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Watershed Restoration Efforts Improve Revegetation, Erosion Control
and Sediment Loads in Bear Creek
Waterbodv irnproved Bear Cree'c was 'istec' on Clean Water Act (CWA) section
303(d) list of impaired waters for sediment in 1991. The source of
sediment was nearby ski resorts, roads and parking lots. Ski resort managers, scientists, regulators
and other organizations collaborated to implement and improve erosion control techniques in the
region. Through rigorous planning, implementation, monitoring, education and outreach, the parties
involved significantly reduced the sediment pollution in the Truckee River watershed, which includes
Bear Creek. Due to these efforts, the 3-mile segment of Bear Creek in Placer County was removed
from the CWA section 303(d) list of impaired waters in 2006.
Problem
Bear Creek is in the Squaw Creek-Truckee River
watershed northwest of Lake Tahoe in Placer County
(Figure 1). It is one of two major tributaries that flow
into the Truckee River in this watershed. Several major
ski resorts are located in this area, and some of them
contribute heavily to sediment deposition in Bear
Creek (via ski runs, roads, parking lots and ski resort
infrastructure). The sediment is carried by runoff and
settles at the bottom of these waterbodies, where it
degrades the natural aquatic habitat and increases the
potential for flooding. All the major waterbodies in this
watershed were added to the CWA section 303(d) list
of impaired waters for sediment, and totai maximum
daiiy loads (TMDLs) were later established for each.
Story Highlights
In 2002 multiple partners began collaborating to
reduce sediment and address TMDLs in Bear Creek
through the Revegetation and Erosion Control for
Ski Areas Project (Project). This effort was led by the
California Alpine Resort Environmental Cooperative
(CAREC); other partners included the State Water
Resources Control Board (SWRCB), Lahontan Regional
Water Quality Control Board (LRWQCB), Integrated
Environmental Restoration Services (IERS), Sierra
Business Council and many other stakeholders,
dischargers, universities, private companies and
nongovernmental organizations. During the Project,
education was provided to the ski resorts and agen-
cies involved. To achieve the Project goals, the Sierra
0 75 150 300
600
Figure 1. Bear Creek is in northern California.
Business Councii collaborated with LRWQCB to
develop the Sediment Source Control Handbook and a
Management Practices Toolkit for this and any future
projects to be used by practitioners, regulators and
other interested parties. Full and standard surface
treatments were installed at 103 test plots identified
at 24 sites at various participating ski resorts covering
approximately 132 acres. Most treatments included
a combination of treatment elements, depending
on site conditions and/or the test questions being

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investigated. However, all treatments can be lumped
into one of two general categories: full treatment or
surface treatment.
Ftfl'l treatment refers to the process of restoring soil
function to the greatest level possible. The process
includes replacing lost soil organic matter, tilling/
mixing that organic matter to a depth of 12-18 inches;
adding an organic, slow-release fertilizer; applying
a native grass-dominated seed mix; and applying a
long-iasting mulch material such as pine needles or
tub-ground wood chips.
Surface treatment, the "standard" treatment, is easy
to implement and has a low initial cost; therefore,
it has been used for many years on erosion control
projects in ski areas arid other disturbed areas. Most
surface treatments consist of applying fertilizer, seed,
mulch and sometimes tackifier on the soil surface.
Fertilizer arid seed are commonly applied using a
hydroseeder. Most types of mulch associated with
surface treatments (such as straw) have a relatively
short functional lifespan.
Results
Data show improvement. Sites that received full sur-
face treatments had on average a sediment yield 3.1
times less than the more common, standard surface
treatment. Infiltration rates dramatically increased at
test plots. The maximum sediment reduction at full
treatment plots was up to 20 times higher than surface
treatment plots. Monitoring results indicate that there
was no sediment yield at 75% of full treatment plots
due to high infiltration and no runoff—as compared
to 35% of surface treatment plots. Across all sites, the
average steady state infiltration rates at full treatment
plots were 1.2 times higher on average than surface
treatment plots. Sediment yield at a highly disturbed
site in the Sierra Nevada is 500 pounds of sediment
per acre per inch of precipitation (Ibs/acre/in).
The treatments in this study have been quantitatively
shown to substantially reduce sediment yields and
increase infiltration rates on highly disturbed sites.
Therefore, It can be inferred that after full surface
treatment, the average sediment yield measured
across all sites was 73 ibs/acre/in, or an 85% reduction
in sediment yield. On 1 acre of highly disturbed land,
such as a graded ski run, full surface treatment would
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Bear Creek
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Figure 2. Bear Creek turbidity sample data (1985-2004).
Data points included 122 individual measurements of
turbidity and 39 monthly means taken from two locations
in the Alpine Meadows Ski Area.
result in a reduction of 427 Ibs/acre/in. Over 132 acres,
the total area of the Project treatment sites, sediment
would be reduced by 56,364 lbs/in. These data sup-
ported implementation of a TMDL for sediment in Bear
Creek, Squaw Creek, Truckee River and Lake Tahoe.
Bear Creek turbidity data were collected from 1985 to
2004 (Figure 2). The Lahontan RWQCB Basin Plan lists
3 nephelometric turbidity units (NTUs) as the water
quality criterion threshold. Only one sample exceeded
the 3 NTU limit. The Surface Water Ambient Monitoring
Program reported a California Stream Condition Index
score of 1.15 in 2000 and 1.16 in 2001. Both scores are
very high, showing a significant improvement to the
benthic community. This data was the evidence used to
remove Bear Creek from the CWA section 303(d) list of
impaired waters in 2006 by the SWRCB. The extensive
work done as part of Project contributed to the delisting.
Partners and Funding
Partners included the Sierra Business Council, SWRCB,
LRWQCB, CAREC, IERS, University of California-Davis,
TEAM Engineering & Management, Tahoe Regional
Planning Agency, U.S. Forest Service, Inyo National
Forests, and the Lake Tahoe Basin Management Unit.
The six participating ski resorts were Heavenly Mountain
Resort, Northstar-at-Tahoe, Mammoth Mountain, Squaw
Valley USA, Resort at Squaw Creek, and Tahoe Donner
Cross Country. The Project was supported by $473,145
In CWA section 319(h) grant funds.
^£D	U.S. Environmental Protection Agency
0** Office of Water
\ Washington, DC
I
epa 84i-f-20-oois
PROt^° October 2020
For additional information contact:
Cindy Wise
Lahontan Regional Water Quality Control Board
530-542-5408 • Cindy.Wise@waterboards.ca.gov

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