A Decision-Making Guide for Restoration
This chapter provides a conceptual framework for ecological restoration activities in water programs. Discussion focuses on important components and issues of decision-making for restoration, rather than a detailed step-by-step protocol for conducting ecological restoration. The decision-making guide is summarized in a series of nested flow charts. The first flow chart shows major components of the decision-making guide, without any complicating details (Figure 4-1, not available electronically); subsequent flow charts and text describe major components in greater detail.
This decision-making guide emphasizes the applicability of restoration techniques for water programs and includes decision points that integrate a broad range of program responsibilities and activities. The process assumes that impaired water resources have already been identified in accordance with the CWA and other requirements. The decision-making guide begins with a selected site where water quality standards, which may include numeric or narrative criteria or designated uses, are not being met or are threatened. In Step 1, an inventory of watershed conditions is used to scope promising opportunities for restoration. In some cases, ecological restoration will be the most effective response to impairment; in other cases, restoration may be one among many candidate tools for achieving water quality standards. Steps 2 and 3 provide an analysis of the availability, applicability, and relative costs of ecological restoration techniques to assist regional and state personnel in making an informed decision. In Step 4, an ecological restoration approach is implemented, where appropriate. Finally, post-implementation monitoring, an essential part of the decision-making guide, is conducted in Step 5 to determine whether impairment has been mitigated.
Several steps in the decision-making guide call for stakeholder involvement. Identification and recruitment of stakeholders may have been done as part of a Watershed Protection Approach or Total Maximum Daily Load (TMDL) process prior to the ecological restoration decision steps described below. If stakeholders have not already been identified and recruited, however, this important element of public participation should be addressed explicitly. Figure 4-1 (not available electronically) illustrates recognition of the larger context of the restoration decision-making process by including an input arrow prior to Step 1. Each user should therefore view these steps as an example model and determine whether the public participation and other components need to be adapted to meet additional requirements.
Step 1: Inventory the Watershed
- Characterize watershed conditions to determine nature of impairment
- Determine feasibility of using restoration to meet waterbody goals
The decision-making process begins with a review or inventory of existing information, designed to yield a preliminary evaluation of the types of restoration activities which may be feasible and appropriate to address impairment. The accompanying Step 1 flow chart, which contains four numbered substeps and three decision points, lays out an example framework for determining when ecological restoration is of potential use (Figure 4-2, not available electronically).
Step 1.1: Do Basic Site Characterization
Basic site characterization and data collection are the first steps in inventorying a watershed. Characterization may include information on water quality; geochemistry; hydrology; fluvial geomorphology; substrate condition; flora; and fauna; and, to the greatest extent possible, identification of stressor sources in the watershed. In addition to traditional point source loading of pollutants, stressors may include nonpoint source pollutant loading and land-use effects, hydrological alterations, point source impacts causing physical habitat alterations, and mining, among others.
In addition to physical and chemical characteristics of the watershed, land ownership and regulatory jurisdictions play an important role in determining opportunities for restoration. Much of this information is geographically based, and amenable to storage and manipulation in a Geographic Information System (GIS). As part of the basic site characterization for potential restoration, managers may wish to consider (1) mapping other opportunities for related ecological improvement projects, such as parks, refuges, Nature Conservancy sites, heritage trust projects, etc.; (2) mapping other public lands, such as active and abandoned military bases, controlled flood protection areas, etc.; and (3) mapping regulatory jurisdictions. Such resource maps are valuable tools to foster public involvement, improve the coordination of restoration activities, and develop cooperative solutions to regulatory conflicts.
Also included in the basic site characterization is the acquisition of historical and current data on regional or landscape-scale habitat characteristics. This type of information is invaluable to planning and evaluating site characterization. It is also useful in later steps of the decision-making process for (1) setting realistic restoration goals and (2) identifying regional issues that must be addressed before undertaking a watershed or site-specific restoration project.
Data collected during site characterization, including both site and landscape-scale data, also provide a baseline for evaluating the performance of restoration projects. These data can be used to establish the environmental benchmarks to be used later ( Step 5) to monitor for success of the restoration practices.
