Advancing Water Resources Research and Management

ABSTRACT: The Oregon Plan for Salmon and Watersheds relies on citizen-led watershed councils to develop local watershed restoration plans. We have developed an assessment manual that can be used by watershed councils to assess current conditions and identify protection and restoration opportunities. The manual is designed to be used by individuals with minimal technical background and experience in watershed assessment. The manual has been developed as discrete sections that focus on different watershed processes. The Start-Up and Issues Identification section describes how to organize a watershed assessment. The Historical Conditions and Channel Habitat Type sections provide a descriptive framework for assessing current conditions. Six sections (Hydrology and Water Use, Riparian/Wetlands, Sediment Sources, Channel Modification, Water Quality, and Fish Habitat) provide a characterization of current conditions. The Watershed Condition Evaluation section describes how to use the technical assessment to identify problem areas and prioritize potential restoration opportunities. The final section, Monitoring and Evaluation, discusses development of a monitoring plan. Over ten watershed assessments have been initiated to date using the manual. Initial response indicates that the manual is extremely useful in organizing and interpreting information about local watershed conditions, and in prioritizing protection and restoration actions.

KEY TERMS: Watershed Assessment, Restoration.
 
 

The State of Oregon has encouraged (through grants and technical assistance) the formation of local watershed councils in response to various initiatives and legal mandates for watershed protection and restoration. Driving this action were the potential listings under the Endangered Species Act (ESA) of several Pacific Salmon stocks, and the listing of many of Oregon’s streams as water-quality limited under the Clean Water Act. The Oregon Plan for Salmon and Watersheds (Oregon Governor’s Office, 1997) was developed to address water quality and fisheries issues. The underlying principle of the plan is that for watershed restoration to be effective, planning and implementation must occur at the local community level. Watershed councils, under the leadership of the Governor’s Watershed Enhancement Board, are charged with developing plans for local watershed protection, restoration and enhancement.

Early in the process it was recognized that a methodology was needed by watershed councils to evaluate the condition of aquatic resources and identify factors limiting aquatic health. The Governor’s Watershed Enhancement Board contracted with Watershed Professionals Network to develop a watershed assessment methodology that could be used by watershed councils to identify areas in need of protection and areas that could benefit from restoration activities. The manual is designed to be used by individuals with minimal technical background and experience in watershed assessment, such as watershed council volunteers.
 
 

Watershed assessment methodologies exist in the Pacific northwest at both the state and federal levels, and were used as a template for development of the Oregon assessment methodology. For example, the State of Washington has developed a watershed analysis procedure (Washington Forest Practices Board, 1997) that is used to regulate forest practices and results in site-specific forest management prescriptions. However, the Washington methodology is regulatory in nature and does not explicitly lead to identification of restoration opportunities. Although many of the procedures outlined in the Washington methodology can be applied in areas of non-forestry land use, it lacks specific assessment approaches for other land uses (for example agricultural and urban). In addition, the Washington methodology is designed to be implemented by natural resource professionals and would be difficult to apply at the community level by watershed councils.

The Federal Guide for Watershed Analysis (Regional Interagency Executive Committee, 1995) is used on much of the federally-managed public lands in the Pacific Northwest. The Federal Guide provides a systematic way to understand and organize ecosystem information to guide decision making on management activities. Although the Federal Guide allows flexibility in adapting an analysis to local conditions, it lacks the structure to be easily applied by watershed councils.
 
 

The purpose and scope of the Oregon manual differs fundamentally from the existing procedures discussed above. The manual is intended to be diagnostic, not prescriptive. The manual is to be used to guide watershed restoration efforts by non-technical groups. This approach has its own peculiar set of constraints: How do we balance the level of technical analysis required with the need to communicate with the local citizens? What is the minimum level of expertise that is potentially available at the watershed council level? It is evident that watersheds are complex and that this manual is an ambitious undertaking. However, if progress is to be made in watershed restoration, it will come from the landowners and the interested parties that have a stake in the watershed.

The manual is directed at watershed characterization and assessment, and less at the more rigorous level of watershed analysis. Data is to be compiled primarily from existing sources of information – maps, reports, aerial photographs, and historical accounts. We expect watershed councils will have some technical assistance from state and federal agencies and we expect that completing watershed assessments will tax the resources of all the involved parties. We also anticipate that the process of completing an assessment will be instructional to all the participants and will advance the agenda of restoring streams.
 
 

The manual is organized as shown in Figure 1. The Introduction provides a review of the concepts of watershed processes and function and how one organizes a watershed assessment. The manual then reviews the statewide issues that are the impetus for watershed restoration in Oregon and guides the council in identifying the relevance of these issues in their watershed. The Start-Up Section describes the logistics of assembling basic physical information on the watershed, acquiring base maps and aerial photographs, and assembling the watershed assessment team.
 
 

The Historical Conditions Assessment is used to gain an understanding of watershed conditions at the beginning of settlement, and the impact of various management practices through time. This snapshot of historical conditions is used to set the context for comparison to the current ecological condition, which will be important in setting goals for restoration. A variety of historical information from museums, agency archives, literature, and oral histories is brought together that relates to aquatic/riparian habitat, fish populations, and water quality. Issues to be explored include settlement patterns, direct impacts to the stream channels, riparian vegetation patterns and change, natural and human-caused disturbance such as floods and fire, fish presence and distribution, and resource use through time.

