**[Topic List:]{.underline}**

1.  Cookhouse Stream Restoration Project -- Craig Oehrli

2.  Cave Rock Revegetation Monitoring Program- Improving Sediment Source
    Control Projects in the Lake Tahoe Basin -- Michael Hogan

**[Topic Summaries:]{.underline}**

**Cookhouse Stream Restoration Project -- Craig Oehrli**

Craig presented details of phase I of the Cookhouse Stream Restoration
project in terms of planning, design, monitoring, and construction.
Cookhouse Meadow is a young meadow and the lowest in a chain of four
glacial meadows in a 6 square mile tributary area to the Upper Truckee
River. The meadow elevation is at 7100 ft within a watershed with an
average elevation of 8100 ft. The watershed receives the greatest
portion of its annual precipitation in the form of snow, with a greater
occurrence of rain on snow events expected at the meadow elevation. The
meadow has a history of impacts from sheep grazing, road building, and
recreation. Aerial photographs show prehistoric debris flows,
progressive surface desiccation of the meadow, conifer encroachment, and
impacts from '63-'63 floods and Forest Service restoration activities.
By 1980 the stream in the meadow exhibited a 4.5 meter incision depth.
The stream and meadow system was determined to be impaired based on
reduced hydrologic function, vegetation changes, and increased flood
peak speeds that cause downstream impacts.

Extensive monitoring of the meadow/stream system occurred between 2001
and 2005 that included installing 14 ground water monitoring wells and a
2003 ecosystem assessment. Five project alternatives were considered and
evaluated that included inset flood plane along existing stream
alignment, utilizing an existing channel in the south area of meadow,
and a new channel alignment. A new channel alignment north of the
existing channel was selected because it would give the maximum benefit
with the least impact to existing natural resources. Pre-project
monitoring included recording ground water levels, and surveys for
vegetation and wildlife including macro-invertebrate sampling.

The keys to the success of the project were: it was completely executed
in-house (from planning to construction), the 2005 wet spring resulted
in good meadow vegetation which was used for sod bank construction,
early and continuous irrigation from stream source of transplanted sod,
and the order of new channel construction allowed for learning on less
critical portions prior to construction of the more challenging and
critical upstream section. Craig noted that continuous assistance with
grade checks was needed during equipment construction of new channel,
because when channel construction occurred without grade check
assistance the work had to be redone. The as-built survey confirmed
project was built to specifications, with a short segment of inset flood
plane below the upper tie-in and grade controls to step down to the
elevation of the lower tie-in. The goals of the project are to raise
ground water level in meadow (pre- project monitoring shows late summer
ground water elevations four to five feet below meadow surface),
maintain riffle crest elevations to maintain maximum ground water
elevations, store and transport sediment, restore flood plane function
(estimate stream flow will exceed new channel capacity two out of every
three years), and restore mesic-wet meadow vegetation. The new channel
was designed with vertical and horizontal variances built-in (i.e.
varying pool depths) to create potential for stream to respond to
natural stream dynamics without failing (i.e. riffles crests may move
horizontally but elevation should hold).

Post project monitoring will continue for 10 years, with more intensive
Adaptive Management monitoring occurring in the first 5 years following
construction, and including aerial photographs of project area. There
are no established adaptive management responses beyond monitoring and
developing responses as needed. In phase 2, to be implemented in 2006,
the old channel will be filled to 90% capacity between vegetation plugs,
except in section below upper tie-in of new channel where there will be
no fill between vegetation plugs to preserve existing vegetation. The
project planning cost \$284,000, and the total construction costs are
budgeted at \$902,000, of which \$627,000 was expended in phase I. Craig
Oehrli is a hydrologist with the Forest Service's Lake Tahoe Basin
Management Unit and can be contacted at
[coehrli@fs.fed.us](mailto:coehrli@fs.fed.uf).

**Cave Rock Revegetation Monitoring Program- Improving Sediment Source
Control Projects in the Lake Tahoe Basin -- Michael Hogan**

Michael Hogan presented details of the monitoring results of the Cave
Rock Revegetation project (designed by KB Foster and constructed by R&K
Erosion Control Company) and a new conceptual approach to erosion
control that moves from a sole focus on vegetative cover to a whole
soil-plant system understanding. Preliminary results from rainfall
simulation work are incorporated to enhance the understanding of
revegetation and erosion control success, including suggestions on how
to monitor source control projects. On project success, Michael shared
that the most important factor is ownership by an individual.