Step 1.2: Identify Nature of Impairment
In some watersheds, point and nonpoint sources of pollutant loads have direct and predictable relationships to waterbody impairment. In many cases, however, the connection between load sources and impairment is less obvious, and physical habitat variation may play an important role in the nature and occurrence of impairment. A spatial analysis of the specific nature and causes of impairments throughout the watershed is usually not feasible during the watershed inventory. Initial identification can, how ever, make use of available information, including databases and extant studies on physical habitat degradation and associated impairment of beneficial uses, such as §303(d) lists, §305(b) Reports, §319 Assessment Reports, Use Attainability Analyses, and other sources. Many studies provide detailed summaries of habitat suitability measures, water quality parameters related to habitat degradation, and associated excursions of water quality standards.
Identified impairments must be addressed within the appropriate regulatory context. In some cases, a narrative criterion or designated use component of the water quality standard may explicitly refer to a habitat use, such as the necessity of maintaining spawning habitat. In other cases, the water quality standard in question may not refer explicitly to a habitat goal or function, but rather to some numeric criterion. In these cases, ecological restoration techniques still have the potential to bring a water resource into compliance with the water quality criterion or standard. For example, a stream may not meet the criterion for un-ionized ammonia. Although in this case the water quality standard does not refer explicitly to a habitat use, restoration of riparian vegetation can lower stream temperature, which can reduce the instream concentration of un-ionized ammonia. Restoration may thus address numeric or narrative criteria. These two branches of the guide are separated at the decision point following Step 1.2.
Combining information on watershed physical characteristics, water quality, habitat, land ownership, and regulatory jurisdictions with the preliminary analysis of the nature of impairment allows selection of the best strategies to develop sustainable rest oration sites, increase regional biodiversity, and, along the way, suggest the places appropriate for economic development.
Step 1.3: Map Opportunities for Restoration
In mapping opportunities for restoration, it should be kept in mind that restoration approaches can have beneficial effects beyond the direct restoration of habitat. For instance, a stream segment might possess adequate functioning wetland habitat to sup port designated uses, but restoring degraded wetlands upstream might mitigate downstream excursions of numeric water quality criteria for metals. A cause-and-effect linkage is often difficult to prove; at this stage, however, only a preliminary, tentative assessment is needed for identifying the problem. Often, this will be based on assumptions and experience with similar sites.
Step 1.4: Evaluate Feasibility of Meeting Goals Via Restoration
Even where good opportunities exist for ecological restoration, establishing whether such techniques are appropriate for further consideration as management options must take into account the technical feasibility of restoration. That is, there will be cases in which ecological restoration opportunities are obvious, yet are not technically feasible with the current state of the science. When direct, instream ecological restoration does not appear feasible, however, riparian or upland restoration options (generally based on source control in the surrounding watershed) may improve habitat. When restoration by either instream, riparian, or upland techniques appears feasible, the decision process continues to Step 2, the identification of goals for restoration. Consideration of economic viability of candidate restoration techniques is addressed both in Step 3 and in Chapter 5.
Step 2: Identify Goals for Restoration
- Develop specific restoration goals and candidate restoration techniques
- Beginning stakeholder involvement at this stage is crucial
The screening analysis laid out in Step 1 is designed to indicate that ecological restoration should be considered as a management option whenever it has the potential to mitigate water resource impairment. Subsequent steps in the decision-making guide attempt to refine this analysis and provide a clear determination of which ecological restoration options, if any, should be pursued. Clarifying exactly what goals are appropriate for ecological restoration at a given site is critical to examining the worth of specific restoration techniques and is the emphasis of Step 2. A detailed flow chart for Step 2 containing six substeps is shown in Figure 4-3 (not available electronically). As indicated on the right-hand side of the flow chart, public participation is an important element in identifying goals for any restoration project. Public participation not only improves the validity of restoration goals, but can be instrumental in finding necessary funding.
