Grantee Research Project Results

Final Report: Ecological, Demographic, and Economic Evaluation of Opportunities and Constraints for Riparian Restoration

EPA Grant Number: R825797
Title: Ecological, Demographic, and Economic Evaluation of Opportunities and Constraints for Riparian Restoration
Investigators: Gregory, Stanley V. , Hulse, David , Whitelaw, E. , Landers, Dixon
Institution: Oregon State University
EPA Project Officer: Hahn, Intaek
Project Period: June 1, 1998 through May 31, 2001
Project Amount: $899,999
RFA: Ecosystem Restoration (1997) RFA Text |  Recipients Lists
Research Category: Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration , Hazardous Waste/Remediation , Land and Waste Management

Objective:

The fundamental objective of the river restoration research project was to develop and demonstrate an integrated system for identifying areas of greater ecological, demographic, and economic potential for restoration of riparian areas. We quantitatively linked the biophysical components of riverine ecosystems with demographic and economic systems to determine the potential for riparian restoration. The research in the first year of the project incorporated: (1) field measurements of fish assemblage structure in the Willamette River; (2) analysis of historical change in the river channel and riparian vegetation; (3) spatially explicit measurement of rates of demographic change; (4) determination of measures of economic characteristics of riparian lands; and (5) development of a screening process for restoration potential of the mainstem Willamette River. Finally, we coordinated development of this process with active stakeholder groups working on the Willamette River (Natural Resources Office of the Governor of Oregon, Willamette Livability Forum, Willamette River Basin Task Force, Willamette River Restoration Initiative).

Summary/Accomplishments (Outputs/Outcomes):

The primary focus of the resource assessment in floodplain rivers was to: (1) spatially identify ecological and social potential for riparian restoration, and (2) identify changes in policies or practices that influenced the outcome of restoration. Patterns of river ecosystems and human land uses create a spatial context for restoration. Biophysical and human processes influence restoration potential differently at different spatial extents. River restoration requires consideration of the: (1) entire river network, (2) high priority river reaches within the network, and (3) focal areas within priority reaches. Potential for increased ecological function of various candidate river reaches and focal areas is related to the difference between current patterns and historical conditions in: (1) river channel complexity and hydrology, and (2) floodplain vegetation. Patterns of human populations, structural development of the floodplain, economic values, and productivity of the land are major constraints and incentives for restoration.

Species Richness in the Willamette River. Fish assemblages were sampled in three major reach types (tributary junctions, braided reaches, single channels) at nine sections of the Willamette River during the summer. Fish species presence was determined by boat shocking, beach seining, microhabitat shocking, fyke nets, and minnow traps. Species richness was 20 percent greater in tributary junctions and braided reaches than in single reaches, but most of the difference was attributed to introduced species. A proportion of the collected species represented by introduced species increased from 4 percent at the upstream end of the river, to more than 60 percent in the more urbanized lower reaches. Incidence of external tumors and lesions on large scale suckers also increased in the downstream reaches.

Demographic Change. A method for performing spatially explicit historical demographic trajectory analysis near the Willamette River has been developed based on the assessment of available historical and contemporary data sources. This method is designed to permit correlation with landcover change over corresponding time intervals. Digital conversion of 1850 settlement, 1930, 1970, and 1990 census tract boundaries has been completed. Population data for 1930 and 1970 have been linked to tracts and human population density computed for those censuses. A spatial analysis of change in human population density from 1930 to 1970 has been completed. A collection of supplementary digital data suitable for use by project researchers has been assembled. A set of digital spatial control points is being used to improve the spatial accuracy of this version of the digital spatial database.

Existing transportation and presettlement vegetation coverages have been updated with recently available additions, and Soil Survey Geographic Database (SSURGO) soils data has been assembled for the study area. We have acquired historic and contemporary Willamette River channel data from collaborators at Oregon State University (OSU) and have coordinated this information into the spatial database.

Economic Characterization. Our literature review, along with conversations with researchers and representatives of various groups, helped us to identify the most important directions for our analysis and defined the objectives for the next stages of the project. We assembled data on urban riparian areas in Portland and Eugene/Springfield. For the non-urban riparian areas of the basin, data on the current vegetation along the mainstem of the Willamette River was assembled by the University of Oregon (UO) and OSU cooperators. We also gathered data on agriculture in the basin and completed a preliminary economic characterization.

