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Hydrology Report Lassen 15 Restoration Project
Nick J. Semenza Date: May/17/2017
Prepared by: Nick Semenza, Hydrologist, Modoc National Forest
1
Figure 1: Overview of the Lassen15 Restoration Project Area, including 7th field watersheds and California Regional
Water Quality Control Board boundaries
2
Purpose and Need for Action For the complete Purpose and Need for Action, refer to the Lassen 15 Restoration Project
Environmental Analysis.
Affected Environment The Lassen 15 Restoration Project analysis area is approximately 25,000 acres. The majority of
the project area is composed of ponderosa and Jeffrey pine dominated stands with scattered areas
of white fir and lodgepole pine. A large portion of the ponderosa/Jeffrey pine dominated stands
are plantations planted after a fire event impacted the area in the early 1940s.
The analysis area encompasses approximately 8,000 acres of proposed treatment, which includes
stream (weir) restoration, culvert replacement, modifications to roads and the Forest road system,
enhancement of natural and plantation stands, timber harvest, fuel reduction treatments, fuel
break maintenance and creation, and aspen enhancement. Forested treatment acres are composed
of ponderosa and Jeffery pine plantations and natural ponderosa pine and mixed conifer stands.
Both the old and young plantations in the analysis area are relatively even-aged stands with little
variability in forest structure, species diversity, size class or stocking level. The majority of
natural stands also exhibit high stocking levels and decreased growth and vigor. In addition,
portions of these stands have a high level of fuel loading. High fuel loads create a higher
mortality potential from wildfire.
Precipitation ranges from 20 – 38 inches per year with the higher precipitation in the elevations
of the south part of the project area and lower precipitation rates in the northern areas. The 2-year
6-hour rate is 1.00 – 1.50 inches. The 100-year-6-hour is double that of the 6-year at 2.00 – 3.00
except for the high elevations in the southwest portion of the project area where the 100-year rate
is 3.00 – 4.00 inches (PRISM 2001).
The project is located in the Surprise Valley and Goose Lake 4th field watersheds, the Upper
Alkali Lake and Willow Creek-Frontal Goose Lake 5th field watersheds, and the Soldier Creek-
Frontal Upper Alkali Lake, Goose Creek-Frontal Upper Alkali Lake, Ross Creek-Frontal Goose
Lake, Davis Creek-Frontal Goose Lake, Lassen Creek-Frontal Goose Lake and Willow Creek 6th
field watersheds. Sixth field (or HUC12) subwatersheds are nested within the larger 5th field (or
HUC10) watersheds. Fifth field watersheds are nested within 4th (or HUC8) field sub-basins.
Table 1 identifies the characteristics and existing beneficial uses for the effected watersheds.
Beneficial uses for the Surprise Valley sub-basin are designated by the Lahontan Regional Water
Quality Control Board and are listed in the Water Quality Control Plan for the Lahontan Region
(California 1995). Beneficial uses for the Goose Lake sub-basin are listed in The Water Quality
Control Plan (Basin Plan) for the California Regional Water Quality Control Board Central
Valley Region (California 2011). Soldier Creek-Frontal Upper Alkali Lake 6th field watershed is
included in Table 1 for beneficial uses analysis; however, no treatments are planned in the
watershed and, therefore, it is not included in cumulative watershed effects analysis. There are
3
no 303(d) listed waterbodies within or affected by the Lassen 15 restoration Project. Table 2
describes the criteria for stream classifications in Table 1 (USDA Forest Service 1991).
Table 1: Attributes of the watersheds effected by the Lassen 15 Restoration Project
4th Field Sub-basin
(Name/HUC#)
5th Field Watershed
(Name/HUC#)
6th Field Sub-watershed (Name/HUC#)
Stream Class1
Beneficial Uses (Existing) Acres
Surprise Valley 18080001
Upper Alkali Lake 1808000101
Soldier Creek-Frontal Upper Alkali Lake 180800010107
I
Water Contact; Recreation Noncontact Water Recreation; Commercial and Sportfishing; Inland Saline Water Habitat, Wildlife Habitat; Rare, Threatened, or Endangered Species2; Spawning, Reproduction, and Development
24,041
Goose Creek-Frontal Upper Alkali Lake 180800010108
I 23,060
Goose Lake 18020001
Willow Creek-Frontal Goose Lake 1802000103
Ross Creek-Frontal Goose Lake 180200010306
I
Agricultural Supply; Water Contact Recreation; Non-contact Water Recreation; Warm Freshwater Habitat; Cold Freshwater Habitat; Wildlife Habitat
10,346
Davis Creek-Frontal Goose Lake 180200010307
I 39,148
Lassen Creek-Frontal Goose Lake 180200010305
I 15,763
Willow Creek 180200010304
I 23,788
1 (USDA Forest Service 1991) 2 Lost River sucker and shortnose sucker
4
Table 2: Stream Class designations in accordance with Modoc NF LRMP
Class Definition Side
Slope (%)
Buffer Zone
Width (ft)
Class I Highly
Significant
These are either perennial or intermittent streams, or segments thereof, which meet one or more of the following criteria: a. Are habitat for large number of resident and/or migratory fish for spawning,
rearing or migration b. Furnish water locally for domestic or municipal supplies c. Have flows large enough to materially influence downstream water quality d. Are characterized by major fishing or other water-oriented recreational uses e. Have special classification or designation, such as wild, scenic, or recreation
rivers f. Have special visual or distinctive landscape features, and are classified as
variety Class A as defined in National Forest Landscaping-Volume 2 (Agr. Handbook 462)
g. Are habitat for threatened or endangered animal species, or contain plants which are potential or viable candidates for threatened or endangered classification
h. Exhibit ethnological, historical, or archaeological evidence that makes them eligible for or are in the National Register of Historical Places
0 – 20 21 – 40 41 – 60
≥ 61
100 150 200 250
Class II Significant
These are either perennial or intermittent streams, or segments thereof, which meet one or more of the following criteria: a. Are used by a moderate number of fish and spawning, rearing, or migration b. Furnish water locally for industrial or agricultural use c. Have enough water flow to exert a moderate influence on downstream
quality d. Are used moderately for fishing or other recreational purposes e. Are of moderate visual quality and meet variety Class B as defined in
National Forest Landscaping-Volume 2 (Agr. Handbook 462) f. Exhibit ethnological, historical, or archaeological evidence that makes them
eligible for State or local registers of historical significant interest
0 – 20 21 – 40 41 – 60
≥ 61
75 100 150 175
Class III Moderate Significant
These are either perennial or intermittent streams, or segments thereof, which meet one or more of the following criteria: a. Are habitat for few fish or spawning, rearing or migration b. Are rarely used for fishing or other recreational purposes c. Have enough water flow to exert minimum influence on downstream, water
quality d. Are of relatively low visual quality in the landscape and classified as variety
Class B as defined in National Forest Landscaping-Volume 2 (Agr. Handbook 462)
e. Exhibit historical or archaeological properties that are of archaeological interest in accordance with the Archaeological Resource Protection act of 1979
0 – 20 21 – 40 41 – 60
≥ 61
50 75
100 125
Class IV Minor
Significance
There are intermittent or ephemeral streams, or segments thereof, not previously classified
0 – 20 21 – 40 41 – 60
≥ 61
50 50 75
100
Methodology Previous surveys, aerial photography, USGS topographical maps, literature review, and field
reconnaissance were used to evaluate areas of hydrologic interest within and affected by the
treatment areas.
5
Existing Conditions Within the Cumulative Watershed Effects (CWE) analysis area, there are 49 miles of perennial,
182 miles of intermittent, and 94 miles of ephemeral channels (Table 3). Of those channels, 21
miles of perennial, 38 miles of intermittent, and 34 miles of ephemeral channels are located
within the project area.
Table 3: Length of channel types within the CWE and project area
6th Field Watershed HUC12
Watershed Acres
Stream Type
Stream length (mi)
CWE Project
Area CWE
Project Area
Willow Creek 180200010304
23,800 5,092
Perennial 19 4
Intermittent 48 4
Ephemeral 33 1
Lassen Creek - Frontal Goose Lake 180200010305
15,770 12,778
Perennial 16 13
Intermittent 26 16
Ephemeral 23 22
Ross Creek - Frontal Goose Lake 180200010306
10,350 923 Intermittent 21 1
Ephemeral 6 0
Goose Creek - Frontal Upper Alkali Lake 180800010108
23,072 5,201
Perennial 14 4
Intermittent 87 17
Ephemeral 32 11
Lassen Creek-Frontal Goose Lake (180200010305) The Lassen Creek-Frontal Goose Lake watershed includes Lassen Creek, Cold Creek, and Lower
Bear Valley. There are 16 miles of perennial, 26 miles of intermittent, and 23 miles of ephemeral
channels within the project area in the watershed. Lassen and Cold creeks are perennial Class I
streams within the project area. Past impacts to this watershed include: livestock grazing,
existing roads, past timber projects, developed and dispersed campsites, and a past fish habitat
improvement project.
Lassen Creek
The character of Lassen Creek varies throughout the project area from steep, rocky sections with
vertical drop/scour-pool bed features to gentle gradient meandering step/pool channels (Rosgen
1994). Lassen Creek is fed by Lassen Fen, several springs and seeps as well as other ephemeral,
intermittent and perennial tributaries including Lower Bear Valley and Cold Creek.