Step 2.1: Identify Specific Water Quality Standards (i.e., Chemical, Physical, and Biological Components) Potentially Addressed by Restoration
Problem identification and analysis in Step 1 focuses on the linkage between waterbody impairment and options for ecological restoration. As impairment is defined in terms of non-attainment of water quality standards, planning for restoration should be firmly based on specific water quality standards to be addressed, including criteria and designated uses. As in Step 1, standards may involve a specific reference to habitat use or other numeric or narrative criteria that are potentially addressed through ecological restoration.
Step 2.2: Begin Stakehold Involvement and Develop Consensus Objectives
Participating programs, agencies, and stakeholders will develop consensus goals and objectives for the ecological restoration project, consistent with the Watershed Protection Approach and TMDL process. Figure 4-4 (not available electronically), adapted from the Anacostia Restoration Team (1991), illustrates a matrix of watershed restoration goals and project objectives identified by participants. Goals and objectives should be directly related to meeting water quality standards in question. The matrix also shows which participants will contribute to individual project objectives. A key to stakeholder acronyms use in Figure 4-4 is included on page 4-10 following the table.
Following Step 2.2, the decision sequence varies depending on whether the waterbody impairment is defined directly in terms of ecological or habitat conditions or in terms of other types of water quality standards, such as non-attainment of numeric standards for chemical concentration, which may be mitigated through use of ecological restoration as a management tool.
Step 2.3: Conduct Ecoregional or Landscape-Level Analysis
An ecoregional or landscape-level analysis can be used to determine the status of particular resource components of the aquatic ecosystem, describe existing reference sites, and identify any large-scale landscape condition that might inhibit achieving ecological restoration goals. Items addressed in a regional or landscape perspective include:
- Endangered species
- Critical resource type (e.g., wetland category)
- Reference conditions
- Large-scale problems
When using restoration to meet a numeric water quality criterion, this step could provide valuable information, but may not be necessary.
Step 2.4: Determine Ecological Functions and Values To Be Restored
When standards specifically mention ecological impairment, determining to what extent (and to what point in time) affected ecosystem functions and values can be restored is important. For some water resources, such as certain wild rivers impaired by recent disturbances, restoration to a pristine, pre-disturbance condition may be realistic. For water resources in areas that are long-settled or surrounded by development, specification of a pre-disturbance baseline may be unclear or irrelevant. In such cases, goals for restoration should be evaluated with respect to the water resource's designated uses in order to determine whether functions and values to be restored are reasonably attainable in the context of the existing surrounding landscape. This ste p is a refinement of the scoping analysis in Step 1.4, conducted at a more rigorous and detailed level.
Step 2.5: Identify Ecological Restoration Techniques
Restoration techniques are often useful to attain numeric criteria for chemical concentrations, which may indirectly relate to habitat conditions, or may be specified for protection of human health. Restoration techniques can also be applicable to attaining non-ecological narrative criteria, such as suitability for recreational use. Similar to Step 2.4, this step provides a more rigorous identification of exactly which restoration techniques (and associated ecosystem functions and values) are potentially available to reduce impairment.
Step 2.6: Select Restoration Goals
The previous steps yield a list of ecological functions and values, and stakeholder consensus objectives, for consideration for restoration. To complete Step 2, these results are summarized by selecting a set of potential ecological restoration goals for further consideration. Typical goals for restoration include meeting applicable water quality standards (consisting of the beneficial designated use or uses of a water resource, the numeric and narrative water quality criteria that are necessary to protect the use or uses of a particular water resource, and an antidegradation statement), maintaining a fishery, preserving specific habitat types, and so on. Such goals are closely related to ecological assessment endpoints, which are developed more formal ly in Step 5 (Monitor for Results) to determine the effectiveness of selected management options (EPA 1992a). (Table 4-1 (not available electronically) summarizes information on assessment and measurement endpoints for ecological restoration.)
Step 3: Identify and Select Candidate Restoration Techniques
- Seek cost effective strategies
- A combination of instream and watershed techniques is often needed
A key to identifying and selecting restoration techniques is to know how much is enough. That is, avoid unnecessary expenditure of resources trying to fix a problem that the system can fix on its own. The general decision framework for Step 3 is shown i n Figure 4-5.