Public Involvement. Through the Willamette Livability Forum, we presented information about the project at the first annual Willamette Confluence, a stakeholders conference that explores basin issues. Governor Kitzhaber used the event to launch the Willamette Restoration Initiative and announce the members of its Board of Directors. In addition, we developed a proposed framework for tracking the health of the Willamette Watershed. The framework or "report card" includes information and proposed indicators concerning restoration of wetlands and riparian areas. The Forum presented and discussed the proposed framework at the Willamette Confluence, and participants provided written comments. Information about the project was presented at two regional meetings of the Forum.

We also identified and recruited stakeholders that advised and responded to the project team on various elements of the study. Members of the Forum and its Resource Group served as stakeholder groups. A Possible Futures Working Group was formed to advise on the development of long-term, alternative scenarios for the Willamette Basin. This working group identified potential restoration efforts as part of one or more scenarios.

Assessment of Restoration Potential for the Willamette River. Floodplains and riparian forests are dynamic elements of any landscape, containing some of the highest levels of biological diversity and habitat complexity. These areas also are highly valued for their access to water, transportation potential, food, recreation, and beauty. Historically, towns and cities along rivers have been built within these floodplains. These communities attempt to prevent channel movement in areas that are, by their nature, dynamic. This inherent contradiction is the challenge for managers of floodplains and riparian forests. Regional assessment of biophysical and socioeconomic patterns in rivers and floodplains improves our understanding and provides greater potential for long-term persistence of river restoration efforts and increased likelihood of ecological effectiveness.

Land use has extensively modified rivers and their floodplains in the Willamette River Basin. Most restoration efforts are based on opportunities (e.g., willing land owners, public lands, and short-term funding sources) and simply are added to other river modification projects. These projects often lack a broader strategic framework that incorporates both human and ecological systems. As a result, attempts to modify rivers or "restore" river systems often fall short of their goals. In some cases, these attempts unintentionally damage ecosystems and ignore the larger river network and its interactions. Restoration efforts based on short-term opportunities are not undesirable. However, their success can be increased by the application of a strategic conceptual framework based on ecological potential and patterns of human activity within the river corridor.

Restoration efforts in riparian areas commonly are based on vegetation, channel characteristics, or floodplain dynamics. These approaches rarely consider the human activities that shape the potential for ecological recovery and create future pressures to modify the river ecosystem. Patterns of human populations and development create critical constraints on the locations and outcomes of restoration.

We have classified four major categories of floodplain restoration. These classes of floodplain land identify areas with both high potential for increased ecological benefit and low socioeconomic obstacles to restoration.

High Restoration Potential. Areas with high potential for ecological recovery and low constraint from human settlement and land value should have the greatest potential for future ecosystem recovery. Such areas are better suited for conservation and restoration because their ecological values could increase more than other areas. Communities invest in projects to prevent channel change and flooding. Because these lands have high potential, economic constraints and demographic pressures frequently are lower and ecological recovery likely is to be greater on these lands, and social pressures to reverse restoration may be lower.

Potential for Policy Change and Incentives. Areas with high potential for increased ecological value and high social constraints have potential for changes in practices and policies. Decision makers can focus on alternative policies or practices that might lower social constraints. Examples include changes in lending rules or interest rates, federal farm assistance requirements, or converting through purchase, private to public lands. Other possibilities include use of land zoning restrictions or taxation policies with minimal economic consequences but major ecological benefits.

Educational Potential. Areas with high human populations and expensive property values likely are to be poor choices for restoration. These sites may provide little ecological benefit, are located in areas where pressures for future modification are high, and may be more costly than other areas because of property values. Several questions should be asked in these floodplains. First, are critical habitats or at risk species present? If so, restoration outcomes may warrant heroic efforts even in the face of large socioeconomic obstacles. Second, do these lands present opportunities to learn about the values of, and approaches for, conservation and ecological restoration?; particularly in urban areas where people live and work. These landscapes provide a tangible link between people and the natural processes upon which we depend.

