geologic resources and slope instability. Unavoidable post-fire effects may occur
within and outside of the project area related to the condition of the burned landscape, but not as a
consequence of project activities.
Project Design Features – Soils and Geology
The following project-specific design features, as described in the DM, will help assure that there will be
little or no project-related erosion, slope failure, and/or sediment delivery as a consequence of project
activities (see DM for a complete list of project design features and BMPs):
Ground Based Equipment and Landings
All landings required for operations are located outside of Riparian Reserves.
Where feasible use existing skid trails, except where existing skid trails from prior entry are or
will cause detrimental soil and hydrologic conditions that could be avoided. If new skids trails
are warranted; limit cumulative soil disturbance to 15 percent or less of the harvest unit area.
The timber sale contract will require erosion control treatments such as water barring on skid
trails and yarding corridors, particularly on moderate to steep slopes with erosive soils, prior to
extended wet weather operational shut down and immediately prior to acceptance per contract
provisions by subdivision (identified on sale area map).
Ground-based equipment will operate on relatively dry soils of high soil strength or bearing
capacity. For the majority of soil types affected in the project area, this is when soil is dry to the
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upper 4 inches depth of mineral soil. This may be waived upon site inspection and
determination by a Forest Service earth scientist.
If present, maintain a well-distributed soil cover of 50 percent on moderate slopes of less than
25 percent, and 60 to 70 percent cover on steeper slopes. Priority for placement of cover is
primary skid trails and winching locations, and shall be completed following each operating
season. Soil cover consists of unburned duff and needle cast, basal live plant cover, fine woody
debris, downed logs and rock.
All landings, skid trails and yarding (end-lining or winching logs) will be assessed in the field in
coordination with the sale administrator, prior to being accepted in compliance with contractual
provision to ensure soil mitigations measures achieve SRNF LRMP standards.
o If during skidding and yarding operations, gouges or gullies are inadvertently created,
acting to channel storm water run-off and delivery off-site to unstable or potentially-
unstable areas, the timber sale contract provisions will require the operator to construct
water-bars, and may be required to place slash material to remedy resource impacts if
necessary. If the Forest Service earth scientist indicates these provisions are insufficient,
slopes may be re-contoured to their pre-operation conditions. Additional manual
placement of fine slash (duff and needle cast), realignment of downed trees (log
contouring), and back-blading debris where soils are barren may be required. These
activities will implemented and funded either by agency personnel, via an agreement or
an independent service contract.
o Prior to contract acceptance, landings should be out-sloped to avoid puddling and drain
storm water run-off. Slash in excess of other resource needs will be scattered. If
feasible, desired soil cover is 50 percent or more on moderate slopes of less than 25
percent, and 60 to 70 percent cover or more on steeper slopes. Material may consist of
either: slash, wood chips, or any combination.
o Skid trails, landings and landing access spurs that are located adjacent to Forest roads
will be blocked with available material (large wood or boulders) and may be mulched in
order to discourage unauthorized motorized vehicles access.
Roads (System and Temporary) including Landing Access Spurs
Existing temporary roads used for operations located within or adjacent to harvest units will be
closed post-operations, prior to winter wet weather shut-down. If a second entry is anticipated
2017-2018, all temporary roads and landing access spurs will be winterized with erosion control
measures installed at the end of the operating season.
Tree felling operations and yarding of logs over unstable cut- or fillslopes, will be avoided to the
extent possible. If damage does result from project activities, and material deposited within the
road prism, it would be removed and placed in a stable location.
Erosion control measures such as waterbarring, recontouring or slash material placement will be
performed to mitigate these impacts. An earth scientist would oversee repairs as needed.
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Riparian Reserves
No project activities shall occur within designated Riparian Reserves. These include tree felling,
tree removal, landings and heavy equipment. Exceptions include log haul on system roads, and
trees determined to be a safety hazard to operations.
Limit heavy equipment disturbance within 20 feet on either side of swales (defined as a sloping
concave feature with no existing channel scour present) by avoiding equipment use upslope of
their axes, and minimizing equipment crossings except where approved by the Forest Service.
Best Management Practices
Implement Water Quality BMPs and include monitoring as described below.
Apply appropriate BMPs, either National or Regional, associated with all project activities, including
timber harvest and road activities and development.