While addressing water column issues is critical to the chemical, physical, and biological restoration of a stream, the focus of management options should include stressors that originate outside the stream channel and riparian zone as well. Management options considered in this step include instream techniques and techniques applied in the surrounding watershed (such as BMPs) that reduce loadings and allow the stream to reach a state of equilibrium with the landscape. State nonpoint source, point source, and wetlands programs can collaborate in the restoration effort to address stressors in the basin impacting the integrity of physical habitat.
Step 3.1: Identify Candidate Restoration Techniques
Building on the assessment conducted in Step 1, this step provides a more comprehensive list of feasible ecological restoration techniques. Instream, riparian, and upland techniques should be considered, individually and in combination. One form this st ep could take is listing categories of stressors or goals that must be addressed and associated restoration techniques that address the stressor to meet the goal. Table 3-1 provides example categories and candidate restoration techniques. There is a growing body of literature and professional expertise in designing restoration techniques to address a broad range of objectives and types of ecological settings.
Step 3.2: Balance and Integrate Instream and Watershed Techniques
Restoration efforts can involve instream and riparian restoration of habitat and upland (watershed or source control) techniques. Achieving a balance among these components is important for many restoration projects. Addressing both symptoms (instream) and causes (in the watershed) is often desirable, but addressing only symptoms may be ineffective. For instance, a project involving channel modification to improve fish habitat in a river degraded by excessive sediment may be wasted effort if the watershed sources of sediment load are not also addressed. Also, once watershed sources of sediment load are addressed, instream techniques to restore habitat may not be needed. Often, a series of complementary management actions at different locations in the watershed will result in greater success.
Step 3.3: Evaluate Costs and Benefits
Selecting and prioritizing restoration efforts must take cost into account. A selected restoration technique should be cost-effective, in addition to resulting in major environmental benefits. Thus, economic criteria are part of the technical process to determine whether restoration techniques are reasonable. A growing number of ecological restoration examples in virtually every environmental setting provide baseline data for estimating economic impacts and costs; particularly detailed studies of relative cost effectiveness of BMPs and point source control technologies have been developed for the Chesapeake Bay basin study (Camacho 1992). Economic viability of nonpoint source BMPs has been demonstrated on many occasions. Restoration can be an extenson of BMPs to include riparian physical habitat problems. Often, restoration leads to benefits that cannot be attained by more traditional water quality controls.
When management options that do not involve direct habitat restoration (e.g., point source controls alone) are also appropriate to address impairment, a relative evaluation of cost should be made. For instance, when a habitat restoration option is one among many options available to address an excursion of a water quality standard, the most cost-effective approach may be preferable. The economic assessment should include secondary economic impacts, such as any employment or recreational benefits of rest oration activities. Finally, the economic evaluation will also aid in assigning priorities to restoration efforts where implementation must proceed in stages. Chapter 5 provides additional detail on cost evaluation of restoration activities.
Step 3.4: Select Best Combination of Restoration Options
Most restoration strategies will involve a combination of specific techniques. If more than one ecological restoration strategy is available for a restoration goal, the best restoration option or options should be selected based on technical and economic feasibility. The process is repeated for additional goals. Selecting an optimal strategy generally requires some sort of quantitative prediction of the effectiveness for candidate restoration techniques. Evaluating technical ability and fine-tuning restoration options may involve the application of simulation models to predict results. Simple physical models of the water resource will be useful for some instream ecological restoration techniques. For instance, when evaluating the use of hydraulic drop structures to address DO problems, it may be necessary only to estimate the re-aeration associated with proposed structures for incorporation into a simple DO model. Similarly, relatively simple models of nonpoint loading can estimate the response to upland (watershed/source control) restoration techniques. On the other hand, quantitative prediction of the ability to attain narrative criteria and designated uses that reflect general ecological health of the water resource often present more challenging problems for analysis.