The goal of the Cave Rock project was to try a new approach to erosion
source control because hydro seeding alone had not been successful in
revegetating or stabilizing the very steep slopes (1.25 to 1). The
report contains the revegetation specifications developed for the
project which included scarification down to exfoliating granite,
application of compost, tilling compost into top three inches of soil,
then application of salvaged top soil, seed, fertilizer and mulch, and
re-wetting of soil profile. Michael promoted using a complete adaptive
management cycle approach for developing erosion control projects; that
is to design and construct projects based on existing information and to
monitor projects to gather information to fill in gaps of understanding
and to analyze the data collected so as to inform subsequent projects.
Michael validated that a forum is needed for getting out the lessons
learned to other project implementers.

The third chapter of the report contains a literature review which
presents the different types of erosion and variables known to effect
erosion. This section also depicts the difference between the
traditional dose-response approach to erosion control of agriculture and
landscaping projects and the wildland approach which attempts to create
a self-sustaining system with a one-time treatment that restores
soil-plant system function. Michael presented the conceptual model for
soil-plant system function and erosion control from the report that
consists of the three elements critical to create sustainability:
nutrient cycling, infiltration/hydrology, and energy capture. Improving
only one element is not sufficient to establish self-sustaining
restoration, i.e. tilled soil will reseal and erode without nutrient
cycling and energy capture. Michael encouraged moving from single
variable understanding of restoration success (vegetation cover) to a
holistic system understanding for more effective and sustainable erosion
control projects. He also promotes the use of simple, useful, and
effective indices for success criteria. Because rain simulation research
has shown that vegetation cover alone did not reduce runoff as
effectively as tilling, Michael suggests augmenting vegetation cover
with other monitoring indices that get at the other elements of the
soil-plant system function, like soil cover (by mulch) for energy
capture, and penetrometer for infiltration/hydrology.

Chapter 5 of the report, Methodologies for Attaining Success, includes
suggestions for site characterization, methods for incorporation of
compost, combating invasive species by adjusting system to give
advantage to native species, and descriptions of amendment alternatives
and mulch characteristics. Michael indicated that while the current
practice for tilling in fieldwork is to go to a depth of 12 to 18
inches, Vic Claussen's current research is suggesting that a mature
shrub needs unconsolidated soil to a depth of 2 meters.

Monitoring data needs to be numerical and repeatable to allow for
statistical analysis; unlike cover point monitoring which is highly
subjective. Monitoring should be performed at appropriate times, for
example north facing slopes exhibit a delay in plant growth as compared
to south facing slopes. Some of the conclusions of the Cave Rock
Revegetation Monitoring were: 1.25 to 1 slopes can be stabilized,
greater than six inches in depth of treated soil (with two inches of
compost) is needed to support a sustainable revegetation, extended
irrigation can be counter productive (promotes shallow root depth), and
high wood content mulch may be better for long term restoration. Michael
also promoted budgeting for some follow-up identification and treatment
to reverse small problems before they cause major failures.

The "Cave Rock Revegetation Monitoring Program -- Improving Sediment
Source control Projects in the Tahoe Basin" report is not currently
available to the public because it is still in review by the funding
agencies, but should be available in the next few months. In the mean
time Michael recommended his Ski Area Handbook developed for the
Lahontan RWQCB for sediment source control. Michael can be contacted at:
<michael.hogan@integratedenvironmental.net>

In Attendance:

Jay Aldean, HDR\*

Scott Carroll, CTC\*

Nancey Carter, ENTRIX

Jerry Dion, Tallac AED

Melanie Greene, Parsons

Jere Harper, USFS-LTBMU\*

Alan Heyvaert, UCD -- TREC/DRI

Michael Hogan, IERS

Zach Hymanson, CTC\*

Christine Kirick, Wood Rodgers\*

Kate Kowalski, JWA

Jack Landy, EPA/Lahontan RWQCB

Derek Norpchen, TRPA

Craig Oehrli, USFS

Chad Praul, NTCD\*

Dave Rios, NTCD\*

Tim Rowe, USGS-WRD\*

Jane Schmidt, NRCS

Catherine Schoen, USFS\*

Mark Sedlock, CTC

Chuck Taylor, USDA-NRCS

Chris Twomey, c2me\*

Rita Whitney, TRPA\*

Next Agenda\*: