For more information on habitat issues, please contact the
WDFW Habitat Program.
For more information on WDFW managed lands including wildlife
areas, please contact the
WDFW Wildlife Program.
Aquatic Habitat Guidelines are based on a number of guiding principles.
These principles embody our ecological understanding about how ecosystems
function, and our priorities for protecting aquatic systems. The Aquatic
Habitat Guidelines Guiding Principles summarize current scientific understanding
about how ecosystems work and reflect current resource agency policy and
technical approaches to protect ecosystem functions. Documenting this
scientific and technical understanding and policy will enable managers
and project prponents to assess the effectivenenss of the Aquatic Habitat
Guidelines to protect and restore salmonid as well as other aquatic and
riparian habitats as scientific understanding improves through time. The
guiding principles progress from general to topical statements. The general
guiding principles are divided into two categories: ecosystem function
and project planning implementation.
The guiding principles were developed by steering committee members of
the Aquatic Habitat Guidelines program in the Departments of Fish and
Wildlife, Transportation, and Ecology, as well as the Department of Fish
and Wildlife's Habitat Program technical staff. Some principles were taken
directly or expanded from other planning documents such as the Wild Salmonid
Policy (WDFW, 1997), the Statewide Strategy to Recover Salmon (State of
Washington, 1999), and Coastal Salmon Conservation: Working Guidance for
Comprehensive Salmon Restoration Initiatives on the Pacific Coast (NMFS,
- Ecological processes create and maintain habitat function. These processes
- Geomorphic processes - the interaction of water, sediment, and
wood that creates channel and shoreline structure. Geomorphic processes
include bank and bed erosion, channel migration and evolution, sedimentation,
debris influences, erosion, accretion, sediment transport, and fire.
- Biological processes (e.g., nutrient cycling, species interactions,
riparian and upland vegetation dynamics, species mediated habitat
forming processes such as beaver activity).
Salmon and other aquatic organisms have evolved and adapted to use the
habitats created by these processes. The long-term survival of naturally
occurring populations of these species is dependant on the continuation
of these processes.
- Ecological processes create and sustain a suite of ecosystem characteristics
and functions that include:
- Ecosystem complexity, diversity, and change;
- Ecological connectivity;
- Riparian interactions;
- Floodplain connectivity;
- Species diversity, adaptation, and survival;
- Water quality and water quantity;
- Invertebrate production and sustained food web function.
- These characteristics and functions have biological value as well
as economic, social, cultural, educational, and recreational values.
- Because these characteristics and functions vary across and within
watersheds, the use of local watershed information in planning and design
will often lead to less risk of adverse project impacts. Natural processes
that are protected and restored will minimize risk and provide sustainability
to ecosystem functions.
This principle is paraphrased from the State of Washington (1999):
- Maintain and restore the freedom of rivers and streams to move
and change, especially during floods.
- Allow time for natural regenerative processes to occur and provide
recovery of river and stream integrity.
- Protect the natural diversity of species and restore the natural
diversity of habitats within river channels and riparian zones.
- Support and foster habitat connectivity.
- Tailor actions locally and to the whole watershed in the proper
sequence of time and place. Match the system's potential and long
term human commitment to stewardship of the system.
The principle is also paraphrased from the National Marine Fisheries
- To ensure no net loss of habitat functions and to enable natural
processes to occur unimpeded, actions should benefit ecological
functions. Actions that adversely affect habitat should be avoided.
- Maintain habitats required for salmonids during all life stages
from embryos and alevins through adults.
- Maintain a well-dispersed network of high-quality refugia to serve
as centers of population expansion.
- Maintain connectivity between high-quality habitats to allow for
reinvasion and population expansion.
- Maintain genetic diversity.
- A holistic approach to project planning employs ecologically relevant
units of management, such as watersheds.
- Our limited understanding of ecological processes and engineered solutions
is addressed by using the best available science and erring on the side
of caution in project management, design, timing, and construction.
- A holistic approach to project planning recognizes and maintains geomorphic
processes (e.g., channel migration, channel evolution, hydrologic changes,
erosion, sedimentation, accretion, and debris influences).
- Appropriate uses of riparian, shoreline, and floodplain systems through
responsible land use practices can maintain natural processes and avoid
adverse cumulative effects.
- A holistic approach to compensatory mitigation and restoration is
desirable; such an approach is based on local watershed conditions,
and it strives to maintain or restore historical ecological functions.
- Compensatory mitigation for adverse impacts has risk and uncertainty
of success. To minimize such risk and uncertainty, adverse impacts are
first avoided and then minimized. Unavoidable adverse impacts are addressed
by compensating for losses.
- Complete compensatory mitigation includes consideration of the project
impacts over time (which usually extend beyond the completion of the
project) and across the landscape (which often extends beyond the boundaries
of the project).
- Appropriate operating and maintenance procedures are necessary to
insure that project objectives are fulfilled and adverse environmental
impacts are minimized.
- Monitoring and adaptive management are critical components of restoration,
mitigation, and management activities.