U.S. Environmental Protection Agency 

 Region IX

FINAL 

Upper Main Eel River and Tributaries 

(including Tomki Creek, Outlet Creek and Lake 

Pillsbury) 

Total Maximum Daily Loads 

for 

Temperature and Sediment

Approved by date 

Original signed December 29, 2004 

Alexis Strauss 

Director, Water Division 
Note: For further information please contact Palma Risler at 415/972-3451 

and risler.palma@epa.gov or Dan Pingaro at 415/977-4275 and 

pingaro.daniel@epa.gov 
Table of Contents 

CHAPTER 1: INTRODUCTION 

 1.1. Overview - 1 

 1.2. Watershed Characteristics - 2

 1.3. Endangered Species Act Consultation - 4 

 1.4. Organization - 4 

CHAPTER 2: PROBLEM STATEMENT 

 2.1. Fish Population Problems - 5 

 2.2. Temperature Problems - 7 

 2.3. Sediment Problems - 14

 2.4. Water Quality Standards - 17 

CHAPTER 3: TEMPERATURE TMDL 

 3.1. Interpreting the Existing Water Quality Standards for Temperature - 18 

 3.2. Temperature Modeling - 20 

 3.2.1 Temperature and Solar Radiation Modeling - 21 

 3.2.2 Selection of Scenario Corresponding to Water Quality Standards - 24 

 3.3.1 Loading Capacity and TMDL – Solar Radiation for all stream reaches - 26 

 3.3.2 Shade Allocations - 26 

 3.3.3 Margin of Safety - 27

 3.3.4 Seasonal Variation and Critical Conditions - 27 

 3.4 Instream Heat TMDL – Van Arsdale to Outlet Creek - 28 

 3.4.1 Selection of Scenario Corresponding to Water Quality Standards - 34 

 3.4.2 Water Quality Indicators – Van Arsdale to Outlet Creek - 34 

 3.4.3 Instream Heat Loading Capacity and TMDL - Van Arsdale to Outlet Creek- 34 

 3.4.4 Instream Heat Allocations – Van Arsdale to Outlet Creek - 35 

 3.4.5 Margin of Safety - 35

 3.4.6 Seasonal Variation and Critical Conditions - 35 
CHAPTER 4: SEDIMENT TMDL 

 4.1. Water Quality Indicators and Targets - 36 

 4.1.1 Summary of Indicators and Targets - 37 

 4.1.2 Instream Indicators - 39

 4.1.3 Watershed Indicators - 43

 4.2. Sediment Source Analysis - 44

 4.2.1 Sediment Source Analysis Methodology - 45 

 4.2.2 Results - 47 

 4.2.3 Summary - 52 

 4.3 TMDL and Allocations - 53

 4.3.1 Loading Capacity and TMDL - 53

 4.3.2 Allocations - 54

 4.3.3 Margin of Safety - 55

 4.3.4 Seasonal Variation and Critical Conditions - 56 

CHAPTER 5: IMPLEMENTATION AND MONITORING MEASURES 

CHAPTER 6: PUBLIC PARTICIPATION 

References - 60 

Appendix A QUAL2E model results report 

Appendix B Sediment Source Analysis 

Appendix C Sediment Tables for the entire watershed and subwatersheds 

Figure 1 Watershed map - 3 

Figure 2 Adult returns to Van Arsdale - 8

Figure 3 Stream Temperature Monitoring Results: Upper Main Eel TMDL area - 13 

Figure 4 Wet Year – Modeled Stream Temperatures - 33 

Figure 5 Very Wet Year – Modeled Stream Temperatures - 33 

Figure 6 Percent sediment delivery by terrain type - 48 

Figure 7 Percent sediment delivery by management association and time period - 50 

Figure 8 Percent sediment delivery by primary land use association - 52 
Table 1 Temperature Categories - 11 

Table 2 Water Quality Standards - 18 

Table 3 Tomki Creek Shade Effects on Stream Temperatures - 25 

Table 4 Tomki Creek: Shade Modeling Results - 25 

Table 5 Flow and Temperature Assumptions for Van Arsdale to Outlet Creek Modeling – 

31 

Table 6 Sediment Indicators and Targets - 38 

Table 7 Measures of Embeddedness in the Upper Eel River Basin - 41 

Table 8 Strata Identified in the Upper Eel River Watershed - 47 

Table 9 Total Erosion and Sediment Delivery from Small and Large Features by Terrain 

Type - 48 

Table 10 Sediment Delivery by Time Frame and Potential Controllability - 49 

Table 11 Sediment Yield by Domain and Primary Land Use - 51 

Table 12 Sediment Loading in the Upper Eel River (1940 – 2004) - 53 

Table 13 Load Allocations over the Entire Basin - 55 
CHAPTER 1: INTRODUCTION 

1.1 OVERVIEW OF THE TMDL PROGRAM 

The primary purpose of the Total Maximum Daily Load (TMDL) program for 

California=s Eel River is to assure that beneficial uses of water (such as salmonid 

habitat) are protected from adverse increases in natural sediment and temperature. 

The water quality problems in the Upper Main Eel River and tributaries (including

the areas of Tomki Creek, Outlet Creek and Lake Pillsbury) addressed in this report 

are related to the decline of salmon and steelhead populations. While many factors 

have been implicated in the decline of west coast salmon and steelhead, we are 

concerned here solely with two inland water quality considerations - increases to

the natural sediment and temperature patterns. The Upper Main Eel (along with

many other watersheds in California and throughout the nation) has been put on a 

list of Aimpaired@ or polluted waters. In this watershed, the listing leads to the 

TMDLs. The TMDLs set the maximum levels of pollutants that the waterbody can

receive without exceeding water quality standards. Development of measures to

implement the TMDL is the responsibility of the State of California. 

The Upper Main Eel River Total Maximum Daily Loads (TMDLs) for sediment 

and temperature are being established in accordance with Section 303(d) of the

Clean Water Act, because the State of California has determined that the water 

quality standards for the Upper Main Eel River are not met due to excessive 

sediment and temperature. In accordance with Section 303(d), the State of 

California periodically identifies Athose waters within its boundaries for which the 

effluent limitations... are not stringent enough to implement any water quality 

standard applicable to such waters.@ In 1992, EPA added the Upper Main Eel River 

to California=s 303(d) impaired water list due to elevated sedimentation and 

temperature, as part of listing the entire Eel River basin. The North Coast Regional 

Water Quality Control Board (Regional Board) has continued to identify the Upper 

Main Eel River as impaired in subsequent listing cycles, the latest in 2002.

In accordance with a consent decree (Pacific Coast Federation of Fishermen=s 

Associations, et al. v. Marcus, No. 95-4474 MHP, 11 March 1997), December 31, 

2004 is the deadline for establishment of these TMDLs. Because the State of 

California will not complete adoption of TMDLs for the Upper Main Eel River by this

deadline, EPA is establishing these TMDLs. Under this consent decree EPA has 

established TMDLs for many watersheds in the North Coast of California, including 

the South Fork Eel, North Fork Eel, Van Duzen and Middle Fork Eel. Additionally, 

the North Coast Regional Water Quality Control Board has established the Garcia 

River TMDL and associated action plan. 

The purpose of the Upper Main Eel River TMDLs is to identify the total 

amount (or load) of sediment and heat that can be delivered to the Upper Main Eel 

River and tributaries without exceeding water quality standards, and then to 

allocate the total amount among the sources of sediment or heat in the watershed. 

EPA expects the Regional Board to develop an implementation strategy that will 

result in implementing the TMDLs in accordance with the requirements of 40 CFR 

130.6. The allocations, when implemented, are expected to result in achieving the 

1 
applicable water quality standards for sediment and temperature for the Upper Main

Eel River and its tributaries. 

These TMDLs apply to the portions of the Upper Main Eel River watershed 

governed by California water quality standards. They do not apply to lands under 

tribal jurisdiction. This is because tribal lands, as independent jurisdictions, are not 

subject to the State of California=s water quality standards. 

1.2 WATERSHED CHARACTERISTICS

The Upper Main Eel River watershed area is located primarily in Mendocino

and Lake Counties in Northwestern California. It is primarily east of Highway 101, 

approximately 150 miles northeast from San Francisco, and includes the town of 

Willits. The Upper Main Eel watershed, as defined by this TMDL is the area from the 

headwaters of the Eel River in Mendocino National Forest above Lake Pillsbury down

to Dos Rios, where the Upper Main Eel meets the Middle Fork Eel. The main 

tributaries are Tomki and Outlet Creeks (see Figure 1.) The Upper Main Eel River 

TMDL area is 688 square miles (approx. 440,384 acres) of which 359 square miles 

are in private ownership and 329 square miles in public ownership. There is no

commonly used name of the area as a whole. This analysis includes all of the 

tributary streams of the Upper Main Eel from the headwaters to Dos Rios. The 

State hydrologic area naming convention is 111.60 Upper Main Eel River HA, 

consisting of 11.61 Outlet Creek, 11.62 Tomki Creek and 11.63 Lake Pillsbury. 

The Potter Valley Project, a small hydroelectric plant and water diversion, is 

contained within the study area. The project has two dams - the larger Scott Dam

and associated Lake Pillsbury and 12 miles downstream a smaller Cape Horn Dam 

and Van Arsdale reservoir, where water is diverted adding water supplies to the

Potter Valley Irrigation District and Sonoma County through Lake Mendocino and 

the Russian River (see Figure 1). The Potter Valley Project has been in operation

for approximately 90 years and is licensed by the Federal Energy Regulatory 

Commission (FERC.) Pacific Gas and Electric (PG&E) was issued a new hydro 

power license in 1983, which contained certain flow requirements. These flow 

requirements were changed with the most recent FERC order amending the license 

(FERC, Jan 2004) generally consistent with the National Marine Fisheries Service 

(NMFS) Biological Opinion under the Endangered Species Act. A June 2004 FERC

order required PG&E to implement the new flow regime. The new flow regime has 

been in effect since the June 2004 order. 

The area=s geology is underlain by the Franciscan terrain that dominates 

most of California=s North Coast. Naturally unstable, this type of geology is 

sensitive to human disturbance. The Upper Main Eel watershed is relatively dry and 

warm, away from the influence of coastal fog. Almost all of the estimated 40 

inches of annual rainfall occurs between November and April. Many smaller 

tributaries dry up in late summer. Land use activities in the Upper Main Eel include 

rural development, ranching, recreation in Mendocino National Forest, timber 

production, agriculture and some urbanized areas in the Willits area. 

2 
<<This page intentionally left blank for insert of Figure 1 – 

Map of major features of Upper Eel River TMDL area>> 

3 
1.3 ENDANGERED SPECIES ACT CONSULTATION 

EPA has initiated informal consultation with the National Marine Fisheries and 

the U.S. Fish and Wildlife Services on this action, under Section 7(a)(2) of the 

Endangered Species Act. Section 7(a)(2) states that each federal agency shall 

ensure that its actions are not likely to jeopardize the continued existence of any 

federally-listed endangered or threatened species. 

EPA=s consultation with the Services has not yet been completed. EPA 

believes it is unlikely that the Services will conclude that the TMDLs that EPA is 

establishing violate Section (7)(a)(2) since the TMDLs and allocations are calculated 

in order to meet water quality standards, and water quality standards are expressly 

designed to Aprotect the public health or welfare, enhance the quality of water and 

serve the purposes@ of the Clean Water Act, which are Ato restore and maintain the 

physical, chemical, and biological integrity of the Nation=s water.@ Additionally, this 

action will improve existing conditions. However, EPA retains the discretion to

revise this action if the consultation identifies deficiencies in the TMDLs or

allocations.

1.4 ORGANIZATION

This report is divided into 6 chapters. Chapter 2 (Problem Statement) 

describes the nature of the environmental problems addressed by the TMDLs - fish

population, stream temperature problems, sediment problems and water quality 

standards. Chapter 3 (Temperature TMDL) describes the modeling used to evaluate

the temperature changes from differing amounts of shade and stream flow, and 

identifies the TMDL and allocations. Chapter 4 (Sediment TMDL) describes the 

sediment source analysis used to evaluate the proportion of human caused sources 

of sediment, sets the TMDL and allocations. Water Quality indicators for sediment

are also identified. Chapter 5 (Implementation and Monitoring Recommendations) 

contains recommendations to the State regarding implementation and monitoring

of the TMDLs. Chapter 6 (Public Participation) describes public participation in the 

development of the TMDLs. 

4 
CHAPTER 2: PROBLEM STATEMENT 

This chapter summarizes temperature and sediment effects on salmonids in 

the Upper Main Eel River and tributaries. It includes a description of the water 

quality standards and salmonid habitat requirements related to temperature and

sediment. In the near future, additional information concerning these issues may 

be available in the Department of Fish and Game’s draft Watershed Assessment for 

Outlet Creek. The DFG assessment will provide additional information on stream 

sediment conditions, water temperature monitoring and other stream habitat 

conditions. 

2.1 FISH POPULATION PROBLEMS

Both chinook and steelhead are widely distributed throughout the watershed. 

Historically their populations may have been more than ten thousand, but presently 

chinook and steelhead are at reduced levels. Coho are only found in a few streams 

tributary to Outlet Creek. Rainbow trout are found in streams above Lake Pillsbury 

in Mendocino National Forest. 

Data on population trends for the entire California Coastal Chinook and 

Northern California steelhead are sparse (NMFS, 2003.) A recent preliminary 

scientific review of the information on salmonid abundance under the Endangered

Species Act (NMFS, draft 2003) concluded that the California Coastal Chinook, 

Northern California Steelhead and California Coastal Coho (including salmonid

populations in the Upper Main Eel TMDL area) are Alikely to become endangered in 

the foreseeable future.@ The available data reviewed included adult spawner 

returns to Cape Horn Dam and surveys of Tomki Creek, both within the Upper Main

Eel TMDL area. The general pattern is one of overall decline combined with a

recent increase. The scientific review panel=s preliminary conclusion is that 

Apopulations would have to maintain themselves for a longer period of time at levels 

considered viable before it could be concluded that they are not at significant 

continuing risk.@ (NMFS, 2003) 

Figure 2 is the adult chinook returns to Cape Horn Dam (Van Arsdale) from 

1946-2003 and the adult steelhead returns from 1922-2003. This data includes

both hatchery returns and returns of wild salmonid populations. Returns from 

hatchery fish are strongly correlated to the numbers of juveniles planted in the 

system in previous years. The chinook data at Cape Horn Dam is considered 

inappropriate for determining population trends (NMFS, 2003) due to concerns 

regarding its location at the limit of spawning habitat.

Changes in fish distribution and abundance are also indicators of problems 

with protection of beneficial uses. Chinook salmon are widely distributed in the 

watershed, except for the areas blocked by Scott Dam since its construction in 

1921. California Department of Fish and Game has conducted carcass surveys 

during the spawning season and reports that during 1987-1989; hundreds of 

spawners were counted in Ryan, Baechetl and Long Valley Creeks -- tributaries to

Outlet Creek. Outlet Creek had nearly 1000 spawners during 1988. Estimates of

the amount of miles blocked by Scott Dam vary from 35-40 miles (NMFS, 2002) to 

5 
100-150 miles of potential habitat (USFS, 1995.) Because chinook salmon 

juveniles do not rear in freshwater during the summer, the summer temperature

problems of the Upper Main Eel are not relevant to chinook. Tomki Creek surveys 

from 1964-1996 indicate a wide variation (0-3600) in returning adult spawners. 

Historical personal accounts report that chinook spawners were more abundant 

before the 1964 flood (MCRCD, 1983.) 

Coho are present in the watershed but only in a few locations and not every 

year. Coho salmon have been reported 4 times since the 1940’s at the Van 

Arsdale, most recently four coho were identified in 2001. Department of Fish and 

Game stream inventory reports also report a few adult coho carcasses during 1987-

1989 in Outlet Creek, and in several tributaries to Outlet Creek (Long Valley, 

Broaddus Creek, Baechtel Creek, Ryan Creek, and Haehl Creek). Juvenile coho

were not reported by DFG in any of these streams during 1995. While the current 

observations are of coho in very small numbers, it appears this may also have been 

the case historically. EPA did not find any information indicating that coho were 

more widely distributed historically. 

Steelhead are widely distributed throughout the watershed, except above

Scott Dam where rainbow trout are resident. The distribution of juvenile steelhead

is of special interest as summer temperatures are an important facet of their 

distribution and abundance. In the Upper Main Eel TMDL study area, juvenile 

steelhead are widely distributed. Department of Fish and Game stream survey 

reports detail the presence of juvenile steelhead in tributaries to Outlet Creek - 

Haehl Creek, Ryan Creek, Bear Pen Canyon Creek, Baechtel Creek, Cherry Creek, 

Bloody Run Creek, Broaddus Creek, and Long Valley Creek. They were also present 

in Willits Creek, Benmore Creek, Tomki Creek and Cave Creek. Mendocino National 

Forest trout streams include: Salmon, Smokehouse, Cold, Rice, Soda, Panther, 

Copper Butte, Hummingbird, Thistle Glade and Blue Slide Creeks. Again, historical 

personal accounts report that steelhead juveniles were more abundant before the

1964 flood: AIt was, at that time, very easy to catch 25 (the limit at that time) pansize trout, 6”-7” long, out of these holes...@ (MCRCD, 1983.) The area between 

Lake Pillsbury and Van Arsdale is often reported to be productive for juvenile 

steelhead. Interested readers can also review previous detailed reports (SEC, 

1998; NMFS, 2002) on salmonids in the Upper Main Eel. 

Many different habitat conditions are crucial for the survival of salmon and

steelhead. Salmonid populations are affected by a number of factors outside of the 

Upper Main Eel TMDL area, including commercial and sport harvest, and ocean

conditions. Additional local habitat conditions such as large woody debris and 

possibly pike minnow predation may also be factors. These TMDLs focus only on 

the achievement of the water quality standards related to sediment and 

temperature, which will facilitate, but not guarantee, population recovery. In 

addition, the temperature TMDL focuses on summer stream temperatures, which 

are most relevant to steelhead, as chinook juveniles do not rear in fresh water 

streams and coho are only found in a few small tributaries. The following sections

summarize how summer stream temperature affect salmonids and how sediment

conditions affect salmonids. 

6 
2.2 STREAM TEMPERATURE PROBLEMS

This section presents the available information on stream temperature

problems for salmonids in the Upper Main Eel and tributaries. Stream temperature

directly governs almost every aspect of the survival of Pacific Salmon (Berman, 

1998). Temperature is such an important requirement that coho, steelhead, 

chinook and rainbow trout are known as Acold water fish.@ Metabolism, food

requirements, growth rates, timing of adult migration upstream, timing of juvenile 

migration downstream, sensitivity to disease and direct lethal effects are affected

by stream temperatures (Spence et al, 1996.) 

