Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-1

Affected Environment and Environmental 

Consequences

3-10 Soil and Cumulative Watershed Effects

3-10.1 Introduction

The following section provides the scope of analysis, methodology, and indicators as well as the current 

affected environment to assess the environmental consequences of the alternatives for soils. The direct, 

indirect and cumulative effects to the soil resource are summarized from the soil specialist report 

Gallegos, 2010 for the KREW project. 

3-10.2 Scope of Analysis, Methodology, and Indicators

3-10.2.1 Scope of the Analysis

The scope of analysis for soil conditions includes an assessment of existing soil types in the project area, 

the collection of soil data, and evaluation of predicted post-treatment soil productivity. This provides 

base data to describe and analyze existing and desired soil conditions (as defined by the regional soil 

standards and guidelines (USDA Forest Service 1995) and management direction provided in the SNF 

LRMP (USDA Forest Service 1991), and to estimate expected effects of the Proposed Action and 

alternatives. Indicators are provided as guidelines to evaluate soil productivity. 

In addition to supporting native vegetation and wildlife, soil plays a critical role in supporting watershed 

and ecosystem health through the functions of accepting, storing, and releasing water. This is known as 

soil hydrologic function. The soil analysis for this Proposed Action is limited to the soil in the analysis 

area. The project area will be used as the geographic basis for analysis for the action alternatives. For the 

No-Action Alternative, the entire analysis area will be used to analyze the impacts of a potential wildfire

The temporal scope for assessment of soil resource environmental effects includes short term 

(1–10 years following vegetation treatment) and long term (10 to 30 years following vegetation 

treatment). This timeframe captures both the immediate effects of the project activities and the 

expected impacts at the point where they are no longer discernable from other activities. The 

cumulative watershed effects analysis uses a 30-year recovery time frame.

Policies that guide vegetation management practices in order to sustain soil quality are found in the 

national and regional Forest Service manuals and handbooks. Soil quality standards and indicators are 

applied to activity areas. For this analysis, activity areas are defined as the individual treatment stands 

and include vegetation treatment stands as described in the proposed action. The activity area is 

considered an appropriate geographic unit for assessing environmental effects to soil because soil 

productivity is a site-specific attribute of the land; soil productivity of one area is not dependent on the 

productivity of an adjacent area. Therefore, the activity area is used in this analysis as the geographic 

unit for assessing direct, indirect, and cumulative soil environmental effects. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-2

Soil quality standards are intended to apply on an area basis. This means that detrimental soil 

disturbance, as defined by the standards, should not exceed a given percentage of the activity area. The 

allowable detrimental soil disturbance is 15 percent as measured within an activity area or treatment 

area. 

Soil productivity is maintained by effective implementation of regional soil S&Gs (USDA Forest Service 

1995) and management direction provided in the SNF LRMP (USDA Forest Service 1992) and the 2004 

SNFPA. Standard and Guidelines 94 and 122 from the 1991 SNF LRMP are specifically applicable. 

3-10.2.2 Methodology and Modeling Used in the Analysis

This report includes information related to the existing (‘baseline’) condition of soil resources and the 

direct, indirect, and cumulative effects of the alternatives. Analysis approaches and indicators are 

described below. Baseline conditions for soil are based on soil grid data collected by PSW including soil 

cover, soil porosity and large woody debris. In addition, Forest Service stand exam data was used to 

further assess large woody debris by treatment unit. The effects analysis is based on soil monitoring 

data that has been collected on the SNF and research publications. In particular, the 2004 North 

American Long-Term Soil Productivity Experiment: Coast-To-Coast Findings From The First Decade is 

used to estimate effects on soil productivity from logging. In addition, a 2006 study of thinning and 

prescribed fire in Teakettle Experimental Forest quantified effects to soil indicators.

Potential effects of soil erosion, soil productivity, and water quality are largely based on an effects 

analysis of direct, indirect and Cumulative Watershed Effects (CWE). The CWE analyses is partially 

based on the CWE Analysis for Kings River Project (Gallegos, 2006), which is presented in terms of 

changes in Equivalent Road Area (ERA). In the ERA approach the percent ERA in a sub-watershed is 

used as an index of watershed disturbance and the risk of impacts to watershed health. Each acre of 

activity is multiplied by a coefficient to express its level of disturbance to watershed function. The 

coefficients for vegetation management activities are established according to silviculture prescription, 

logging system, and soil types. ERAs are reduced over time, assuming a period to recovery of baseline 

conditions of 30 years (USDA 1990: Chapter 20). 

The potential effects from the proposed treatments and from potential future wildfires are evaluated 

against the Soil Quality Standards. Effects that meet these standards are considered to be less than 

significant. To evaluate the comparative effects on soil quality, results from vegetative loss modeling 

(See Fire/Fuels Specialist Report) were used.

3-10.2.3 Soil Indicators

Soil types and properties are established in the SNF Soil Survey (Giger, 1993). Soil pits were excavated 

and distributed throughout both the Providence and Bull management units to obtain site-specific data 

on soil porosity, soil cover, and large woody debris (LWD) and provide baseline soil conditions from

which to compare future soil conditions. Data were collected by PSW (Fresno) and Carolyn Hunsaker, 

coordinator for the KREW studies, provided raw data in the form of Microsoft Excel spreadsheets and 

ACCESS Database information. This information was evaluated and analyzed and found to meet the 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-3

standards for determining if soil conditions meet Forest Soil Standard and Guidelines. LWD was 

collected using a different protocol than what is used in Region 5 Soil Management Handbook 

Supplement for soil monitoring. The R5 method calls for counting LWD over 10 feet long and at least 12 

inches in diameter, within a 37 foot radius, at every 5th point, along a 20-point transect, whereas the 

KREW protocol measures all LWD along a transect, in 1 square meter (m) quadrants, at 2, 7 and 12 m 

along a 22 m transect (Gallegos, 2006). Determining whether LWD measurements along KREW 

transects meet Regional Soil S&Gs is difficult because of the different protocols. However, 5 logs that are 

10 feet long and 12 inches in diameter would cover a 50 square feet, which is 0.1 percent of an acre. 

This suggests that 0.1 percent cover in a 1 square meter quadrant meets the 5 pieces of large woody 

debris per acre requirement.