Channel Habitat Typing provides the spatial organization for the watershed assessment. Channel Habitat Types expected in Oregon are described and the method of identifying channel types from topographic maps, other source maps, and aerial photos is explained. Channel Habitat Typing is based primarily on channel gradient, valley confinement, and position of the channel segment in the watershed. We chose to organize the stream reaches in this manner specifically to identify the variability in fish use inherent with different channels and to organize the assessment to focus on areas where restoration measures will be most meaningful. Channel Habitat Typing, along with assessment of historical conditions, are the first steps in the assessment process, and provide context for the subsequent characterization of the remaining components of the assessment.

The Hydrology and Water Use Section is separated into two parts. The first part characterizes the basic hydrology (streamflow and climate)of the watershed, and identifies potential alterations to the natural hydrologic cycle (potential increases in peak flows and/or reductions in low flows) associated with land uses found in the watershed. Because hydrologic impacts are particularly difficult to assess, this section provides a screening method to help watershed councils decide if there is the potential for a hydrologic impact from a particular land use, and directs them to further (more complex) analyses that can be pursued beyond this process. The second part of this section evaluates the consumptive water uses in the watershed and identifies locations and types of potential impacts associated with water use.

The Riparian/Wetland section of the manual is broken into two parts. The first part describes the methods to assess current riparian vegetation conditions, the impacts of current conditions on recruitment of large wood, and the ability of riparian stands to provide stream shading. Information on current riparian zone vegetation composition and continuity is identified from aerial photographs, and compared to reference conditions for the ecoregion that the particular watershed is located in. Part two describes methods to characterize wetland conditions in the analysis area. Wetland locations are derived from the National Wetland Inventory, state and local wetland studies, soil surveys, topographic maps, and aerial photos. Wetland attributes are evaluated where information can be generated on wetland size, classification, buffer widths, and position in the landscape.

Sediment production is a potential concern in most river basins in Oregon. The approach of the Sediment Source Section is to identify local features that have the potential to contribute high amounts of sediment to streams. In developing the methodology, we recognized that sediment sources vary in importance around the state; therefore, the initial exercise is a screening tool to identify the processes that are active in the watershed (for example, road instability, slope instability, urban runoff, agricultural runoff). The analyst will complete different methodologies depending on which sediment sources are determined to be important in the watershed. Identification of sediment sources occurs within the framework of ecoregions, which provides the landscape context for natural variability in erosional processes.

The Channel Modification Section uses flood plain maps to identify areas where channel dikes and levees have disconnected the river from its floodplain. Other channel modifications are determined from a variety of information and include dams, agricultural impoundments, channelization, riprap, sand and gravel mining, and roads next to streams. Information on historic channel modification identified in the Historic Condition review is displayed as a theme on the existing modification map.

The Water Quality section focuses on evaluating water quality parameters that are most often of concern in Oregon – temperature, dissolved oxygen, pH, nutrients, bacteria, and contaminants. The water quality evaluation follows a logical process of identifying the beneficial uses, the applicable criteria, and comparing available data to the criteria. Data analysis is reduced to actions that can easily be accomplished by citizens – ranking the data, finding the median, and counting the number of data points that exceed the criteria.

In the Fish and Fish Habitat section the analyst compiles and evaluates information on fish populations, in-stream habitat and migration barriers through a four step process. First, the temporal distribution and abundance of fish species within the watershed are documented. Second, potential interactions between species of concern (such as listed species under the Endangered Species Act) are identified. Third, the analyst compiles existing habitat data and makes comparisons with established Oregon Department of Fish and Wildlife benchmarks to evaluate instream habitat conditions within the watershed. Finally, human-caused barriers to fish passage in the watershed are identified and a methodology for prioritizing restoration of passage is identified.

In the Watershed Condition Evaluation, the overall condition of the aquatic-riparian system, fish populations, and water quality are summarized; issues are identified that may require additional assessment or data-gathering; and portions of the watershed are identified and prioritized for protection and restoration. The Condition Evaluation process links summaries from each assessment component to the fish distribution and Channel Habitat Type information. The final products are tables summarizing key findings from each of the manual components and maps showing the distribution of factors limiting productive aquatic habitat, fish populations, and water quality. Watershed councils will use the results of the Condition Evaluation to understand how past and current resource management and land uses are impacting aquatic resources. This process will conclude with a prioritized list of action items, including protecting key areas and restoring areas of degraded habitat.

The final chapter, Monitoring and Evaluation, provides guidance in conducting studies to fill in data gaps identified during the assessment, and to evaluate the success of restoration projects. The monitoring section is intended to address the questions of what and why to monitor, not to describe detailed monitoring procedures. References are provided for monitoring procedures that are being developed as part of the Oregon Plan for Salmon and Watersheds. The emphasis of this section is on linkages to more detailed procedures rather than a self-contained methods manual.
 
 

Funding to complete watershed assessments in Oregon comes primarily through the Governor's Watershed Enhancement Board (GWEB). To date, GWEB has given a higher priority to funding requests in areas that currently have fish species that are listed under the ESA (for example coastal coho). A regional prioritization approach for funding watershed assessments is currently being developed by GWEB.

In addition to providing funding for conducting watershed assessments, GWEB also acts as a liaison between watershed councils and agencies that can provide information and technical assistance. Several technical workshops and conferences have been hosted by GWEB to provide further technical outreach to watershed councils. A full-time staff outreach position to aid watershed councils in developing and implementing assessments is anticipated sometime this year.

Over ten watershed assessments, distributed among all of the geographical regions of Oregon, have been initiated to date using the Oregon manual. Initial feedback from watershed councils indicates that the manual is extremely useful in organizing and interpreting information about local watershed conditions, and in prioritizing protection and restoration actions.

Although it is still too early to know if watershed assessments will result in improved protection and restoration of aquatic resources, initial results suggest that completing these assessments has improved public awareness of watershed conditions, and how the actions of individuals and communities affect aquatic resources.
 
 

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