The most sensitive period in the Eel River is the summer, when young

salmonids rear for several summers before migrating to the ocean and stream 

temperatures are hottest. Thus, this is the period analyzed in the temperature 

TMDL. 

Stream temperatures in the Pacific Northwest naturally provide a wide range 

of summer conditions for rearing salmonids. However, removing riparian

vegetation from timber harvesting, road building, grazing, and urbanization can

increase stream temperatures. Changes in the timing and amount of the natural 

streamflow, such as water diversions and impoundments, can also change the 

water temperatures downstream. Increases in sediment input also change the

stream channel by widening streams, filling pools and eliminating riparian

vegetation during flood events. Of primary interest to water quality standards and 

this TMDL is determining the extent to which the summer stream temperatures are

natural and to what extent they have been influenced by human activities. Chapter 

3 investigates whether or not the stream temperatures monitored in the Upper 

Main Eel and tributaries are natural. This section summarizes the literature on

stream temperatures and salmonids, regardless of whether or not those 

temperatures are natural. 

In order to summarize stream temperatures, which are often monitored

hourly or more and fluctuate daily and seasonally, this TMDL uses the maximum

value of the 7-day running average of all recorded temperatures. Although the 

term MWAT (maximum weekly average temperature) is used often in the literature, 

it is an inexact term and used inconsistently. The abbreviation max7daat is used 

herein for the 7day running average of all recorded temperatures. 

EPA summarizes the condition of streams for steelhead summer rearing 

based on the max7daat. This evaluation, shown in Table 1, categorizes the quality 

of summer stream habitat in regard to temperature based on previously compiled 

reviews of the literature. The literature on which this evaluation is based has 

investigated salmonid response in both the laboratory and the field. The primary 

literature reviews used by EPA to compile Table 1 are EPA Region 10, 2001a&b; 

Sullivan et al., 2000 and Myrick & Cech, 2001. This TMDL focuses on steelhead 

temperature tolerances because chinook are not present in the summer and coho

are only found in a small area of Outlet Creek. These temperature habitat 

evaluations (adequate, lethal etc) are not precise in the stream or in the literature, 

because salmonids are affected by many factors, including the degree of fluctuation 

in temperature, presence of competition and disease, food availability and access to

cool water refugia areas. 

7 
<<<This page left intentionally blank for insert of Figure 2 – 

Adult returns to Van Arsdale>>

8 
EPA concludes that any increase to natural stream temperatures is adverse 

to the success of steelhead rearing when the monitored max7daat summer 

temperatures is between 13-27EC. It appears from the literature review that 

salmonids benefit from cooler summer temperatures, except at very high or low 

temperatures. Given that low summer temperatures do not exist in the Upper Main 

Eel TMDL area, EPA did not consider in detail issues regarding effects (beneficial or

adverse) of raising temperatures cooler than optimal. 

For this TMDL, incremental changes to very warm stream temperatures are a 

key concern. In the main channel of the Eel below Van Arsdale, monitored 

temperatures are between 24 ̊ - 27.8EC. Lowering these temperatures to good or 

adequate rearing temperatures (13-19EC) is not achievable. Thus, EPA scrutinized 

the literature to determine if more modest temperature changes were beneficial. 

For example, is it beneficial to lower the max7daat from 28EC to 27EC or from 26 ̊C 

to 25EC? EPA determined that the evidence is that these decreases are beneficial,

albeit they will not result in the presence of abundant steelhead. 

EPA considered that for salmonids mortality is a function of magnitude and

duration of exposure to stream temperatures (Sullivan, 2000.) Sullivan 

summarizes: Acontinuous exposure of 3-30 hours are necessary to cause mortality 

at temperatures between 24EC to 26EC...The duration of time necessary to cause

mortality decreases sharply with small increments of temperature above 

approximately 26EC. Short duration excursions (less than 2 hours) above 27EC are 

very likely to cause mortality of some individuals...@ The USEPA Seattle (USEPA, 

2001) temperature project noted the following: “With cautious acclimation...rainbow

trout may not experience LT50 (50% mortality) until a week at 26°C. Even with 

careful acclimation, 27°C results in high or complete mortality in less than 24 

hours... and temperatures of 29-30°C result in 50% mortality in 1-2 hours.” 

McCullough, 1999 (as reviewed in USEPA, 2001) found that: “in general, a 

maximum temperature of 22-24°C represents the normal upper temperature limit 

in the field...as this limit is approached, juvenile density declines to zero.”

While it appears from the literature that streams with a max7daat of >26EC 

will cause mortality1

, field observations and some literature indicates that streams

with these monitored temperatures are used by steelhead. Most of these

observations included areas of cooler water refugia. Thermal refugia refers to 

cooler water areas within a stream. Streams often have a variety of areas that 

provide cooler water formed from cooler tributary inflow, groundwater or spring

inflow, intergravel flow or stratification of pools. These thermal refugia can provide

a much-needed refuge in hot periods of the day and during the hottest times of the 

year. Nielsen & Lisle (1994) noted that cold pockets in the nearby Middle Fork Eel

Awere consistently about 3.5E C cooler than surface water and as great as 7.8E C 

cooler.@ Nielsen also noted steelhead actively feeding in water with temperature of 

24 ̊C. Stream temperature monitoring does not often monitor these refugia 

conditions or localized variations. Advances in stream temperature monitoring, 

such as FLIR, show that localized cool patches are a common feature of many 

streams. 

 

1

Outlet Creek, with a 26.5EC max7daat, had 25 days with 2 hours over 26EC and 15 days with 6 hours over 26EC 

(HC RCD database 2000.) 

9 
These types of refugia areas exist in the Upper Main Eel. Steelhead are 

localized into refugia areas of cooler water in the Upper Main Eel between Tomki 

and Outlet Creek. Areas of cool spring flow were mentioned by Kubicek around 

Hearst where >several= steelhead were also observed, and stratified pools were also

noted at Fish Creek. In addition, there appear to be several cooler tributaries 

where stream temperatures are consistently low. Garcia Creek appears to provide

cool conditions and National Marine Fisheries Service staff (Jahne, personal 

communication) noted that numerous juvenile steelhead use the main channel of

the Eel despite the daily average temperature of 24EC near this cooler tributary 

inflow. DWR also monitored stratified pools with satisfactory bottom temperatures

above Tomki Creek in 1973. Two ten foot pools were monitored and bottom 

temperatures ranged from 21 - 24.5C. Kubicek also noted spring flow in the area

between Van Arsdale and Tomki Creek.

 Based on the literature, EPA expects that the incremental reductions in 

temperature to warm streams, where the max7daat is 24E-27EC, are beneficial, 

although the improvements for in juvenile populations are expected to be modest.. 

Table 1 summarizes the literature concerning the effects of varying stream 

temperatures on juvenile steelhead. 

There are approximately 35 locations with summer stream temperature

monitoring data. Many of these locations have been monitored for multiple years 

from 1996-2003 (HCRCD, 1996-2003.) Figure 3 shows many monitoring locations 

and their associated max7daat during the summers of 1996 – 1999. 

Figure 3 illustrates that most stream monitoring locations have summer

stream temperatures which are categorized as marginal, stressful or lethal (19EC - 

>24EC). Only four smaller tributaries had summer stream temperatures evaluated 

as good (17EC.) When compared with other areas of the Eel (HCRCD, 2003) the 

monitoring indicates that the stream temperatures in the Upper Main Eel TMDL area 

are quite warm. In Chapter 3, Temperature TMDL, modeling results indicate that

this warmer pattern is characteristic. 

Observations of steelhead presence and stream temperatures in the Upper 

Main Eel TMDL area are generally consistent with Table 1 above. For example, the 

area between Lake Pillsbury and Cape Horn Dam has been considered a productive

area for rearing steelhead, this area has a max7daat of approximately 20EC. In 

contrast, juvenile steelhead are not consistently observed between Tomki Creek 

and Outlet Creek on the Upper Main Eel where stream temperatures are monitored

at 24-28C max7daat. When juvenile steelhead were observed in Tomki Creek and 

Outlet Creek only individuals or stressed steelhead were usually noted (DFG, 1997

– 1998.) 

10 
Table 1. Evaluation of Effects of Stream Temperatures on Juvenile 

Steelhead

Stream

temperature 

evaluation 

Stream temperature

monitoring period 

(Max7daat) 

maximum 7 day average

of all monitored 

temperatures

References/Notes 

(a) USEPA (2001a, b)

(b) Sullivan et al, 2000 

(c) Myrick, Cech (2001) 

GOOD 13-15E C (59E F) 

maximum growth - food limitation 

preferred range 

13-15° C (a) protective threshold for summer 

rearing in the Pacific NW, adjusted from daily max to 

daily mean. 13°C applicable in Oregon at >3000 

foot elevation 

GOOD 15-16.99E C (59-63E F) within preferred range 

ADEQUATE 17-18EC (63-66EF) 

18- 19 

19C upper end of maximum growth – optimal 

conditions 

17C maintenance of population abundance within

10% (b) 

MARGINAL 19-20 20C upper end of preferred range 

STRESSFUL

20 - 21 

21- 22 

increased risk of disease 

22C cessation of feeding 

STRESSFUL

22 - 23 

23- 24 22-24°C maximum temperature, juvenile density 

declines to zero (a) 

LETHAL

(within days)

24 - 25EC (75E F) 

Lethal -chronic conditions - upper incipient (7day 

LD50) within days (a, b, c) 

steelhead presence noted in water with 

temperatures >24C when cool water refugia areas 

are present 

LETHAL 25 - 26 Lethal - 6 hour LT10 (a) 

LETHAL

(within hours)

> 26 

Lethal - 26.5 1 hour LT10 (a) 

Critical thermal max (28 - 32C) instantaneous loss

of equilibrium 

11 
Trends in stream temperature

The natural or historical stream temperatures are not known for the Upper 

Main Eel. No information on pre-dam conditions was uncovered, nor general 

stream temperatures before the 1964 flood. However, information regarding

stream channel changes and riparian vegetation changes indicates that shade over

certain channels is less than prior to the 1964 flood. Interviews with long time 

residents of the Tomki Creek area reported that AMost of the deep pools (over 10 

feet deep) were filled with gravels and sediment during the major flood events... 

During the 1920s to 1930s, most of Tomki Creek from Cave Creek to Wheelbarrow 

Creek had no perennial flow, with the riffles drying up during the summer and the

holes remaining full. Above the Hearst-Willits Road ford crossing many of the pools

were 15’ - 20’ in depth... It was impossible to see String Creek from the road 

because of the dense vegetation.@ (MCRCD, 1983.) In addition to the general loss 

of riparian vegetation, Tomki Creek also experienced a loss of shade because of

stream widening. Between the mouth of String Creek and Cave Creek, 1952 photos 

indicate maximum channel widths of 200 feet; around 1983 it was 400 feet, 

primarily due to gravel extraction during that time period. 

Temperature monitoring for the Eel was conducted extensively during 1973 

(Kubicek, 1977), but this was conducted after much of the shade and flow

alterations had already taken place. In general, Kubicek reports the same patterns 

noted by the Humboldt County RCD database - stressful and lethal temperatures in

the main channel, with limited cool water refugia noted. The Humboldt Country 

RCD temperatures are presented in Figure 3. A comparison of 1996 stream

temperatures to the Kubicek 1973 temperatures in some locations in the Upper 

Main Eel TMDL area has been conducted (HCRCD, 1998.) Five locations were 

compared and none had significant variation. 

12 
 

<<<<This page intentionally left blank for insert of Figure 3 – 

Map of temperature monitoring sites and max7daat in Upper Eel>>>> 

13 
2.3 SEDIMENT PROBLEMS 

Salmon requirements related to stream sediment 

This section presents available information related to sediment problems in 

streams in the Upper Eel River and tributaries. Salmonids have a variety of 

requirements related to sediment. Salmonids have different water quality and

habitat requirements at different life stages (spawning, egg development, juveniles, 

adults). Sediment of appropriate quality and quantity is needed for redd (i.e., 

salmon nest) construction, spawning, and embryo development. Excessive 

amounts of sediment or changes in size distribution (e.g., increased fine sediment) 

can adversely affect salmonid development and habitat. 

Excessive fine sediment can reduce egg and embryo survival and juvenile

salmonid development. Tappel and Bjornn (1983) found that embryo survival

decreases as the amount of fine sediment increases. Excess fine sediment can

prevent adequate water flow through salmon redds, which is critical for maintaining 

adequate oxygen levels and removing metabolic wastes. Deposits of these finer 

sediments can also prevent the hatching fry from emerging from the redd, resulting 

in smothering. Excess fine sediment can cause gravels in the water body to

become embedded (i.e., the fine sediment surrounds and packs in against the 

gravels), which effectively cements them into the channel bottom. Embeddedness 

can also prevent the spawning salmon from building redds. 

An imbalance between fine or coarse sediment supply and transport can also

adversely affect the quality and availability of salmonid habitat by changing the 

morphology of the stream. It can reduce overall stream depth and the availability 

of shelter, and it can reduce the frequency, volume, and depth of pools. Pools 

provide salmon a resting location and protection from predators. 

Excessive sediment can affect other factors important to salmonids. Stream 

temperatures can increase as a result of stream widening and pool filling. The 

abundance of invertebrates, a primary food source for juvenile salmonids, can be

reduced by excessive fine sediment. Large woody debris, which provides shelter 

and supports food sources, can be buried. Increased sediment delivery can also 

result in elevated turbidity, which is highly correlated with increased suspended

sediment concentrations. Increases in turbidity or suspended sediment can impair 

growth by reducing availability or visibility of food sources, and the suspended 

sediment can cause direct damage to the fish by clogging gills. 

Sediment conditions in the Upper Main Eel

Historical trends 

The flow of the Eel River and its tributaries above Lake Pillsbury is 

unregulated and highly influenced by rain events. Downstream of the Scott Dam, 

which forms Lake Pillsbury, the river flows through a narrow canyon until much of 

the flow is diverted through a tunnel to a Pacific Gas and Electric Company

powerhouse in Potter Valley where it converges with the East Fork of the Russian

River and through Lake Mendocino. The un-diverted flow drains into the Van 

14 
Arsdale Reservoir, which is formed by the Cape Horn Dam. Flow is then released

from the dam and continues downstream towards the ocean. 

Much of the bedrock in the Upper Eel River watershed is sedimentary and 

metamorphic rock along with ultramafic and volcanic rocks from the Jurassic period. 

Weathering, which is impacted by slope, aspect, wind, rainfall, temperature, 

bedrock composition, and biological activity (decomposition of organic matter), 

produces soils that may be subject to landslides and erosion. Soils with a high 

hazard rating (higher tendency to slump or slide) cover about 40 percent of the

watershed and only 3 percent is considered to have a low hazard rating. Slides, 

slumps, and erosion are fairly common in the watershed and nearly one-sixth of the 

area upstream of Van Arsdale Reservoir is prone to landslides (USFS 1995). 

Lake Pillsbury has become a trap for the sediment that erodes from the most 

northern portion of the watershed, retaining 94 percent of sediments supplied from 

upstream (Brown and Ritter, 1971). Coarse materials are preferentially trapped, 

resulting in the lack of gravel recruitment to downstream areas (Brown and Ritter,

1971). The lake had an initial storage capacity of 94,400 acre-feet, which was 

reduced to 86,780 in 1959 (Porterfield and Dunnam 1964 in USFS 1995) and 

80,700 in 1984 (Brooks et al. 1984 in USFS 1995), resulting in a 14.8 percent

reduction in the storage capacity since 1921. Tracking the loss of storage capacity

in Lake Pillsbury can be used as a surrogate measure of the amount of sediment 

deposited to the upstream tributaries over time. The sediment deposited to Lake 

Pillsbury also contributes to the turbidity problem in the lake, which is exacerbated 

by the presence of fine-grained clays that stay in suspension for extended periods

of time (USFS 1995). Downstream of Lake Pillsbury, the Van Arsdale Reservoir is 

small enough and filled enough that it does not appear to impair sediment transport 

past Cape Horn Dam.

Other factors that have historically impacted erosion and sediment delivery in

the watershed include trails, roads, grazing, and fire. For example, upstream of

Van Arsdale, American Indians and ranchers historically used trails for traveling, 

while many roads were built in the 1930s and later became the backbone for 

today’s transportation network. Increased logging operations forced the

development of additional roads, many of which were not designed to withstand 

large rainfall events (USFS 1995). Grazing and fire both reduce vegetation, thus 

making soil available for erosion. Grazing controls have been in place since 1907 

with the creation of the Mendocino National Forest; however, fire has increased

erosion in several subwatersheds, especially during the 1987 fire season (USFS

1995). 

In the winter of 1964, warm rain falling on the snowpack triggered the 

release of a tremendous amount of water in a short period of time, causing a great

flood. This flood was very damaging to areas of the Mendocino National Forest and

other forests in northwestern California. It has been estimated that the highest 3 

days of the 1964 flood were responsible for moving over one-half of all sediment

transported during a 10-year period upstream of Scott Dam (Brown and Ritter 1971 

in USFS 1995). 

Information regarding specific effects of the 1964 flood in the Upper Eel River 

watershed exist for Tomki Creek. As discussed in Section 2.2, Tomki Creek was 

15 
greatly widened, lost much of its riparian cover and lost most of the deep pools that

were present before the 1964 flood (MCRCD, 1983.) Additionally areas of Tomki 

Creek were used for gravel extraction and were greatly widened, from 200 foot 

maximum channel width to 400 foot maximum channel width. 

Current conditions & evaluation of stream recovery

Very little information is available regarding the recovery of the Upper Eel 

River after the 1964 flood. The California Department of Fish and Game is 

scheduled to complete a draft watershed assessment on Outlet Creek during the

Winter 2004/2005. This watershed assessment is expected to provide additional

instream sediment measurements, as well as other information on the stream 

condition. The California Department of Fish and Game Stream Inventory Reports 

provided useful information regarding current sediment conditions in the watershed 

(CDFG Stream Inventory Reports 1991-1998). Using pool embeddedness 

(estimated visually) as an indicator, streams in the Upper Eel River were found to

have variable conditions for salmon. Of the eighteen streams observed for 

embeddedness, only two streams had over 50% of pools with very good conditions

and three streams had over 50% of pools with very poor conditions or conditions

completely unsuitable for spawning. The majority of streams were in between, 

ranging from 26-75% embedded. These observations, while not a comprehensive 

inventory, covered large portions of tributaries including Alder Creek, Baechtel 

Creek, Bear Pen Canyon Creek, Benmore Creek, Bloody Run Creek, Broaddus 

Creek, Cave Creek, Cherry Creek, Haehl Creek, Long Valley Creek, Outlet Creek, 

Ryan Creek, String Creek, Tomki Creek, Unnamed Tributary #1 to Cave Creek, 

Unnamed Tributary #2 to Cave Creek, Unnamed Tributary #3 to Cave Creek, and 

Willits Creek. 

Upstream of Van Arsdale Reservoir, in the Lake Pillsbury Hydrologic Unit Area

(HUA), the USFS has noted that in some areas, the roads and trails often function

as first order streams by transporting water and sediment to other drainages (USFS 

1995). In particular, there are over 175 miles of trails (including about 100 miles 

of designated off-highway vehicle trails) and over 760 miles of road (about 3900

road/stream crossings). These conditions facilitate the transport of sediment to

streams and without proper maintenance and planning, can increase erosion and

sediment available for transport. In addition, approximately 70 percent of the 

roads in the watershed are insloped, which may cause the roads to deliver water 

and sediment to nearby drainages (USFS 1995). Many of the current roads have 

been designed to reduce their erosion potential; however, ongoing maintenance is 

required to control sedimentation. Overall, the Lake Pillsbury HUA is considered to 

be in better condition than other portions of the watershed and has a lower road 

density than many other regions of the North Coast. 

Lake Pillsbury continues to trap sediments draining from the upstream area. 

In 1992, USFS personnel indicated that the rate of lake filling is similar to the 1959-

1984 rate described previously (USFS 1995). The base of the sediment wedge 

from the Rice Fork tributary is approaching the base of the dam. The lake is not 

yet filled to a critical point; however, bathymetry measurements are expected to be 

taken in the coming years to better clarify the extent of the problem. 

16 
In summary, data regarding the sediment conditions for many streams in the 

Upper Eel indicate adverse impacts from the combined effects of the 1964 flood and

land use practices at that time. It is likely that the widespread sedimentation and 

channel changes that occurred following the 1964 flood provided difficult conditions

for salmonid survival (e.g., higher proportions of fine sediment, filling of pools, 

etc.). While there may be some recovery of the stream channel since the 1964

flood, an overall assessment of stream conditions is not available and the available

information from DFG reports indicates variable conditions. 

2.4 WATER QUALITY STANDARDS 

In accordance with the Clean Water Act, TMDLs are set at levels necessary to

achieve the applicable water quality standards. Under the federal Clean Water Act, 

water quality standards consist of designated uses, water quality criteria to protect 

the uses, and an antidegradation policy. The State of California uses slightly 

different language (i.e., beneficial uses, water quality objectives, and a nondegradation policy). This section describes the State water quality standards 

applicable to the Upper Main Eel River TMDL using the State=s terminology. The 

remainder of this document simply refers to water quality standards. 

The beneficial uses and water quality objectives for the Upper Main Eel River 

are contained in the Water Quality Control Plan for the North Coast Region (Basin

Plan), as amended (NCRWQCB 2001). The Basin Plan identifies many beneficial 

uses for the Upper Main Eel River, specifically: Municipal and Domestic Supply;

Agricultural Supply; Industrial Process Supply; Groundwater Recharge; Water 

Contact Recreation; Non-contact Water Recreation; Commercial and Sport Fishing;

Cold Freshwater Habitat; Rare, Threatened or Endangered Species; Migration of 

Aquatic Organisms; and Spawning, Reproduction and/or Early Development. 

The water quality objectives pertinent to the Upper Main Eel River 

temperature and sediment TMDLs are listed in Table 2. In addition to water quality

objectives, the Basin Plan includes two prohibitions specifically applicable to 

logging, construction, and other associated sediment- producing nonpoint source 

activities: 

the discharge of soil, silt, bark, sawdust, or other organic and earthen 

material from any logging, construction, or associated activity of whatever nature

into any stream or watercourse in the basin in quantities deleterious to fish, 

wildlife, or other beneficial uses is prohibited; and 

the placing or disposal of soil, silt, bark, slash, sawdust, or other organic and 

earthen material from any logging, construction, or associated activity of whatever 

nature at locations where such material could pass into any stream or watercourse

in the basin in quantities which could be deleterious to fish, wildlife, or other 

beneficial uses is prohibited. 

17 
Table 2. Water Quality Objectives 

Parameter Water Quality Objectives 

Suspended

Material

Waters shall not contain suspended material in concentrations that cause 

nuisance or adversely affects beneficial uses. 

Settleable 

Material

Waters shall not contain substances in concentrations that result in deposition

of material that causes nuisance or adversely affect beneficial uses. 

Sediment 

The suspended sediment load and suspended sediment discharge rate of 

surface water shall not be altered in such a manner as to cause nuisance or 

adversely affect beneficial uses. 

The natural receiving water temperature of intrastate waters shall not be 

altered unless it can be demonstrated to the satisfaction of the Regional Water 

Board that such an alteration in temperature does not adversely affect 

beneficial uses. Temperature 

At no time or place shall the temperature of any COLD (water with a beneficial

use of cold freshwater habitat) water be increased by more than 5  ̊F above 

natural receiving water temperature.

Turbidity

Turbidity shall not be increased more than 20 percent above naturally occurring

background levels. Allowable zones of dilution within which higher percentages 

can be tolerated may be defined for specific discharges upon the issuance of 

discharge permits or waiver thereof. 

18 
CHAPTER 3: TEMPERATURE TMDLs 

This chapter describes the analytical basis for the temperature TMDLs, along 

with the TMDLs and allocations. The TMDL is divided into two parts. The first

analysis is for shade for all stream reaches in the Upper Main Eel area. The second

analysis is for the stream reach between Van Arsdale and Outlet Creek where 

diversions from the Potter Valley Project are an additional concern. 

The analysis described in this chapter indicates that alterations in shade 

result in alterations in stream temperature in the Upper Main Eel River and 

tributaries. Furthermore, the analysis indicates that temperature alterations are 

possible under some interpretations of the State’s Forest Practices Rules. If

harvesting of larger riparian conifers takes place extensively within the watershed,

the cumulative effects will adversely affect steelhead. 

The second part of the analysis -- the impacts of flow on stream temperature 

from Van Arsdale to Outlet Creek -- indicates that flow alterations result in 

temperature alterations under many conditions. In addition, EPA concludes that the

stream temperatures likely to result from the new June 2004 FERC flow 

requirements will facilitate attainment of water quality standards. 

This chapter first describes EPA=s interpretation of the narrative water quality 

standard for temperature. The chapter then describes the temperature modeling for 

solar radiation and shade for all stream reaches and sets a TMDL for solar radiation 

(in terms of langleys/day) and allocations in terms of shade for all stream reaches. 

A instream heat TMDL (in terms of BTUs) is also set for the reach between Van 

Arsdale and Outlet Creek because temperatures in that reach are affected by 

hydrological modification as well as shade. 

3.1 INTERPRETING THE EXISTING WATER QUALITY STANDARDS 

FOR TEMPERATURE 

This temperature TMDL is calculated to attain the applicable water quality 

standards. The Basin Plan identifies the following two temperature objectives for 

surface water: 

AThe natural receiving water temperature of intrastate waters shall not be altered 

unless it can be demonstrated to the satisfaction of the Regional Water Board that 

such an alteration in temperature does not adversely affect beneficial uses.@

AAt no time or place shall the temperature of any COLD <i.e. water with a 

beneficial use of cold freshwater habitat> water be increased by more than 5E

degree F above natural receiving water temperature.@

19 
EPA interpreted the above standards for the TMDL as follows. EPA used a 

model to compare Anatural stream temperatures@ with current stream temperatures

and temperatures under likely future management conditions. In considering the 

first objective, EPA then examined whether these alterations (changes in stream

temperatures) would adversely affect the most sensitive beneficial use - that is, 

cold water fish during the summer rearing period. EPA=s evaluation of Aadverse@

effects is based on the scientific literature on steelhead temperature tolerances 

(summarized in Table 1). EPA evaluated whether or not the changes in stream 

temperature also negatively affected the quality of stream temperatures. In

general, any increase (warming) of natural summer stream temperatures is 

adverse to rearing steelhead. 

The second objective (i.e., not increasing the stream temperature more than 

5 degrees F) was evaluated by comparing every modeled point on the stream for 

exceedance of the 5 degree objective. This objective is more difficult to exceed

than the first objective; therefore, the attainment of the first objective will meet the 

second objective. 

3.2 TEMPERATURE MODELING

Stream temperature has been widely studied and the physics of heat transfer

is one of the better understood processes in natural watershed systems (TFW, 

2000.) Many factors affect stream temperature including solar radiation, air 

temperature, local shading, climate, stream flow and depth, channel morphology, 

groundwater inflow and upstream temperatures. Modeling of stream temperature

is a well developed area of inquiry and many models are available to assist 

policymakers in understanding the factors controlling stream temperatures. 

EPA funded Tetra Tech Inc. to develop and run the Q2ESHADE model to 

evaluate both the influences of different flow scenarios and different shade 

scenarios. The Q2ESHADE model allows EPA to examine how stream temperatures

change in relation to different assumptions on flow, upstream temperatures, and

shade (as influenced by the size of riparian vegetation, specifically conifers.) 

Appendix A provides a more complete discussion of the model components, 

assumptions and data. The Q2ESHADE combines elements of two models (Qual2E

and SHADE) to examine cumulative effects on stream temperature throughout all 

modeled areas in a stream network. Qual2E, the first model, is a publicly available 

model and is widely used in analyzing many water quality problems. Chen, et al

(1998) originally developed a model called SHADE that when linked to other 

models, can provide basinwide (e.g. cumulative effects) information regarding 

streamside vegetation changes. The Tetra Tech version of SHADE is a simplification

of certain components of the Chen model (see appendix A.) Inputs from the 

SHADE model are linked to Qual2E to provide routing of local stream heating or

cooling (from vegetation, flow changes, tributary cooling etc) downstream through

the stream network. 

Details on the models calibration performance is available in Appendix A. 

Calibration performance is available for hourly, daily and max7daat. 

The model was applied to two separate subareas of the Upper Main Eel TMDL 

area - Tomki Creek and the main channel of the Eel between Van Arsdale and 

20 
Outlet Creek. Tomki Creek, including tributaries to Tomki Creek, was modeled for 

alterations in shade. Tomki Creek was chosen because the proportion of vegetation

types represent a middle ground condition between the heavily forested

subwatersheds in Mendocino National Forest and the less forested area of Outlet 

Creek. In addition, sufficient data was available for Tomki Creek. This modeling 

approach was used to develop a temperature TMDL for solar radiation for all stream

reaches. 

 The main channel of the Upper Eel from Van Arsdale downstream to Outlet

Creek was modeled separately to take into consideration the flow diversion at Van 

Arsdale. EPA wanted to explicitly analyze the different flow regimes for this reach 

to evaluate their attainment of the narrative water quality standard. An additional

TMDL component for instream heat (in BTUs) is calculated for the main channel of

the Eel between Van Arsdale to Outlet Creek. This is needed due to the additional 

influence of hydrological modification on stream temperature in this reach. 

In response to comments on the draft TMDLs, EPA revised the modeling for 

the final TMDL for the reach between Van Arsdale and Outlet Creek. The revisions 

were a reinterpretation and averaging of the existing detailed data on stream width,

depth and velocity. While this resulted in changes in the magnitude of the effect of

flow on stream temperature, the basic relationships between scenarios is the same

as in the draft TMDL. 

3.2.1 Temperature and Solar Radiation Modeling 

Tomki Creek was selected as a representative area of the entire Upper Main 

Eel to determine if changes in riparian vegetation allowed under current 

management practices alter natural stream temperatures in the Upper Main Eel 

TMDL area. The majority of stream riparian areas are managed either by private

landowners or the Mendocino National Forest. 

The Mendocino National Forest manages under the Northwest Forest Plan,

which protects the riparian zone from timber harvest and promotes natural riparian

vegetation. The Northwest Forest Plan does allow some harvest of larger diameter 

tree, however, not in the riparian reserves. Riparian reserves are approximately 

300 feet on each side of the edge of the active stream channel for fish bearing 

streams and 150 feet for periennial, non-fish bearing streams. 

 The Mendocino National Forest prohibits timber harvest in riparian reserves 

except to further promote riparian restoration and only if large woody debris needs 

are met. Thus EPA’s interpretation is that the Northwest Forest Plan will result in

natural size of conifers in the riparian zone. For roads that may be affecting shade, 

the Mendocino National Forest standards also require minimizing road locations in 

riparian reserves. In addition, USFS projects are required to comply with the 

Regional Water Board’s current Waiver for discharges related to Timber Operations. 

This waiver reiterates the water quality standard of no alteration of stream

temperature. 

Private lands are managed by private landowners, and riparian vegetation

can be removed or altered by grazing, vineyard development, housing development 

or timber harvest. Timber harvest is permitted under the State’s Forest Practices

Rules. The Forest Practices rules specify a 85% canopy retention and the retention

21 
of the 10 largest conifers per 330 feet of stream, if the stream is anadromous fish 

bearing. Canopy retention for other streams is 50%. However, the canopy 

retention can be met while harvesting the tallest trees and depending upon the 

width of the stream and other site conditions, shade over the stream is potentially 

reduced. 

The analysis below assumed that the type of vegetation currently present in 

riparian areas does not change (e.g. conifer, hardwood, grassland, brush areas 

remain in the same vegetation type.) An additional assumption is that all the

riparian vegetation is managed the same way at the same time. EPA uses this 

assumption to analyze cumulative effects of different management styles. Actual 

stream temperature effects will be a combination of both the type of riparian 

management, the proportion of landowners choosing different types of riparian 

management and the timing and frequency of riparian management. 

EPA evaluated the following five riparian management scenarios with the 

Q2ESHADE model described above for the Tomki Creek watershed. As described

previously, the analysis for Tomki Creek is a surrogate for the effects in the entire 

Upper Eel TMDL area, including USFS and private lands: 

1 - Current condition (baseline) This scenario is developed using the size of the

vegetation as provided by the data and assumptions detailed in Appendix A. In the

Tomki Creek area, there was significant timber harvest during the late 1940s 

through the 1960s affecting over 50% of the watershed (Mendocino County RCD, 

1983). It appears the current condition includes a substantial recovery in 

vegetation from that period; there were no recent timber harvest plans in the area. 

2 - Topographical shading only. This scenario was developed to determine the

general importance of vegetation shade in the watershed; it is not meant to reflect 

current or future conditions. In this scenario, the only shade over the stream is 

from unvegetated topography such as adjacent hillslopes. All shade from trees 

(both conifer and hardwood) was eliminated from the model for the purposes of this 

scenario. 

3 - 18 inch diameter at breast height (dbh) conifer- private timber management. 

Changes to the riparian area are generally at the discretion of private landowners,

except for timber harvest for which permits are required under the State=s Forest

Practice Rules. This scenario was developed to illustrate the result under the 

State=s Forest Practice rules. The rules have a requirement for 50-85% canopy

retention, however it cannot be generalized what size tree is left in the riparian 

zone given this minimum requirement. Theoretically, an owner can harvest all 

trees as small as 12 inch dbh under the Forest Practice Rules, but generally it is not

economical to do so. In addition, silvicultural management styles vary amongst 

different private landowners. This scenario represents the result if the entire 

watershed was harvested at the same time resulting in 18” dbh conifer trees after

harvest. The riparian areas for grassland or brush are modeled without riparian

tree species. 

4 - 24 inch dbh conifer-alternative private timber management. Given the variety 

of private timberland management styles, EPA also modeled a stand of 24 inch dbh

conifers as another possible representation of future conditions under private 

22 
timber management. Again this scenario illustrates cumulative effects if the 

conifer areas in entire watershed were harvested at the same time. This is

considered somewhat unlikely given that in Tomki and Outlet Creek there are many

owners with smaller parcels.. 

5 – Natural (full growth conifer 48” dbh, plus significant riparian species recovery.)

While it is difficult to generalize on the natural size of conifers, given the range of

site conditions, 48 inch dbh conifers adequately represent Anatural@ growth for the 

purposes of determining shade (see appendix A for a discussion of potential conifer 

size.) This Anatural@ scenario is compared to different management scenarios to

examine the incremental temperature increases from timber harvest in the area. 

In addition, this scenario also represents the expected future result of USFS

management practices regarding timber harvest in riparian areas. The modeling 

was also designed to add riparian tree species in all areas modeled under 

grassland, brush or hardwood vegetation type. This type of riparian (alder, willow 

etc) cover did exist historically in Tomki Creek. 

Tables 3 and 4 provide the results of the modeling. The model uses the 

riparian condition scenarios 1-5 described above. The model first calculates the 

resultant heat input into the stream channel (in Langleys). Langleys are a measure 

of heat energy per surface area per time (or gram calories per cubic centimeters.)

The solar radiation heat input, expressed as Langleys, can also be expressed 

as shade. Shade is calculated by dividing the total amount of heat energy from

solar radiation at this latitude by the amount of heat energy input into the stream

after shading provided by riparian vegetation and topography. This shade 

percentage can be thought of as the inverse of heat or a proportion of the available

heat shaded. The heat input into the stream channel is then converted to a stream

temperature which is then routed downstream to account for cumulative effects. 

The results are presented in Tables 3 and 4, summarized with EPA’s evaluation of

the effect of stream temperatures on juvenile steelhead. 

The modeling results indicate that the size of riparian vegetation and 

specifically the height of the riparian trees strongly influence the existence of cooler 

stream temperatures in Tomki Creek. For example, topographical shading only 

(e.g. no trees) results in the smallest amount of the stream (4.4 miles) in the 

good/adequate/marginal categories (less than 20°C). These results indicate that 

juvenile steelhead populations in these areas would be adversely affected by the 

total loss of riparian vegetation. The size of conifers also alters stream 

temperatures, even though this watershed has a significant proportion of riparian 

area without conifers. There is an increase in the miles of stream with warmer

temperatures, if the watershed were managed for smaller conifers (18 & 24 inch

dbh) compared to the Anatural@ scenario where 48 inch dbh trees exist. This is 

illustrated in Table 3 by a slightly larger amount (approximately 2 stream miles) in

the watershed greater than 24°C when there are 18 or 24” dbh conifers compared

to a natural condition. 