Lassen Creek is a perennial stream, which flows north-northeast for 16 miles from approximately
one half-mile northeast of Buck Mountain 16 miles to Goose Lake. Approximately 9.3 miles of
Lassen Creek are on the Forest. Lassen Creek provides habitat for Goose Lake redband trout.
Various surveys have been conducted on Lassen Creek over the last thirty years from the
perspective of different specialties such as hydrology, range management, and fisheries and with
different survey protocols within each specialty. Difficulty arises in making direct correlations
between the studies.
6
In 1985 and 1988, Pfankuch surveys were conducted on Lassen Creek (Pfankuch 1978). These
surveys measured width, depth, velocity, discharge, gradient, and sinuosity. The focus of the
Pfankuch survey is to assess stream stability based on bank gradients, erosion, vegetation
coverage, size composition of bottom material, and other observations. Stability indicators are
checked off in columns labelled excellent, good, fair, and poor with numerical values and tallied
providing a numerical value corresponding to stability condition. Out of ten surveys in different
locations, Lassen Creek scored from poor to excellent. Overall averages of scores would have
rated fair. Width to depth rations ranged from 9.3:1 to 20:1 with an average of 17.9:1.
In the 2000 Warner Mountain Rangeland Project Environmental Assessment, Lassen Creek was
rated as Unsatisfactory/Properly Functioning due to less than desired vegetative components
with less than three hardwood species present, width to depth ratios in excess of 12:1, and water
temperatures in excess of 70 degrees Fahrenheit (WMRP EA 2000).
A Properly Function Condition (PFC) survey of Lassen Creek was conducted in February 1999
using Technical Reference 1737-9 (USDI BLM 1998). The survey divided Lassen Creek in four
sections (Figure 2). The topmost section from the headwaters to 46N30, 104, was determined to
be in PFC with an upward trend. The second section from 46N30 to the Lassen Creek Pasture
fence was determined to be in PFC with a static tend. High width to depth ratio, lack of diverse
age class of vegetation, and lack of revegetation on point bars were factors in the trend
determination. The third and fourth sections from the Lassen Creek Pasture fence to the Cold
Creek confluence and from the confluence to the Forest boundary were determined to be in PFC
with an upward trend.
7
Figure 2: PFC reaches
In 2010, the State of California Natural resource Agency Department of Fish and Game Heritage
and Wild Trout Program conducted fish surveys on Lassen and Cold creeks from downstream of
Harris Flat to approximately 1/4–mile downstream of Lassen Creek Campground (Weaver and
Mehalick 2010). During the study, width-to-depth ratio ranged from 3:1 to 35:1. Average width-
to-depth ratio was 12.9:1 based on average wetted widths and average water depths throughout
the study area or 17.1:1 based on average measured width-to-depth ratios. Temperatures ranged
from 48.9 to 57.2°F with an average of 53.0°F.
The Pacific Southwest Region Stream Condition Inventory (SCI) protocol is to collect intensive
and repeatable data from stream reaches to document existing stream condition and make
reliable comparisons over time within or between stream reaches (Frazier, et al. 2005). Lassen
8
Creek contains an SCI site upstream of Harris Flat. The site was established and surveyed in
2013 (Table 4). SCI reaches are monitored every five years.
Table 4: Results of SCI analysis
Parameter Reading
% Shading (averaged for reach) 45.3
Temperature (°F) 60
pH 7.1
Alkalinity (ppm CaCO3) 36
Mean Particle Size (D50) 20.27-26.96
Width to Depth Ratio (average) 27.12-76.97
Pfankuch Stability Rating Fair
Rosgen Channel Type C4
Lassen Fen covers approximately 40 acres in the headwaters of Lassen Creek. A proper
functioning condition (PFC) for fens assessment was conducted in September 2015 at the upper
reach of the fen (Weixelman and Cooper 2009). Due to conifer encroachment and trampling by
livestock, it was determined that the fen was non-functional but capable of rehabilitation (Guana
2015).
A PFC survey was conducted August 2016 using Technical reference 1731-15 2nd Edition
(Dickard, et al. 2015) in the same reached as the 1999 PFC (Figure 2). One difference between
the 1998 and 2015 editions is the selection of either monitored or apparent trends. Due to lack of
detailed information from the 1999 survey, apparent trend was used in all cases. Reach 104 was
rated as PFC with a static apparent trend. Reach 103, 102, and 101 were rated PFC with an
upward trend. It was noted on reached 101 and 102 that weirs installed in the 80s had been
successful in slowing flow, preventing entrenchment, but had led to widening channel or the
prevention of the channel to narrow directly up and downstream of the weirs. The PFC surveys
indicate Lassen Creek has not attained the desired condition but it is moving towards the desired
condition.
There is an undersized and misaligned culvert on the tributary to Lassen Creek from Lower Bear
Valley on Forest Service Road (FSR) 46N30. This is an intermittent stream providing historical
fish habitat in high flow years. This project proposes to replace and realign this culvert with a
larger culvert to provide improved fish passage.
A fish habitat improvement project was conducted 1984-1987. For this project, 835 large
boulders 56 log weirs, and 7,000 juniper trees were installed on Lassen Creek. The objectives of
log weir installation are to create pools for trout rearing habitat, establish spawning areas,
stabilize the stream gradient, and raise the water table. The objectives of boulder placement are
to provide both current and hiding cover for trout in areas that lack adequate pools, improve
pool/riffle ratio, and deflect flows away from eroding stream banks. The objectives of juniper
9
revetment are to stabilize eroding stream banks by: 1) providing for sediment catchment, 2)
providing a watered site for reestablishment of riparian vegetation, 3) slow water velocities near
the bank, and 4) reduce trampling by livestock on the eroding banks. An additional objective is
to improve fisheries by narrowing the stream channel and providing cover for fish.
Initially, the log weirs likely met the original intent of creating pools and slowing flow.
However, there were many adverse and unforeseen consequences, such as significant increase in
width/depth ratios. Additionally, the stream has undercut several structures, leaving wood
disconnected from the stream at low flow.
Out of the 40 log weirs surveyed and mapped, ten were undercut and no longer function as
intended. Under the proposed action, these weirs would be repaired (riffle augmentation, beaver
dam analogs, etc) creating fish and wildlife habitat. In areas where juniper had been anchored,
the anchors and wires are still present creating a safety hazard but the juniper has long since
decomposed. Many of the juniper treatments were successful indicated by the presence of willow
and healthy stream banks, though willow did not recover in all treatment areas.
Figure 3: Examples of fish habitat improvements on Lassen Creek: log weir (left) and anchored juniper (right)
The following set of photos (Figure 4, Figure 5, Figure 6) were taken in the same location
approximately 350-feet upstream of the bridge downstream of the Lassen Creek Campground
showing how the area has improved.
10
Figure 4: Lassen Creek photo point, 1947 and 1961
Figure 5: Lassen Creek photo point, 1989 and 1997
Figure 6: Lassen Creek photo point, 2015 and 2016
Historically, forest roads are a major source of sediment to streams (Goode, Luce and Buffington
2012). Figure 7 shows an example of surface erosion on a road within the project area on two
11
segments of FSR 45N22 at SW¼ SE¼ NE¼ Sec05 T45N R15E and NE¼ SW¼ SE¼ Sec05
T45N R15E where road material is eroding into Lassen Creek.
Figure 7: Road material eroding into Lassen Creek along FSR 45N22 at SW¼ SE¼ NE¼ Sec05 T45N R15E and NE¼
SW¼ SE¼ Sec05 T45N R15E into Lassen Creek
Cold Creek
Cold Creek is a perennial tributary of Lassen Creek flowing from Cold Springs to Lassen Creek.
PFC surveys were conducted in 1999 and 2016. It was determined that Cold Creek was in PFC
with an upward trend during both surveys.
The following set of photos (Figure 8, Figure 9, Figure 10) were taken in the same location
approximately ¾-mile upstream of the Cold Creek/Lassen Creek confluence showing how the
area has improved. The willow on the left side of the photo died sometime between the time the
2015 and 2016 photos were taken, however, the aspen stand along the creek have improved.
12
Figure 8: Cold Creek photo point, 1949 and 1961
Figure 9: Cold Creek photo point, 1989 and 1997
Figure 10: Cold Creek photo point, 2015 and 2016
13
Willow Creek (180200010304) Willow Creek is a perennial Class 1 stream. From its spring fed headwaters, Willow Creek flows
NNE 2.5 miles in NFS land, 4.5 miles through private land in Fandango Valley, 1.5 miles in NFS
land, then back onto private lands on to Goose Lake. Past impacts to this watershed include
livestock grazing, existing roads, and past timber projects. Evidence of grazing and stream bank
trampling was evident on a 0.20-mile segment of Willow Creek immediately north of the private
property.
A PFC survey was conducted on Willow Creek in August 2016. The creek was found to be in
PFC with an upward apparent trend.
Goose Creek - Frontal Upper Alkali Lake (180800010108) The Goose Creek-Frontal Upper Alkali Lake watershed contains Goose Creek and Shartel
Canyon that flow into Upper Alkali Lake. Both Goose Creek and Shartel Canyon are Class II
perennial streams fed by numerous springs including a small fen. Past impacts to this watershed
include livestock grazing, existing roads, and past timber projects.
A culvert on FSR 46N30A crossing Goose Creek showed signs of erosion on the upstream side
and is in need of repair (Figure 11).