Soil quality metrics used as the basis for the effects analysis are defined and discussed below:

3-10.2.4 Soil Porosity

Soil porosity is the space between individual particles and influences the rate of transmission of air and 

water (hydraulic conductivity) through soils. Reduced soil porosity reduces the air and water available 

to plant roots, creating anaerobic and/or dry conditions. Furthermore, reduced soil porosity makes the 

soil denser, creating more of a challenge for roots to penetrate. Thus, maintenance of natural soil 

porosity is important for maintaining healthy native plant communities and for maintaining the 

hydrologic function of the soil. Since soil compaction decreases infiltration and hydraulic conductivity, it 

may consequently increase surface runoff, erosion potential and reduce groundwater recharge, thereby 

causing effects at the watershed scale and beyond (i.e. 'cumulative watershed effects’). 

3-10.2.5 Soil Cover

Soil cover refers to effective soil cover for reducing the risk of accelerated erosion and includes living 

vegetation (grasses, forbs, and prostrate shrubs), plant and tree litter (fine organic litter), surface rock 

fragments, and applied mulches. Accelerated erosion can impair site productivity and water quality. 

The A-horizon is the most fertile and biologically active part of the soil profile due to its enrichment by 

organic matter in varying stages of decomposition. Loss of all or part of this horizon through erosion 

impairs the ability of the soil to support natural vegetation communities and often imparts a competitive 

advantage to non-native invasive species (weeds). When eroded soil is deposited in water bodies, it can 

impact water quality and aquatic habitats. 

3-10.2.6 Large Woody Debris 

LWD provides microhabitat and nutrients for soil flora and fauna (e.g., bacteria, fungus, and insects). It 

also helps reduce overland flow of water and trap sediment that may be mobilized by overland flow. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-4

3-10.2.7 Cumulative Watershed Effects 

A cumulative watershed effects (CWE) assessment was conducted for the KREW Project following the 

direction set forth in FSH 2509.22, and includes a qualitative discussion about how the direct and 

indirect effects are likely to be transmitted through the stream system. Two thresholds of concern (TOC) 

are employed in the analysis, a lower TOC and an upper TOC. The purpose of the lower TOC is to identify 

those watersheds where the risk of CWE could occur in order to initiate a detailed, field-based, 

cumulative watershed effects analysis. The upper TOC is the level where cumulative effects are expected 

to occur and, accordingly, management actions are adjusted to avoid exceeding the upper TOC. The 

lower TOC is variable based on sensitivity of the watersheds. The upper TOC on the SNF is established at 

14 percent (Gallegos 2006). 

The Baseline Assessment (Gallegos, 2006) was conducted using the ERA model to determine if the ERAs 

in any subwatersheds are currently at or over their lower TOC. ERA values are derived by assigning 

each land disturbing activity, e.g., timber harvest log landings, stock yarding sites, and mine sites, a 

numerical coefficient equating such disturbance to that of a road. A road is assumed to be the largest 

impact on a watershed and has a coefficient of 1. For example, 5 miles of road would have an ERA of 5. 

Other disturbance coefficients are varying degrees of effect less than 1. A summary of ERAs for activities 

conducted in a watershed are then compared to the total acres in a watershed and a percent ERA is 

established. 

In the ERA model, the percent ERA in a subwatershed is used as an index of watershed disturbance and 

the risk of impacts to watershed health. Coefficients for vegetation management activities are 

determined based on silvicultural prescription, logging system, and soil types. ERAs are prorated by 

their age, assuming a recovery period of 30 years (USDA 1990: Chapter 20, Gallegos 2010).

Major assumptions that were used in the CWE analysis include:

The scale of the analysis is equivalent to a HUC 8 watershed, which for the project area 

ranges from approximately 600 to 1,950 acres.

Subwatersheds vary in their sensitivity to management based on their watershed 

characteristics that include percent of unstable lands, percent of sensitive soils, and the 

bifurcation (breaking into two) ratio of the channels in the subwatershed.

An upper limit to tolerance to disturbance exists for each watershed. This limit, or upper 

TOC, has been estimated to be 14 percent for each watershed measured in terms of ERA. 

The risk of initiating adverse CWE greatly increases as this upper limit is approached 

and exceeded. 

A lower limit to tolerance of disturbance exists for each watershed based on its 

watershed sensitivity. This limit, or lower TOC, has been estimated to be 4 percent for 

highly sensitive watersheds, 5 percent for moderately sensitive watersheds, and 6

percent for watersheds with a low sensitivity. The purpose of the lower TOC is to 

identify those watersheds where the risk of CWE could occur to conduct a detailed, field 

based, cumulative watershed effects analysis. Subwatersheds currently under the lower 

TOC have been determined to not have concerns for CWE and are not further analyzed 

in the detailed CWE analysis.
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-5

Management activities can be measured in terms of ERA. This is referred to as the ERA 

model. 

Key indicators of unacceptable degradation can be identified for watershed processes. 

An indicator of a cumulative watershed effect response could be one or more of the 

following: filling of channel pools with fine sediment; unstable channel banks; and/or 

poor aquatic habitat.

Land disturbances recover to 95 percent in 30 years.

The potential for initiating adverse CWE can be reduced by dispersing land disturbing 

activities in time and space; controlling the physical size, shape, location, and timing of 

land disturbing activities; and implementing best management practices to mitigate 

adverse onsite effects.

Watersheds should not reach or exceed the upper TOC of 14 percent.

The baseline CWE assessment was conducted using 2011 as the base year, with project implementation 

being initiated that same year. The baseline assessment and ERA calculations considered existing roads 

and trails, grazing, past logging and timber harvesting and the planned Dinkey North and Dinkey South 

Projects (see Appendix). Future foreseeable actions, including the Soaproot Project and East Fork 

Project are proposed in subwatersheds 519.0008, 519.0011, and 520.3151. These projects have been 

considered qualitatively in the CWE assessment and are not accounted for in the ERA calculations.

3-10.3 Affected Environment

3-10.3.1 Regulatory Setting

Soils

Direction relevant to KREW Project as it affects the soil resource includes the following:

National Forest Management Act, 1976: Renewable Resource Program includes “(C) recognize 

the fundamental need to protect and, where appropriate, improve the quality of soil, water, and air 

resources.”

Forest Service Manual 2526.03-2: This policy manages riparian areas under the principles of 

multiple use and sustained yields, while emphasizing protection and improvement of soil, water, 

vegetation, and fish and wildlife resources. It gives preferential consideration to riparian 

dependent resources when conflicts among land use activities occur. 

Forest Service Manual 2500 – Watershed and Air Management, Chapter 2550 – Soil 

Management, Amendment No. 2500-2010-1, Effective Date: November 23, 2010. The 

objective of this manual direction is to: maintain or restore soil quality on National Forest System 

lands; and manage resource uses and soil resources on National Forest System lands to sustain 

ecological processes and function, so that desired ecosystem services are provided in perpetuity.
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-6

SNF Forest Land and Resource Management Plan, 1991: This plan provides for soil 

management S&Gs to all management areas and analysis areas or aggregates of analysis areas. The 

pertinent S&Gs are presented below:

1. Avoid tractor logging on highly erodible soils, where sustained slopes exceed 35 percent, 

except where supported by on-the-ground ID team review (SG 125).

2. Apply appropriate erosion prevention measures on all ground-disturbing activities (FSH 

2409.23) prior to fall storms (October 1) and immediately upon completion of activity 

begun after November 1 (SG 127).

3. Apply appropriate erosion prevention measures on high erosion hazard soils under the 

following conditions (SG 128):

a. When exposed soils from an average of several 500-foot linear transects:

i. Exceed 150 feet on slopes of 15-35 percent,

ii. Exceed 75 feet on slopes 35-65 percent, or

iii. Exceed 25 feet on slopes over 65 percent,

b. On linear disturbances, such as skid trails and fire lines, cross-drain area at the 

following intervals: 

 

Interval between cross-drain (feet)

% Slope

HEHR

(High Erosion 

Hazard Ratings)

VHEHR

(Very High Erosion 

Hazard Ratings)

0-15 150 125

15-35 75 45

35-65 35 20

65+ 15 15

4. Road construction on areas with high and very high erosion hazard will follow standards on 

areas with high and very high erosion hazard will follow standards in FSM 2521, Sierra Supp. 

No. 8, which gives direction concerning soil stabilization and road surface drainage (SG 129 and 

LMP Letter of Correction, USDA, 2009). 

5. Plan and execute activities such as timber harvesting, site preparation and fuels reduction on 

soils sensitive to loss of productivity by using the following standards (see FSH 2509.18):

a. Avoid mixing or removing soils below the A horizon. Roads, skid trails, fire lines 

and log landings are exceptions. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-7

b. On completion of a ground disturbing project on less than 35 percent slope, 

maintain an average accumulation of 50 percent protective ground cover density in the 

1- to 100-hour fuels with some 1000-hour fuels up to 10” in diameter1. 

c. On slopes over 35 percent with very High and/or High Erosion Hazard soil, an 

ID team will evaluate ground cover needs and develop prescriptions.

3-10.3.2 Existing Condition

The Bull Unit map ranges in elevation from approximately 7,050 to 8,100 feet and roughly corresponds 

to the limits of the Bull Creek Watershed, also referred to as subwatershed 520.3002. The boundary of 

the management unit also includes adjacent subwatersheds, including the headwaters of Deer Creek 

(520.3052) and the headwaters of the East Fork of Deer Creek (520.3151). Bull Creek is a tributary to 

Deer Creek, which flows into Dinkey Creek. Dinkey Creek flows into the North Fork of the Kings River 

upstream of Pine Flat Reservoir. 

The Providence Unit ranges in elevation from 4,000 to 6,600 feet, somewhat lower than the Bull Creek 

watershed, and does not correspond as closely to watershed boundaries as the Bull Unit. Several 

privately-owned parcels abut and surround parts of the Providence Unit. As such, the Providence Unit 

includes the headwaters of a number of streams. HUC-8 subwatersheds in the KREW Project area are: 

Lost Creek (519.0005)

Duff Creek (519.0007)

Providence Creek and experimental watershed (519.0008)

Un-named tributary to Big Creek (519.0011)

Dinkey Meadow Creek (520.0014)

Forked Meadow Creek (520.0016)

Glen Meadow Creek (520.0017)

Bull Creek (520.3002)

East Fork Deer Creek (520.3151)

PSW researchers have instrumented portions of these watersheds and delineated additional 

subwatersheds (or ‘sub-subwatersheds’) within the HUC-8 subwatersheds. For research purposes, 

these are referred to as B201, B203, and B204 in the Bull Creek watershed. A portion of the Teakettle 

Creek watershed (T003) will be used a control for the Bull Creek research area and, as such, no 

treatments are proposed in this area. Research sub-subwatersheds in the Providence Unit are referred 

to as P301, P303, P304, and D102. P304 is the control for the Providence Creek research area, and D102 

is located within the Duff Creek watershed. 

 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-8

Cumulative Watershed Effects

The baseline assessment of the nine subwatersheds in the KREW Project area identified three 

subwatersheds 520.0014, 520.0016, and 520.0017 that are exceeding their lower TOC value due to past, 

present and future foreseeable actions (see Table 3-10-1). The only subwatershed where a detailed 

assessment was conducted is subwatershed 520.0014. Subwatersheds 520.0016 and 520.0017 show 

ERA above their respective lower TOC and have not had a detailed CWE assessment. The ERA values in 

the baseline assessment for subwatersheds 520.0016 and 520.0017 include treatment acres planned in 

the Dinkey North and Dinkey South Projects. These projects are planned to be implemented in 2011. 

The ERA values in these subwatersheds without the Dinkey North and Dinkey South Projects are well 

below their lower TOC values of 4.00 percent and 5.00 percent.

Table 3-10-1. Cumulative Watershed Effects (CWE) Baseline Assessment Values

SUBWS # Total WS 

Acres

Watershed 

Sensitivity

Lower 

TOC

Grazing 

Allotment 

ERA

Roads 

ERA

Harvest 

ERA

Total 

ERA

519.0005 1,140 High 4.0% 0.95 0.78 0.44 2.18

519.0007 1,719 High 4.0% 1.00 1.04 1.76 3.81

519.0008 1,976 High 4.0% 0.80 1.00 1.93 3.74

519.0011 1,246 High 4.0% 0.95 0.41 2.51 3.87

520.0014 1,066 Moderate 5.0% 1.18 1.56 6.33 9.07

520.0016 591 Moderate 5.0% 0.92 1.54 4.66 7.12

520.0017 1,952 High 4.0% 1.33 1.23 4.44 7.01

520.3002 1,661 Moderate 5.0% 0.76 1.47 0.63 2.86

520.3151 1,317 Moderate 5.0% 0.75 1.13 0.61 2.50

520.0014 was reviewed in the field by a watershed interdisciplinary team to determine whether a CWE 

response is currently occurring and to determine the risk of triggering a CWE response, as a 

consequence of implementing the Kings River Project (Sanders and Hopson, 2005, Hopson, 2005). 

Private land occurs on 791 acres of the 1066-acre watershed. Southern California Edison treated 320 

acres of the private land as recently as 1995 and 2005. Visual observations showed stable stream banks 

and little sediment in the channel. Large woody debris was common throughout the reach. Evidence of 

CWE were not observed in this subwatershed.

Subwatersheds 520.0016 and 520.0017 were not reviewed in the field because the baseline Total ERAs 

are over the lower TOC from future foreseeable actions from activities planned in the Dinkey North and 

Dinkey South Projects. Baseline evidence of CWE are not expected to occur in these subwatersheds,

because actual existing ERA are not above the lower TOC values of 5.00% and 4.00% respectively.

Measurements of sediment depth in pools suggest that sediment accumulation is on the order of 10%, 

which is at the desired condition of 10-20 percent pool sedimentation. Embeddedness, a measure of fine 

sediment intrusion into the channel substrate (primarily gravels), was low throughout the reach. 

Aquatic species survey data is not available for this sub-watershed (Hopson, 2005). Based on the data 

collected, it did not appear that this sub-watershed is experiencing a CWE response (Gallegos, 2006). 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-9

The Providence Unit soils are underlain primarily by Mesozoic granitic rocks with inclusions of 

Mesozoic basic intrusive rocks (Bateman and Wones, 1972). The Bull Unit soils are underlain primarily 

by pre-Cretaceous metasedimentary rocks and Mesozoic granodiorite (Matthews and Burnett, 1965).

The Providence and Bull management units are underlain by 13 soil types, which vary in their 

sensitivity to management. Potential effects on soils include the following: 

1. Areas commercially thinned with ground-based logging systems, e.g., tractor piling, may 

compact soils that are highly susceptible to reduction of soil porosity caused by heavy 

equipment operating when soils are moist or wet.

2. Areas commercially thinned with ground-based logging systems on slopes that are too steep or 

have shallow soils will displace soil horizons that could result in accelerated erosion and 

reduced soil productivity.

3. Areas treated with prescribed fire will have reduced soil cover and accelerated erosion may 

occur, resulting in a loss of soil productivity.

KREW Providence Soils

In the Providence Unit, soils are mostly Shaver family, Gerle family, Cagwin family, Dystric Lithic 

Xerocrepts and Holland family soils (See Figure 2). The Shaver family and Holland family soils are both 

deep (over 40 inches), well drained soils derived from granitic parent material; however, the Shaver 

family soil is a coarse sandy loam, whereas the Holland family is a sandy clay loam. The Gerle family and 

Cagwin family soils are moderately deep (20 to 40 inches), well drained to somewhat excessively 

drained soils derived from granitic parent material; these soils range from loamy coarse sand to coarse 

sandy loams. The Dystric Lithic Xerocrepts are shallow (less than 20 inches) and somewhat excessively 

drained soils derived from metasedimentary parent material; this soil is a combination of cobbly loam 

and rock outcrop. Small areas of Chawanakee family, Chaix family and Cannel family soils are also 

present. 

Gallegos (2006) concluded existing conditions for soil porosity, soil cover, and large woody debris 

within the Providence Unit meet the Regional Soil S&Gs. The basis for this conclusion is summarized 

below:

Nineteen soil pits were excavated in the Providence sub-watersheds: Five in sub-watershed P301, four 

in sub-watershed P303, four in sub-watershed P304, and six in sub-watershed D102. One sample in 

sub-watershed D102 and another sample in sub-watershed P304 have soil bulk density values of 1.37 

and 2.17 g/cm3, respectively. These values are on the outer range for soil bulk density for the soil types 

and could indicate compaction in the A-horizon. Based on all the soil bulk density data, 11 percent of the 

soils in the Providence Management Unit are compacted. 

Fifty-two vegetation transects that measure soil cover and LWD were completed in the Providence subwatersheds: 14 in sub-watershed D102, 13 in sub-watershed P301, 15 in sub-watershed P303, and 10 in 

sub-watershed P304. Soil cover ranged from 77 to 95 percent and large woody debris ranged from 16 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-10

to 20 percent. Based on all the soil cover and large woody debris data, there is an average of 89 percent 

soil cover and 18 percent large woody debris throughout the Providence Management Unit. 

Holland family soils are most sensitive to management. They have a moderate soil compaction hazard 

and a high to very high maximum erosion hazard rating. These soils are located in the southwest corner 

of the management unit as soil map units 137 and 139. Some areas with Holland family soils are 

proposed for thinning. Soil compaction in moist, fine-textured soils (e.g., clays or clay loams) can occur 

down to 12 inches deep, while soil compaction in coarse-textured soils (e.g., sands or loams) generally 

does not occur and, in some cases, may actually increase soil productivity by increasing the available 

water holding capacity (Powers et al., 2005). Approximately 135 acres of the Providence Unit has been 

treated with mechanical equipment in the last 5 years and the area with Holland family soils has some 

compaction limited to the existing skid trails (Gallegos 2005).

Soil map units with high amounts of impervious surfaces such as rock outcrop or shallow soil are also 

sensitive to management because they are susceptible to runoff and subsequent erosion of soil adjacent 

to the rock outcrop. These soils are located along the northern edge and in a band trending northwest 

through the center of the management unit as map units 116, 148 and 150. Some areas with these soils 

are proposed for thinning and others are proposed for thinning and burning. These soils have very slow 

infiltration and transmission rates, which may result in increased runoff from and subsequent erosion of 

soils adjacent to the impervious surfaces.

KREW Bull Soils 

In the Bull Unit, soils are mostly Cagwin family, Cannel family, Gerle family, and Typic Xerumbrepts 

(Figure 2). These soils are moderately deep (20 to 40 inches) to deep (over 40 inches), somewhat 

excessively drained to well drained soils derived primarily from granitic parent material. Soil textures 

for these soils range from loamy coarse sand to coarse sandy loams. Small areas of rock outcrop are also 

present. 

Gallegos (2006) concluded existing conditions for soil porosity, soil cover, and large woody debris 

within the Bull Unit meet the Regional Soil S&Gs. The basis for this conclusion is summarized below.

Twenty five soil pits were excavated in the Bull sub-watersheds: Six soil pits in sub-watershed B201, six 

soil pits in sub-watershed B203, six soil pits in sub-watershed B204 and seven soil pits in sub-watershed 

T003. Two samples in sub-watershed B201 and one sample in B203 have soil bulk density values of 

1.40, 1.42 and 1.39 g/cm3, respectively. These values are on the outer range for soil bulk density for the 

soil types and could indicate compaction in the A-horizon. Based on all the soil bulk density data, 12 

percent of the soils in the Bull Unit are compacted. 