The modeling indicates that Tomki Creek is unusually warm, even under 

natural conditions, compared to other watersheds in the Eel. The proportion of 

stream miles in stressful and lethal stream temperatures predicted by the model, 

even under natural conditions for Tomki Creek, is unusual compared to the results 

23 
of modeling conducted previously in other watersheds in the Eel. For example, 

99% of stream miles were <19EC in the Upper Black Butte, and 84% were <19EC 

in the North Fork of the Middle Fork (USEPA, 2003), both in the Mendocino National

Forest. In the North Fork of the Eel, there were no stream miles in the northern 

tributaries (USEPA, 2002) predicted to have lethal temperatures under natural 

conditions. Tomki Creek is most similar to Rattlesnake Creek in the South Fork of 

the Eel, where natural stream temperatures were modeled to result in 78% of 

stream miles >19EC (stressful and lethal). EPA’s findings illustrate that a wide 

range of natural stream temperatures were likely to exist in the entire Eel basin. 

3.2.2 Selection of Scenario Corresponding to Water Quality

Standards 

The narrative water quality standard states Athe natural receiving water

temperature ...shall not be altered unless it can be demonstrated...that such an 

alteration in temperature does not adversely affect beneficial uses.@

EPA concludes that the natural scenario (scenario 5) corresponds best to the 

“natural stream temperatures shall not be altered@ phrase in the State’s Water

quality standards. EPA examined the modeling results and concluded that private

landowner practices in the riparian zone have the potential of adversely altering 

these natural stream temperatures, even under the restrictions of the State=s Forest

Practice Rules. EPA also finds that this amount of alteration in stream temperature

is adverse to the beneficial use of COLD from increases in stream temperature 

during the summer that affect steelhead rearing. Given the small amount of 

adequate and good habitat, any degradation in stream temperatures from natural 

conditions would adversely affect beneficial uses. Note that the projected riparian

condition of USFS management under the Northwest Forest Plan was modeled using

the same assumptions as the natural condition. EPA considers this likely for the 

size of riparian conifers. The USFS riparian conditions regarding shade impacts 

from sediment in this TMDL area are not analyzed in this Chapter. Chapter 4 

discusses sediment. 

3.3 SOLAR RADIATION TMDL 

Section 303d of the Clean Water Act and EPA regulations require that a TMDL 

be established. In this report, we are establishing the TMDL and allocations for the

Upper Main Eel and tributaries in two parts. The first part addresses the effects of

solar radiation from changes to riparian shade and applies to all of the stream 

reaches in the watershed. The second component is discussed is Section 3.4 and 

addresses the hydrological modifications in the area of the main channel Eel 

between Van Arsdale and Outlet Creek. 

24 
<<<This page left intentionally blank for insert of Tables 3 and 4 >>>> 

25 
3.3.1 Loading Capacity and TMDL – Solar Radiation for all stream 

reaches

The TMDL is the total loading of a pollutant that the river can assimilate and 

still attain water quality standards for temperature. In this TMDL, the pollutant is 

heat, measured in Langleys/day (ly/day). A Langley is a measure energy per unit 

area (equal to 1 gram calorie/cm2) and can be converted to metric units such as

joules (1 ly = 41,850 joules/m2

) or watts or BTUs. We are setting the TMDL equal 

to the amount of heat the waterbody would receive under the natural scenario (e.g. 

scenario #5.) 

In the model (see Appendix A) Aglobal solar radiation@ over each stream

segment - i.e., the solar radiation that exists above the vegetation at this latitude

Bis reduced by topography and vegetation characteristics, resulting in a smaller 

amount of heat reaching the stream for each segment. The model calculates the 

actual amount of radiation/heat in langleys that would reach each stream segment 

after accounting for topographical shading, stream orientation, stream width and 

the potential height of the riparian vegetation. The model calculates the amount of 

heat for each stream sampling point, however, the TMDL is expressed as an 

average of all stream sampling points for summary purposes. 

The TMDL for the Upper Eel and tributaries is set equal = 

average of 289 langleys/day. 

This is based on the modeled calculations for Tomki Creek. Tomki Creek is a

generally representative vegetation condition, between the more heavily forested 

subwatersheds in Mendocino National Forest and the less forested area of Outlet 

Creek. The TMDL number is a mathematical average of the amount of heat that

would reach the stream surface for each stream segment modeled after accounting

for full natural growth of conifers and also riparian species for grassland, brush and 

hardwood areas. 

This is the loading capacity of the stream, and will allow water quality 

standards for temperature to be achieved. 

3.3.2 Shade Allocations 

In accordance with EPA regulations, the loading capacity (i.e. TMDL) is

allocated to the various sources of heat in the watershed, with a margin of safety. 

There are no point sources, therefore the wasteload allocations in the watershed is 

zero. This TMDL has an implicit margin of safety that is provided by assumptions 

rather than a direct calculation. Therefore, the TMDL is set equal to the loading 

capacity and the allocations result in the TMDL. The TMDL is set in langleys and the

allocations are expressed in shade. 

While it is theoretically possible to measure langleys/day for streams in 

practice, shade is more often measured by land managers. The concept of shade, 

as it relates to heat input, has a significant time component as it varies daily and

seasonally. Shade as expressed here is the accumulated reduction in solar 

radiation from the daily amount of stream in shadow or shade. This can be

measured directly with a solar pathfinder or less exactly with other shade 

26 
measurements. We have calculated the allocations using the model, by translating

the TMDL in langleys/day into an average shade allocation for the watershed. 

For all stream reaches in the Upper Main Eel TMDL area 

TMDL = sum of the allocations for each stream sampling point. 

The allocations are an average of 49-50% shade for all stream segments 

The allocations are expressed as percent shade. Percent shade for all stream 

segments is the amount of solar radiation reaching the stream surface divided by 

the potential solar radiation. This is after shading provided by natural vegetation. 

This will be an average of 49-50% shade for all stream segments. 

3.3.3 Margin of Safety 

Under EPA regulations, a margin of safety may be provided explicitly by not 

allocating a portion of the available TMDL or implicitly through use of using 

conservative analytical assumptions. In this TMDL, an implicit margin of safety is 

provided through the conservative analytical assumptions. First, the selected 

model scenario evaluated management effects throughout the entire Tomki Creek 

watershed for cumulative shade and temperature alterations when in fact, smaller, 

less frequent timber harvest plans are often normal. Thus if harvest plans that

reduce shade are less frequent and small they may in fact not result in significant 

stream temperature effects. Second, implementing the temperature TMDL will 

result in larger riparian vegetation, which will increase the potential for

contributions of large woody debris to streams. Increases in large woody debris 

benefit stream temperatures and associated cool water habitat by increasing the 

number and depth of pools, which provide areas of cooler water for fish. These 

indirect beneficial effects were not accounted for in the analysis, but provide an

implicit margin of safety. Third, refugia from existing stratified pools or streams 

dominated by springs provide cooler temperatures than were accounted for in the

TMDL analysis. As a result, we would expect more cool water habitat to exist than 

the TMDL analysis predicts. Finally, larger vegetation also will tend to create 

microclimates that will lead to improvements in stream temperatures. These 

effects were not accounted for in the temperature analysis, but provide an

additional implicit margin of safety.

3.3.4 Seasonal Variation and Critical Conditions 

In accordance with EPA regulations, the TMDL must account for seasonal

variations and critical conditions. In the Upper Main Eel watershed, the summer 

period defines the critical period when stream temperatures are most likely to have

adverse impacts on beneficial uses (young salmonids growing in the streams before 

migrating to the ocean). To account for seasonal variations and critical conditions, 

the analysis is based on the max7daat (i.e., the maximum weekly average of the 7 

day running average of all monitored temperatures). Temperatures are not limiting 

to beneficial uses during the winter period. 

27 
3.4 INSTREAM HEAT TMDL- VAN ARSDALE TO OUTLET CREEK 

This section describes the analysis supporting the calculations of a TMDL and 

associated allocations to address the effects of hydrological modification on stream

temperatures for the section of the Upper Main Eel between Van Arsdale and Outlet 

Creek. This stream reach was selected for additional inquiry because stream flow is 

diverted during the summer at Van Arsdale. Given that flow is an important 

influence on stream temperature, EPA sought to investigate the extent and 

importance of the temperature alteration from the flow diversion. The modeling 

described below predicts that alterations in flow will alter downstream temperatures

under many conditions in the Upper Main Eel. In addition, EPA concludes that the

stream temperatures likely to result from the new flow requirements from the June

2004 FERC order are likely to result in attainment of water quality standards. 

EPA’s conclusion is based upon a comparison of a construction of possible “natural” 

stream temperatures. Natural stream temperatures were not measured 

historically. Based on the analysis, EPA developed an instream heat TMDL and 

allocations for this portion of the Upper Main Eel. 

The Potter Valley Project=s influence on stream temperature and cold water 

habitat is complex. Temperatures upstream of Lake Pillsbury are warmer 

(approximately 22.5EC at the Rice Fork and inlet at Lake Pillsbury) than those below

Lake Pillsbury (18E-20EC), because Lake Pillsbury stratifies and cool bottom water is

released into the Eel during the summer. Scott Dam at Lake Pillsbury while it

provides summer cooling along this 12 mile stretch, also blocks access to many

miles of summer cold water habitat for steelhead, plus spawning habitat for chinook 

and steelhead. The 12 mile area between Lake Pillsbury and Van Arsdale has 

significant summer flow (100 cfs on average) and this large block of water resists 

heating and remains approximately 20EC max7daat. After the diversion, where 

approximately 7 cfs was released at Van Arsdale until the summer of 2004, the

stream quickly heats and was measured to be 24EC as a max7daat around Tomki 

and 27EC by Outlet Creek under the pre-2004 summer flow regime. 

There are two possible alterations in temperature that were not considered

quantitatively in this portion of the analysis. First, the stream reach that is now

Lake Pillsbury likely had some temperature alteration from natural conditions. 

There is a lack of information regarding the stream condition pre-project and Lake 

Pillsbury currently provides cold water and habitat for rainbow trout and does not 

appear to be temperature impaired. Therefore, EPA did not analyze changes in 

steam temperature in this reach related to the project. Second, temperature 

alterations on the stream reach between Lake Pillsbury and Van Arsdale were not 

modeled. EPA concluded that this alteration is beneficial to salmonids, as it 

provides cooler stream temperatures and is likely to continue under all future 

management scenarios. 

EPA=s analysis does not include an analysis of the alteration in habitat access 

by the Potter Valley Project. To recall the water quality standard - AThe natural 

receiving water temperature of intrastate waters shall not be altered unless it can

be demonstrated to the satisfaction of the Regional Water Board that such an 

alteration in temperature does not adversely affect beneficial uses.@ This TMDL is 

designed to attain that water quality standard, and thus focuses on changes to 

28 
stream temperatures. Although, both spawning habitat for chinook and rearing 

habitat for steelhead are blocked by Scott Dam, it would be beyond the scope of

the TMDL to analyze the overall benefits to salmonids of a natural condition as 

compared to conditions with the Potter Valley project. This is an important 

difference between this analysis and other forums, such as the Endangered Species 

Act consultation or FERC proceedings concerning the Potter Valley Project.

Recall that the applicable water quality standard states Anatural stream

temperatures shall not be altered....@. EPA sought to determine what was the range 

of Anatural@ stream temperatures compared to both the measured temperatures

prior to summer 2004 and the temperatures predicted under the 2004 flow

requirements. The June 2004 flow requirements are an increase in summer flow

compared to the conditions from the 1920s - 2003. The temperatures resulting 

from those flows needed to be modeled as the monitoring results were not fully 

available for this analysis. 

There are many difficulties in determining the natural stream temperatures in

the area of the Potter Valley Project. The Potter Valley Project dates from the 

1920’s and almost no information regarding pre-project stream conditions and 

temperatures was uncovered by EPA. A historian with the USFS who studied the 

Mendocino National Forest reported an absence of detailed ethnohistoric period

information about Gravelly Valley (now Lake Pillsbury) (Supernowicz, 1995.) 

Therefore, the “natural” stream temperatures used for comparison were modeled

using a wide range of assumptions. These possible Anatural@ stream temperatures 

were then compared to both the 1975-2003 flow conditions and the flow conditions

that are likely to result from the June 2004 FERC order. 

The data and scenarios used for comparing Anatural@ stream temperatures 

with Aaltered@ stream temperatures are as follows: 

1975-2003 - baseline conditions: This scenario represents flow and temperature

conditions that have been monitored in the recent past. The average flow below

Van Arsdale was modeled as 7 cfs based on USGS records. The starting

temperature at Van Arsdale modeled was 20.9EC based on temperature on the 

max7daat 2003 monitoring results. The 1975-2003 flow schedule did not vary

between water year types. 

FERC/NMFS. This scenario represents flow and temperatures conditions 

projected under the 2004 FERC order. Three water year types were modeled. The 

summer flow specified in the FERC order was used, along with the same 20.9EC 

temperature at Van Arsdale. EPA assumed that the FERC/NMFS flows would be at

the current outlet temperatures. EPA did not make adjustments because the FERC

proceedings did not resolve issues regarding the availability of current cool water 

from Lake Pillsbury. The summer flows specified in the FERC order are as follows: 

Very Wet - 30 cfs 

Wet - 15 cfs

Dry - 9 cfs

29 
Natural Stream temperatures. To estimate natural stream temperatures from

Van Arsdale to Outlet Creek, EPA considered available information on both natural 

flow and natural stream temperatures at Van Arsdale. Data on unimpaired (e.g. 

natural) flow were developed for the FERC proceedings and provided important 

natural flow assumptions to EPA. The FERC/NMFS water year types are triggered

by a cumulative inflow to Lake Pillsbury as of May 15, but a precise relationship

between the actual trigger and the unimpaired flow was not available therefore a

review of the unimpaired flow record was used. Additionally, although two sets of 

unimpaired data are in existence, EPA was only able to acquire the PG&E dataset 

during the time frame available. Table 5 provides a summary of the flow and 

temperature assumptions used for these and all other scenarios. 

The other important assumption concerns the starting stream temperature at 

Van Arsdale associated with the unimpaired flow. We could not use the available 

monitored temperatures at Van Arsdale because, as discussed below, these 

temperatures have been altered – in fact, lowered – as a result of the Potter Valley 

Project. As the project has been in existence for nearly a century, no record exists

of natural stream temperatures. Thus the range of starting temperatures modeled

was intended to represent the largest possible range and a discussion of how each 

lower (cooler) and upper (warmer) bound was generated follows. The lower bound 

is 22.5EC - which is the average of the max7daat of the 2 primary tributaries above 

Lake Pillsbury - Eel at the inlet of Lake Pillsbury and Soda Creek. This lower 

(coolest) bound scenario assumes that the stream does not heat during its 

approximate 20 mile flow from the Eel above Lake Pillsbury to Van Arsdale. This

lack of downstream heating, EPA considers possible although with reservations. The 

area between Lake Pillsbury and Van Arsdale does have both topographic and 

vegetation shading and cooler subsurface water appears to be present (Jahne, 

personal communications.) It is also possible that the area of Hullville and Gravelly

Valley (now Lake Pillsbury) was significantly influenced by subsurface flow. For 

example, the FLIR (Thermal Infrared and Color Videography) monitoring of the

nearby North Fork Eel River has an area where the river reemerges from the 

subsurface gravel and has cooled from lethal temperatures by approximately 4-6EC 

to 21.3EC. In addition, the Scott River cools by 2-3 ̊C over a distance of 4.3 miles 

as cooler ground water emerges at the downstream end of the alluvial Scott Valley. 

The geologic setting of Gravelly Valley is very similar to that of Scott Valley: a large 

alluvial valley with a bedrock canyon downstream. These types of valley settings 

often create conditions where a significant volume of ground water enters the 

stream channel draining the valley (McFadin, personal communication.)

 However, both these examples provided cooling only for a limited distance. 

EPA uses this scenario to represent the coolest possible natural stream

temperature. Natural stream temperatures cooler than this were extremely 

unlikely and EPA does not have any information on larger streams that cool as they 

flow downstream for significant distances, without the influence of significant cool 

tributary inflow or cooler coastal air temperatures. 

The upper bound (warmest) possible Anatural@ stream temperature scenario 

was developed to reflect some downstream stream heating as follows. EPA used 

30 
the modeled reach between Tomki Creek and Outlet creek as a surrogate of the 

upstream channel. The current channel morphology between Lake Pillsbury and 

Van Arsdale has been changed by the hydrological modification and sediment filling 

around Van Arsdale, thus the temperatures associated with this portion of the 

channel are not representative of the natural condition. The upper bound scenario 

accounts for the resistance to heating of increases in the bulk of water (10 cfs, 20

cfs and 50 cfs) with a stream in a similar climate and geography. The distance 

used was 20 miles (the approximate amount of stream inundated by Lake Pillsbury 

plus the distance from Lake Pillsbury to Van Arsdale.) EPA believes this to be the

warmest stream temperatures likely for the reach between Van Arsdale and Outlet 

Creek. The rate of stream heating is characteristic of a less shaded stream than

would likely exist, plus the river flows generally north/south in the modeled reach, 

whereas the Anatural@ channel generally flows east/west. For these reasons, EPA 

modeled these temperatures as the upper bound (warmest) natural stream

temperatures. This also accounts somewhat for natural variations in stream

temperature by water year type. 

The following table summarizes the scenarios described above:

Table 5: Flow and temperature assumptions for Van Arsdale to 

Outlet Creek scenarios 

YEAR 

TYPE 1975-2003 FERC/NMFS Natural - lower Natural - 

Upper 

CFS EC at Van 

Arsdale CFS EC at Van Arsdale CFS EC at Van Arsdale CFS EC at Van

Arsdale

DRY 7 20.9E 9 20.9E 10 22.5° 10 25C 

WET 7 20.9E 15 20.9E 20 22.5E 20 24.3C

VERY WET 7 20.9E 30 20.9E

50 & 

60 22.5E 50 23.5C

 

 Using the information in the table above, the resultant temperatures in the 

reach between Van Arsdale and Outlet Creek were predicted by modeling.

31 
Modeling results are available for the three year types analyzed -- dry, wet

and very wet. Detailed results from the dry year scenarios are presented in

Appendix A. In dry years, the model predicts that there are no temperature 

alterations associated with the flow scenarios. The flow conditions for dry years 

range only slightly between 7 and 10 cfs. Thus the dry year results are not used in 

calculating the TMDL and allocations. 

For wet and very wet years, the modeling results demonstrate alteration to

stream temperatures and so wet and very wet years were used in calculating this

TMDL component. 

