Transcript Landuse and River Restoration in the Willamette Basin: Linkage Between River Management, Geomorphic Process, and Salmonid Recovery ABSTRACT The Willamette Valley is set.

Landuse and River Restoration in the Willamette Basin: Linkage Between River
Management, Geomorphic Process, and Salmonid Recovery
ABSTRACT
The Willamette Valley is set in a dynamic landscape characterized by
mountainous river systems, recreational water ways, a world renowned sport
fishery, and prosperous agriculture. If these natural resources are not carefully
restored and managed, they may be lost forever. River restoration projects are
commonly used where waterways have been damaged by human impact.
Current studies are focused on determining the natural variability of river
systems and restoring natural processes to pre-settlement conditions. In order
to reach this goal of natural river restoration, several criteria must be met: (1)
understanding of river complexities and geomorphic process, (2) development of
theoretical similarities between river systems,(3) formulation of new criteria and
standards for monitoring techniques, (4) practical application of scientific
modeling, and (5) development of effective models tempered by economic and
social realities. With these methodologies, current river systems may be
restored and future damage may be entirely avoided. This paper examines the
river restoration process, with examples of work in the Willamette Basin.
INTRODUCTION
Like many fluvial ecosystems of the United States the Willamette Valley
has undergone numerous environmental changes since the introduction of man.
Our impact on the environment was largely unrealized by the scientific
community until the negative effects of our actions became readily apparent in
the river ecosystems in the form of declining water quality, which in turn
damaged faunal and floral diversity within the fluvial systems expounding the
already decreasing fluvial health.
Prepared by:
Patrick Stephenson
ES 473 Environmental Geology
Figure 2. (Wohl, 2006)
•Upstream view of Vindal River, northern Sweden, 2002
•Stream was modified from two channels into single channelized flow
•Secondary flow blocked by rock dike at secondary head
•Figure 3(Left) is an
overlay of Spring Chinook
runs in western Oregon
fluvial systems and which
part of the river is vital for
each stage of a salmons
life cycle
•Figure 4(Below) is a
picture of a fish ladder
implemented on the
adjacent portions of a
manmade river
impediment, to assist
salmonids in their
upstream migration
•Figure 5(Upper Right)
depicts where river barriers
are on all fluvial systems
throughout Oregon
Figure 5. (ODFW, 2004)
Beginning flow through the
coffer dam constructed behind
Marmot dam on the Sandy river. This
project began in 1999 and final dam
removal was completed in 2007.
Coffer dams are composed of fill
material normally found in the river
system and are easily eroded
through normal fluvial processes.
Scope and intent of the dam removal
is to recreate an uninterrupted fluvial
system on the Sandy river, which has
been influenced by humans since
Figure 6. (PGE, 2007)
1912 when Marmot dam was
constructed.
CONCLUSIONS
River restoration practices are becoming more and more important as
scientists study the negative impacts of our previous river engineering
projects, forest practices, and fisheries management. Marmot dam is the
largest dam removal project undertaken in the state to date. Studies
conducted on the after effects and how well the river system and fishery
recovers will likely influence future dam removal projects on other rivers in
the state. Our understanding of the complexities of river systems is
increasing, which in turn is progressing our capabilities to prevent further
damage on future projects and mitigation strategies to repair previously
damaged areas.
Figure 3. (ODFW, 2004)
REFERENCES CITED
Portland General Electric, 2008, Marmot Dam: Internet Web Resource, URL:
http://www.marmotdam.com/marmot_home.htm
Table 1. (Wohl, 2005)
Oregon Department of Fish and Wildlife, 2008, Water Quality and Quantity
Program: Internet Web Resource, URL:
http://www.dfw.state.or.us/fish/water/index.asp
Oregon Department of Fish and Wildlife, 2008, Fish Programs and Plans:
Internet Web Resource, URL:
http://www.dfw.state.or.us/fish/programs.asp
Wohl, E., and others, 2005, River Restoration: Water Resources Research,
VOL. 41, W10301, doi:10.1029/2005WR003985, 2005
Figure 1. (Wohl, 2006)
Figure 4. (ODFW, unknown year)
Wolh, Ellen, 2006, Human Impacts to Mountain Streams: ScienceDirect
Geomorphology xx (2006) xxx-xxx.