Sixty vegetation transects that measure soil cover and LWD were completed in the Bull sub-watersheds: 

10 in sub-watershed B201, 15 in sub-watershed B203, 15 in sub-watershed B204, and 20 in subwatershed T003. Soil cover ranged from 85 to 94 percent and LWD ranged from 23 to 32 percent. Based 

on all the soil cover and LWD data, there is an average of 91 percent soil cover and 27 percent LWD

throughout the Bull Unit. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-11

There are no Holland family soils in the Bull Unit. Soil map units with high amounts of impervious 

surfaces such as rock outcrop or shallow soil are the most sensitive to management. These soils are 

located in the center of the management unit as map unit 116. Some areas with these soils are proposed 

for burning. These soils have very slow infiltration and transmission rates, which may result in 

increased runoff and subsequent erosion of soils adjacent to the impervious surfaces.

LWD and snag levels in the proposed treatment units were also intensively sampled as part of the 

inventory of vegetative conditions. Approximately 325 LWD plots and snag plots were systematically 

located across the project area and samples of almost all stands were conducted. These plots were 1/8 

rectangular plots and downed logs were tallied it they were at least 10 inches in diameter at the large 

end and at least 10 feet long. Snags larger than 9 inches dbh were also measured. These protocols were 

deemed sufficient by the Forest Soil Scientist to meet monitoring protocol requirements for the Soil 

Quality Standards. Tables 3-10-2 and 3-10-3 provide a summary of the number of large logs per acre 

and snag per acre in each of the stands. These data indicate that the area currently exceeds 5 downed 

logs per acre, meeting the R5 Soil S&Gs. Snags are an important component of long-term soil 

productivity because they provide for future recruitment of organic matter over time as the current 

LWD decomposes. Table 3-10-3 summarizes the number of snags per acre in each of the treatment 

stands. 

LWD data indicated that all stands currently have at least 5 logs per acre and meet the R5 Soil S&Gs. 

However the data shows that the average mean diameter of the logs are less than 20” in diameter for 

most of the treatment units. This is not to say that there are not at least 5 logs per acre that are 20” in 

diameter and 10’ long. The data supports a determination that there is sufficient LWD to maintain long 

term soil productivity.
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-12

Table 3-10-2 - Large Woody Debris (Logs) per Acre in Treatment Stands 

Treatment 

Stand

Logs per Acre Cubic Feet per 

Acre

Tons per Acre Average Mean Log 

Diameter

KREW Bull

796 17.68 1397 12.8 20.23

811 10.22 869 6.82 19.79

838 21.09 1111 8.43 19.16

961 13.18 970 7.53 17.82

962 20.80 762 5.48 15.64

964 14.74 1612 13.69 21.64

965 11.50 1094 10.33 18.66

1043 17.78 1037 10.58 12.67

1056 17.41 2048 16.37 20.20

1057 21.65 16.16 14.27 16.82

KREW 

Providence

235 9.85 995 9.31 14.92

236 8.00 672 5.37 15.43

280 8.94 1254 10.03 19.25

281 12.92 1160 11.00 17.97

295 13.33 788 8.35 10.28

299 8.00 444 3.83 10.42

301 12.50 1355 11.04 15.71

306 22.00 1344 11.99 22.00

316 17.00 1550 12.52 19.99

331 11.73 480 5.08 11.77

346 10.29 1788 15.95 19.81

365 16.73 1001 6.47 16.46

380 12.00 662 4.36 10.37

449 11.73 2137 16.03 16.85

454 9.6 1131 15.91 11.90

499 23.00 1166 10.61 13.35
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-13

Table 3-10-3 - Snags per Acre in Treatment Stands 

Treatment Stand BSNG1524 BSNG2435 BSNG35up SNG_15UP

KREW Bull

796 2.1 0.9 1.4 4.4

811 1.1 1.3 1.6 3.9

838 3.1 0.8 0.9 4.9

961 5.1 1.8 0.5 7.5

962 1.3 0.8 1.1 3.2

964 1.8 1.3 0.1 3.1

965 1.7 0.5 0.0 2.2

1056 1.3 0.9 1.0 3.3

1057 5.7 2.5 1.8 10.1

Average 2.6 1.2 0.9 4.7

KREW Providence

208 2.7 1.7 1.0 5.4

235 9.1 4.2 1.6 14.9

236 2.0 1.2 0.2 3.5

250 2.2 1.2 1.9 5.3

280 4.3 1.4 2.4 8.1

281 5.8 2.6 0.3 8.6

292 0.4 1.1 0.0 1.5

295 5.8 1.3 0.1 7.1

299 3.8 0.5 0.0 4.3

301 6.9 4.3 0.3 11.4

306 6.1 1.2 1.0 8.3

316 2.2 2.0 1.0 5.2

331 5.3 1.9 0.7 7.9

346 2.0 0.4 0.7 3.1

365 2.2 0.6 1.0 3.8

380 5.7 2.2 0.9 8.8

449 4.1 0.4 0.0 4.5

450 1.4 0.6 0.2 2.2

499 0.7 0.1 0.0 0.8

1043 2.7 0.3 0.0 3.0

Average 3.8 1.5 0.7 5.9

Grand Total 3.7 1.4 0.8 6.0

The data indicate that the following stands are of concern with regard to the number of snags per acre: 

965, 292, 450, 499, and 1043. These low levels of snags are a potential concern for long-term soil 

productivity as the snags provide a source of future recruitment for LWD on the soil surface that 

eventually breaks down to provide soil organic matter. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-14

3-10.3.3 Desired Condition

Desired conditions for soils have been identified in several Forest Service planning documents that 

are applicable to this project. The following are desired conditions for soil resources in the KREW 

Project:

1. Enhance or maintain soil physical, chemical, and biological properties that support the 

productive capacity of the land, its ecological processes, such as, hydrological function of 

watersheds, and the ecosystem services identified in land management plans (USDA Forest 

Service, 2010). 

2. Soil with favorable infiltration characteristics and diverse vegetative cover absorb and filter 

precipitation and sustain favorable conditions of stream flow (USDA Forest Service, 2004). 

3. Implement practices designed to retain soil stability and maintain site productivity (USDA 

Forest Service, 1991)

4. The thresholds and indicators represent desired conditions for the soil resource. Use of the 

thresholds and indicators provides a consistent method to analyze, describe, and report on soil 

condition throughout the region. The following are a list of the Regional Soil S&Gs that apply to 

this project (USDA, 1995) and are the Desired Conditions for the soil resource. 