Figure 4 summarizes the results of different flow and natural stream 

temperature scenarios for wet years. Increased flow decreases downstream

temperatures, however, this benefit of increased flow becomes minimal past Twin 

Bridges Creek. In addition, stream temperatures are warm (>24°C as a max7daat) 

under all scenarios, just past Tomki Creek. This is in the range of stream

temperatures which will cause some mortality to juvenile salmonids given that the 

max7daat metric indicates sustained temperatures of >24°C. These conditions are

predicted under both the coolest possible natural conditions and the warmer 

possible natural conditions and all management scenarios. The June 2004 flow

requirements are predicted to provide the coolest possible stream temperatures. 

Importantly, the June 2004 flow requirements are in the range of possible natural 

stream temperatures. Therefore, the June 2004 flow requirements will likely attain 

water quality standards. 

Figure 5, shows the modeling results for very wet years. In contrast to the 

dry and wet years, these larger changes in flow are predicted to result in a 

reduction in stream temperatures for the entire stream reach modeled - down to

Outlet Creek. Compared to the flows prior to 2004, very wet year flows under the 

current flow regime are predicted to result in temperature reductions over the

entire stream reach. Also during very wet years, the June 2004 flow requirements

are predicted to result in approximately two kilometers of the stream less than 

22 ̊C. 

However, for most of the stream reach, even though stream temperatures

are predicted to be lowered under increased flow, stream temperatures will not 

normally result in abundant juvenile populations. Most of the main Eel between 

Tomki Creek and Outlet Creek is predicted to be warmer than 24 ̊C as a max7daat. 

The literature suggests that these temperatures will cause some mortality and are 

above the stream temperatures associated with presence of steelhead in the field. 

Based on EPA’s review of the literature on juvenile rearing and temperatures, given 

that the area has small refugia populations, lowering of stream temperatures is 

considered to be beneficial. This benefit is in addition to the benefit in the two 

kilometers less than 22 ̊C below Van Arsdale. Again these warm temperatures 

were likely natural, as indicated by the predictions of the natural scenarios. 

Therefore, the June 2004 flow requirements are predicted to attain water quality 

standards. 

32 
<<<This page left intentionally blank for insert of Figures 4&5 – 

Line graphs of stream temperatures for Upper Main Eel>>> 

33 
3.4.1 Selection of Scenario Corresponding to Water Quality

Standards

EPA is using the 2004 FERC/NMFS flow schedule to calculate the instream

heat TMDL for the stream reach of Van Arsdale to Outlet Creek. The TMDL is

calculated using both wet and very wet years. EPA found that the current

FERC/NMFS summer flow schedule likely results in stream temperatures cooler or

nearly equal to the possible natural stream temperatures. This means that the

FERC/NMFS flow schedule is projected to attain water quality standards. 

3.4.2 Water Quality Indicators: Van Arsdale to Outlet Creek 

Stream temperature monitoring can be used as a water quality indicator to 

determine if the TMDL is meeting water quality standards. Temperature monitoring

at from 1999-2003 resulted in an average max7daat of 26.7EC. There was

significant variation due to yearly differences in weather and possibly monitor 

placement (25.8E, 26.8E, 26.5E, 26.9E, and 27.7EC.) Within this natural variation,

the State will need to consider using a complete set of information to assure that

stream temperature monitoring is viewed in light of meterology, flow and starting

temperatures at Van Arsdale. The model predicts that given similar meterological 

conditions the stream temperatures at will be approximately 26EC during wet years 

and 24.4EC during very wet years.

3.4.3 Instream Heat Loading Capacity and TMDL – Van Arsdale to 

Outlet Creek 

Under EPA regulations, the Total Maximum Daily Load is Athe sum of the

individual Wasteload allocations, for point sources and Load allocations for nonpoint 

sources and natural background.@ The regulations governing TMDL development 

provide for the expression of TMDLs as Aeither mass per time, toxicity or other 

appropriate measures.@ (40CFR 130.2(h)). EPA is establishing the TMDL for the 

portion of the Upper Main Eel between Van Arsdale and Outlet Creek in terms of 

instream heat (in BTUs.) This TMDL is calculated to address heat inputs from

changes in instream heat that result from hydrological modifications as well as solar

radiation. This component of the TMDL is expressed in total BTUs and is referred to 

as the instream heat loading capacity. The TMDL is calculated using the

FERC/NMFS flow regime, which was determined to attain water quality standards. 

The instream BTU TMDL is applicable at stream sampling point #56 for both wet

and very wet year types. 

TMDL Very Wet Year = 4.19 E+10 Total BTUs 

TMDL Wet Year = 2.63 E+10 total BTUs 

This total heat load is derived from the stream heat (in BTUs) for the stream 

sampling point #56. It is the total heat contained within that portion of the stream

reach for the max7daat period. The TMDL calculation assumes the FERC/NMFS flow

regime. Thus, if the flow or temperatures at Van Arsdale are significantly different 

than assumed, the TMDL, and water quality standards are not likely to be attained. 

34 
3.4.4 Instream Heat Allocation - Van Arsdale to Outlet Creek 

In accordance with EPA regulations, the loading capacity (i.e. the TMDL) is 

allocated to the various sources of heat in the watershed, with a margin of safety. 

As there are no point sources in this stream reach, the wasteload allocation is set at

zero and the TMDL equals allocations for nonpoint sources, plus natural sources. 

EPA is allocating the TMDL at between the Potter Valley Project and the other 

cumulative sources of stream heating along the stream reach between Van Arsdale

and . These other cumulative sources are primarily solar radiation and tributary 

inflow. EPA also expresses the solar radiation inputs in Section 3.3.2. The 

calculation was from the model given the total BTUs from stream sampling point 1 

(Van Arsdale) for the Potter Valley Project. This amount was then subtracted from

the total BTUs at stream sampling point #56. The load allocation for “other 

cumulative sources” including the solar radiation inherently includes the 50% shade

allocation.

TMDL Very Wet Year = 4.91 E+10 Total BTUs 

 4.32 E+10 Potter Valley Project Load Allocation 

 + 0.60 E+10 other cumulative source of stream heating at 

Load Allocation 

TMDL Wet Year = 

2.63 E+10 total BTUs Load Allocation Potter Valley Project 

+ 0.46 E+10 other cumulative sources of stream heating at

3.4.5 Margin of Safety 

Under EPA regulations, a margin of safety can be provided by explicitly 

reserving a portion of the available loading capacity or included implicitly through 

analytical assumptions within the TMDL analysis. For the stream reach between

Van Arsdale and Outlet Creek, EPA has included the following conservative 

assumptions in the TMDL analysis. In analyzing possible Anatural@ stream

temperatures, EPA included a low (cold) and high (warm) range by which to 

compare current stream temperatures. In fact, the FERC/NMFS flow regime on

which the TMDL is calculated is closest to the cooler possible natural stream 

temperatures. 

3.4.6 Seasonal Variation and Critical Conditions 

In accordance with EPA regulations, the TMDL must account for seasonal

variations and critical conditions. In the Upper Main Eel watershed, the summer 

period defines the critical period when stream temperatures are most likely to have

adverse impacts on beneficial uses (young salmonids growing in the streams before 

migrating to the ocean). To account for seasonal variations and critical conditions, 

the analysis is based on the max7daat (i.e., the maximum weekly average of the 7 

day running average of all monitored temperatures). In addition, the TMDL set for 

the Van Arsdale to Outlet Creek stream reach specifically considered 3 different 

year types in order to account for variable hydrological conditions. 

35 
CHAPTER 4 – SEDIMENT TMDL 

Summary

 This chapter presents analysis supporting the sediment TMDL for the Upper

Main Eel River. The first section identifies water quality indicators, which are 

interpretations of the water quality standards. These indicators can also be used to

evaluate stream and watershed conditions and progress toward or achievement of

the TMDL. The second section of this chapter summarizes the results of the 

sediment source analysis. The third section presents the calculations of the TMDL. 

The TMDL is the total loading of sediment that the Upper Main Eel River and its 

tributaries can receive without exceeding water quality standards. This third 

section also includes the distribution of the total load among the major categories 

of sediment sources in the watershed, i.e., the allocations. 

The sediment source analysis for the Upper Eel River conducted by Pacific 

Watershed Associates (PWA) and the United States Forest Service (USFS)

concluded that 33 percent of total sediment load was related to human activity. 

Sediment production from human disturbance appears to be associated primarily 

with road conditions and timber harvest. Human-related sediment delivery rates 

are higher on private lands than on public lands. Most of the naturally caused 

sediment-delivery was from landslides, which have a higher rate of delivery on

public lands than on private lands. Although USFS lands had a higher rate of 

landslides than private lands, public lands have a smaller rate associated with 

human causes. The results suggest that the Upper Eel River watershed is less 

disturbed by human caused sediment than most other watersheds studied in the 

North Coast, probably due to the limited management activity in the basin. 

4.1 WATER QUALITY INDICATORS AND TARGETS

Indicators and targets can be used to represent attainment with Basin Plan

objectives. This section identifies numeric water quality indicators and targets 

specific to the Upper Main Eel River. Because of complexities associated with the

effects of increased sediment loading on stream water quality, surrogate instream

and watershed indicators are used to evaluate quantifiable Basin Plan objectives. 

For each indicator, a numeric or qualitative target value is identified to define the

desired condition for that indicator. 

Because of the inherent variability associated with stream channel conditions, 

and because no single indicator applies at all points in the stream system,

attainment of the targets is intended to be evaluated using a weight-of-evidence

approach. That is, when considered together, the indicators are expected to 

provide good evidence of the condition of the stream and attainment of water 

quality standards.

Instream indicators reflect sediment conditions that support healthy salmonid 

habitat. They relate to instream sediment supply and deposition and are important 

because they are direct measures of stream “health.” In addition to instream 

indicators, we are including watershed indicators in this TMDL because watershed 

indicators focus on imminent threats to water quality that can be detected and 

36 
corrected before sediment is actually delivered to the stream, and because 

watershed indicators are often easier to measure than instream indicators. These

watershed indicators are established to identify conditions in the watershed 

necessary to protect water quality. They are set at levels associated with wellfunctioning watersheds. 

Watershed indicators reflect conditions in the watershed at the time of

measurement, whereas instream indicators can take years or decades to respond to 

changes in the watershed. Specifically, time lags between sediment production and

delivery make it difficult to predict when and how a stream will respond to sediment 

loading. Also, watershed indicators tend to reflect local conditions, whereas 

instream indicators often reflect upstream watershed conditions as well as local

conditions. Thus, watershed indicators help to identify conditions in the watershed 

that will prevent water quality from deteriorating. Ultimately, both instream and

watershed indicators are appropriate to use in describing the attainment of water 

quality standards. While the indicators are not directly enforceable by EPA, the 

turbidity indicator uses language similar to the Basin Plan turbidity water quality 

objective, which is enforceable by the NCRWQCB. 

4.1.1 Summary of Indicators and Targets 

This section describes several sediment indicators for the Upper Eel River 

TMDL. Table 6 summarizes the indicators along with their target, description and 

purpose. Very little information is available on current values of the indicators in

the watershed; however, anecdotal information suggests that the watershed may 

be in relatively good condition when compared to other North Coast basins, 

although some subwatersheds may have greater sediment problems (D. Leland, 

personal communication, 2003). Regional Water Board staff have also developed

additional information and detail on each of these indicators in developing 

implementation plans for other North Coast TMDLs (NCRWQCB, 2002). EPA 

expects that future monitoring of these indicators will provide additional information 

to assess whether the water quality standards are being attained and whether the 

TMDL is effective in meeting water quality standards. 

37 
Table 6. Sediment Indicators and Targets

INDICATOR TARGET DESCRIPTION PURPOSE

Instream

Spawning Gravel 

Quality 

<14% < 0.85 mm

<30% < 6.4 mm;

Bulk samples during low-flow period, 

at riffle heads in potential spawning 

reaches. Discussion of indicators and 

targets by Kondolf (2000), Chapman 

(1988).

Indirect measure of fine 

sediment content relative to

incubation and fry emergence 

from the redd. 

Indirect measure of ability of 

salmonids to construct redds 

Turbidity and 

Suspended 

Sediment 

Turbidity < 20% 

above naturally 

occurring 

background (also 

included in Basin

Plan) 

Measured upstream and 

downstream of sediment discharging 

activity or between “paired” 

watersheds or reference streams. 

Indirect measure of fish 

feeding/growth ability related to

sediment, and impacts from 

management activities 

Riffle 

Embeddedness 

<25% or improving 

(decreasing) trend 

toward 25% 

Estimated visually at riffle heads 

where spawning is likely, during 

low-flow period (Flosi et al 1998)

Indirect measure of spawning

support; improved quality & size 

distribution of spawning gravel

V* <0.21 Residual pool volume. Measure

during low-flow period. (Lisle and 

Hilton 1992) 

Estimate of sediment filling of

pools from disturbance 

Macroinvertebrate 

community 

composition 

Improving trends EPT, Richness & % Dominant Taxa 

indices. Methods should follow 

CDFG-WPCL (1996) or refined

methods currently under 

development, including USFS local 

methods. 

Estimate of salmonid food 

availability, indirect estimate of

sediment quality. 

Thalweg profile Increasing variation 

from the mean 

Measured in deposition reaches 

during low-flow period. 

Estimate of improving habitat 

complexity & availability

Pool/riffle 

distribution & depth 

of pools 

Increasing trend 

toward >40% in

primary pools 

Trend or greater than % (by 

length), measured low-flow period. 

Estimates improving habitat

availability

Watershed Indicators 

Diversion potential 

& stream crossing 

failure potential 

<1% crossings in

100 yr storm

Conduct road inventory to identify

and fix stream crossing problems 

(Weaver and Hagans 1994). See

USDA (1999) Roads Analysis for 

assessing road network.

Estimates potential for reduced 

risk of sediment delivery from 

hillslope sources to the 

watercourse 

Hydrologic 

connectivity of

roads 

Decreasing length

of road 

Conduct road inventory to identify

and fix road drainage problems 

(Weaver and Hagans 1994).

Estimates potential for reduced 

risk of sediment delivery from 

hillslope sources to the 

watercourse 

Annual road 

inspection &

correction 

Increased mileage 

inspected and 

corrected 

Roads inspected and maintained, or 

decommissioned or hydrologically

closed prior to winter- No migration 

barriers. 

Estimates potential for reduced 

risk of sediment delivery from 

hillslope sources to the 

watercourse 

Road location, 

sidecast 

Reduce density next

to stream, 

increased % 

outsloped 

See text. Minimize sediment delivery 

Activities in 

unstable areas

Avoid and/or 

/eliminate

Subject to geological/geotechnical 

assessment to minimize delivery 

and/or show that no increased 

delivery would result

Minimize sediment delivery from 

management activities 

38 
4.1.2 Instream Indicators 

Spawning Gravel Quality: Percent Fines <0.85 mm: ≤14%; Percent Fines 

<6.4 mm ≤ 30%

Streambed gravels naturally consist of a range of particle sizes from finer 

clay and sand to coarser cobbles and boulders. Kondolf (2000) described how 

various gravel sizes and mixtures can influence different salmonid life stages 

including redd construction, egg incubation and alevin emergence. In addition, 

spaces between clean cobbles provide important cover for salmonid and other fry at 

a critical and vulnerable time in their life history. The percent fines <0.85 mm is

defined as the percentage of subsurface fine material in pool tail-outs <0.85 mm in 

diameter. These indicators and targets represent adequate spawning, incubation, 

and emergence conditions relative to substrate composition. Excess fine sediment 

can decrease water flow through salmon redds and sufficient water flow is critical 

for maintaining adequate oxygen levels and removing metabolic wastes. Deposits 

of these finer sediments can also prevent the recently hatched fry from emerging

from the redds, resulting in entrapment. Monitoring should be conducted by bulk 

sampling during low-flow periods at the heads of riffles in potential spawning 

reaches. The target of ≤30% for particles less than 6.4mm sizes is based on 

literature relating size class survival to emergence (summarized in Chapman 1988,

and Kondolf, 2000). 

DFG Stream Inventory Report for Willits Creek (on the golf course in the 

Brooktrails Community Service District) reported that 5 sites were sampled for 

percent fines using a McNeil gravel sampler. The samples are then wet sieved to

determine their size class. All of the samples were greater than 15% fine, with a

combined sample mean of 24%. This indicates that fine sediment is a problem in

Willits Creek; however, this urbanized land use is not typical of the watershed

(CDFG, 1991). 

Turbidity and Suspended Sediment: <20% above naturally occurring 

background levels

Turbidity is a measure of the ability of light to shine through water (with 

greater turbidity indicating that more material is in the water blocking the light). 

Although turbidity levels can be elevated by both sediment and organic material, in 

California’s North Coast, stream turbidity levels tend to be highly correlated with 

suspended sediment. High turbidity in a stream affects fish by reducing visibility, 

which may result in reduced feeding and growth. The deleterious effects on

salmonids were found not only to be a function of concentration of fine particles but 

also a function of the duration of exposure. Sigler et al (1984) found as little as 25

NTUs of turbidity caused reduced fish growth. The North Coast Basin Plan presently 

stipulates that turbidity shall not be increased more than 20 percent above

naturally occurring background levels by an individual activity. This indicator 

should be measured during and following winter storm flows, and upstream and

downstream of a management activity to compare changes in the turbidity levels 

that are likely attributable to that activity. Information should include both the 

magnitude and duration of elevated turbidity levels. 

39 
Eel River water is known for its high turbidity. Several factors contribute to 

this water quality problem. During high discharge events, heavy suspended 

sediment loads create turbid conditions. In the Upper Eel River, high turbidity 

levels in late fall and winter are also attributable to the continual suspension of 

montmorillionite clays (USFS, 1995). 

The water in Lake Pillsbury is turbid through much of the year due to such 

fine-grained clays that are washed into the lake (USFS, 1995). These clays are 

weathered from volcanic bedrock generally located along the Rice Fork (Brooks, et 

al., 1984). Their settling rates vary depending on lake water chemistry, specifically

sodium, calcium, and pH, in addition to the shape and management of the 

reservoir. Lake Pillsbury discharges the most turbid water during the fall when the

lake level is lowest. During the winter months, the reservoir is refilled with turbid 

water from the surrounding tributaries. After some settling occurs, the deep water

is often disturbed in the springtime as cold water from the tributaries drains into

the lake, slipping below the warmer surface waters. Then, in the warmer months, 

the deeper waters of the lake tend to have high pH values, which keep some of the 

clays in suspension. Because some clays do tend to settle, there is generally a slow

clearing of the deep waters during the summer months. The turbidity levels in Lake

Pillsbury impact the downstream reaches of the Upper Eel River due to the 

discharge of highly turbid deep waters from Scott Dam, especially during the fall 

months when the water level is low (USFS, 1995). 