Spatial Framework. The floodplain provides the most constant and quantifiable spatial framework for comparing physical, biological, demographic, and economic characteristics of the river corridor. Channel position, forests, and land use may change, but the floodplain remains relatively constant. We mapped 1 km "slices" of the Willamette River Floodplain at right angles to the floodplain's center axis. Within each of 228 1 km slices, numbered 0 (zero) starting at the confluence of the Willamette and Columbia Rivers and ending with 227 at the confluence of the Middle and Coast Forks of the Willamette, we measured characteristics of channel complexity, floodplain forests, human systems, and economic patterns. The longitudinal display of these features illustrates the characteristics of the Willamette River Floodplain and allows simultaneous analysis of the river and the human systems along its course.

We use this spatial framework for each slice to compare the presence and amount of several key factors that influence restoration planning. There are important advantages for allowing natural processes (e.g., floods) to assist in accomplishing restoration goals. It also is imperative that these processes operate in ways that minimize risk to human life and property.

Analytical Components

Geomorphic Characteristics. Channels, floodplains, and hydrology create the physical setting for the development of the ecological properties of a river system. The primary role of these physical processes is recognized in fundamental ecological ideas, such as the river continuum concept and the flood pulse concept. Restoration is a process of change, and channel features prone to frequent change (e.g., river tributary junctions, multiple channel reaches) have greater potential for rapid restoration. On the other hand, when people attempt to stabilize these dynamic reaches, enormous investments are required by agencies and local communities to confine channels. Historical patterns of river channels offer useful contexts for determining potential responses to restoration in the future.

Floodplain Vegetation/Channel Complexity. Dynamic channel patterns and regular flooding are cycles of river ecosystems that enhance biodiversity and aquatic productivity. Beginning in the 1860s, the federal government invested in the clearing of large wood, eliminating side channels and other obstructions from the Willamette River. Most of these river alterations in the 1800s were intended to improve navigability of the Willamette River because riverboats were a primary means of transportation, particularly in the wet winter months when valley roads were flooded and impassable for extended periods. As landowners and communities began to build closer to the river, floods became a major risk, and the natural processes of erosion and deposition were a hindrance to property owners along the river. Revetments and bank armoring with riprap were used by the federal government, local communities, and private citizens to stop bank erosion and close off side channels. Eleven federal flood control reservoirs were built in the basin from 1948 -1964, and these reservoirs reduced peak flows of small to moderate floods by approximately 30-50 percent. All of these control measures over the last 150 years have simplified the channels and islands of the Willamette River, converting much of a previously complex network of mainstem, side channels, alcoves, and islands into a riverine thread with far less channel complexity.

Demographic Characteristics. Patterns of population density and human land use create a context for considering potential future ecosystem patterns and locations for restoration efforts. Efforts to limit the impacts of development along the major rivers in the region have intensified as measures to limit development in floodplains and minimize impervious surface areas are being applied in rapidly urbanizing lands. Major urban development in river floodplains largely is irreversible over the near future, while adjacent agricultural and forest lands at the urban fringes offer much greater potential for change.

Economic Characteristics. Economic production influences landowner decisions about the use of lands along the Willamette River. Prices of goods and services derived from riparian lands provide an indication of the likelihood of landowner participation in restoration efforts. Regulatory processes also influence landowner decisions, and the longevity of governmental policies may be sources of uncertainty for landowners. Patterns of land productivity strongly influence the feasibility of restoration and must be evaluated along with patterns of river modification and ecological condition.

Spatial Data. We developed Geographic Information Systems (GIS) maps of the Willamette River for 1850, 1895, 1932, and 1995. We worked with the U.S. Army Corps of Engineers (ACE) to develop GIS maps of the inundation boundaries of historical floods in 1861, 1895, 1943, 1964, and 1996. We documented ACE channel modification projects from 1865-1995 on the GIS maps of the Willamette River, and collaborated with agency staff to verify the revetment locations.

Preliminary analysis of changes between 1850, 1895, 1932, and 1995 indicates that the southern half of the basin has experienced greater loss of secondary river channels than the downstream half of the basin. Area of islands has decreased in both portions of the river. More than half of the floodplain forests that were present in 1850 has been converted to agricultural and urban lands. The southern end of the mainstem Willamette historically was covered by extensive floods that extended several kilometers laterally to the active channel, but the downstream (northern) end of the river generally was constrained, even during major floods.

Maps of the river from 1850, 1895, 1932, and 1995 provide a scientifically robust basis for determining the extent and location of river channels in the Willamette River and its floodplain. The extents of flooding were combined for these major floods and depicted in a map of the total extent of known floodplain inundation since EuroAmerican settlement. The floodplain axis provides the most constant and quantifiable context for tracking changes in the river channels because the position of the channel changes, but the overall area inundated by past floods relatively is constant. We mapped 1 km slices of the Willamette River Floodplain at right angles to the center axis of the floodplain.

Patterns. To determine the potential for restoration, we compared the longitudinal patterns of channel complexity along the Willamette River in 1850 and 1995. Prior to settlement and river modification, the Willamette River exhibited three major geomorphic reach types. The upper (southern) river from Eugene to Albany contained the most complex river channels, with more than 100-400 ha of river channel within 1 km of floodplain. Floodplains within this reach of the river contained as much as 11 km of channel length within a 1 km floodplain distance, and most of the reach included 4-8 km of channel per km of floodplain. The reach from Albany to Newberg flows through several volcanic mountain ranges that extend across the valley floor. The river "bounces" between these resistant lateral landforms, creating a floodplain that varies greatly in width. As a result, the section from Albany to Salem relatively was simple in 1850, and the section downstream of Salem near Mission Bottoms, one of the early settlements in the Willamette Valley, is more extensive and complex. From Newberg to Portland, the Willamette River flows within a narrow basaltic trench that developed early in the geologic formation of the basin. The floodplain in this reach is narrow and relatively unchanging.

By 1995, human attempts to control the river had eliminated large amounts of river habitat and simplified the river. Area of river channel in the upper reach was reduced by more than half compared to 1850. The length of river decreased even more through the elimination of side channels and the armoring of its banks. By 1995, the upper river remained the most complex overall, but the lengths of channels within 1 km of floodplain have been reduced to 20-30 percent of the length present before river modification. The middle section of the river also changed, but not to the extent observed in the upper river. Area and length of river channel in the geomorphically simpler lower river remain similar to the historical patterns of channel complexity.

Potential for Restoration. The potential response of the river to efforts to restore channel complexity and area of riverine habitat differ along the Willamette River in relation to its geologic and hydrologic characteristics. Historical patterns of channel complexity provide a context for evaluating potential gains in river complexity through restoration actions. The difference between the graphs of channel complexity in 1850 and 1995 provides a longitudinal measure of the relative loss or gain of channel complexity. This graph depicts the areas of loss and gain and illustrates the analysis of the different river reaches described above. Clearly, the upper river section has the greatest potential for future recovery of channel complexity lost through past river modification. The area downstream of Salem also has been simplified, and ecological function could respond with increased aquatic area and channel complexity. Some of this land is managed by the Oregon Parks and Recreation Department, and park managers actively are restoring some of the side channels and floodplain features that have been modified over the last 150 years.

The maps and longitudinal illustrations of channel complexity also can be used to project future restoration potential through alternative futures. We examined aerial photographs for remnant channels and river features, and identified historical channels that could be reconnected to the river in the future. In the mainstem Willamette River from Eugene to Portland, approximately 200 km of river channel could be reconnected. These reconnected channels are incorporated into the Conservation 2050 alternative future. If we continue to simplify the channel at the same rate of loss that has occurred since 1932, we will lose additional riverine habitat, an alternative depicted in Development 2050.

Costs and Benefits of River Restoration. Restoration of biological and physical ecosystem functions in the floodplain of the Willamette River can generate economic costs, benefits, or both for owners of the land where restoration occurs, owners of other lands, and the overall economy.

The potential costs can materialize in several ways. Besides the labor and other costs associated with restoration projects, there may be costs associated with onsite and other lands. If restoration would curtail the production of goods or services from a parcel of land, then the cost would be the forgone net revenues. If it would reduce a parcel’s attractiveness for use as a homesite, then the cost would be the reduction in the value of the land and associated structures, driveways, and other improvements. If restoration would reduce the ability of public lands to provide services, the cost would be the additional expense of securing replacement services. These land-related costs might materialize, for example, if restoration involving reestablishment of the river's access to multiple historic channels occasionally resulted in increased flooding of nearby parcels, reducing the net revenues from farm production, the market price of a riverbank home, or the utility of a public roadway.

A final category of costs would occur if restoration reduced the aesthetic, recreational, or related values of the river and its riparian zones. These costs might arise, for example, if the reestablishment of riparian forest blocked an attractive view of the river or if reestablishment of multiple channels made fishing and boating more difficult.

The potential economic benefits from riparian restoration equally are diverse. In general, the primary intended benefit would come from a boost to populations of desirable species, such as salmon, and a reduction in populations of undesired ones, such as exotic weeds. Restorative efforts that reconnect the river with its historic floodplain would increase the land’s ability to store flood water, thereby potentially reducing the downstream risk of flood damage. A net benefit would materialize if the avoided damage downstream—especially on high—value, urbanized lands?outweighed the increased damage from the flooding of an upstream floodplain with agricultural or other lands with a lower value.

Restoration efforts resulting in improved water quality downstream would provide benefits to municipal-industrial water users, recreationists, and fish and wildlife. Improvements in quality could arise because restoration slowed the flow of pollutants into the river or stimulated natural processes that remove pollutants from the river.

In some cases, restoration might increase the net revenues water users derive from agricultural, commercial, or industrial uses. Reconnecting the river to multiple channels, for example, might reduce the river's erosional power and, hence, the costs property owners incur to resist this power. If significant improvement in the aesthetic or recreational attractiveness of the river were to result from restoration, it could raise the values of nearby residential properties, or increase the revenues for nearby restaurants and similar types of commercial enterprises.

Standard economic reasoning indicates that restorative efforts generally should be targeted toward lands where the net economic benefits (gross benefits minus gross costs) for society as a whole would be greatest. Currently, however, the available data are insufficient to support a determination of the net benefits of alternative restoration strategies. Nonetheless, the current data offers insight into the patterns by which some of the potential costs and benefits vary along the floodplain.

Data from county assessors (data for Yamhill County were not accessible) on each parcel of land, called a taxlot, show the existence of patterns in land uses that might be impeded by restoration efforts. Information from the 1990 land use/land cover data reveals patterns in the incidence of crops county extension agents in the Willamette Valley considered most flood resistant.

As a first approximation, the higher the value of the land, the greater the expected land costs associated with restoration. The lowest land costs are associated with lands with assessed values less than $2,500 per acre, for they typically are classified for agricultural use and have little potential for future residential or urban development. The greater the incidence of improvements, such as buildings and roads, the greater the potential land costs if restoration were to interfere with ongoing land uses, however, benefits would increase if restoration were to enhance these uses or reduce flood risks. The greater the incidence of agricultural lands with flood-resistant crops or other vegetation, the lower the expected land costs associated with restoration efforts that would increase temporary flooding.

Outside the cities, the incidence of taxlots whose land has assessed values less than $2,500 per acre generally exceeds 20 percent and often exceeds 50 percent. The pattern of land improvements is less distinctive. Nearly all taxlots in the cities have improvements, but so too do many taxlots outside the cities. Flood resistant crops (e.g., orchards, sugar beets, and radish seeds) occur most frequently at the mouth of the Willamette River, downstream of Salem, near the confluence of the Santiam and Willamette Rivers, and around Harrisburg.

The conceptual frameworks and the longitudinal pattern data were used to identify the potential for ecological benefit of floodplain restoration and to link it to the social and economic likelihood of restoration. The following sections summarize the Willamette River: (1) geomorphic patterns and potential for change, (2) floodplain forest properties of the river network, (3) human system patterns and structural development, and (4) economic values and processes that guide community choices.