5. Soil loss should not exceed the rate of soil formation (approximately the long-term average of 1 

ton/acre/year). Maintain sufficient soil cover to prevent accelerated soil erosion from 

exceeding the rate of soil formation.

6. Soil porosity should be at least 90 percent of total porosity found under natural conditions. A 10 

percent reduction in total soil porosity corresponds to a threshold soil bulk density that 

indicates detrimental soil compaction.

7. Fine organic matter occurs over at least 50 percent of the area. Fine organic matter includes 

plant litter, duff, and woody material less than 3 inches in diameter. The dry weight of fine 

organic matter without woody material is about 0.2 to 3 tons per acre.

8. Large woody material is at least 5 well distributed logs per acre representing the range of 

decomposition classes in Exhibit 02 of the Regional Soil S&Gs. Desired logs are at least 20 inches 

in diameter and 10 feet long. To alleviate the risk of adverse fire effects, dry weight should be 

less than about 3 tons per acre. 

3-10.4 Environmental Consequences

A direct effect is the immediate result of an action, whereas an indirect effect occurs at a later time and is 

usually spatially separated. Road construction, road maintenance, fire line construction and 

reconstruction, fuel reduction burns, and vegetation removal activities, such as skidding, yarding, and 

construction of skid trails, temporary roads, and log landings, would have a direct effect on vegetation. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-15

Some trees, soil, shrubs, forbs, and grasses would be displaced or removed. This would expose bare soil 

and create a potential for soil compaction and erosion, which would result in an indirect effect of 

increased runoff that may increase sediment delivery to streams. Disturbed soil may indirectly affect the 

beneficial uses of the water for fisheries and water quality if this soil is transported and deposited into 

streams or meadows. 

Implementation of one or more of the project alternatives could affect soil productivity by reducing soil 

porosity, soil cover, and LWD. Issues that will be evaluated to determine the potential environmental 

consequences of the alternatives on soil resources are:

the effects of mechanical harvest on soil, the effects of mastication treatment areas on soil,

the effects of treatment of brush and noxious weeds by use of glyphosate, and the effects of 

prescribed fire.

An analysis was conducted to determine the effects of the No Action Alternative and the four action 

alternatives. The results are described in the following effects section. Direct and indirect effects are 

first described for Alternative 1 (No Action), then together for Alternatives 2 through 5. 

3-10.4.1 Alternative 1—No Action

Direct and Indirect Effects

If vegetation is left in its current state of high fuels and high wildfire risk, it is inevitable that a wildfire 

will occur. While there would be no effect on soil porosity, soil loss could range from 10–60 tons per 

acre in these areas. Past monitoring of wildfire areas on the nearby Stanislaus National Forest has found 

that bare ground averaged about 70 percent by spring of the first year and by spring of the second year 

bare ground averaged 27 percent (Janicki and Potter, 2003). LWD would probably be consumed in a fire 

and long term soil productivity could be decreased without LWD. Existing snags would also be lost, 

leading to a reduction in long-term recruitment of LWD and surface/subsurface organic matter. New 

snags would be created in a wildfire, but these snags would fall down within a short time of each other 

leaving a lack of snags in future years as a new stand is established.

Potential soil erosion modeling (Gallegos 2006) was conducted in the nearby Bear Fen Management Unit 

area, which is south of the Providence Unit and east of the Bull Unit. The assumptions regarding the soils 

and the road system were reviewed and found to be applicable to the KREW Project; the characteristics 

of the road systems are similar, with regard to such attributes as road density, road geometry, widths of 

roads, and lengths of road and stream crossings. Sediment modeling of the No-Action Alternative with a

wildfire occurring in the year 2014 predicted 52 tons per hectare per year of soil would be lost (Gallegos 

2006). Modeling of the Proposed Action with a fire in the year 2014 predicted 13 tons per hectare per 

year of soil would be lost. This analysis shows that if a fire were to occur in the year 2015, the No Action 

Alternative would result in 400 percent more erosion than the Proposed Action. This modeling exercise 

demonstrates that the No Action Alternative would have a significant effect on erosion and soil 

productivity if a wildfire occurs and that the Proposed Action would reduce the predicted erosion and 

associated effects on soil productivity. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-16

Under the No Action Alternative, roads that are in need of maintenance or reconstruction would not be 

treated and would continue on their current trend. In most cases the trend is road deterioration 

including erosion and loss of soil contributing sediment to streams. 

Cumulative Effects 

The ERA model would show continuing recovery from previous management actions as past 

disturbances recover over time. Other planned actions that are not part of this decision would still 

occur, but the total ERAs in the project sub-watersheds would be lower than if the project was 

implemented. Roads would continue their current contribution to CWEs. Some segments may 

deteriorate as described above, but the overall cumulative impact from the roads probably would not 

change relative to the current condition.

3-10.4.2 Alternatives 2 through 5 

The effects of Alternatives 2, 3, 4, and 5 on soils and cumulative watershed effects are expected to be the 

same. The treatment acres and methods are the same, although the intensity of tree removal may vary 

due to slightly different thinning targets. Soil disturbance is expected to be same as skidding patterns 

are assumed to be the same, as well as follow-up prescribed burning operations. 

Direct and Indirect Effects

Effects of Mechanical Harvest 

Mechanical harvest will cause soil disturbance and poses increased risk of soil compaction and erosion. 

Implementation of soil and water protection design features (SO-1 through SO-6) and BMPs would 

reduce the risk of erosion and promote surface stabilization and re-vegetation. The soils in the project 

area are highly productive so rapid natural re-vegetation is expected. To prevent soil compaction soil 

moisture needs to be dry enough to reduce the susceptibility to compaction. The ideal moisture content 

varies between soils and should not be above 14 percent to prevent soil compaction. A soil scientist or 

other earth scientist should be consulted prior to mechanical equipment operating on soils that have a 

moderate soil compaction hazard, especially outside of the standard operating season (June 1 to October 

15). There could be an occasional summer storm event that could cause accelerated erosion of bare 

exposed soils. In the event that this should occur, soil erosion sites may be restored to pre-storm 

conditions either through contracts or appropriated funds. Soil compaction will be reduced by 

subsoiling skid trails and landings to ensure that soil S&Gs are being met in the management units. 