Riffle Embeddedness: <25% or improving (decreasing) trend

Embeddedness is a measure of fine sediment that surrounds and packs-in 

gravels. A heavily embedded riffle section may limit the ability of an adult female 

fish to construct a redd. When constructing its redd, generally at a pool tail-out (or 

the head of a riffle), the spawning fish essentially slaps its tail against the channel 

bottom, which lifts unembedded gravels and removes some of the fine sediment. 

This process results in a pile of cleaner and more permeable gravel, which is more 

suited to nurturing the eggs. Embedded gravels do not generally lift easily, which

prevents spawning fish from building their redds. Flosi et al. (1998) suggest that 

gravels that are less than 25% embedded are preferred for spawning. This target

should be estimated during the low-flow period, generally at riffle heads, in 

potential spawning reaches. 

Embeddedness is measured as part of the CDFG stream inventory program. 

Results from various stream inventory reports are presented in Table 7. Overall, 

the results indicate very few of the measured streams were dominated by pool tailouts that were less than 25% embedded. To fully assess this indicator, follow-up

studies are required at the same locations to characterize the trend in each stream. 

Additionally, more recent studies reported the percent of pool tail outs categorized 

as unsuitable due to the presence of boulders, bedrock, or sediment too small for 

spawning. As with most of the other categories, the results vary depending on the 

stream sampled, with some streams scoring poorly (unsuitable or highly unsuitable 

for spawning) and others scoring well (less embedded streams that are more 

suitable for spawning). 

40 
Table 7. Measures of Embeddedness in the Upper Eel River Basin 

Percent Embedded 

Waterbody Name 

Number of 

Pool Tail-Outs 

Measured 

< 25% 26-

50% 

51-

75% 

76-

100% 

Unsuitable 

for 

Spawning

Alder Creek 75 8% 57% 49% Not reported

Baechtel Creek 436 3% 17% 13% 67% Not reported

Bear Pen Canyon Creek 13 0% 31% 69% 0% Not reported

Benmore Creek 51 6% 25% 27% 6% 10% 

Bloody Run Creek 182 9% 49% 14% 28% Not reported

Broaddus Creek 131 30% 18% 25% 26% Not reported

Cave Creek 55 15% 38% 24% 2% 22% 

Cherry Creek 144 4% 33% 24% 39% Not reported

Haehl Creek 121 1% 28% 1% 59% Not reported

Long Valley Creek 373 0% 24% 46% 30% Not reported

Outlet Creek 164 9% 27% 32% 32% Not reported

Ryan Creek 99 53% 22% 2% 23% Not reported

String Creek 107 14% 42% 30% 14% Not reported

Tomki Creek 133 21% 33% 8% 4% 34% 

Unnamed Tributary #1 to 

Cave Creek 

10 50% 30% 0% 0% 20%

Unnamed Tributary #2 to 

Cave Creek 

4 0% 25% 25% 0% 50%

Unnamed Tributary #3 to 

Cave Creek 

4 0% 25% 75% 0% 0%

Willits Creek 27 15% 30% 37% 18% Not reported

Sources: California Department of Fish and Game Stream Inventory Reports, 1991-1998.

V* <0.21 (Franciscan geology)

V* is a measure of the fraction of a pool’s volume that is filled by fine

sediment, and represents the in-channel supply of mobile bedload sediment (Lisle

and Hilton 1992). This is not an appropriate tool for use in large rivers, but in large

river systems, it is suitable for use in tributaries. Lisle and Hilton (1992) describe

methods for monitoring, which should be conducted during low-flow periods and the

target of less than 0.21 (Franciscan geology) is based on Knopp (1993). V* 

quantifies the quality of the pool habitat; when less of a pool is filled (a lower pool 

volume) it is cooler and deeper, offering protection from predators, a food source, 

and a resting location. 

Macroinvertebrate Community Composition: Improving trends in EPT, 

% dominant taxa and species richness indices

Benthic macroinvertebrate populations are greatly influenced by water 

quality and are often adversely affected by excess fine sediment. This TMDL 

recommends several indices be calculated, following the CDFG Water Pollution 

Control Laboratory Stream Bioassessment Procedures (1996) until refined indices 

are available. Alternatively, methods that are generally consistent with the CDFG

41 
procedures may be utilized, such as those employed by USFS

(http://www.usu.edu/buglab/).

1. EPT Index. The EPT Index is the number of species within the orders 

Ephemeroptera, Plecoptera, and Trichoptera (EPT), more commonly known as 

mayflies, stoneflies and caddisflies. These organisms require higher levels of 

water quality and respond rapidly to improving or degrading conditions. 

2. Percent Dominant Taxa. This index is calculated by dividing the number of 

organisms in the most abundant taxa by the total number of organisms in the 

sample. Collections dominated by one taxa generally represent a disturbed 

ecosystem.

3. Richness Index. This is the total number of taxa represented in the sample. 

Higher diversity can indicate better water quality. 

One USFS bioassessment sampling location was identified in the watershed 

(location R5BIO-001 on Bear Creek). Two different habitats at this site were 

sampled twice in 2001 (June 12 and June 22). The EPT Index calculated from these 

sampling events varied from 20-27.and the taxa richness varied from 41-54. The

percent dominant taxa could not be calculated from the data reported. 

Thalweg Profile: Increasing variation of elevation around the mean slope

Variety and complexity in habitat is needed to support fish at different times 

in the year or throughout their life cycle. Both pools and riffles are used for 

spawning, incubation of eggs, and the emergence of the fry. Deeper pools, 

overhanging banks, or logs provide cover from predators. Measuring the thalweg 

profile is an indicator of habitat complexity, with more variability in the profile 

indicating greater complexity in stream habitat. This indicator can reveal

inadequate availability of pool-forming features, such as bedrock or large woody 

debris. The thalweg is the deepest part of the stream channel at a given cross 

section. The thalweg profile is a plot of the elevation of the thalweg as surveyed in

a series of cross sections. Harrelson et al. (1994) provide a practical guide for 

performing thalweg profiles and cross sections. The profile appears as a jagged but 

descending line with relatively flat pool areas and sharply descending cascades. 

The comparison between the mean slope (i.e., the overall trend of the descending 

stream) and the details of the slope is a measure of the complexity of stream 

habitats. Because change in the profile will occur relatively slow, and because not

enough is yet known about channel structure to establish a specific number that

reflects a satisfactory degree of variation, the target is simply an increasing trend in

variation from the mean thalweg profile slope. This indicator should be measured 

during the low-flow period every 5-10 years after large storm seasons. 

Primary Pool Distribution and Depth: Increasing inventory of reaches 

which are >40% pools; increasing primary pool depth

Pools generally account for more than 40% of stream length in streams with 

good salmonid habitat (Flosi et al. 1998). Frequent pools are important for 

providing feeding stations and shelter and may also serve locally as temperature

refugia. Backwater pools are used by salmonids as overwintering habitats (Flosi et 

al. 1998) by providing shelter from high storm flows and lateral scour pools (i.e., 

pools formed near either bank) tend to be heavily used by fish for cover and 

42 
refugia. Primary pools are defined by Flosi et al. (1998) as follows: For 1st and 2nd

order streams, they have a maximum residual depth (the maximum depth of a pool

minus the maximum depth of its downstream riffle crest, or the depth of the pool at

the point of zero flow) of at least two feet, occupy at least half the width of the low

flow channel, and are as long as the low flow channel width. For 3rd and 4th order 

streams, they have a maximum residual depth of at least three feet, occupy at 

least half the width of the low flow channel, and are as long as the low flow channel 

width. (Small, un-branched, perennial tributaries that terminate at an outer point 

are designated 1st order; the junction of two 1st-order streams is designated 2nd

order, and the junction of two 2nd-order streams is designated 3rd order, etc.). 

Information in this watershed should include the depth of pools because in this 

watershed deeper pools may also be important as temperature refugia. This 

indicator should be measured during the low-flow period every 5-10 years after 

large storm seasons. 

4.1.3 Watershed Indicators

Stream Crossings with Diversion Potential or Significant Failure 

Potential: <1% of all stream crossings divert or fail as a result of a 100-

year or smaller flood

Most roads, including skid roads and railroads, cross ephemeral or perennial 

streams. Crossings are built to capture the stream flow and safely convey it 

through, under, or around the roadbed. Stream crossings can fail, depositing 

sediment from the crossing structure (i.e., fill) and/or from the roadbed directly 

into the stream. Crossings that are likely to fail or divert pose a significant threat

to streams. Stream crossing failures are generally related to undersized, poorlyplaced, plugged, or partially-plugged culverts. When a crossing fails, the total 

sediment delivered to the stream usually includes the volume of road fill associated 

with the crossing and the sediment from collateral failures, such as debris torrents,

that scour the channel and stream banks. Diversion potential is the potential for a

road to divert water from its intended drainage system across or through the road

fill, thereby delivering road-related sediment to a watercourse. Another important 

problem occurs when water drains down the road away from the stream crossing, 

which can result in the creation of a new channel. 

The potential to deliver sediment to the stream can be eliminated from

almost all stream crossings by removing inboard ditches, outsloping roads, or 

installing rolling dips (USEPA, 1998). Less than 1% of stream crossings have 

conditions where modification is inappropriate because it would endanger travelers 

or where modification is impractical because of physical constraints. 

Hydrologic Connectivity: Decreasing length

A road is hydrologically connected to a stream when the road drains directly 

into the channel. This causes an increase in the intensity, frequency, and

magnitude of flood flows and suspended sediment loads in the adjacent stream, 

which can ultimately destabilize the stream channel and have a devastating effect 

on salmonid redds and growing embryos (Lisle, 1989). Outsloping roads and 

creating road drainages that mimic natural drainage, among other practices, can

significantly reduce connectivity (USDA, 1999; Weaver and Hagans, 1994). 

43 
Annual Road Inspection and Correction: 

EPA’s analysis indicates that in watersheds containing road networks without

excessive road-related sedimentation, roads are either (1) regularly inspected and 

maintained; (2) hydrologically maintenance free (i.e., they do not alter the natural 

hydrology of the stream); or (3) decommissioned or hydrologically closed (i.e., fills 

and culverts have been removed and the natural hydrology of the hillslope has 

largely been restored). 

Road Location and Sidecast: Prevent sediment delivery

Roads located in inner gorges and headwall areas are more likely to fail than 

roads located in other topographic locations. Roads should be removed from inner 

gorges and potentially unstable headwall areas, except where alternative road

locations are unavailable and the road is clearly necessary. In addition, sidecast 

soil on steep slopes can trigger earth movements and result in potential sediment

delivery to watercourses. These factors reflect the highest risk of sediment delivery 

from roads and should be the highest priorities for correction (C. Cook, M. Furniss, 

M. Madej, R. Klein, G. Bundros, pers. comm., 1998; in EPA, 1998). 

This target calls for: (1) the removal of all roads alongside inner gorge areas 

or in potentially unstable headwall areas unless alternative road locations are 

unavailable and the need for the road is clearly justified; and (2) the stabilization

(or pulling back) of sidecast or fill on steep (i.e., greater than 50%) or potentially 

unstable slopes that could delivery sediment to a watercourse. 

Activity in Unstable Areas: Target: avoid or eliminate, unless detailed 

geologic assessment by a certified engineering geologist concludes there is 

no additional potential for increased sediment loading

Unstable areas are those areas that have a high risk of landsliding, including 

steep slopes, inner gorges, headwall swales, stream banks, existing landslides, and 

other locations identified in the field. Any activity that might trigger a landslide in 

these areas (e.g., road building, harvesting, yarding, terracing for vineyards, etc.) 

should be avoided, unless a detailed geologic assessment by a certified engineering

geologist concludes there is no additional potential for increased sediment loading. 

An analysis of chronic landsliding in the Noyo River basin indicated that landslides

observed on aerial photographs largely coincide with predicted chronic risk areas, 

including steep slopes, inner gorges and headwall swales (Dietrich et al., 1998). 

Several other studies have shown that landslides are larger or more common in

some harvest areas, particularly in inner gorges (US EPA, 2000). Weaver and 

Hagans (1994) also suggest methods for eliminating or decreasing the potential for

road-related sediment delivery.

4.2 SEDIMENT SOURCE ANALYSIS

This section summarizes the results of the sediment source analyses

conducted by PWA and the USFS. The purpose of the sediment source analyses 

was to identify and estimate the relative amounts of sediment from the various 

sediment delivery processes and sources in the watershed. This section is a 

summary of the methodology, results, and relevance of the PWA/USFS sediment 

source analysis. Appendix B contains additional information obtained during the

sample collection and analysis efforts. Appendix C contains sediment tables for the 

44 
entire watershed and subwatersheds. Sediment numbers in Tables 8 and 12 related 

to excel spreadsheets were corrected.

4.2.1 Sediment Source Analysis Methodology

The sediment source analysis for the Upper Eel River and tributaries was

conducted to identify the relative contribution of sediment delivered to stream 

channels from various erosional processes that occur on hillslopes and in stream

channels throughout the watershed. The source analysis provides gross estimates 

of sediment production at the order-of-magnitude accuracy. Sediment loads from

private and public lands as well as human and natural sources are identified. There 

were two general components to the sediment source analysis: the quantification 

of “large” (sources >3,000 cubic yards [yds3

] that are most ameniable through air 

photography analysis) and “small” (sources <3,000 yds3 that are more difficult to 

detect with air photo analysis) sediment sources. The large sources were mapped 

and quantified using aerial photographs, while the small sources were quantified 

during a stratified random sampling field study.

All erosional features mapped on the aerial photos or within the random

sample plots had the same suite of data collected. These data include: 1) whether 

the feature was road-, skid trail- or hillslope-related, 2) terrain type (stratum) and

dominant vegetation type, 3) type of sediment source, 4) volume of erosion, 5) an

estimate of the volume of sediment delivered to streams, 6) hillslope location and 

average hillslope steepness where the erosion occurred, 7) any apparent land 

use/management associations, and 8) geomorphic association.

The USFS analyzed 1952, 1969, 1979, and 1998 photographs for part of the 

Tomki Creek, Rice Fork, Soda Creek, and Upper Main Eel CALWAA watershed units. 

Additionally, the USFS used 1981, 1988, and 2003 photographs in selected areas to 

evaluate landslide re-vegetation rates. PWA analyzed photos taken in 1952, 1965, 

1981, and 1999 for the Outlet Creek and Tomki Creek CALWAA watershed units. 

These years were selected to allow analysis of at least two sets of aerial photos 

under different management conditions in the watershed, specifically pre-1970 and 

post-1970, with the goal of quantifying changes in erosion under different operating

conditions. During this general time period, there were both formal shifts in 

management and changes instigated by the legal system. The formal shifts include

the implementation of the Forest Practice Rules (FPR) on private lands in the 1970s 

and the Northwest Forest Plan on public lands in the early 1990s. In addition, there 

were several lawsuits filed in the early 1970s regarding timber harvesting and the 

Endangered Species Act that resulted in an immediate, informal change in

management practices. 

Aerial photographs for the entire watershed were analyzed to identify all 

visible large sediment sources. The following sediment sources were quantified if

they exceeded 3,000 yds3

 of past erosion: shallow debris slides, debris flow

sources, debris torrent tracks, active earthflows, gullies, and streambank erosion. 

This analysis estimated the sediment volume delivered to the stream system and

then assigned a management association (road-related, harvest-related, etc.) to 

sources when there was a management activity visible above the feature in the 

photo. Sources with no management association were assumed due to natural 

45 
causes. This information was verified at some locations if they were near plots 

sampled during the field study to identify small sources of sediment. 

A stratified random sampling (STRS) study was performed to estimate small 

sediment sources (USEPA, 1999b, 2002). Before fieldwork was performed, plot 

sizes were identified and the watershed was stratified by terrain type. To

determine the optimal plot size, data from Jordan Creek, a tributary of the lower Eel 

River that is geologically similar to the Upper Eel River, were used. This process is 

described in detail in the “Sediment Source Investigation for the Van Duzen River 

Watershed” (Pacific Watershed Associates, 1999). This statistical analysis

determined that 41.8 acres (450 feet x 450 feet) is the optimal plot size for the

STRS study. PWA stratified the Upper Eel River watershed into five strata or 

geologies by reviewing the USFS and State Geology maps of bedrock and lumping 

similar rock types into 5 basic geologies. These five strata are identified in Table 8 

along with their total area and the number of sample plots within each stratum. 

To achieve a statistically robust random sample that provides a satisfactory

coefficient of variation (CV), a sample size of eighty (80) 41.8-acre plots per study

is considered optimal. Due to cost constraints and the interest in treating the 

public and private ownership domains as separate analyses, a sample size of 40 

plots in each of the ownership domains was selected for the Upper Eel River STRS 

study. Real estimates calculated for the Van Duzen TMDL revealed that the CV for

erosion from features <5,000 yds3

 equaled 0.21 and the CV calculated for sediment 

yield from features <5,000 yds3

 equaled 0.17. 

To select the location of the sample plots, a grid was developed for the entire 

basin area with each grid cell equal to 41.8 acres. The sample grid was overlain

with the five terrain types to create a layer that identified the dominant terrain type

for each grid cell. Two hundred grid cells were randomly selected for each 

ownership domain (public and private). The first consecutive forty (40) plots from 

each list of 200 plots were chosen for each ownership domain. Landowner 

permission for access was requested for private domain plots and those plots within

the public domain that had some private ownership. When landowner permission 

could not be obtained, the next sequential cell on the list for the appropriate 

stratum was selected. In addition, if a cell was randomly selected, but contained a

large sediment source (>3,000 yds3

), it was eliminated and another grid cell was 

systematically selected. All 40 of the public plots were sampled and 33 out of the

40 private plots were sampled (seven were not sampled due to lack of permission 

to access the land). The number of sample plots for each stratum was based on 

estimates from previous studies (Van Duzen, EPA 1999 and North Fork Eel, EPA

2001). These values are identified in Table 8. 

For the STRS field study, small sediment sources (less than 3,000 yds3

) were

placed in the following source categories: debris slide, debris torrent track, bank 

erosion, road related gully, non-road related gully, stream crossing, channel 

incision, surface erosion, debris flow source, and active earthflow. The primary

natural and anthropogenic source not quantified in the STRS study was creep rate. 

In addition to mapping these small sources, the volume of erosion was quantified 

and the sediment delivered to streams was estimated before assigning a 

management association to the source. 