Geomorphic Channel Complexity. Three major areas of the Willamette River exhibit high potential for restoration of channel complexity. The reach between Corvallis and Eugene offers some of the highest remaining channel complexity, and at the same time has lost more than most other sections of the river. It combines both existing qualities to be protected and high potential for additional recovery. This reach also includes some of the most extensive bank armoring and revetment outside the Portland metropolitan area. These structures could be strategically modified or removed to restore channel function. This also is true of the second area near Albany. A third important area for river restoration is the portion of the middle reach downstream of Salem. This section has lost channel complexity and includes substantial amounts of land in state parks and other public ownerships. This combination of recovery potential and public lands makes it well suited for restoration of channel complexity. The distribution of areas for restoration of channel complexity along the river also is an important flood storage design criterion for river managers and restoration planners.

Floodplain Forests. Forest restoration is simpler than channel restoration because of the ease and success of planting native tree species. Restoration could include natural reestablishment of wild floodplain forests, planting to regrow native forests, or cottonwood plantations. All provide some portion of natural floodplain forest functions and offer options for design of regional restoration efforts. The entire Willamette River has experienced extensive loss of floodplain forests, and the upper two-thirds above Newberg has lost the greatest total area. The middle reach between Newberg and Albany historically and currently contains the highest percent of the floodplain in forest cover, which gives it a higher priority for forest restoration. The upper river has a greater area of floodplain, and therefore has a high potential for forest area increase, even though the percent of the floodplain in forest might be lower. One of the largest blocks of floodplain forest historically was at the confluence of the Santiam and Luckiamute Rivers with the Willamette River. That forest greatly has been reduced, but it still contains one of the best examples of late-successional cottonwood forest in Luckiamute Landing State Park. This historical potential and intact remnant of floodplain forest on public land makes this reach another high priority for forest restoration.

Human Systems. The areas around urban centers—Portland metropolitan area, Salem, Albany, Corvallis, and Eugene—exhibit high population density and structural development. In general, Eugene has some of the highest densities of dwellings and people within the floodplain, and Portland has some of the highest structural modification in its industrial areas. Road systems are a much greater constraint in the floodplains around Portland than in any other section of the river. This means that pressures to continue modifications of the river and biological communities will be highest in these areas. In terms of restoration within the floodplain, presence of roads, bridges, and other structures gives these reaches lower potential due to the long-term human investment in maintaining a stable landscape pattern, and the resistance this creates to allowing natural processes, e.g., floods, to operate across their full range of variation. At the same time, tributary junctions in these reaches should be recognized as critical nodes in the river that offer ecological value and are essential for the migration of aquatic and terrestrial organisms from the Willamette River into the upper watersheds of these tributaries (e.g., coho salmon, winter steelhead, spring Chinook salmon). Examples of such tributary junctions in urban centers along the Willamette are the Clackamas, Tualatin, Mollala, Calapooia, Marys, and McKenzie Rivers. Another critical property of these urban areas is the potential for highly visible projects and educational opportunities in public areas. Important examples are Oak Bottoms in Portland, Minto-Brown Island in Salem, Baxter Park in Albany, Willamette Park in Corvallis, and Alton Baker Park in Eugene.

Public lands particularly are important opportunities for floodplain restoration because they are lands in common ownership and can be managed to meet the long-term needs of society without directly impacting private landowners. There are many types of public lands within the Willamette River Floodplain—state, county and city parks, rights-of-way for roads and bridges, and grounds for public buildings and utilities—all exist along the length of the Willamette River. Several major holdings downstream of Salem, the Luckiamute River confluence, and the municipal parks around Corvallis and Eugene offer substantial areas that could include both high use park areas and functional components of native forests. These readily are accessible and well distributed opportunities for regional restoration planners. A thoughtfully prioritized entire-river network of such restoration efforts could be a critical dimension of enhanced flood protection and a more naturally functioning river.

Economic Values and Commodity Production. Three major reaches of the river—downstream of Salem, downstream of Albany, and between Corvallis and Eugene—have lower land values, predominantly in agricultural uses. The area downstream of Salem, and the area between Corvallis and Eugene, also have comparatively lower investments in land improvements. The area downstream of Albany also has a high proportion of flood resistant crops. Such characteristics make these areas well suited for restoration because the land costs encountered in conservation easements, leases, or land acquisition with willing land owners would be less than in other reaches of the river. The need to protect these sections from flood damage also would be lower because of the lower land values. These sections of the river coincide with areas of high potential for ecological benefits related to floodplain forest restoration and recovery of channel complexity.