Figure 11: Road stream crossing FSR 46N30A and Goose Creek
Environmental Consequences
Proposed Action (Alternative 1) For the complete Proposed Action, refer to the Lassen 15 Restoration Project Environmental
Analysis.
14
Direct and Indirect Effects
The proposed action alternative has the potential to temporarily affect aquatic resources;
primarily as a result of vegetation removal, slash piling, pile burning following treatment, and
building of temporary roads. Each activity has the potential to disturb soil. Soil displacement,
compaction, or change in ground cover could cause an effect on watershed condition and aquatic
habitat. Conservation measures incorporated into the project would be implemented to control
erosion and sedimentation. The implementation of BMPs and Design Features would avoid or
minimize potential increases in sediment loads to streams during project implementation.
Change in annual downstream flow due to change in evapotranspiration (ET) would be
negligible under the action alternative. ET as a factor of canopy cover and precipitation may
decrease approximately 3-5% within each treatment unit assuming a canopy cover reduction of
25%. As a result, more water may be available for release downstream. However, annual change
in water availability in Lassen Creek would be negligible. Using the 6th Field Willow
Creek-Frontal Goose Lake watershed where Lassen Creek flows as an example:
Average precipitation within the watershed is 20-38 in/yr.
Approximately 34% of the watershed contains treatment units.
The project would be conducted over several years (approximately 5).
After 5 years, ET returns to pre-treatment levels.
At year-5, when the maximum change in ET would be realized, increase in available
water to the watershed due to the change in ET may be 0-1%.
A wide range of activity-specific BMPs are designed to minimize detrimental soil disturbance,
protect water quality, and maintain physical stability and hydrologic connectivity of riparian and
aquatic habitats (see Appendix 1 for a list of applicable BMPs). There is little potential for the
proposed action alternative to adversely affect the geomorphic, hydrologic, or riparian
characteristics and aquatic habitats in affected watersheds. This is due to the limitations imposed
on operations within Riparian Conservation Areas (RCAs) and Streamside Management Zones
(SMZs), and use of activity specific BMPs.
Two of the five 6th field watersheds with proposed treatments (Davis Creek - Frontal Goose Lake
and Goose Creek - Frontal Upper Alkali Lake) have only a small number of treatment acres
within them (83 and 162 acres, respectively). This amounts to approximately 0.2% of the Davis
Creek - Frontal Goose Lake watershed and 0.7% of the Goose Creek - Frontal Upper Alkali Lake
watershed total acres being proposed for treatment with this project (Table 5). The remaining
watersheds with proposed treatments make up the rest of the acres. Due to the small number of
proposed treatment acres within the Davis Creek, CWE analysis was only performed for the
Goose Creek, Lassen Creek, Willow Creek, and Ross Creek watersheds. Treatment acres for
analysis were based on GIS and may not equal survey acres in the Proposed Action.
15
Table 5: Proposed treatment acres within 6th level field (HUC10) watersheds
6th Field Watershed HUC12 Watershed Acres
Lassen15 Restoration Project Treatment Area within Watershed
Acres of Treatment Proposed
Acres of Treatment Proposed
Davis Creek - Frontal Goose Lake 180200010307 39,163 83 0.2%
Goose Creek - Frontal Upper Alkali Lake 180800010108 23,072 162 0.7%
Lassen Creek - Frontal Goose Lake 180200010305 15,770 5,511 34.9%
Willow Creek 180200010304 23,800 1,505 6.3%
Ross Creek - Frontal Goose Lake 180200010306 10,350 752 7.3%
Thinning and prescribed (Rx) burning activities will improve the watershed by reducing the
threat of unnaturally damaging wildfires which could cause flooding or erosion.
With application of the project design features and BMPs detailed in Appendix 1 of this report,
including slope restrictions for mechanical operations, limiting the impact of soil disturbing
activities that exceed soil property thresholds for soil cover, soil porosity, and organic matter
content (see Lassen 15 Restoration Soils Report for more details), and restricting ground-based
operations during wet soil conditions, erosion and sediment delivery are not expected to result in
watershed effects. Erosion will be limited in extent and would be separated by buffers from
delivery corridors such as channels.
The streams, springs/seeps, and fens within the project area with the exception of the Lassen
Creek Fen are currently in good functioning condition, and the proposed project activities would
not cause any direct effects to the conditions of these features. SMZs have been identified within
the RCAs and define an equipment exclusion zone immediately adjacent to the stream channels,
springs/seeps, fens, and meadows. The RCA and SMZ widths applicable to this project are
presented in Table 13.
In SMZs and meadow areas, mechanical equipment would not operate (except at approved
crossings). In these areas, treatments would be accomplished with hand crews.
In the 1980s a stream restoration project was conducted on Lassen Creek. Under the proposed
project, approximately ten of the weirs installed in the 1980s that are no longer functioning will
be repaired. Weir repair would occur within the fisheries limited operating period (LOP) for
instream work as determined in coordination with the Fisheries Biologist. Repairing these weirs
will raise the creek level closer to the flood plain promoting natural regeneration of riparian
vegetation and improving aquatic habitat. See Figure 14 in Appendix 4 for weir locations.
16
The direct effect of replacing the culvert on 46N30 would be a realignment of the channel to a
more natural path and a short term disturbance to the substrate. Because the replacement would
occur when the channel is flowing, no sediment would enter Lassen Creek. After replacement,
during periods of high flow, aquatic organisms would be able to pass up the channel unimpeded.
Realignment of the channel would decrease streambank scour and erosion in the vicinity of the
culvert. See Figure 14 in Appendix 4 for culvert location.
The direct effect of weir repair on Lassen Creek depends on the method used. Methods
considered range from the willow planting to construction of beaver analogs to complete weir
removal. Methods may be a combination of several methods using the best available science.
The direct effects may include temporary increased turbidity in the stream channel during
construction. If mechanical equipment is used, there is the risk of soil compaction. The use of
BMPs would reduce or eliminate excess turbidity downstream of any construction. Indirect
effects would include an acceleration in the reduction in width to depth ratios, the increase in
sinuosity and pool numbers, and the decrease in stream temperature, all beneficial effects.
Cumulative Effects
Past and present activities within the analysis area include grazing, timber harvest, fuels
reduction, road maintenance, and past stream restoration. Future management activities in the
project area include the continuation of livestock grazing and road maintenance. Potential future
activities may include timber management and fuels reduction projects; however, none are
currently proposed and site-specific information (e.g. location, dates, affected area, etc.) is not
available for these potential future activities. Typically, these activities would not be expected to
cause significant effects due to prescribed mitigation measures and BMPs. The Lassen 15
Restoration Project, when analyzed cumulatively with other projects, would not be expected to
put any of the affected watersheds over threshold. If additional activities are proposed within the
project area in the future, those activities would be fully analyzed as part of the planning process.
The following tables include a list of all the potentially affected 6th field subwatersheds, their
numbers, and percent Threshold of Concern (TOC) used for the proposed action and no action
alternative (Table 6 though Table 8). Initial mechanical treatments are estimated to begin in
2020. Table 6 displays CWE analysis for the action alternative for 2020. Prescribed burning is
estimated to begin in 2025. Table 7 displays CWE analysis for the action alternative for 2025.
Table 8 displays CWE analysis displayed as a TOC used for the current condition and proposed
action through 2035 showing recovery from mechanical treatments and prescribed burns for ten
years following the prescribed burns. Analysis of nineteen subwatersheds did not indicate a
substantial increase in the TOC as a result of the proposed action. All watersheds remain within
the TOC with or without the action alternatives.
Table 6: CWE Analysis for proposed action alternative for 2020
HUC12 (6th Field Watershed)
TOC (ac)
Watershed Acres
2020
ERA Used ERAs Used ERAs Remaining
17
(%) (ac) (ac)
180200010304 3,570 23,800 11.1% 396 3,173
180200010305 2,365 15,770 51.2% 1,210 1,155
180200010306 1,553 10,350 11.8% 184 1,369
180800010108 3,461 23,072 1.1% 37 3,423
Table 7: CWE Analysis for proposed action alternative for 2025
HUC12 (6th Field Watershed)
TOC (ac)
Watershed Acres
2025
ERA Used (%)
ERAs Used (ac)
ERAs Remaining (ac)
180200010304 3,570 23,800 10.1% 359 3,210
180200010305 2,365 15,770 48.8% 1,154 1,212
180200010306 1,553 10,350 11.6% 181 1,372
180800010108 3,461 23,072 0.8% 29 3,431
Treatments would use existing landings where possible in order to utilize previously compacted
sites. Skid trail patterns would be designed to minimize soil disturbance and compaction. Proper
drainage on these features would reduce the potential for water concentration and runoff. Water
barring and slashing of skid trails and landings would reduce the potential for sedimentation and
erosion. Decommissioning of roads was not factored into the CWE analysis although
decommissioning roads in the Lassen Creek 6th field watersheds will further reduce the CWE in
those watersheds.