Tractor logging is planned for areas with slopes under 35 percent, which will reduce excessive soil 

displacement. In areas where tractor piling of slash is planned, it is a normal Forest practice to leave at 

least 50 percent, well distributed soil cover for erosion protection on slopes under 35 percent. If slopes 

are greater than 35 percent, soil cover should be at least 70 percent. Past observations on the SNF have 

found that this amount of soil cover generally prevents accelerated erosion. For tractor logging and 

piling, a design feature has been included to conduct tractor logging and piling when the soil is dry to 

avoid soil porosity loss (compaction). A buffer of 100 feet will be provided around rock outcrop to 

prevent accelerated erosion of the adjacent soils from rapid runoff from rock outcrops.
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-17

In the Providence Unit, some areas with Holland family soils are proposed for thinning with tractor 

piling. Since these soils are highly susceptible to soil porosity loss due to compaction from heavy 

equipment operation when soils are moist or wet, operating on soil dry enough to prevent rutting and 

displacement of topsoil will minimize the possible effects. If monitoring determines that over 15

percent of a treatment unit is compacted due to legacy compaction and recent compaction, subsoiling of 

the major skid trails would be implemented as a mitigation measure. In the Bull Unit, there are no 

Holland family soils. In both Providence and Bull Units, tree removal on slopes greater than 35 percent

is very limited. It should be noted that these treatment units do not occur on soil map units with high 

amounts of rock outcrop, which will reduce excessive soil displacement. Trees on slopes in excess of 35

percent would be removed by end-lining or by skidding the logs downslope to minimize soil 

disturbance.

In both Providence and Bull Units, no detrimental soil disturbance is expected to occur. Significant 

impacts to soil productivity are not expected to occur because the vast majority of mechanical harvest 

will occur on coarse-textured soils; slopes are less than 35 percent and design measures have been 

included to protect soils and prevent soil disturbance.

Effects of Mastication on Soils 

Areas planned for mastication pose little risk of causing negative effects to soil because this treatment 

increases soil cover, reducing the erosion hazard and generally causes little soil disturbance and 

compaction. 

In the Providence Unit, mastication will occur on the rock outcrop-dystric lithic xerochrepts complex 

(soil map unit 150), the Gerle-Cagwin family (soil map units 134 and 135), and the Shaver family (soil 

map unit 157). In the Bull Unit, mastication will occur the Cagwin-Cannel family (soil map unit 112) and 

the Cagwin family (soil map unit 111). 

Since these soils are not susceptible to excessive compaction, and there would be an increase in fine 

woody material to help sustain long-term soil productivity, no significant impacts are expected in either 

the Providence or Bull Units, provided that mastication is done with sufficient care to avoid significantly 

increasing bare area. 

Effects of Glyphosate Use on Soils 

Glyphosate provides a means of vegetation control that causes little, if any, direct soil disturbance. The 

dead foliage and leaf drop onto the soil surface continues to provide protection from erosion until seeds 

present sprout. It biodegrades within weeks of application into natural products including: carbon

dioxide, nitrogen, phosphate and water. The only potential impact to the soil resources is from direct 

disturbance and displacement of the soil by applicators walking on the ground. This potential impact is 

negligible because walking on the soil surface would not disturb the soil surface and cause erosion. 

The primary metabolite of glyphosate is aminomethylphosphonate (AMPA). The position taken by U.S. 

EPA/OPP (2002) that AMPA is not of toxicological concern regardless of its levels in food appears to be 

reasonable and is well-supported (SERA 2003; p. 3-25). The half-life of glyphosate can range from 20 to 

60 days (SERA 2003). Effects on soil microflora are minimal and not pronounced (Ghassemi and others, 

1981). There is very little information suggesting that glyphosate will be harmful to soil 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-18

microorganisms under field conditions and a substantial body of information indicating that glyphosate 

is likely to enhance or have no effect on soil microorganisms (SERA 2003; p. 4-7). R-11 is also broken 

down by soil microorganisms.

Since the glyphosate has little, if any, impact of soil productivity and will applied to limited areas, no 

significant impacts are expected in either the Providence or Bull management units. 

Effects of Prescribed Fire on Soils

Areas planned for prescribed fire pose little risk of causing significant effects to soil productivity based 

on the past performance of the HSRD prescribed fire program. Past prescribed fires on the District has 

resulted in low burn severity where the fire has burned in a mosaic leaving patches of unburned 

vegetation and patches of burned area where duff and litter has burned. Most trees are left undamaged 

except for a few small patches that have burned at a moderate burn severity. Soil quality standards have 

been met from past prescribed fires and are expected to be met from the proposed action. Soil cover of 

50 percent is expected to be met on slopes less the 35 percent and 70 percent on slopes greater the 35

percent. Monitoring of prescribed fire areas has shown that soil quality standard are being met in the 

last 5 years of prescribed fire on the HSRD (USDA Forest Service 2000-2005). 

In the Providence Unit, prescribed burning will occur on the Shaver family (soil map unit 150), the 

Gerle-Cagwin family (soil map units 134 and 135), and the rock outcrop-dystric lithic xerochrepts 

complex (soil map unit 150). In the Bull Unit, prescribed fire will occur on the Cagwin Family (soil map 

unit 111), the Cagwin-Cannel Family (soil map unit 112), the Cagwin Family-Rock Outcrop complex (soil 

map unit 116), and the Typic Xerumbrepts complex (soil map unit 170). 

No significant impacts are expected in either the Providence or Bull Units because soil compaction is 

expected to be minimal, soil cover and disturbed soil would meet Regional Soil S&G requirements, and 

erosion control measures would be implemented in a timely manner. There will be some loss of LWD

from prescribed fire. All treatment units have at least 5 trees per acre. However, treatment units 235, 

236, 280, 299 and 454 have less than 10 logs per acre and prescribed fire could consume logs and result 

in less than 5 trees per acre in the short term (5 years). Future recruitment of LWD from snags may 

result in less than 5 trees per acre in treatment units 965, 292, 450, 499, and 1043 because existing 

snags are low in these treatment units. Most of the treatment stands will meet the LWD soil S&G.

Cumulative Soil and Watershed Effects 

The CWE analysis has two components consisting of the R5 Baseline and Detailed CWE Assessments 

following the direction in FSH 2509.22, and a qualitative discussion about how the direct and indirect 

effects are likely to be transmitted through the stream system. The CWE Baseline Assessment is 

documented in the aforementioned Affected Environment section.