Simulation models of ecosystem responses to changes in physical and chemical conditions are research tools, which are difficult to implement and produce results of limited reliability (Fausch et al. 1988; Marcus et al. 1990). For this reason, it is generally necessary to work in terms of surrogate or indicator variables or combine a simulation and empirical approach to assess which restoration options are best. In a case where a designated use of salmonid habitat is impaired by the reduction of spawning substrate caused by fine sediment loads, building a model of salmonid population dynamics that incorporates sediment loading as a forcing variable is unlikely to be practical. A more sensible and cost-effective approach to the evaluation is the use of a n empirical relationship between substrate embeddedness (which is governed by the loading of fines) and spawning success. This approach can be combined with simulations of sediment loading and transport, perhaps incorporating the potential effect of an instream restoration technique such as enhancing wetlands for sediment trapping and upland technique of watershed erosion control.
A phased approach to TMDL development that includes a schedule for implementation of controls and a monitoring plan that provides useful information for refining TMDLs is often appropriate when addressing nontraditional problems such as nonpoint sources o r degraded habitat. The exact effects on water quality of many ecological restoration techniques are difficult to predict a priori. The phased approach provides for continuing efforts based on the success of previous efforts.
Step 3.5: Assign Priorities to Restoration Efforts
Restoration efforts can often address multiple ecological endpoints. Given limitations of funding and human resources, assigning priorities to restoration efforts is important so that efforts providing the greatest return, or addressing the most time-sensitive impairments, can be implemented first.
Step 3.6: Plan for Monitoring
In any restoration effort, monitoring is needed to evaluate progress in achieving goals. Planning for this monitoring must begin before the project is implemented and the waterbodies' characteristics are modified. Further details on monitoring are provided in Step 5.
Step 4: Implement Selected Restoration Techniques
- Address practical issues of implementation
- Achieving voluntary stakeholder participation may determine success
Implementation of selected restoration techniques (Figure 4-6, not available electronically) may present many challenges, including the following:
- Collaboration Among Organizations:
- Restoration projects may require information and resource contributions from several agencies that are often unaccustomed to working together. This can be remedied through early recruitment of stakeholders and the establishment of meaningful partnerships in the early phases of the project. Several states that are developing Watershed Protection Approaches are establishing formal relationships with other resource agencies to facilitate collaboration on projects.
- Voluntary and Regulatory Approaches:
- Flexibility is needed in the development of management strategies. In many cases, management strategies will combine enforceable point source controls with voluntary controls for nonpoint source dischargers. Managers will have to assess carefully the balance between voluntary and enforceable management options designed to meet water quality objectives. Methods for ensuring compliance, a key issue for both options, will vary from situation to situation.
- Cost Effectiveness:
- Cost incentives encourage the application of restoration techniques. In spite of indirect benefits associated with most restoration projects, the cost of restoration will need to be competitive with traditional control strategies. Accurate cost comparisons and justifications contribute greatly to effective implementation of restoration strategies.
- Local Planning:
- Many restoration projects will require consideration of BMPs and land-use restrictions, and water quality agencies will be required to collaborate with local land-use planning authorities. Involvement in local planning affairs will be a resource-intensive component that will require great sensitivity and is best accomplished through early and effective stakeholder participation.
Step 4.1: Identify Incentives and Mandates for Action
Ecological restoration requires cooperation among programs and agencies that have not traditionally worked together. Identifying incentives and mandates to form the basis of joint action plans will focus on scheduling activities, securing the commitment of resources, and eliminating barriers. Identifying incentives for a discharger may yield a more cost-effective approach to reducing the stressor. For a land owner (public or private), the incentive may involve, for example, sharing costs of the restoration project. The framework for both regulatory and voluntary control programs must be clearly delineated for all participants. In addition to supporting statutes and programs that are derived from the CWA, there are additional federal, state, and local mandates and agencies that can contribute to restoration efforts. For instance, timber permits could provide an important regulatory component of a restoration plan to reduce sediment loads. The Montana Streams Preservation and Protection Act is an excellent example of a state mandate that can be used to bolster ecological restoration efforts.