Table 8: CWE Analysis displaying percent of Threshold of Concern used and recovery through 2035
HUC12 6th Field Watershed
Acres
2016 %TOC Used Current &
Proposed Action
2020 %TOC Used Proposed
Action
2025 %TOC Used Proposed
Action
2030 %TOC Used Proposed
Action
2035 %TOC Used Proposed
Action
180200010304 23,800 6.4% 11.1% 10.1% 7.2% 5.6%
180200010305 15,770 16.8% 51.2% 48.8% 35.0% 25.5%
180200010306 10,350 3.9% 11.8% 11.6% 8.9% 7.0%
180800010108 23,072 0.5% 1.1% 0.8% 0.7% 0.6%
No Action Alternative (Alternative 2)
Direct and Indirect Affects
Due to the amount of fuel loading within the project area, there would be a higher risk of wildfire
than with the action alternative. Wildfires within the area would result in increased sediment load
and erosion within the watersheds and could endanger riparian areas and streams within the
project area. Risk of post fire erosion depends on fire severity, soil type and rock content,
hillslope gradient and length. The Erosion Risk Management Tool (ERMiT) is used to predict
erosion risk on a single slope (Robichaud, et al. 2014). Projections of sediment load after a high
intensity indicate a 20% chance of 1.86 tons per acre on a single 1,000 foot slope. See Appendix
3.
18
There would be no change in ET and therefore no change in available stream flow under the no-
action alternative.
On Lassen Creek, the majority of weirs installed in the 1980s are functioning as designed. Under
the no action alternative, the non-functioning weirs would not be repaired. The condition of
Lassen Creek would remain unchanged in the areas where the restoration project was proposed.
Not replacing the culvert would result in continuing streambank scour and erosion in the vicinity
of the culvert. Passage of aquatic organisms would continue to be impeded by the culvert.
Not repairing the weirs would have no direct effect on Lassen Creek. The indirect effect of not
repairing the weirs potentially could be geomorphic changes to the stream channel in the
immediate vicinity of log weirs where the stream flows around the weirs. Failure of those weirs
could result in the creation of headcuts.
Cumulative Effects
Past and present activities within the analysis area include grazing, timber harvest, fuels
reduction, road maintenance, and past stream restoration. Future management activities in the
project area include the continuation of livestock grazing and road maintenance. Potential future
management activities include the Lassen Creek Grazing EA for grazing management on
approximately 24,020 acres of the project area. Other future activities may include timber
management and fuels reduction projects; however, none are currently proposed and site-specific
information (e.g. location, dates, affected area, etc.) is not available for these potential future
activities. The No Action Alternative would not incrementally increase or decrease effects from
other projects.
The following tables include a list of all the potentially affected 6th field subwatersheds, their
numbers, and percent Threshold of Concern (TOC) used for the proposed action and no action
alternative (Table 9 though Table 11). Table 10 displays CWE analysis for the no action
alternative for 2025. There was no change in percent TOC used between the years 2030 and
2035 so CWE analysis is displayed only up to 2030. Analyses of nineteen subwatersheds
indicate a continual recovery from past actions. All watersheds remain within the TOC with or
without the action alternatives. A detailed explanation of the Equivalent Roaded Acres and
Cumulative Watershed Effects analysis process can be found in Appendix 2.
19
Table 9: CWE Analysis for no action alternative for 2020
HUC12 (6th Field Watershed)
TOC (ac)
Watershed Acres
2020
ERA Used (%)
ERAs Used (ac)
ERAs Remaining (ac)
180200010304 3,570 23,800 4.3% 152 3,418
180200010305 2,365 15,770 9.2% 219 2,147
180200010306 1,553 10,350 3.2% 50 1,502
180800010108 3,461 23,072 0.4% 14 3,446
Table 10: CWE Analysis for no action alternative for 2025
HUC12 (6th Field Watershed)
TOC (ac)
Watershed Acres
2025
ERA Used (%)
ERAs Used (ac)
ERAs Remaining (ac)
180200010304 3,570 23,800 2.7% 96 3,474
180200010305 2,365 15,770 5.2% 122 2,243
180200010306 1,553 10,350 2.8% 43 1,509
180800010108 3,461 23,072 0.3% 12 3,449
Table 11: CWE Analysis displaying percent of Threshold of Concern used and recovery through 2030 (No change %TOC
2030 to 2035)
HUC12 6th Field Watershed
Acres
2016 %TOC Used Current &
Proposed Action
2020 %TOC Used Proposed
Action
2025 %TOC Used Proposed
Action
2030 %TOC Used Proposed
Action
180200010304 23,800 6.4% 4.3% 2.7% 2.2%
180200010305 15,770 16.8% 9.2% 5.2% 4.5%
180200010306 10,350 3.9% 3.2% 2.8% 2.7%
180800010108 23,072 0.5% 0.4% 0.3% 0.3%
Law, Regulation, and Policy applicable to Hydrology Laws, regulation, and policy applicable to managing water quality include the Clean Water Act
(EPA 2002) and 1991 Modoc National Forest Land and Resource Management Plan (LRMP) as
amended by the 2004 Sierra Nevada Forest Plan Amendment (SNFPA).
Applicable management requirements and constraints provided by the 2004 Sierra Nevada Forest
Plan Amendment include:
X Aquatic Management Strategy (AMS) goals and objectives
X Riparian Conservation Areas
X Riparian Conservation Objectives (RCO) Analysis standards and guidelines
X Critical Aquatic Refuges
Long-term strategy for anadromous fish-producing watersheds
Long-term strategy for anadromous fish-producing watersheds applies only to the Lassen
National Forest and is therefore not applicable to this project area.
20
Riparian Conservation Objectives Analysis The RCOs listed in the Sierra Nevada Forest Plan Amendment Record of Decision (USDA
Forest Service 2004) were reviewed for applicability to the project. The need to define riparian
conservation areas exists in the project area. RCOs 1, 2, 3, 4, and 6 apply to the project and are
further reviewed below. RCO 5 does not apply because the project does not include grazing.
RCOs 1, 2, 3, 4, and 6 apply to the project, contain standards and guidelines, and are further
reviewed below. These are outlined and explained in the next section.
X RCAs and CARs: Conduct a site-specific project area analysis to determine the appropriate
level of management within RCAs or CARs. Determine the type and level of allowable
management activities by assessing how proposed activities measure against the riparian
conservation objectives and their associated standards and guidelines.
X Riparian Conservation Objective #1: Ensure that identified beneficial uses for the water
body are adequately protected. Identify the specific beneficial uses for the project area, water
quality goals from the Regional Basin Plan, and the manner in which the standards and
guidelines will protect the beneficial uses. (RCO #1 is linked to the following AMS goals: #1:
Water Quality; #2: Species Viability; #7: Watershed Condition)
X Riparian Conservation Objective #2: Maintain or restore: (1) the geomorphic and
biological characteristics of special aquatic features, including lakes, meadows, bogs, fens,
wetlands, vernal pools, springs; (2) streams, including in stream flows; and (3) hydrologic
connectivity both within and between watersheds to provide for the habitat needs of aquatic-
dependent species. (RCO #2 is linked to the following AMS Goals: #2: Species Viability; #3:
Plant and Animal Community Diversity; #4: Special Habitats; #5: Watershed Connectivity; #6:
Floodplains and Water Tables; #8: Streamflow Patterns and Sediment Regimes; #9: Streambanks
and Shorelines)
X Riparian Conservation Objective #3: Ensure a renewable supply of large down logs that:
(1) can reach the stream channel and (2) provide suitable habitat within and adjacent to the RCA.
(RCO #3 is linked to the following AMS goals: #2: Species Viability; #3: Plant and Animal
Community Diversity)
X Riparian Conservation Objective #4: Ensure that management activities, including fuels
reduction actions, within RCAs and CARs enhance or maintain physical and biological
characteristics associated with aquatic- and riparian-dependent species. (RCO #4 is linked to the
following AMS Goals: #2: Species Viability, #7: Watershed Condition)
Riparian Conservation Objective #5: Preserve, restore, or enhance special aquatic features,
such as meadows, lakes, ponds, bogs, fens, and wetlands, to provide the ecological conditions
and processes needed to recover or enhance the viability of species that rely on these areas.
(RCO #5 is linked to the following AMS goals: #1: Water Quality, #2 Species Viability, #3 Plant
21
and Animal Community Diversity, #4 Special Habitats; #7: Watershed Condition; #9: Stream
Banks and Shorelines)
X Riparian Conservation Objective #6: Identify and implement restoration actions to
maintain, restore or enhance water quality and maintain, restore, or enhance habitat for riparian
and aquatic species. (RCO # 6 is linked to all AMS goals)
Riparian Conservation Areas and Critical Aquatic Refuges
Standards and Guidelines Associated with RCAs and CARs:
91. Designate riparian conservation area (RCA) widths as described in Part B of this appendix.
The RCA widths displayed in Part B may be adjusted at the project level if a landscape
analysis has been completed and a site-specific RCO analysis demonstrates a need for
different widths.
Stream Side Management Zones are required under the Modoc National Forest Land
Resource Management Plan (USDA Forest Service 1991) and California Code of
Regulations (14 CCR § 916.5 2013). The Sierra Nevada Forest Plan Amendment directs us to
meet the goals of the CWA on page 42 of the ROD under desired conditions.
Previous forest SMZ direction provided the following widths in slope distance in feet. The
values provided in Table 12 are used as a guide. Field conditions including stream type and
project objectives should dictate the SMZ widths.
Table 12: SMZ Widths in Feet (Slope Distance)
Stream Class % Side Slope
0-20 21-40 41-60 61+
Class I 100 150 200 250
Class II 75 100 150 175
Class III 50 75 100 125
Class IV 50 50 75 100
SMZs are nested inside RCAs (Table 13) and define an equipment exclusion zone
immediately adjacent to the streamside for the purpose of creating a filter strip to trap
potential sediment. Treatments in this zone would be dependent on treatment objectives.