Example Approaches to Prioritization. Restoration of ecologically significant processes in places where human population density and land use intensity are high may require reversal of long standing investments in land form and water course alteration. If ecological restoration and the benefits of built environments are in opposition—gain in one necessarily causing loss of the other—then the conceptual model expresses the nature of the prioritization task: at the network extent in those reaches where two conditions exist, investment in constructed conditions is low, and the potential for increased ecological benefit is high. If potential ecological gain is high, but the existing structural investment is as well, then future net gain is interpreted as small, as is the likelihood of community acceptance of large scale restoration projects. While we choose to illustrate this particular conception of restoration priorities, it is important to note that there are many other valid sets of restoration priorities. Both the magnitude of human investment and potential restoration value refer to complex sets of factors whose definitions and relative importance may differ among reasonable people.

An example of how data on longitudinal patterns can be used to identify areas with relatively high restoration potential is illustrated below. In this example, the specific restoration objectives are to increase channel complexity and floodplain forest area (with associated beneficial effects on terrestrial and aquatic biodiversity and water quality, as discussed in preceding sections) and increase non-structural flood storage. The potential ecological benefits of restoration are represented by three biophysical factors and the social constraints are represented by five different demographic and economic factors.

Human factors and relative weightings (constraints):
(1) 1990 population density per 1 km slice 0.11
(2) 1990 rural structure density per 1 km slice 0.11
(3) 1990 road density per 1 km slice 0.22
(4) 1990 area of private land per 1 km slice 0.22
(5) 1990 percent of slice worth more than $2,500/ac. 0.34

Biophysical factors and relative weightings (opportunities):
(1) change in length of forest per 1 km slice 1850-1990, 0.4
(2) change in length of channel per 1 km slices 1850-1995, 0.4
(3) percent of channel length in revetment 1995, 0.2

These factors, and their weightings at right above, are then used to quantitatively rank each slice using two independent indices describing: (1) social constraints, and (2) biophysical opportunities. The former consists of five components: population, structure, road, private land ownership, and higher price taxlot areal densities within each slice. Biophysical opportunities are then described by three components: change in length of river bank woody vegetation, change in length of channel complexity, and percent of bank revetted per slice. Each component is assigned a number between 0 and 1, using a linear relationship between the minimum value (or, in the case of forest change and channel length change, a threshold) and the maximum value. Then, a weighted sum of these normalized components is computed to form each composite index. A restoration potential value is then defined for each slice using these two indices, and the median value of each index is used to divide the space into quadrants. Each slice falls into a single quadrant.

A color-coded map shows the priority locations that emerge from these restoration purposes and their corresponding factors and weightings. The contiguous green slices, to pale orange slices, are locations where high potential for increased ecological benefit (green) occurs next to places that are already functioning relatively well ecologically and have less likelihood of future pressure for development (pale orange). Analyses such as these provide a coarse-grained prioritization of candidate river reaches at the whole-river network extent. Such analysis is only the first step in a multi-scale process for prioritizing reaches and focal areas for restoration.

Reach and Focal Area Selection. The analysis on the preceding pages provides a coarse-grained prioritization for the whole river network, but the choice of project focal areas requires a more detailed study of local conditions. This includes the willingness of local landowners to consider restoration actions, the proximity of population centers, the percentage of public land ownership, the presence of transportation infrastructure, the degree to which remnant channel features are present, the type and extent of revetments, historic channel dynamics, flood storage capacity, and finer-grained analysis of historical floodplain vegetation.