Step 4.2: Continue Stakeholder Involvement
Stakeholder involvement and buy-in is crucial to the success of most restoration efforts. Stakeholder involvement should begin at least as early as Step 2.2 in the decision process, and should continue throughout. The matrix illustrated in Figure 4-4 ca n be used as a planning tool for identifying roles and responsibilities of participants. A project plan that describes the contribution expected from each stakeholder can reinforce collaboration and cooperation. Ecological restoration projects have been excellent examples of coordination among agencies lending their own unique expertise. Many restoration projects are driven by local initiative with resource agencies playing a support role; state agencies should therefore look for opportunities for contributing to ongoing projects to achieve their own water quality objectives. The state is in a good position to encourage the collaboration among regulatory and voluntary programs and to integrate federal and local efforts. Many restoration projects have also been made the centerpiece of community revitalization programs, and state water quality agencies could play a leading stewardship role in recruiting and promoting local understanding and involvement in the process. Most restoration projects will involve both regulatory and voluntary control programs. Regulatory controls are enforceable (e.g., NPDES permits), but voluntary controls require stakeholder participation. Success in obtaining sufficient stakeholder participation cannot be assumed a priori. In some cases, a restoration technique may not be feasible due to insufficient stakeholder buy-in.
The state can play a key role in promoting restoration projects and ensuring that participants commit the necessary resources to achieve restoration goals and objectives by clearly communicating the need and rationale for the project and by using grant re sources, regulatory requirements, permit fees, and information management resources skillfully.
Step 4.3: Establish Schedule and Implement
A schedule should establish clear milestones to be completed in a realistic time frame. The schedule should be keyed to project objectives and endpoints. A growing number of restoration projects currently use a broad range of techniques from which to derive an estimate of project duration and time required for the project to yield results.
The project team should give careful consideration to an implementation schedule and associated recovery milestones. Project milestones and measures of success can be grouped into three general categories: near-term, mid-term, and long-term, in a phased project implementation schedule. The following is an example of such a schedule:
- Near-Term Recovery—Improve Physical Habitat Quality:
- Stream habitat quality sometimes can be improved quickly through the use of physical habitat restoration techniques, such as the placement of log drop structures, channel deepening and restoration , placement of boulders in the stream bed, and placement of boulders, logs, and/or brush along stream banks to restore bank stability, etc. BMPs, such as grazing enclosures and grass buffer strips placed along riparian areas and areas with high erosion potential, will enhance infiltration of surface runoff and reduce inputs of sediments, nutrients, and other chemicals to the stream. Restoration of riparian areas with woody vegetation is a longer-term goal. All of these measure can lead to significant, short-term improvements in habitat and water quality.
- Mid-Term Recovery—Restore Benthic Macroinvertebrate Community:
- The establishment of a diverse, productive benthic macroinvertebrate community indicates the restoration of a major component of a healthy functioning stream ecosystem. It is a mid-term measure of success that can be accomplished within a few years. The longer time required for establishment of a diverse, productive macroinvertebrate community, compared to the short-term restoration of physical habitat, is primarily a function of the time required to establish the more substantial, vegetative components of the restoration management plan, such as woody vegetation in riparian areas and buffer zones, and wetlands. These components, along with those established in the short-term, can greatly enhance water quality. If these short-term and mid-term milestones have been attained, then the ecosystem should be providing quality food resources, should be efficiently and effectively processing potentially toxic chemicals, nutrients, and sediments, and should be preventing temperature and pH extremes.
- Long-Term Recovery—Restore Fish Community:
- The restoration of a diverse, productive native fish community is, in most cases, a long-term measure of success. Because of their longer life cycles, fish populations require a longer time for recovery fr om adverse environmental effects than benthic macroinvertebrates, algae and macrophytes; therefore, for restoration of a fish community, the types of short-term and mid-term habitat restoration practices discussed above must have been accomplished on a watershed scale that will prevent or at least significantly reduce even fairly infrequent episodes of stress that may adversely affect the fish community, especially the more sensitive and vulnerable species. For example, an episode of high concentrations of sediment or a toxic chemical occurring just once a year or even once every several years may prevent the successful reproduction and recruitment of sensitive fish species.