Objectives for the SMZ portion of the RCA are maintenance or improvement of riparian
values, to provide unobstructed passage of storm flows, to control sediment and other
pollutants entering the stream course, and to restore the natural course of any stream as soon
as practicable when diversion of the stream has resulted from management activities.
Prescribed widths for RCAs are 300 feet either side for perennial streams, 150 feet for
seasonally flowing streams, and 300 feet for special aquatic features. This area is a zone of
22
closely managed activities and not a zone of equipment exclusion like SMZs. Project specific
SMZs and RCAs are provided in Table 13.
Table 13: SMZ and RCA widths (Feet) specific to the Lassen 15 Restoration Project
SMZ Width
RCA Width
Perennial Streams 100 300
Intermittent Streams 75
Ephemeral Streams 50
Seasonally Flowing Streams (includes intermittent and ephemeral streams) 150
Special Aquatic Features (lakes, wet meadows, bogs, fens, wetlands, vernal pools, and springs )
100 300
Design Features
Heavy equipment will be excluded from the SMZs except at designated crossings.
Slash and other logging debris will be removed from stream courses except where it will
contribute to riparian values.
Trees will be fallen away from stream courses and special aquatic features unless required for
riparian enhancement.
Landings and decking areas will not be located in SMZs.
No pile burning activities will be implemented within RCAs.
92. Evaluate new proposed management activities within CARs and RCAs during environmental
analysis to determine consistency with the riparian conservation objectives at the project
level and the AMS goals for the landscape. Ensure that appropriate mitigation measures are
enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2)
minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species.
All project activities within SMZs would be conducted by hand, using chainsaws, or with
mechanical equipment outside of SMZs. No pile burning would occur within RCAs. These
proposed activities would be consistent with the RCOs and AMS landscape goals.
93. Identify existing uses and activities in CARs and RCAs during landscape analysis. At the time
of permit reissuance, evaluate and consider actions needed for consistency with RCOs.
The project does not include a landscape analysis. However, the proposed actions are
consistent with the RCOs as discussed in this document. All streams will be evaluated and
assigned a RCA and SMZ appropriate for local field conditions. BMP 1.4 provides
documentation of prescribed SMZ widths for the Lassen 15 Restoration Project.
23
94. As part of project-level analysis, conduct peer reviews for projects that propose ground-
disturbing activities in more than 25 percent of the RCA or more than 15 percent of a CAR.
Ground disturbance by the Lassen 15 restoration Project is not expected to affect more than
13% of the RCA or more than 13% of the Goose Lake CAR.
122. Determine which critical aquatic refuges or areas within critical aquatic refuges are
suitable for mineral withdrawal. Propose these areas for withdrawal from location and entry
under U.S. mining laws, subject to valid existing rights, for a term of 20 years.
This project is not associated with mineral extraction.
123. Approve mining-related plans of operation if measures are implemented that contribute
toward the attainment or maintenance of aquatic management strategy goals.
There is no mineral extraction being proposed for this project
Riparian Conservation Objective #1
Ensure that identified beneficial uses for the water body are adequately protected. Identify the
specific beneficial uses for the project area, water quality goals from the Regional Basin Plan,
and the manner in which the standards and guidelines will protect the beneficial uses.
Standards and Guidelines Associated with RCO #1:
95. For waters designated as “Water Quality Limited” (Clean Water Act Section 303(d)),
participate in the development of Total Maximum Daily Loads (TMDLs) and TMDL
Implementation Plans. Execute applicable elements of completed TMDL Implementation
Plans.
The Modoc National Forest has no water bodies identified by the State as “Water Quality
Limited” in or affected by this project area.
96. Limit pesticide applications to cases where project level analysis indicates that pesticide
applications are consistent with riparian conservation objectives.
Pesticides would not be applied within RCAs.
97. Within 500 feet of known occupied sites for the California red-legged frog, Cascades frog,
Yosemite toad, foothill yellow-legged frog, mountain yellow-legged frog, and northern
leopard frog, design pesticide applications to avoid adverse effects to individuals and their
habitats.
There is no known suitable habitat for California red-legged frog, Cascades frog, Yosemite
toad, foothill yellow-legged frog, mountain yellow-legged frog, and northern leopard frog
within or adjacent to the project area. However, no pesticides would be applies within RCAs.
24
See Lassen15 Restoration Project Fisheries/Aquatics reports for more information on frog
and toad habitats.
98. Prohibit storage of fuels and other toxic materials within RCAs and CARs except at
designated administrative sites and sites covered by a Special Use Authorization. Prohibit
refueling within RCAs and CARs unless there are no other alternatives. Ensure that spill
plans are reviewed and up-to-date.
To protect resources in the event of a spill, the construction contractor must use a
containment device in which to store hazardous fuels. The device would be large enough to
contain all spilled materials per BMP 2.12, Servicing and Refueling Equipment. Service and
refueling locations of all equipment would be located on landings or roads and would be
located outside of the RCA. Chainsaws would also be refueled outside of RCAs. These
refueling locations would follow forest spill plan direction. The forest would have a spill plan
if the volume of fuel on site exceeds 660 gallons in a single container or a total storage at the
site exceeds 1,320 gallons. It is not expected that any sites would exceed 660 gallons. If this
project exceeds this, the spill plan would include: the types and amounts of hazardous
materials located within the project area, Forest Service approved locations for hazardous
materials storage and fueling/maintenance activities (should be located outside of the RCAs),
methods for containment of hazardous materials in the event of a spill, and a contingency
plan to implement in the event of a spill.
Riparian Conservation Objective #2 Maintain or restore: (1) The geomorphic and biological characteristics of special aquatic
features, including lakes, meadows, bogs, fens, wetlands, vernal pools, springs; (2) streams,
including in stream flows; and (3) hydrologic connectivity both within and between watersheds
to provide for the habitat needs of aquatic-dependent species.
Standards and Guidelines Associated with RCO #2:
100. Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and
other special aquatic features by identifying roads and trails that intercept, divert, or disrupt
natural surface and subsurface water flow paths. Implement corrective actions where
necessary to restore connectivity.
Road maintenance is included in this project proposal. During road maintenance, water
quality protection would be provided by minimizing drainage problems and blockage of
drainage facilities. Implementation of SMZs would result in protection of stream/meadow
function and eliminate/reduce the potential for diversion/disruption of water flow.
101. Ensure that culverts or other stream crossings do not create barriers to upstream or
downstream passage for aquatic-dependent species. Locate water drafting sites to avoid
adverse effects to in stream flows and depletion of pool habitat. Where possible, maintain
25
and restore the timing, variability, and duration of floodplain inundation and water table
elevation in meadows, wetlands, and other special aquatic features.
Streamflow would not be adversely affected by this project. Culvert replacements on Willow
Creek and the tributary to Lassen Creek between Lassen Creek and Lower Bear Valley will
be designed to improve aquatic fish passage. Water drafting sites will be located in order to
avoid adverse effects to in stream flows and depletion of pool habitat.
102. Prior to activities that could adversely affect streams, determine if relevant stream
characteristics are within the range of natural variability. If characteristics are outside the
range of natural variability, implement mitigation measures and short-term restoration
actions needed to prevent further declines or cause an upward trend in conditions. Evaluate
required long-term restoration actions and implement them according to their status among
other restoration needs.
Channel characteristics for all perennial streams near and downstream of the project area
important to stream stability and function have developed due to an abundance of willows,
rushes, grasses, and other riparian vegetation surrounding the channel providing root mass
and stream bank stability. Stream Stability Ratings after Pfankuch (1978) on Willow Creek
and Cold Creek indicate the channels are in good condition. Stream Stability Ratings on
Lassen Creek varied depending on location. Where conditions are outside the range of
natural variability, repair of weirs installed in 1985-1987 will result in an upward trend and
will result in conditions within the natural range of variability.
103. Prevent disturbance to streambanks and natural lake and pond shorelines caused by
resource activities (for example, livestock, off-highway vehicles, and dispersed recreation)
from exceeding 20 percent of stream reach or 20 percent of natural lake and pond
shorelines. Disturbance includes bank sloughing, chiseling, trampling, and other means of
exposing bare soil or cutting plant roots. This standard does not apply to developed
recreation sites, sites authorized under Special Use Permits and designated off-highway
vehicle routes.
Implementation of SMZs during the project would serve to prevent disturbance to
streambanks during the project.
104. In stream reaches occupied by, or identified as “essential habitat” in the conservation
assessment for, the Lahonton and Paiute cutthroat trout and the Little Kern golden trout,
limit streambank disturbance from livestock to 10 percent of the occupied or “essential
habitat” stream reach. (Conservation assessments are described in the record of decision.)
Cooperate with State and Federal agencies to develop streambank disturbance standards for
threatened, endangered, and sensitive species. Use the regional streambank assessment
protocol. Implement corrective action where disturbance limits have been exceeded.
26
This project does not include grazing of livestock.
105. At either the landscape or project-scale, determine if the age class, structural diversity,
composition, and cover of riparian vegetation are within the range of natural variability for
the vegetative community. If conditions are outside the range of natural variability, consider
implementing mitigation and/or restoration actions that will result in an upward trend.
Actions could include restoration of aspen or other riparian vegetation where conifer
encroachment is identified as a problem.