The following BMPs from the Region 5 Regional Water Quality Management Handbook and/or the USDA
Forest Service National Core BMPs will apply to soil and water-quality protections and protection of
unstable or potentially unstable areas within or adjacent to harvest units. The practices that provide the
greatest water quality and soil productivity protections will be selected from one or the other BMP
guidance document.
These BMPs will be identified on the ground and recorded on a by-unit, site-specific basis. Best
Management Practice sites will be subject to 100 percent implementation monitoring post-harvest, by
means of a checklist and harvest maps and cards (standard waiver provision), and to 100 percent
effectiveness monitoring following one or more post-harvest winters (special provision for this project).
Effectiveness monitoring results, and any follow-up corrective measures taken, will be reported to the
Water Board by July 15th in the year following harvest. If areas are entered in a subsequent year to
harvest later dying trees, these same provisions and timetable will apply, based on the year of entry.
Effectiveness monitoring results will be scored and reported using the Regional BMPEP methodology.
Applicable Regional BMPs for soils/geology/slope stability:
1.1 Timber Sale Planning Process
1.2 Timber Harvest Unit Design
1.3 Determining Surface Erosion Hazard for Timber Harvest Unit Design
1.6 Protecting Unstable Lands
1.9 Determining Tractor-loggable Ground
1.10 Tractor Skidding Design
1.12 Log Landing Location
1.13 Erosion Prevention and Control Measures During Timber Sale Operations
1.14 Special Erosion-prevention Measures on Disturbed Land
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1.16 Log Landing Erosion Control
1.17 Erosion Control on Skid Trails
1.20 Erosion-control Structure Maintenance
1.21 Acceptance of Timber Sale Erosion-control Measures Before Sale Closure
2.30 Timing of Construction Activities
2.11 Control of Sidecast
2.22 Maintenance of Roads
Applicable National Core BMPs:
Veg-1 Vegetation Management Planning
Veg-2 Erosion Prevention and Control
Veg-3 Aquatic Management Zones
Veg-4 Ground-Based Skidding and Yarding Operations
Veg-6 Landings
Veg-8 Mechanical Site Treatment
Road-3 Road Construction and Reconstruction
Road-4 Road Operations and Maintenance
Road-5 Temporary Roads
Road-6 Road Storage and Decommissioning
Road-7 Stream Crossings
Road-9 Parking and Staging Areas
Road-10 Equipment Refueling and Servicing
Monitoring
The following monitoring guidelines will be followed, and accompanied by a detailed, site-specific
monitoring plan to ensure water quality waiver compliance and minimization of erosion, sediment
delivery and slope failure:
Soil Monitoring
Daily monitoring of haul routes, landings, and skid trails consisting of BMP forms or daily diaries will
document implementation and effectiveness of BMPs. Project activities will be curtailed and corrective
action taken when any of the following are encountered or expected:
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Erosion of Road Material
o Scour or sediment deposition evident and extending more than 20 feet below outlet
of cross drain.
o Scour or sediment movement into riparian reserve or drainage way from road
surface, cut slope, or fill slope.
Ruts/Rill
o More than 10% of road segment length has rills more than 2 inches deep and 20
feet in length that continue off road.
o Ruts formed that can channel water past erosion control structures.
o Numerous rills present at stream crossing (>1 rill per lineal 5 feet), apparently active
or enlarging, evidence of some sediment delivery to stream.
Culverts
o Sediments or debris is blocking 30% of inlet or outlet.
o More than 10% of the flow to pass beneath or around culvert, or noticeable piping
evident.
Skid Trails/ Harvest Areas
o More than 20% of skid trail or log skid path lengths have rills present that are over 2
inches deep and more than 10 feet in length. Log skid paths are channeling water
and/or sediment offsite or to sensitive or unstable areas.
o More than 10% of skid trail surface length has ruts greater than 2 inches deep.
o Rills or sediment deposition extends more than 20 feet below waterbar outlet.
o More than 10% of waterbars fail to divert flow off skid trails or cableways
o Sediment movement into a riparian reserve.
o Presence of gullies (erosional features greater than 4” deep and 6”wide).
Landings
o Rills (greater than ½” deep and 10’ in length) or sediment deposition has extended
more than 20 feet off of landing.
o More than 1 cubic yard of material (from erosion or slope failure) has moved into
riparian reserve.
BMP Implementation and Effectiveness Monitoring, Water Quality Monitoring
Follow an enhanced BMPEP monitoring plan. Track implementation of all BMPs through the timber sale
administration program, via sale administrator’s daily diaries (SF-181s) and the standardized BMP