The chosen restoration purposes were to: (1) increase channel complexity, (2) increase area of native floodplain forest, and (3) increase non-structural storage of flood water. With slice priorities mapped at the full river network extent, a reach was chosen which met the criteria listed under “Reach Extent Selection Criteria,” which had a large number of contiguous green slices. Harkens Lake has more than twice as much revetment as adjacent areas, and has experienced significant declines in channel complexity and woody vegetation along the bank. Thus, it is a high priority focal area within this reach for restoration. Harkens Lake not only is the potential focal area, but is used here to illustrate how the approach may lead to restoration on the ground. Seven potential focal areas lying within the reach between Corvallis and Eugene were evaluated for focal area selection within this reach. Harkens Lake was chosen based on rankings among criteria under "Focal Area Selection Criteria" and "Focal Area Ranking Criteria" that support the purposes listed above. Emphasis included: coincidence between areas of high flood storage potential, ratio of predicted increase in channel complexity and forest area to cost of restoration actions, and strategic public landownership. This too employs a constraints and opportunities approach, but through flood storage, adds protection of downstream life and property as an objective of fluvial process restoration.

Example Conservation and Restoration Actions. The primary opportunities at Harkens Lake are to conserve riparian forests on private lands and to restore floodplain forest on publicly owned land. Reconnecting the floodplain depression and the oxbow (i.e., Harkens) lake to the main river channel can be accomplished by breaching the barriers created by road embankments and revetments. This will allow more floodwater to be stored and gradually released during a flood, reducing the severity of downstream flooding. This increased exposure to regular flooding at Harkens Lake will facilitate reforestation of native floodplain forests, thus harnessing the natural tendencies of riverine processes to sustain native terrestrial and aquatic ecosystems through time.

The simulation compares how Harkens Lake might evolve during a flood comparable in magnitude to the December 1996 flood, depending on whether or not the river is allowed access to a remnant side channel through breaching an existing revetment. In addition, simulation compares flood conditions prior to restoration with the simulated flood conditions after restoration.

Accomplishing Restoration Goals. Accomplishing such change in landscapes dominated by privately owned land will require fair compensation to landowners for reductions in economic production. Incentive programs offer one way to meet this growing need. Landowner participation in restoration incentive programs has been low, primarily because the programs are fragmented, complex, and inadequately staffed. With high priority locations for restoration identified, it may be possible to examine technical support requirements, reduce regulatory barriers, link federal and state programs, and devise the specific tools (e.g., easements, habitat plans, and stewardship agreements) to meet the individual circumstances of owners of high priority lands. New and more flexible incentives for private landowners are needed to encourage natural resource stewardship, together with adequate funding for existing conservation and restoration programs. Linking these efforts with the type of restoration approaches mentioned in this chapter, holds much promise for the future of the Willamette River, its floodplain, and those dependent on it.

Journal Articles:

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Supplemental Keywords:

riparian vegetation, floods, restore, river, Oregon, OR., RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Geographic Area, Water, Economic, Social, & Behavioral Science Research Program, Restoration, Economics & Decision Making, EPA Region, State, Ecosystem Protection, Aquatic Ecosystem Restoration, Ecology, Ecosystem/Assessment/Indicators, decision-making, Monitoring/Modeling, integrated assessment, Region 10, compensation, public values, bioavailability, ecological condition, ecological effects, ecosystem health, environmental consequences, forest, riparian, satellite, sociological, rivers, economic benefits, public issues, public resources, valuing environmental quality, aquaculture, aquatic biota , assessment methods, biodiversity, ecological risk assessment, ecosystem assessment, ecosystem condition, water quality, ecosystem, estuaries, stakeholder groups, economic goals, community-based, cost benefit, ecosystem valuation, policy analysis, social impact analysis, ecological assessment, habitat, incentives, monitoring, nonmarket valuation, streams, community involvement, stakeholder, aquatic, biotic integrity, ecosystem management, diversity, property values, public policy, remote sensing, surveys, wildlife, wetlands, biodiversity option values, cost/benefit analysis, environmental values, adverse impacts, ecological integrity, ecological exposure, social constraints, decision analysis, economic incentives, psychological attitudes, residential property values, social psychology, valuation, ecological indicators, ecological research, estuarine ecosystems, demographic, floods, GIS, modeling, social resistance, OR, aquatic ecosystems, contingent valuation, adaptation, ecological response, evaluating ecosystem responses, fish , ecological recovery, environmental assets, fish, river, socioeconomic, spatial analysis, stream, watershed, conservation, environmental policy, ecological impacts, ecosystem integrity, environmental benefits assessment, biological indicators

Progress and Final Reports:

Original Abstract

1998 Progress Report

1999 Progress Report