Channel characteristics for all perennial streams near and downstream of the project area
important to stream stability and function have developed due to an abundance of willows,
rushes, grasses, and other riparian vegetation surrounding the channel providing root mass
and stream bank stability. Stream Stability Ratings after Pfankuch (1978) on Willow Creek
and Cold Creek indicate the channels are in good condition. Stream Stability Ratings on
Lassen Creek varied depending on location. Where conditions are outside the range of
natural variability, repair of weirs installed in 1985-1987 will result in an upward trend and
will result in conditions within the natural range of variability.
106. Cooperate with Federal, Tribal, State and local governments to secure in stream flows
needed to maintain, recover, and restore riparian resources, channel conditions, and aquatic
habitat. Maintain in stream flows to protect aquatic systems to which species are uniquely
adapted. Minimize the effects of stream diversions or other flow modifications from
hydroelectric projects on threatened, endangered, and sensitive species.
Instream flows would not be affected by this project.
107. For exempt hydroelectric facilities on national forest lands, ensure that special use
permit language provides adequate in stream flow requirements to maintain, restore, or
recover favorable ecological conditions for local riparian- and aquatic-dependent species.
There are no hydrologic facilities in the project area.
Riparian Conservation Objective #3: Ensure a renewable supply of large down logs that: (1) Can reach the stream channel and (2)
provide suitable habitat within and adjacent to the RCA.
Standards and Guidelines Associated with RCO #3:
108. Determine if the level of coarse large woody debris (CWD) is within the range of natural
variability in terms of frequency and distribution and is sufficient to sustain stream channel
physical complexity and stability. Ensure proposed management activities move conditions
toward the range of natural variability.
27
The proposed project will not decrease the supply of large woody debris. The project will
promote the growth of more desirable species which should increase the long term supply
over the present.
Riparian Conservation Objective #4: Ensure that management activities, including fuels reduction actions, within RCAs and CARs
enhance or maintain physical and biological characteristics associated with aquatic- and
riparian-dependent species.
Standards and Guidelines Associated with RCO #4:
109. Within CARs, in occupied habitat or “essential habitat” as identified in conservation
assessments for threatened, endangered, or sensitive species, evaluate the appropriate role,
timing, and extent of prescribed fire. Avoid direct lighting within riparian vegetation;
prescribed fires may back into riparian vegetation areas. Develop mitigation measures to
avoid impacts to these species whenever ground-disturbing equipment is used.
The Lassen15 Restoration Project is located within a Critical Aquatic Reserve area for the
redband trout (Oncorhynchus mykiss). Ground disturbing equipment will not be used within
SMZ in the project area. Mitigation measures are included in National BMP Fire-A Use of
Prescribed Fire. See fisheries section for additional required mitigations.
110. Use screening devices for water drafting pumps. (Fire suppression activities are exempt
during initial attack.) Use pumps with low entry velocity to minimize removal of aquatic
species, including juvenile fish, amphibian egg masses, and tadpoles, from aquatic habitats.
During management activities water drafting may occur to help reduce dust in the project
area or used for fuels management. Utilization of a screening device to protect aquatic
species during activity would be utilized.
111. Design prescribed fire treatments to minimize disturbance of ground cover and riparian
vegetation in RCAs. In burn plans for project areas that include, or are adjacent to RCAs,
identify mitigation measures to minimize the spread of fire into riparian vegetation. In
determining which mitigation measures to adopt, weigh the potential harm of mitigation
measures, for example fire lines, against the risks and benefits of prescribed fire entering
riparian vegetation. Strategies should recognize the role of fire in ecosystem function and
identify those instances where fire suppression or fuel management actions could be
damaging to habitat or long-term function of the riparian community.
Prescribed burning would not directly ignite material in the RCA. Pile burning would occur
at or near landings. National BMP Fire-A would be followed to reduce potential effect to soil
and water quality.
28
112. Post-wildfire management activities in RCAs and CARs should emphasize enhancing
native vegetation cover, stabilizing channels by non-structural means, minimizing adverse
effects from the existing road network, and carrying out activities identified in landscape
analyses. Post-wildfire operations shall minimize the exposure of bare soil.
The Lassen15 Restoration Project is not a post-wildfire project.
113. Allow hazard tree removal1 within RCAs or CARs. Allow mechanical ground disturbing
fuels treatments, salvage harvest, or commercial fuelwood cutting within RCAs or CARs
when the activity is consistent with RCOs. Utilize low ground pressure equipment,
helicopters, over the snow logging, or other non-ground disturbing actions to operate off of
existing roads when needed to achieve RCOs. Ensure that existing roads, landings, and skid
trails meet Best Management Practices. Minimize the construction of new skid trails or roads
for access into RCAs for fuel treatments, salvage harvest, commercial fuelwood cutting, or
hazard tree removal.
Hazard tree removal utilizing low ground pressure equipment could be allowed in designated
RCAs. Equipment would not be allowed in SMZs; however, material could be removed
through end-lining. Under no circumstances would material be skidded along the stream
course.
114. As appropriate, assess and document aquatic conditions following the Regional Stream
Condition Inventory protocol prior to implementing ground disturbing activities within
suitable habitat for California red-legged frog, Cascades frog, Yosemite toad, foothill and
mountain yellow-legged frogs, and northern leopard frog.
There is no suitable habitat for California red-legged frog, Cascades frog, Yosemite toad,
foothill and mountain yellow-legged frogs, and northern leopard frog within the Lassen15
Restoration Project area.
115. During fire suppression activities, consider impacts to aquatic- and riparian-dependent
resources. Where possible, locate incident bases, camps, helibases, staging areas, helispots,
and other centers for incident activities outside of RCAs or CARs. During pre-suppression
planning, determine guidelines for suppression activities, including avoidance of potential
adverse effects to aquatic- and riparian-dependent species as a goal.
This requirement is not applicable because no fire suppression activities are proposed.
116. Identify roads, trails, OHV trails and staging areas, developed recreation sites, dispersed
campgrounds, special use permits, grazing permits, and day use sites during landscape
analysis. Identify conditions that degrade water quality or habitat for aquatic and riparian-
1 SNFPA 2004 Record of Decision, Riparian Conservation Objective #4, point 113, pg 64 to 65
29
dependent species. At the project level, evaluate and consider actions to ensure consistency
with standards and guidelines or desired conditions.
The project does not include a landscape analysis. However, the proposed actions are
consistent with the RCOs as discussed in this document.
Riparian Conservation Objective #6: Identify and implement restoration actions to maintain, restore or enhance water quality and
maintain, restore, or enhance habitat for riparian and aquatic species. (RCO # 6 is linked to all
AMS goals)
Standard and Guideline Associated with RCO #6
122. Identify roads, trails, OHV trails and staging areas, developed recreation sites, dispersed
campgrounds, special use permits, grazing permits, and day use sites during landscape
analysis. Identify conditions that degrade water quality or habitat for aquatic and riparian-
dependent species. At the project level, evaluate and consider actions to ensure consistency
with standards and guidelines or desired conditions.
Repair of weirs along Lassen Creek will improve habitat for fish and other fauna, slow
stream flow, and promote riparian vegetation growth. The culvert on FSR 46N30 on a
tributary of Lassen Creek was identified as impairing fish passage and determined to be
undersized and misaligned. Replacing the culvert is proposed.
30
Works Cited 2016 California Forest Practice Rules, California Code of Regulations, title 14, section 916.5,
Table 1, applied to all waterbodies. 2016. Accessed October 19, 2016.
http://bofdata.fire.ca.gov/regulations/ca_forest_practice_rules_other_title_14_codes/calif
ornia_forest_practice_rules/2016_forest_practice_rules_and_act.pdf.
California Regional Water Quality Control Board Central Valley Region. 2011. "The Water
Quality Control Plan (Basin Plan) for the California Regional Water Quality Control
Board Central Valley Region." Sacramento.
California Regional Water Quality Control Board Lahontan Region. 1995. "Water Quality
Control Plan for the Lahontan Region." South Lake Tahoe.
Dickard, M., M. Gonzalez, W. Elmore, S. Leonard, D. Smith, S. Smith, J. Staats, P. Summers, D.
Weixelman, S. Wyman. 2015. Riparian area management: Proper functioning condition
assessment for lotic areas. Technical Reference 1737-15. U.S. Department of the Interior,
Bureau of Land Management, National Operations Center, Denver, CO.
EPA. 2002. "Clean Water Act."
Frazier J.W., K.B. Roby, J.A. Boberg, K. Kenfield, J.B. Reiner, D.L. Azuma, J.L. Furnish, B.P.
Staab, S.L. Grant 2005. Stream Condition Inventory Technical Guide. USDA Forest
Service, Pacific Southwest Region - Ecosystem Conservation Staff. Vallejo, CA. 111 pp.
Goode, Jaime R., Charles H. Luce, and John M. Buffington. "Enhanced sediment delivery in a
changing climate in semi-arid mountain basins: Implications for water resource
management and aquatic habitat in the northern Rocky Mountains." Geomorphology 139
(2012): 1-15.
Guana, Forest J. 2015. "Lassen Allotment 9/17/15 Field IDT Fen Assessments. Message to N.
Semenza, A. Cuzick, S. Goheen, Z. Guerrero." October 9.
MDF Cumulative Watershed Effect Process Development of Threshold of Concern (TOC). 2010.
Alturas, CA: Modoc National Forest.
Pfankuch, P F. 1978. Stream Reach Inventory and Channel Stability Evaluation, USDA Forest
Service, R1. Washington, D.C.: Government Printing Office, 26.