Alternatives 2, 3, 4, and 5 would result in seven subwatersheds exceeding their lower TOC for CWE (see 

Table 3-10-4). These subwatersheds includes: 519.0007, 519.0008, 519.0011, 520.0014, 520.0016, 

520.0017, and 520.3002. None of the subwatersheds in the KREW project area would exceed the upper 

TOC of 14 percent. The risk of initiating adverse CWE greatly increases as this upper limit is 

approached or exceeded. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-19

The potential for CWE to occur from increased sedimentation is a risk based assessment dependent on 

the occurrence of large storm events that occur in these sub-watersheds. If large storm events (10 or 20 

year storm events) occur, the risk of CWE response increases. If a proposed treatment area has below 

normal precipitation the following winter, and storm events are less than 2-year events, the risk of CWE 

is reduced. The vulnerability of a sub-watershed for CWE is within the first year of the disturbance and 

significantly decreases after the 2nd and 3rd years. Risk is defined with 4 classes; “Unlikely” is expected 

to withstand a twenty-year storm event without incurring a CWE response, “Low” is expected to 

withstand a ten-year storm event, “Moderate” is expected to withstand a five-year storm event, and 

“High” is expected to incur a CWE response from a 2-year storm event. See Table 3-10-4 for CWE risk 

classes of the affected subwatersheds.

Table 3-10-4. Summary of Cumulative Watershed Effects

SUBWS # Total WS 

Acres

Watershed 

Sensitivity

Lower 

TOC

Grazing 

Allotment 

ERA

Roads 

ERA

Harvest 

ERA

Total 

Existing 

ERA

Total 

Proposed 

ERA

Potential 

CWE

519.0005 1,140 High 4.0% 0.95 0.78 0.44 2.18 2.18 Unlikely

519.0007 1,719 High 4.0% 1.00 1.04 11.61 3.81 13.65 Low

519.0008 1,976 High 4.0% 0.80 1.00 11.51 3.74 13.32 Low

519.0011 1,246 High 4.0% 0.95 0.41 6.29 3.87 7.66 Unlikely

520.0014 1,066 Moderate 5.0% 1.18 1.56 6.33 9.07 9.07 Unlikely

520.0016 591 Moderate 5.0% 0.92 1.54 9.64 7.12 12.10 Low

520.0017 1,952 High 4.0% 1.33 1.23 6.87 7.01 9.44 Unlikely

520.3002 1,661 Moderate 5.0% 0.76 1.47 8.05 2.86 10.29 Unlikely

520.3151 1,317 Moderate 5.0% 0.75 1.13 1.04 2.50 2.92 Unlikely

The potential for CWE to occur in subwatersheds 519.0005, 519.0011, 520.0014, 520.0017, 520.3002, 

and 520.3151 is unlikely. There is increased potential for CWE in the Providence and Bull Units in 

subwatersheds 519.0007, 519.0008 and 520.0016, because ERA are approaching the upper 14 percent

TOC. There is a low potential for CWE to occur in these three subwatersheds. However, there are 

mitigating factors to consider in determining if CWE will occur in these subwatersheds. The cumulative 

effect of increased sediment into channels draining the project area is highest in stands where soil 

disturbance would occur. Soil disturbance would occur where tractor piling for fuel treatment is 

proposed, but can also occur where skid trails are not being properly drained and maintained. This will 

most likely occur in subwatersheds 519.0007, 519.0008 and 520.0016.

Subwatershed 519.0007 includes a Southern California Edison (SCE) project that plans on treating 416 

acres, which accounts for 7.27 percent ERA and a FS proposal that is proposing to treat 142 acres, which 

accounts for 2.57 percent ERA. Considering the planned SCE lands and the FS lands, 33 percent of this 

subwatershed will be treated within one to three years of each other. 

Subwatershed 519.0008 includes a SCE project that plans on treating 79 acres, which accounts for 

1.06% ERA and a FS proposal that is proposing to treat 757 acres, which accounts for 8.52 percent ERA. 

Considering the planned SCE lands and the FS lands, 42 percent of this subwatershed will be treated 

within one to three years of each other. 
Final Environmental Impact Statement Kings River Experimental Watershed Project

Chapter 3-10 - Soils 3.10-20

Subwatershed 520.0016 is an undersized subwatershed (591 acres) for a HUC 8 Subwatershed with 212 

acres (36 percent) of private land. This subwatershed includes 107 acres from the Dninkey North and 

South Projects and accounts for 18.11 percent of the subwatershed and 4.53 percent ERA. The 

Providence project proposes to treat 119 acres, which accounts for 4.98 percent ERA. Considering the 

Dinkey North Project, Dinkey South Project and Providence project, 38 percent of the subwatershed will 

be treated within one to three years of each other. 

Project design measures have been developed to reduce the likelihood of CWE, including initiating the 

under burns in first year after the mechanical treatment is implemented.

Design measures include implementing BMPs requiring adequate erosion control and retaining at least 

50 percent soil cover. These measures would minimize soil erosion and subsequent sedimentation into 

stream channels. Another mitigating factor is the prevention of sediment moving below sediment 

basins in the four research watersheds. Sediment in these basins will be excavated out of the basins and 

deposited and stabilized and revegetated on slopes adjacent to the sediment basins. This will prevent 

downstream transport of any sediment into Big Creek.

Several subwatersheds across the SNF, with ERA above the lower TOC, in similar soils and at similar 

elevations have had a detailed CWE assessment. This includes Rock Creek (Gott 2008), Gertrude Timber 

Sale (USDA Forest Service 2000b), Horsethief Timber Sale (USDA Forest Service 1999), and Dawn 

Thinning Project (USDA Forest Service, 2001d). All of these projects concluded that channel conditions 

and aquatic habitat was generally stable and had fair quality. The CWE assessments in these project 

areas concluded that a CWE response was unlikely. CWE are not expected to occur because ERA values 

would be below the upper TOC of 14 percent; the project area has mostly coarse textured soils; and 

project design measures have been designed to minimize erosion and sedimentation.

There are potential CWE from prescribed burning. Increases in erosion will be most likely be from steep 

headwater slopes and in areas where fuel concentrations are higher (see Fuel section of this EIS) in the 

proposed treatment areas. Some of these areas may result in small pockets (1-2 acres) of moderate to 

high soil burn severity and may not meet the 50 percent ground cover standard. 

Other Projects and Uses Considered in the Cumulative Effects Analysis – The ERA model addressed all 

ground disturbing projects listed in Table 3-1 and Table 3-2 (Past, Present, and Reasonably Foreseeable 

Actions) in Chapter 3. The project file contains more information about the rationale behind the 

consideration of cumulative effects that could result from each of the listed actions.

3-10.5 Comparison of Alternatives

There is no difference between Alternatives 2, 3, 4 and 5.