46 
Table 8. Strata Identified in the Upper Eel River Watershed * 

Strata Area Number and 

Description

Area

(mi2)

Percent 

of Basin

Number 

of Grid 

Cells 

Proposed 

Number of 

Sample Plots 

Number 

of Plots 

Sampled

1. Franciscan Schist 145.1 21.1% 2,223 15 15

2. Franciscan Melange 64.4 9.4% 985 14 14

3. Alluvium 16.9 2.5% 259 6 5

4. Franciscan Coastal Belt 64.9 9.4% 994 15 13

5. Franciscan undifferentiated 396.8 57.7% 6,076 30 26

Totals 688.1 100% 10,537 80 73

*Appendix C contains tables for the entire watershed and for each subwatershed. 

The results of the STRS study were extrapolated to estimate small source 

sediment yield for the entire basin. After the large and small sources were 

quantified, the estimated basin-wide small source and aerial photo data were 

combined to determine the total Upper Eel River sediment yield and rates of erosion 

for different management associations, time periods, and strata, which are 

presented in the following section. 

4.2.2 Results

A total of 13,310,714 yds3 of sediment yield is estimated as being delivered 

to the Upper Eel River basin mostly between 1940 and 2004. Table 9 summarizes 

earthflow (continuous, deep-seated, slow moving large features, often ground 

water driven) and non-earthflow (episodic, relatively rapid movement, often storm

related) sediment yield for the small features (<3,000 yds3

) and large features 

(>3,000 yds3

) and Figure 6 illustrates the percent sediment production by terrain

type. As identified in Table 9 and Figure 6, terrain type #5, Franciscan, delivers the 

most sediment (6,206,774 yds3

) of all the terrain types, nearly one-half of the total 

sediment yield. Schist (terrain type #1) delivers the second highest volume of

sediment (3,384,536 yds3

) and when compared to the other terrain types, alluvium 

delivers a relatively small amount of sediment to the basin (227,024 yds3

). 

Non-earthflow sources deliver nearly 94% of all sediment to the basin and 

large features (earthflow and non-earthflow) contribute 57% of the total sediment 

delivered. In addition, the data indicate that the primary source of sediment for the 

schist and mélange terrains are large features, while non-earthflow features are the 

primary source for the alluvium terrain. When compared to nearby watersheds 

(USEPA, 1999b, 2002), there is a more equal distribution between large and small 

sources in regards to sediment delivery rates. This is most likely due to both a

decrease in the contribution from large features, such as landslides, and an

increase in management-related sediment delivery from small features. 

47 
Schist

25%

Melange

15%

Alluvium

2%

Franciscan

47%

Coastal Belt

11%

Schist

Melange

Alluvium

Coastal Belt

Franciscan

Figure 6. Percent sediment delivery by terrain type

Table 9. Total Erosion and Sediment Delivery from Small and Large

Features by Terrain Type (1940-2004)

Small Features <3,000 yds3

(Extrapolated from STRS study)

Large Features >3,000 yds3 

(Identified from aerial photos) 

Terrain 

Type/ 

Geology Units

Non earthflow 

Sediment 

Delivery

Earthflow 

Sediment

Delivery 

Non earthflow 

sediment 

Delivery 

Earthflow 

Sediment

Delivery 

Total

Sediment

Delivery

yds3 467,783 0 2,830,120 86,633 3,384,536 Schist 

yds3

/mi

2

/yr 50 0 305 9 364 

yds3 485,764 18,209 1,244,569 222,102 1,970,644 Melange 

yds3

/mi

2

/yr 118 4 302 54 478 

yds3 207,674 0 19,350 0 227,024 Alluvium 

yds3

/mi

2

/yr 192 0 18 0 210 

yds3 613,337 0 885,955 22,444 1,521,736 Coastal Belt 

yds3

/mi

2

/yr 148 0 213 5 366 

yds3 3,627,160 320,428 2,095,365 163,821 6,206,774 Franciscan

yds3

/mi

2

/yr 143 13 83 6 244 

yds3 5,401,718 338,637 7,075,359 495,000 13,310,714 Totals 

yds3

/mi

2

/yr 123 8 161 11 302

48 
For all erosional features identified within the sample plots or on aerial

photographs, PWA attempted to identify the decade in which the erosion was 

initiated and whether the feature was still actively eroding in 2004. The age of

vegetation on or adjacent to an erosional feature provides the most useful

information in deriving the origination age and activity level. Table 10 identifies all

the management- and non-management-associated sediment delivery features that 

PWA estimated were initiated prior to 1970 and those that were initiated after 

1970. PWA chose to separate the data around 1970 due to the shifts in

management taking place in that time period. Any differences in sediment volumes 

may provide some indication as to the degree to which modern (post-1970) 

management practices have improved over past practices. 

Table 10 and Figure 7 indicate the following: 1) 67% of all measured 

sediment yield occurred pre-1970; 2) management- and non-management 

associated sources accounted for nearly the same sediment yield on private lands 

pre-1970, whereas on the public lands, management-related sediment yield 

accounts for less than one-fourth of the total pre-1970 yield; and 3) post-1970 

sediment yields are considerably lower than during the pre-1970 period. In both 

the private and public domains, non-management related yield accounts for 

approximately twice as much sediment as the management-associated yield during

the post-1970 period. 

The data suggest considerably less natural and management related 

sediment is being produced in the Upper Eel River basin in the post-1970 period 

(8,956,268 yds3 pre-1970 compared to 4,360,730 yds3 post-1970). This may

reflect differences in the frequency and magnitude of storms, which trigger 

widespread watershed response, but also could be partially attributed to

improvements in land management practices. 

Table 10. Sediment Delivery by Time Frame and Potential 

Controllability (1940-2004)

Total Yield by Time Period for

Management Sediment Yield 

(yds3 & %)1

Total Yield by Time Period for

Non- Management Sediment Yield

(yds3 & %) Ownership domain 1

Non Earthflow Earthflow Non Earthflow Earthflow 

Total by 

Ownership 

Pre-1970 

(30 years) 2,299,049 (32%) 27,961 (<1%) 2,342,797 (33%) 439,219 (6%) 5,109,026 

(71%)

Post-1970 

(34 years) 698,328 (10%) 3,703 (<1%) 1,139,359 (16%) 202,832 (3%) 2,044,222 

(29%)

Private 

Subtotals 2,997,377 (42%) 31,664 (<1%) 3,482,156 (49%) 642,051 (9%) 7,153,248 

(100%)

Pre-1970 

(30 years) 711,708 (12%) 10,516 (<1%) 3,044,859 (49%) 80,159 (1%) 3,847,242 

(62%)

Post-1970 

(34 years) 612,852 (10%) 8,748 (<1%) 1,628,123 (26%) 66,785 (1%) 2,316,508 

(38%)

Public

Subtotals 1,324,560 (22%) 19,264 (<1%) 4,672,982 (75%) 146,944 (2%) 6,163,750 

(100%)

Basin-wide Totals 4,321,937 (32%) 50,928 (<1%) 8,155,138 (61%) 789,000 (6%) 13,316,99 

49 
0%

10%

20%

30%

40%

50%

60%

Private Public

Perc

e

nt Se

dim

e

nt D

eliv

ery

Pre-1970 No Management Association Pre-1970 Management Association

Post-1970 No Management Association Post-1970 Management Association

Figure 7. Percent sediment delivery by management association and 

time period 

Table 11 summarizes the extrapolated estimates of Upper Eel River basin 

sediment yield by ownership according to the primary land use association. All 

erosional features mapped in the field sample plots or on the aerial photos were 

assigned a primary land use association based on field and air photo evidence. 

Table 11 categorizes erosional features as having the following land use 

associations: 1) no apparent land use linkage (naturally occurring), 2) road related

(logging, ranch, county or CalTrans road), 3) timber harvest, 4) agriculture or 

grazing (includes erosion due to vegetation loss and the movement of animals), 

and 5) fire. Figure 8 illustrates the percent sediment delivery by land use 

association for public and private domains. The original data table (Table B-6), 

presented in Appendix B, also separates the results by large and small features. 

While the sediment loading rates are similar for public and private lands (309 

yds3

/mi2/yr for private and 290 yds3/mi2/yr for public), the sources delivering 

sediment vary significantly. The data indicate that of the total past sediment yield

(earthflow plus non-earthflow) from private and public domains, approximately 

57% and 78%, respectively, were determined to be natural and not clearly 

associated with any past land management activities (Table 11). The

management-associated rate of sediment delivery on private lands is nearly twice 

50 
the rate on public lands. For private lands, management-associated sources of

sediment yield account for about 133 yds3

/mi2/year, which is approximately 43% of 

the total on private lands. These are divided between road sources (16%), timber 

harvest (20%), agriculture/grazing (7%), and fire (<1%). Management sources 

are less influential on public lands. Specifically, management-associated sources 

account for about 66 yds3

/mi

2

/year on public lands, which is approximately 23% of 

the total (road sources (12%), timber harvest (11%), agriculture/grazing (<1%), 

and fire (<1%)). Non-earthflow sources account for a vast majority of the 

sediment delivery in both public and private lands with natural land uses

contributing the greatest proportion of sediment for both earthflow and nonearthflow sources. 

Table 11. Sediment Yield by Domain and Primary Land Use (1940-

20040 

Domain / Ownership (area)

Private (359.4 mi2) Public (328.7 mi2) Basin-wide (688.1 mi2)

Primary Land Use Association yds3/mi2/yr % yds3/mi2/yr % yds3/mi2/yr % 

No land use 150 53 221 77 184 65 

Timber harvest 61 22 30 10 46 16 

Road Related 48 17 33 11 41 14 

Agriculture / Grazing 21 8 <1 <1 11 4 

Fire 2 <1 1 <1 1.5 <1

Non-Earthflow 

Total non EF sediment yield 282 100 285 100 283 100 

No land use 26 96 5 94 16 95 

Timber harvest 0 0 <1 <1 <1 <1

Road Related 1 4 <1 <1 0.7 4 

Agriculture / Grazing 0 0 0 0 0 0 

Earthflow 

Fire 0 0 <1 5 <1 <1

Total EF sediment yield 27 100 5 100 17 100 

Total sediment yield 

(non-Earthflow + Earthflow) 309 100 290 100 300 100 

51 
0%

10%

20%

30%

40%

50%

60%

70%

80%

Private Public

Perc

e

nt Se

dim

e

nt D

eliv

ery

No land use Timber harvest Road related Agriculture/Grazing Fire

Figure 8. Percent sediment delivery by primary land use association 

(1940-2004) 

4.2.3 Summary 

Based on the results from the sediment source analyses, historical sediment 

delivery estimates can be generated from all sources in the basin. The results 

presented in Table 12 are a compilation of the data analyzed for the large and small 

sediment sources. Large sources (>3,000 yds3

) were quantified through the 

analysis of aerial photographs across the basin. Data collected during a stratified

random sampling study were analyzed to determine the sediment input from small 

sources (<3,000 yds3

). These values were then extrapolated basin-wide and 

combined with the results from the large source analysis to obtain the unit area

sediment input for the entire Upper Eel River basin (Table 12). 

52 
Table 12. Sediment Loading in the Upper Eel River (1940 – 2004)

Private (359.4 mi2) Public (328.7 mi2) Basin-wide (688.1 mi2) 

Sediment Source yds3

/mi2/yr tons/mi

2

/yr % of 

Private yds3

/mi2/yr tons/mi

2

/yr % of 

Public yds3

/mi2/yr tons/mi

2

/yr % of 

Total 

Natural Sediment Sources 

Large features 

(>3,000 yds3

) 69 106 22% 183 282 63% 123 190 41% 

Small features 

(<3,000 yds3

) 109 168 35% 44 68 15% 78 120 26% 

Total Natural 

Sources 178 274 57% 227 350 78% 201 310 67% 

Human (Land Management) Related Sources 

Large features 

(>3,000 yds3

) 55 86 18% 36 55 12% 46 71 16% 

Road related 

(small feature) 26 40 8% 9 14 3% 18 28 6% 

Timber harvest 

(small feature) 30 46 10% 18 28 6% 24 38 8% 

Agriculture/Grazing1

(small feature) 19 30 6% 0 0 0% 10 16 3% 

Total Human

Related 131 202 43% 63 97 22% 99 152 33% 

Total - All Causes 309 476 100% 290 447 100% 300 462 100% 

1

Agriculture/grazing causes less than 1 yd3/mi2/yr of sediment delivery on public land and is therefore considered negligible. 

4.3 TMDL AND ALLOCATIONS

4.3.1 Loading Capacity and TMDL

This TMDL is set equal to the loading capacity of the Upper Eel River. The

TMDL is the estimate of the total amount of sediment, from both natural and 

human-caused sources, that can be delivered to streams in the watershed without 

exceeding applicable water quality standards. The approach taken focuses on

sediment delivery rather than a more direct measure of salmonid habitat (i.e. 

instream conditions). Sediment delivery can be subject to direct management by

landowners (i.e., roads can be well-maintained), whereas instream conditions (pool 

depth, percent fines) are subject to upstream management that may not be under 

the control of local landowners. While it would be desirable to mathematically

model the relationship between salmon habitat and sediment delivery, these tools 

are not available for watersheds with landslides and road failure hazards. 

Sediment movement is complex both spatially and temporally. Sediment

found in some downstream locations can be the result of sediment sources far 

upstream. Instream sedimentation can also be the result of land management from 

decades past. Nevertheless, management activities can clearly increase sediment 

delivery, and instream habitat can be adversely affected by increased sediment 

inputs. Therefore, it is reasonable to link increases in sediment delivery to

decreased stream habitat quality. The approach also assumes that salmon can be

supported in streams even with the yearly variation of natural rates of erosion

observed in the 20th century. Although sediment delivered to the streams has 

53 
varied over time, salmon have adjusted to the natural variability by using the 

habitat complexity created by the stream’s adjustments to the varying sediment 

loads. In addition, we are assuming that the natural amount of sediment can 

generally be increased to some extent and not adversely affect fish. We postulate 

this because historically, fish populations were thriving throughout the North Coast, 

even though there was human caused sediment from ranching, the tanbark 

industry, and some logging. 

EPA is using a method of setting the TMDL and allocations similar to that

employed in other basins (e.g., North Fork Eel, Noyo, Big and Albion Rivers, Middle

Fork Eel [USEPA, 1999a, 2000, 2002 and 2003]). It is based on the assumption

that a certain amount of loading greater than what is natural is acceptable, and will 

still result in meeting water quality standards. Most of the basins in the North 

Coast historically had some management activity occurring in the basin, while fish 

populations remained stable. Prior TMDL studies of the relationship between 

sediment loading rates and fish habitat effects found that many North Coast waters

supported healthy fish habitat conditions during periods in which sediment loads 

were up to 125% of natural loading rates. In the Upper Main Eel River basin, EPA 

considers 125% to be appropriate because management activity is not high in the

basin relative to other watersheds on the North Coast. We are basing the loading 

capacity and TMDL for the Upper Eel River basin on a calculation of 125% of natural 

loading. 

TMDL = Loading Capacity = 125% x (310 tons/mi2

/year) = 388 tons/mi

2

/year

The TMDL is set slightly higher than in the draft TMDL based on minor revisions in

the source analysis calculation. 

4.3.2 Allocations

In accordance with EPA regulations, the loading capacity (i.e. TMDL) is

allocated to the various sources of sediment in the watershed, with a margin of

safety. That is: 

TMDL = sum of “wasteload allocations” for individual point sources, 

+ sum of the “load allocations” for nonpoint sources, and 

+ sum of the “load allocations” for background sources 

Although nonpoint sources are responsible for most sediment loading in the 

watershed, limited point sources may also discharge some sediment in the 

watershed. Current and prospective point sources that may discharge in the 

watershed and are therefore at issue in this TMDL include: 

− CalTrans facilities (e.g., State Highway 162) that discharge pursuant to 

the CalTrans statewide NPDES permit issued by the State Water 

Resources Control Board, and 

− Construction sites that discharge pursuant to California’s NPDES general

permit for construction site runoff. 

Because the discharge from these point sources cannot be readily

determined, and because possible loading from point sources is not distinguished

54 
from general management-related loading in the source analysis, EPA considers the

rates set as load allocations (i.e., for nonpoint sources) to also represent wasteload 

allocations (i.e., for those point sources that would be covered by general NPDES 

permits). There are no other wasteload allocations, as there are no other individual 

point sources of sediment in the basin. 

The load allocations for the Upper Eel River Sediment TMDL are presented in

Table 13. The allocations clarify the relative emphasis and magnitude of erosion 

control programs that need to be developed during implementation planning. The

load allocations are expressed in terms of yearly averages (tons/mi2

/yr). They can

be divided by 365 to derive daily loading rates (tons/mi2

/day), but EPA is 

expressing them as yearly averages because sediment delivery to streams is highly 

variable on a daily basis. In fact, EPA expects the load allocations to be evaluated 

on a ten-year rolling average, because of the natural variability in sediment delivery 

rates. In addition, EPA does not expect each square mile within a particular source

category throughout the watershed to necessarily meet the load allocation; rather, 

EPA expects the watershed average for the entire source category to meet the load 

allocation for that category.

Some of the load allocations are slightly changes from those in the draft 

TMDL because of the revised TMDL number. 

Table 13. Load Allocations Averaged over the Entire Basin 

SEDIMENT SOURCE 

Load Allocation

(tons/mi2/yr) 

1940-2004 Loading 

(tons/mi2/yr) 

Percent

Reduction 

Natural Sediment Sources 

Large features (>3,000 yds3) 190 190 none

Small features (<3,000 yds3) 120 120 none

Total Natural Sources 310 310 none

Human (Land Management) Related Sources 

Large features (>3,000 yds3) 36 71 49%

Road related (small feature) 14 28 50% 

Timber harvest (small feature) 20 38 47% 

Agriculture/Grazing (small feature) 8 16 50% 

Total Human Related 78 152 49% 

Total - All Causes 388 462 16% 

4.3.3 Margin of Safety

The margin of safety must be included in a TMDL to account for uncertainties

concerning the relationship between pollutant loads and instream water quality and

other uncertainties in the analysis. The margin of safety can be incorporated into 

conservative assumptions used to develop the TMDL, or added as an explicit, 

separate component of the TMDL. This TMDL incorporates a Margin of Safety 

through use of conservative assumptions.

There is uncertainty concerning the interpretation of the amount of sediment 

delivery associated with management activities versus natural background sources. 

55 
The USFS and PWA generally attributed most or all of the sediment load of any 

landslide occurring within a recent harvest unit as being harvest or road related. 

This is a conservative assumption because some slides may have occurred naturally 

even if the land had not been harvested recently. Because the TMDL is calculated 

based on the amount of natural loading, this results in a more conservative TMDL

calculation. 