PRISM Climate Group. 2001. Oregon State University. Accessed June 29, 2015.
http://prism.oregonstate.edu.
Robichaud, Peter R., William J. Elliot, Fredrisk B. Pierson, David E. Hall, and Corey A. Moffet.
2014. Erosion Risk Management Tool (ERMiT). Moscow, ID: U.S. Department of
Agriculture, Forest Service, Rocky Mountain Research Station.
http://forest.moscowfsl.wsu.edu/fswepp/.
31
Rosgen, David L. 1994. "A classification of natural rivers." Catena 169-199.
Sarmiento, Alvin. July 2016. "RE: Lassen15: Roads added to System. Message to N. Semenza".
USDA Forest Service. 1991. Land and Resource Management Plan. Modoc National Forest,
Alturas: Modoc National Forest.
USDA Forest Service. 2012. "National Best Management Practices for Water Quality
Management on National Forest System Lands."
USDA Forest Service. 2004. "Sierra Nevada Forest Plan Amendment Final Supplemental
Environmental Impact Statement Record of Decision, Pacific Southwest Region."
Vallejo, California.
USDA Forest Service. 2000. "Water Quality Management for National Forest System Lands in
California, Best Management Practices."
U.S. Department of the Interior Bureau of Land Management Proper Functioning Condition
Work Group, 1998, RIPARIAN AREA MANAGEMENT Process for Assessing Proper
Functioning Condition, Technical Reference 1737-9 1993; Revised 1995, 1998, U.S.
Department of the Interior Bureau of Land Management Service Center, Denver, CO.
Warner Mountain Ranger District, Modoc National Forest. 2000. Warner Mountain Rangeland
Project Environmental Assessment. USDA Forest Service, Pacific Southwest Region,
Modoc National Forest, Warner Mountain Ranger District.
Weaver, J. and Mehalick, S. 2010, Lassen Creek Watershed 2010 Summary Report, July 8-13,
2010, State of California Natural Resources Agency Department of Fish and Game
Heritage and Wild Trout Program.
Weixelman, Dave A., and J. Cooper David. "Assessing proper functioning condition for fen
areas in the Sierra Nevada and Southern Cascade Ranges in California, a user guide."
Gen. Tech. Rep. R5-TP-028. Vallejo, CA. US Department of Agriculture, Forest Service,
Pacific Southwest Region (2009): 4-4.
32
Appendix 1
National Best Management Practices: National Core BMP Monitoring
The National BMP Program was developed to improve agency performance and accountability
in managing water quality consistent with the Clean Water Act (CWA) and State water quality
programs. Current Forest Service policy directs compliance with required CWA permits and
State regulations and use of BMPs to control nonpoint source pollution to meet applicable water
quality standards and other CWA requirements.
In some cases, Regional BMPs were found to be more protective than the National BMPs.
Regional BMPs are prefaced by “R5”.
General Planning Activities
Plan-2 Project Planning and Analysis
The objective of this practice is to use the project planning, environmental analysis, and
decisionmaking processes to incorporate water quality management BMPs into project design
and implementation.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
Plan-3 Aquatic Management Zone Planning
The objective of this practice is to maintain and improve or restore the condition of land around
and adjacent to waterbodies in the context of the environment in which they are located,
recognizing their unique values and importance to water quality while implementing land and
resource management activities. Management activities in these zones are designated to improve
habitat for riparian dependent species. Additionally, objectives of SMZs are to provide for
unobstructed passage of stormflows, control sediment and other pollutants from entering
streamcourses, and restore the natural course of any stream as soon as practicable, where
diversion of the stream has resulted from management activities.
It is expected that development of RCAs (Riparian Conservation Areas) are included under these
BMPs. RCAs include aquatic and terrestrial ecosystems and lands adjacent to perennial,
intermittent, and ephemeral streams, as well as around meadows. The purposes of RCAs are to
protect these areas as well as dependent natural resources during site-specific project planning
and implementation2. Forest Strategy also maintains or restores soil properties and productivity
to ensure ecosystem health, soil hydrologic function, and biological buffering capacity3.
2 Sierra Nevada Forest Plan Amendment ROD, 2004, page 42 3 Sierra Nevada Forest Plan Amendment ROD, 2004, page 42-43
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Forest strategy provides direction to maintain or improve conditions for riparian dependent
resources. Riparian dependent resources are those natural resources that owe their existence to
the presence of surface or groundwater.
SMZ should not be considered replacement of RCAs, but a nested zone contained in the RCA
developed for the filtering capability of the streamside zone. All streamcourses would be
protected and assigned SMZs. The streamcourses mapped (, ) on the Project Area Map provides
information for development of watercourse protection maps.
Any material resulting from project activities causing obstruction of stormflows would be
removed.
All channels have designated SMZs, which is to be treated as an equipment exclusion
zones. Material may be removed from this zone however heavy equipment is excluded.
Ephemeral drainages would have minimum SMZs of 50 feet, intermittent 75 feet, and
perennial streams as well as springs and meadows would have a minimum SMZs of 100
feet based on field investigations.
No Borax or rodenticide would be applied within RCAs and SMZs.
Within Riparian Conservation Areas (RCAs) reduce as much as possible ground
disturbing impacts (i.e., soil compaction, vegetation disturbance, etc.).
BMPEP form T01 would be utilized to evaluate implementation on those units with
SMZs and other aquatic protection.
Riparian Conservation Objectives provide direction for the RCAs and prescribe widths of 300
feet either side for perennial streams, 150 feet for seasonally flowing streams, and 300 feet for
special aquatic features. Within this area all standards and guidelines for RCAs need to be met.
This area is a zone of closely managed activities and not a zone of equipment exclusion like
SMZs.
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Figure 12: Stream courses in the Lassen15 Restoration Project - North End
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Figure 13: Stream courses in the Lassen15 Restoration Project - South End
Aquatic Ecosystems Management Activities
AqEco-1 Aquatic Ecosystem Improvement and Restoration Planning
The objective of this practice is to reestablish and retain ecological resilience of aquatic
ecosystems and associated resources to achieve sustainability and provide a broad range of
ecosystem services.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
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AqEco-2 Operations in Aquatic Ecosystems
The objective of this practice is to avoid, minimize, or mitigate adverse impacts to water quality
when working in aquatic ecosystems.
AqEco-3 Ponds and Wetlands
The objective of this practice is to design and implement pond and wetlands projects in a manner
that increases the potential for success in meeting project objectives and avoids, minimizes, or
mitigates adverse effects to soil, water quality, and riparian resources.
AqEco-4 Stream Channels and Shorelines
The objective of this practice is to design and implement stream channel and lake shoreline
projects in a manner that increases the potential for success in meeting project objectives and
avoids, minimizes, or mitigates adverse effects to soil, water quality, and riparian resources.
Chemical Use Management Activities
Chem-1 Chemical Use Planning
The objective of this practice is to use the planning process to develop measures to avoid,
minimize, or mitigate adverse effects to soil, water quality, and riparian resources from chemical
use on NFS lands.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
Chem-2 Follow Label Directions
The objective of this practice is to avoid or minimize the risk of soil and surface water or
groundwater contamination by complying with all label instructions and restrictions required for
legal use.
Chem-3 Chemical Use near Waterbodies
The objective of this practice is to avoid or minimize the risk of chemical delivery to surface
water or groundwater when treating areas near waterbodies.
Chem-5 Chemical Handling and Disposal
The objective of this practice is to avoid or minimize water and soil contamination when
transporting, storing, preparing and mixing chemicals; cleaning application equipment; and
cleaning or disposing chemical containers.
Chem-6 Chemical Application Monitoring and Evaluation
The objective of this practice is to:
1. determine whether chemicals have been applied safely, have been restricted to intended
targets, and have not resulted in unexpected nontarget effects
2. document and provide early warning of possible hazardous conditions resulting from
potential contamination of water or other nontarget resources or areas by chemicals
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Wildland Fire Management Activities
Fire-1 Wildland Fire Management Planning
The objective of this practice is to use the fire management planning process to develop
measures to avoid, minimize, or mitigate adverse effects to soil, water quality, and riparian
resources during wildland fire management activities.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
Fire-2 Use of Prescribed Fire
The objective of this practice is to avoid, minimize, or mitigate adverse effects of prescribed fire
and associated activities on soil, water quality, and riparian resources that may result from
excessive soil disturbance as well as inputs of ash, sediment, nutrients, and debris.
Road Management Activities
Road-1 Travel Management Planning and Analysis
The objective of this practice is to use the travel management planning and analysis processes to
develop measures to avoid, minimize, or mitigate adverse effects to soil, water quality, and
riparian resources during road management activities.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
Road-2 Road Location and Design
The objective of this practice is to locate and design roads to avoid, minimize, or mitigate
adverse effects to soil, water quality, and riparian resources.
R5 Road-3 Road Construction and Reconstruction
The objective of this practice is to avoid or minimize adverse effects to soil, water quality, and
riparian resources from erosion, sediment, and other pollutant delivery during road construction
or reconstruction.
R5 Road-4 Road Operations and Maintenance
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources by controlling road use and operations and providing adequate
and appropriate maintenance to minimize sediment production and other pollutants during the
useful life of the road.
Road-5 Temporary Roads
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources from the construction and use of temporary roads.
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Road-6 Road Storage and Decommissioning
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources by storing closed roads not needed for at least 1 year (Intermittent
Stored Service) and decommissioning unneeded roads in a hydrologically stable manner to
eliminate hydrologic connectivity, restore natural flow patterns, and minimize soil erosion.
R5 Road-7 Stream Crossings
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources when constructing, reconstructing, or maintaining temporary and
permanent waterbody crossings.
Road-8 Snow Removal and Storage
The objective of this practice is to avoid or minimize erosion, sedimentation, and chemical
pollution that may result from snow removal and storage activities.
R5 Road-9 Parking and Staging Areas
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources when constructing and maintaining parking and staging areas.
Road-10 Equipment Refueling and Servicing
The objective of this practice is to avoid or minimize adverse effects to soil, water quality, and
riparian resources from fuels, lubricants, cleaners, and other harmful materials discharging into
nearby surface waters or infiltrating through soils to contaminate groundwater resources during
equipment refueling and servicing activities.
Road-11 Road Storm-Damage Surveys
The objective of this practice is to monitor road conditions following storm events to detect road
failures; assess damage or potential damage to waterbodies, riparian resources, and watershed
functions; determine the causes of the failures; and identify potential remedial actions at the
damaged sites and preventative actions at similar sites.
Mechanical Vegetation Management Activities
Veg-1 Vegetation Management Planning
The objective of this practice is to use the applicable vegetation management planning processes
to develop measures to avoid, minimize, or mitigate adverse effects to soil, water quality, and
riparian resources during mechanical vegetation treatment activities.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
Veg-2 Erosion Prevention and Control
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources by implementing measures to control surface erosion, gully
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formation, mass slope failure, and resulting sediment movement before, during, and after
mechanical vegetation treatments.
Veg-3 Aquatic Management Zones
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources when conducting mechanical vegetation treatment activities in the
AMZ.
Veg-4 Ground-Based Skidding and Yarding Operations
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources during ground-based skidding and yarding operations by
minimizing site disturbance and controlling the introduction of sediment, nutrients, and chemical
pollutants to waterbodies.
Veg-5 Cable and Aerial Yarding Operations
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources during cable and aerial yarding operations by minimizing site
disturbance and controlling the introduction of sediment, nutrients, and chemical pollutants to
waterbodies.
Veg-6 Landings
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources from the construction and use of log landings.
Veg-7 Winter Logging
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources from winter logging activities.
Veg-8 Mechanical Site Treatment
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources by controlling the introduction of sediment, nutrients, chemical, or
other pollutants to waterbodies during mechanical site treatment.
Water Uses Management Activities
WatUses-1 Water Uses Planning
The objective of this practice is to use the applicable authorization and administrative planning
processes to develop measures to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources during construction, operation, maintenance, and restoration of
water use infrastructure.
This document constitutes the incorporation of water quality and hydrologic consideration into
the project planning process.
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R5 WatUses-3 Administrative Water Developments
The objective of this practice is to avoid, minimize, or mitigate adverse effects to soil, water
quality, and riparian resources when developing and operating water sources for Forest Service
administrative and resource management purposes.
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Appendix 2
Cumulative Watershed Effects: Equivalent Roaded Acre (ERA) Method
Summary
The risk of cumulative watershed effects (CWE) is assessed using the Equivalent Roaded Acre
(ERA) method developed by R5 USFS. In this method, an index is calculated for an entire
watershed that expresses most land use in terms of the percent of the watershed covered by
roads. Based on the ERA and a threshold of concern (TOC), a given watershed is assigned a
relative risk – low, moderate, high, or very high – of CWE. The primary cumulative impact of
concern is an increase in sediment delivery to streams and degradation of aquatic habitat.
Important aspects of the ERA method
Roads, which are considered to have the greatest potential to increase runoff and sediment to
streams, are given a value of 1.0. The number of acres of roads in a watershed is divided by the
size of the entire watershed (in acres) x 100. This gives the percent of the watershed covered by
roads. For each land disturbance activity other than roads, the number of acres is multiplied by a
number less than 1.0 (Table 14).
Table 14: ERA coefficients for past and proposed activities
Activity ERA Coefficient
Mechanical thinning treatments (tractor) 0.15
Hand Thinning 0.01
Mechanical piling 0.12
Hand piling 0.02
Pile burning 0.03
Broadcast burning 0.08
Mechanical overstory removal and sanitation cut 0.20
Mechanical clearcut and seed-tree treatments 0.25
Mastication 0.04
Yarding 0.10
Constant Features
Road (Forest Service), miles. FS roads are assumed to be 13-feet wide 1.60
Road (Non-Forest Service and Private), miles, other roads are assumed to be 25’ wide 3.00
Grazing, suitable grazing areas as a proportion to watershed acres, this is considered a constant feature
3.00
The result (for each land disturbance activity) is then divided by the number of acres of the entire
watershed x 100.
This gives the percent of the “equivalent roaded acres” in the watershed for each type of land
disturbance.
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The values for equivalent roaded acres for all of the land disturbance activities are added
together. The final number represents the percent of the watershed that is covered by the
‘equivalent’ of roads.
The threshold of concern (TOC) is usually between 10 and 18 percent. That is, when 10 to 18
percent of a watershed is covered by the equivalent of roads, there is a “high risk” that increased
peak flows of streams and sediment delivery to streams will occur. This does not mean these
effects will occur precisely when the ERA reaches the TOC, or that an increase in peak flows
and sediment delivery to streams will automatically result in a degradation of fish habitat or
diminish the experience of recreationists. It is merely a warning that cumulative effects might
occur.
Assumptions and limitations of the ERA method
The method is intended for watersheds between 3,000 and 10,000 acres in size, although the
method is commonly used for watersheds slightly outside of this range.
ERA values, as well as the TOC, are only indicators of the risk of cumulative impacts occurring.
They cannot be used to determine the percent or numerical amount of increase of sediment
delivery to streams, stream channel eroded, fish habitat degraded or lost, or any other change in
watershed condition. Such quantitative assessments require additional analysis. The location of
land disturbance activities within a watershed is not considered. For example, roads near streams
are treated exactly the same as roads that are far from streams. In reality, roads located within or
next to riparian areas contribute more sediment to streams than roads in upland areas. Recovery
of the watershed from land disturbing activities occurs with time. For timber harvest activities,
hydrologic recovery is assumed to be thirty years (i.e. ERA contribution is zero thirty years after
timber harvest.)
The ERA calculations do not take into account site-specific BMPs that will be applied. ERA
values start one year after a land use is implemented.
ERA calculations for grazing use the suitable grazing acreage as a percentage of 6th field
watershed acreage multiplied by the ERA coefficient.
ERA calculations for existing roads assumed FS roads are 13 feet wide and private roads are 25-
feet wide. Roads listed as added or constructed under the proposed action are factored into the
ERA calculations. Because these roads already exist as non-system roads, there is no need for
additional construction, as these roads would added to the Forest Transportation system
(Sarmiento July 2016). Other non-system roads within the project area that are not proposed to
be added to the Forest Transportation System are not figured into the ERA calculations because
these roads will eventually return to their natural state. ERA calculations for decommissioned
roads are calculated by taking negative mileage of the roads multiplies by the ERA coefficient.
Decommissioning roads leads to a decrease in TOC used.
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Risk categories
Low risk of CWE - ERA is less than 50% of TOC
Moderate risk of CWE - ERA is between 50% and 80% of TOC
High risk of CWE - ERA is between 80% and 100% of TOC
Very high risk of CWE - ERA is greater than TOC
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Appendix 3
Erosion Risk Management Tool
User Inputs*
FORT BIDWELL CA
clay loam soil texture, 20% rock fragment
13% top, 19% average, 30% toe hillslope gradient
1000 ft hillslope horizontal length
high soil burn severity on forest
*User inputs were modeled on a 1,000-foot slope within the Cold Creek 7th field watershed.
100 - YEAR MEAN ANNUAL AVERAGES
Total in 100 years
16 in annual precipitation from 8548 storms
0.23 in annual runoff from rainfall from 318 events
0.32 in annual runoff from snowmelt or winter rainstorm from 181 events
Rainfall Event Rankings and Characteristics from the Selected Storms
Storm Rank based on runoff (return interval)
Storm Runoff (in)
Storm Precipitation (in)
Storm Duration (h)
10-min Peak Rainfall Intensity (in h-1)
30-min Peak Rainfall Intensity (in h-1)
Storm Date
1 1.31 2.19 2.68 2.79 2.25 March 14 year 66
5 (20-year)
0.83 1.53 2.10 1.17 1.07 March 13 year 59
10 (10-year)
0.71 1.52 3.68 2.61 1.93 July 17 year 4
20 (5-year)
0.55 1.24 4.61 2.00 1.51 November 8 year 25
50 (2-year)
0.25 1.24 5.25 N/A N/A January 17 year 17
75 (11/3-year)
0.11 0.80 3.86 1.29 0.97 May 31 year 42
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Sediment Delivery
Probability that sediment yield will be exceeded
20%
Event sediment delivery ( ton ac-1 )
Year following fire
1st year 2nd year 3rd year 4th year 5th year
Untreated 1.86 0.32 0 0 0
Erosion Risk Management Tool event sediment delivery table
There is a 20% chance that sediment delivery will exceed 1.86 ton/ac in the first year following
the fire.
There is a 20% chance that sediment delivery will exceed 0.32 ton/ac in the second year
following the fire.
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Appendix 4 Figure 14: Restoration work location map
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Figure 14: Restoration work location map