EPA does not expect each square mile within a particular source category to 

necessarily meet the allocation; rather, EPA expects the average for the entire 

source category to meet the allocation across the basin for that category. 

There is inherent annual and seasonal variation in the delivery of sediment to

the stream channel from the source mechanisms. The allocations are expressed as

10-year rolling averages to account for variability in delivery rates. The TMDL also

includes watershed indicators to reflect sediment delivery risks. 

This TMDL includes an implicit margin of safety based on EPA’s conservative

assumptions regarding the uncertainty associated with the sediment source 

analysis, as well as with the need to protect the resource. USEPA Region IX

considered the lack of instream and watershed data, other than the source analysis,

in making these conservative assumptions. 

4.3.4 Seasonal Variation and Critical Conditions

The TMDL must describe how seasonal variations were considered. Sediment 

delivery in the Upper Eel River watershed has considerable annual and seasonal 

variability. The magnitudes, timing, duration, and frequencies of sediment delivery 

fluctuate naturally depending on intra- and inter-annual storm patterns. Since the 

storm events and mechanisms of sediment delivery are largely unpredictable year

to year, the TMDL and load allocations are designed to apply to the sources of

sediment, not the movement of sediment across the landscape, and to be evaluated 

on a ten-year rolling average to account for inherent inter-annual variation. USEPA 

Region IX assumes that by controlling the sources to the extent specified in the 

load allocations, sediment delivery will occur within an acceptable range for 

supporting aquatic habitat, regardless of the variability of storm events. 

The TMDL must also account for critical conditions for stream flow, loading, 

and water quality parameters. Rather than explicitly estimating critical flow 

conditions, this TMDL uses indicators, which reflect net long-term effects of 

sediment loading and transport for two reasons. First, sediment impacts may occur 

long after sediment is discharged, often at locations far downstream of the 

sediment source. Second, it is impractical to accurately measure sediment loading 

and transport, and the resulting short-term effects, during the high magnitude flow

events that produce most sediment loading and channel modifications. 

56 
CHAPTER 5: IMPLEMENTATION AND MONITORING 

MEASURES 

The main responsibility for water quality management and monitoring resides 

with the State. EPA fully expects the State to develop and submit implementation 

measures to EPA as part of revisions to the State water quality management plan, 

as provided by EPA regulations at 40 C.F.R. Sec. 130.6. The State implementation 

measures should contain provisions for ensuring that the allocations in the TMDL

will in fact be achieved. These provisions may be non-regulatory, regulatory, or

incentive-based, consistent with applicable laws and programs, including the State=s 

recently upgraded nonpoint source control program.

For the Temperature TMDL, EPA recommends that timber harvest permits on

private lands be evaluated to assure that natural shade is protected in order to 

assure compliance with the TMDL and thus water quality standards. The State 

should also assure that adverse cumulative effects are avoided in watersheds where 

timber harvest plans are frequent or widespread. As a practical matter and one

that accounts for site-specific information, the TMDL calculation can be simplified

during implementation as setting the TMDL equal to no allowable changes to 

natural shade. 

Current standards and guidelines under the North West Forest Plan may be 

sufficient to attain riparian vegetation characteristics consistent with the

temperature load allocations for shade that apply to streams on USFS lands. All 

USFS management practices should be reviewed to assure that actual shade 

conditions are attained and that water quality standards are attained as a result. 

EPA also has several recommendations regarding data collection and 

monitoring for stream temperature and flow. In reviewing the preliminary data 

from the 15 cfs flows during summer 2004, several unusual conditions were found. 

Specifically unusually warm temperatures were measured during July downstream 

of Scott Dam. This appears to result from maintenance activity at the dam. 

However, no temperature monitoring of the hypolimium in Lake Pillsbury was 

attempted. In addition, PG&E should attempt to document the management and

mixing of the releases at Scott Dam. 

For future temperature modeling to be validated and improved, EPA also 

recommends the following: 

- Duplicating DFG temperature monitoring at nearby locations. This will 

assure that analysis is not compromised by the yearly problem of theft and loss of 

monitoring devices. EPA recommends that PG&E supplement DFG’s monitoring to 

assure that resource problems are not an issue. This is especially important just

below Van Arsdale. That site is essential to characterizing the system. 

- Additional agencies monitor additional pool/riffle combinations to 

supplement DFG monitoring. 

- PG&E might consider updating the hydrology/stream morphology

information before additional stream temperature modeling is conducted. The

current data is nearly 20 years old and was not directly collected for use in stream

57 
temperature models. 

For the Sediment TMDL, EPA specifically recommends that more in-stream 

information be gathered on tributaries on USFS lands and all streams on private 

lands throughout the basin. EPA also suggests that the State consider using the

information developed from the sediment source analysis in setting priorities for

any new sediment reduction programs in the watershed. EPA recommends that

timber harvest permits on private lands be evaluated to ensure consistency with 

sediment load allocations with the TMDL and thus water quality standards. The

State should also assure that adverse cumulative effects are avoided in watersheds

where timber harvest plans are frequent or widespread. On USFS lands, it appears 

that sediment loading is largely due to natural causes. USFS lands may meet 

sediment load allocations if future management practices and the intensity of 

management are not changed from the recent past, as provided under the NWFP. 

58 
CHAPTER 6: PUBLIC PARTICIPATION

EPA provided public notice of the draft Upper Main Eel River Temperature and 

Sediment TMDLs by placing a notice in the Willits News and Santa Rosa Press 

Democrat, papers of general circulation in Mendocino and Trinity Counties. EPA

also met with major stakeholders – PG&E, Friends of the Eel River and NMFS during

the Fall of 2003. EPA held an informational meeting in Willits in the summer of

2004 for landowners whose land was to be surveyed for the sediment source 

analysis. The public notice regarding availability of the draft Upper Main Eel TMDLs 

was posted on EPA’s web site, along with the document. The public notice was also

mailed or emailed to additional parties. EPA’s response to the public comments

received is available as a separate document. 

59 
References 

Berman, 1998. Oregon Temperature Standard Review. U.S. EPA, Region 10. 

Seattle, WA. 

Brooks, J., Ekman, E., Faust, B., and James, A. 1984. Lake Pillsbury Basin 

Watershed Analysis, under the direction of the California Department of Fish and

Game, Region III; the Mendocino National Forest; the Mendocino County Fish and 

Wildlife Advisory Committee; the Pacific Gas and Electric Company; and the 

Sonoma County Water Agency. 

Brown, W.M., III, and Ritter, J.R., 1971, Sediment transport and turbidity in the

Eel River basin, California. U.S. Geological Survey Water Supply Paper 1986, 70 p. 

California Department of Fish and Game (CDFG). 1995 - 1998. Salmon and 

Steelhead Restoration and Enhancement Program, Stream Inventory Reports.

California Department of Fish and Game (CDFG). 1991. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Willits Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Alder Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Baechtel Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Bear Pen

Canyon Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Bloody Run 

Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Broaddus 

Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Cherry Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Haehl Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Long Valley 

Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Outlet Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Ryan Creek. 

California Department of Fish and Game (CDFG). 1995. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: String Creek. 

60 
California Department of Fish and Game (CDFG)-Water Pollution Control 

Laboratory. 1996. California stream bioassessment procedure. Rancho Cordova, 

CA. 

California Department of Fish and Game (CDFG). 1997. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Cave Creek. 

California Department of Fish and Game (CDFG). 1997. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Cave Creek. 

California Department of Fish and Game (CDFG). 1997. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Unnamed 

Tributary #1 to Cave Creek. 

California Department of Fish and Game (CDFG). 1997. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Unnamed 

Tributary #2 to Cave Creek. 

California Department of Fish and Game (CDFG). 1997. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Tomki Creek. 

California Department of Fish and Game (CDFG). 1998. Salmon and Steelhead

Restoration and Enhancement Program, Stream Inventory Report: Unnamed 

Tributary #3 to Cave Creek. 

Chapman, D.W. 1988. Critical review of variables used to define effects of fines in 

redds of large salmonids. Transactions of the American Fisheries Society. Volume 

117, No. 1.

Chen, Y.D. et al. 1998. Stream Temperature Simulation of Forested Riparian Areas.

I. Watershed Scale Model Development. Journal of Environmental Engineering, 

124(4), 304-315. 

Dietrich, W.E., R. Asua, Coyle, J. Orr, B., Trso, M. 1998 A Validation Study of the 

SHALSTAB model in forested lands in Northern California; prepared for the 

Louisiana Pacific Corporation, Calpalla, CA. June 29, 1998. 

Department of Water Resources, State of California (DWR). October 1982. Middle

Fork Eel River Watershed Erosion Investigation. DWR, Northern District - Red Bluff, 

CA. 

Federal Energy Regulatory Commission. January 28, 2004. Pacific Gas and Electric 

Company, Project No. 77-110. Order Amending License. 

Flosi, Gary, S. Downie, J. Hopelain, M. Bird, R. Coey and B. Collins. 1998. 

California salmonid stream habitat restoration manual, third edition. California 

Department of Fish and Game. Inland Fisheries Division. Sacramento, CA. 

Garman, S.L., S.A. Acker, J.L. Ohmann, T.A. Spies. 1995. Asymptotic heightdiameter equations for twenty-four tree species in western Oregon. Oregon State 

University Forest Research Laboratory, College of Forestry. Research Contribution 

10. September. 

Harrelson, C.C., C.L. Rawlins, and J.P. Potyondy. 1994. Stream channel reference

sites: an illustrated guide to field technique. USDA Forest Service, General 

Technical Report RM-245. 

61 
Herbst, D. 2003. Summary of recent findings regarding a comparison of data 

generated by CDFG, USFS, Lahontan RWQCB, and EPA-EMAP macro invertebrate field

protocols. Presentation given to the Surface Water Ambient Monitoring Program 

(SWAMP) Bioassessment Monitoring Committee, Lahontan Regional Water Quality

Control Board Office, South Lake Tahoe, September 25. 

Humboldt County Resource Conservation District. May 15, 1998. Final Report, Eel 

River Water Quality Monitoring Project. Fields Landing, CA. 

Humboldt County Resource Conservation District. 1996-2003. Temperature 

monitoring data (available on CDs.)

Jones, W.E. 1992. Historical distribution and recent trends of summer steelhead, 

Oncorhynchus mykiss in the Eel River, CA. Paper presented for the Eel River 

Workshop, Redding, CA, February 6, 1992. Region 3, California Department of Fish

and Game. 

Knopp, Chris. 1993. Testing indices of cold water fish habitat. North Coast Regional 

Water Quality Control Board and California Department of Forestry, Santa Rosa. CA. 

Kondolf, G.M. 2000. Assessing salmonid spawning gravel quality. Transactions of 

the American fisheries Society 129:262-281. 

Kubicek, P.F. August 1977. ASummer Water Temperature Conditions in the Eel 

River System, with reference to Trout and Salmon@. Masters Thesis, Humboldt State 

University.

Lisle, T.E. 1989. Sediment transport and resulting deposition in spawning gravels,

north coastal California. Water Resources Research. Vol. 25., no. 6. Pp. 1303-1319.

June. 

Lisle, T.E. 1993. The fraction of pool volume filled with fine sediment in northern 

California: relation to basin geology and sediment yield. Final report to Calif. Dept. 

of Forestry and Fire Protection. Aug. 20. 

Lisle, T.E.. and S. Hilton. 1992. The volume of fine sediment in pools: an index of

sediment supply in gravel bed streams. Water Res. Bulletin. 28:2. Paper No. 

981120. April 1992. 

Mendocino County Resource Conservation District. December 1983. North Coast 

Erosion and Sediment Control Pilot Project, Tomki Creek Watershed. Ukiah, CA. 

Morford Consultants. 1995. Eel River hydrology and Chinook salmon: An analysis 

of USGS streamflow data collected at Scotia, Humboldt County, California with 

emphasis on fisheries. Willits, CA. September 1995. 

Myrick, C. A., and J.J. Cech, Jr. 2001. Temperature Effects on Chinook Salmon and

Steelhead: A review focusing on California’s Central Valley Population. Bay Delta 

Modeling Forum Technical Publication 01-1. 

National Marine Fisheries Service (NMFS). February 20, 2003. Draft Report. 

APreliminary Conclusions regarding the updated status of listed ESUs of West Coast 

salmon and steelhead, B. Steelhead Trout@. Northwest Fisheries Science Center. 

Seattle, WA. 

62 
National Marine Fisheries Service (NMFS). November 26, 2002. Final. Biological

Opinion on the Proposed License Amendment for the Potter Valley Project (FERC 

77-110). Southwest Region. Long Beach, CA. 

Nielsen, J., and T. Lisle. (1994) AThermally Stratified Pools and their use by

Steelhead in Northern California Streams@ Transactions of the American Fisheries 

Society 123:613- 626 

North Coast Regional Water Quality Control Board (NCRWQCB). 2002. Action Plans 

for the Albion River, Big River, Noyo River, and Ten Mile River Sediment TMDLs. 

North Coast Regional Water Quality Control Board (NCRWQCB). 2001. Water 

Quality Control Plan for the North Coast Region. Last amended June 28, 2001. 

Ode, P.R. 2003. Summary of recent findings regarding a comparison of data generated 

by CDFG, USFS and EPA-EMAP macro invertebrate field protocols. Presentation given 

to the Surface Water Ambient Monitoring Program (SWAMP) Bioassessment Monitoring 

Committee, Lahontan Regional Water Quality Control Board Office, South Lake Tahoe,

September 25.

Pacific Watershed Associates. 1999. Sediment source investigation for the Van

Duzen River watershed: An aerial photo analysis and field inventory of erosion and

sediment delivery in the 429 mi2 Van Duzen River Basin, Humboldt County, 

California. Arcata, CA. November 1999. 

Porterfield, G. and Dunnam, C.A. 1964. Sedimentation of Lake Pillsbury, Lake 

County, California. U.S. Geological Survey Water Supply Paper 1619-EE. 46 pp. 

SEC (Steiner Environmental Consulting). 1998. Potter Valley Project monitoring

program (FERC no. 77, Article 39): Effects of operations on upper Eel River 

Anadromous Salmonids, March 1998 Final Report. Prepared for Pacific Gas and

Electric Company, San Ramon, CA. 

Sigler, J.W., T.C. Bjornn and F.H. Everest. 1984. Effects of chronic turbidity on

density and growth of steelheads and coho salmon. Transactions of the American 

Fisheries Society 113:142-150. 

Spence, B.C. et al. 1996. An ecosystem approach to salmonid conservation. TR4501-96-6057. ManTech Environmental Research Services Corp. Corvalis, OR. 

Sullivan, K., D.J. Martin, R.D. Cardwell, J.E. Toll, and S. Duke. December 2000. AAn 

analysis of the Effects of Temperature on salmonids of the Pacific Northwest with 

implications for selecting temperature criteria A Sustainable Ecosystems Institute, 

Portland, OR. 

Supernowicz, D. April 1995. Heritage Resource Investigations along the Upper Eel 

River Watershed within the Mendocino National Forest, including Portions of 

Mendocino and Lake Counties. Mendocino National Forest, Willows, CA. 

Timber - Fish - Wildlife Project, December 2000. Evaluation of Prediction Models 

and Characterization of Stream Temperature Regimes in Washington. Washington 

Department of Natural Resources, Olympia, WA 

63 
Tappel, P.D. and T.C. Bjornn. 1983. A new method of relating size of spawning 

gravel to salmonid embryo survival. Idaho Cooperative Fishery Research Unit. 

North American Journal of Fisheries Management 2:123-135. 

US EPA. 1998. South Fork Trinity river and Hayfork Creek sediment total maximum 

daily loads. Region IX Water Division. San Francisco, CA. December 1998. 

US Environmental Protection Agency (USEPA). 1999b. Van Duzen River and Yager 

Creek Total Maximum Daily Load for Sediment. San Francisco, CA. December 

1999. 

US EPA. 2000. Big River total Maximum Daily Load for Sediment. San Francisco,

CA. December 2000. P32 

US Environmental Protection Agency (USEPA), Region 10. 2001a. Technical 

Synthesis Scientific Issues Relating to Temperature Criteria for Salmon, Trout and 

Char native to the Pacific Northwest. EPA 910-R-01-007. August 2001 

US Environmental Protection Agency (USEPA), Region 10. 2001b. Issue Paper 5. 

Summary of Technical Literature Examining the Physiological Effects of

Temperature on Salmonids. EPA-910-01-005. May 2001 

US Environmental Protection Agency (USEPA). 2002. North Fork Eel River total 

Maximum Daily Loads for Sediment and Temperature. San Francisco, CA. 

December 2002. 

US Environmental Protection Agency (USEPA). 2003. Middle Fork Eel River total 

Maximum Daily Loads for Sediment and Temperature. San Francisco, CA. 

December 2003. 

USDA Forest Service (USFS). 1999. Roads Analysis: Informing Decisions about 

managing the National Forest Transportation System. Misc. Rep. FS-643. 

Washington, D.C.: U.S. Dept. of Agriculture Forest Service. 222 p. 

USDA Forest Service (USFS). May 1995. Watershed Analysis Report for the Upper 

Main Eel River Watershed. 

VTN Oregon, Inc. 1982. Potter Valley Project (FERC No. 77) Fisheries Study. Final

Report Vols. I & II. Prepared for Pacific Gas and Electric Company, San Ramon, 

CA. 320 pp. + app. 

Washington State Department of Ecology (WDOE). December 2000. Evaluating

Standards for Protecting Aquatic Life in Washington=s Surface Water Quality 

Standards Temperature Criteria. 00-10-070 

Weaver, W.E. and D.K. Hagans. 1994. Handbook for forest and ranch roads: a 

guide for planning, designing, constructing, reconstructing, maintaining and closing 

wildland roads. Prepared for the Mendocino County Resource Conservation District, 

Ukiah, CA, in cooperation with the California Department of Forestry and Fire

Protection and the USDA Soil Conservation Service. 

64 
Personal Communications 

Hope, D. and Feiler, S. NCRWQCB. 2003; Hope, D., Wright-Shacklett, C. Macedo, 

R., Ambrose, C.. Communications with Palma Risler

Jahne, J. NMFS Santa Rosa. 2004. Communications with Palma Risler.

Leland, D. NCRWQCB. October 2003. Communications with Janet Parrish. 

McFadin, B. NCRWQCB. 2004. Communications with Palma Risler 

APPENDICES

Appendix A: Temperature Modeling 

available as a separate document

Appendix B: Sediment Source Analysis 

available as a separate document

Appendix C: 

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