Step 5: Monitor for Success
- Determine whether goals of restoration are achieved
- Adequate monitoring is essential, and provides the opportunity to fine-tune the restoration effort
Determining whether the goals of a restoration project are being achieved can only be accomplished by a well-designed monitoring program that evaluates, with an acceptable degree of certainty, whether habitat restoration has caused a significant improvement in water resource quality and the biological community of the water resource. Although the potential benefits of restoration are many, some are not quantifiable, and the efficacy of an ecological restoration technique in achieving water quality standards at a given site is difficult to predict a priori. Further, many restoration projects will depend in part on voluntary (nonenforceable) stakeholder participation. It is therefore essential to monitor for results and, if desired results are not obtain ed, re-evaluate and adjust the restoration effort, as needed.
As first steps, monitoring for a restoration project should specify (1) assessment endpoints for the restoration project, (2) measurement endpoints, and (3) methods used to extrapolate from measurement endpoints to assessment endpoints. Then, the data collection program can be designed. Finally, data are collected and evaluated to determine the success of the project. General suggestions for structuring the step are shown in Figure 4.7 (not available electronically).
Step 5.1: Identify Assessment and Measurement Endpoints
Assessment endpoints are ecological values to be restored such as quantity and quality of habitat and water quality standards (consisting of the beneficial designated use or uses of a water resource, numeric and narrative water quality criteria that are necessary to protect the use or uses of a particular water resource, and an antidegradation statement). They represent the final form of the restoration goals selected in Step 2. In many cases, these assessment endpoints are not readily quantifiable, so measurement endpoints, which are measurable responses that are related to the valued characteristics chosen as the assessment endpoints, should be selected (EPA 1992a). Measurement endpoints can be used to determine whether ecological values selected as assessment endpoints have been attained. In many cases, numeric water quality data will be emphasized as measurable indicators of the attainment of restoration goals. Table 4-1 summarizes information on assessment and measurement endpoints for ecological restoration.
A clear relationship between assessment and measurement endpoints is essential. Avoid assessment endpoints that are vague or cannot be quantified. The best assessment endpoints, such as those listed in Table 4-1, are those f or which there are well developed test methods, field measurements, and predictive models. Not all assessment endpoints meet these criteria, however. For example, if the assessment endpoint for an ecological restoration project is elimination of ambient toxicity to resident species, and the measurement endpoint is attainment of numeric water quality criteria, it is possible to attain all relevant numerical water quality criteria and still have ambient toxicity; conversely, it is possible to have exceedances of water quality criteria for toxic chemicals without ambient toxicity being present. As another example, if the assessment endpoint is restoration of biological integrity, it may be difficult to have both a reference condition and an index that can serve as an unambiguous, measurement endpoint.
Step 5.2: Design Data Collection Plan
Evaluation goals and standards for data accuracy should be specified a priori in data quality objectives (DQOs). High variability or uncertainty in results, however, often reduces the usefulness of field data, especially for ecological measurements. In designing data collection plans, the water quality manager is frequently forced to evaluate tradeoffs between an increase in uncertainty and the cost associated with reducing the uncertainty in the measured variables (Reckhow and Chapra 1983). Major components of uncertainty that can sometimes be controlled by a well specified survey design include variability, error, and bias:
- Variability can be caused by natural fluctuations in chemical and biological indicators over time and space;
- Error may be associated with inaccurate data acquisition, measurement errors, or errors in data reduction; and
- Bias occurs when samples are not representative of the population under review and frequently when samples are not randomly collected.
Sources of uncertainty should be evaluated prior to selecting a sampling design to minimize the effect of these factors on the decision-making process (Reckhow 1992). Good discussions of sampling designs applicable to ecological restoration projects are presented in Reckhow (1992) and Warren-Hicks et al. (1989).
Step 5.3: Collect and Evaluate Data
After the data collection plan is designed, data are collected and evaluated to determine whether desired benefits are being achieved. Data evaluation techniques depend on the design of the monitoring program and hypotheses to be evaluated (Step 5.2).
Evaluating data proceeds on two basic levels. First, evaluate whether the data collection plan is adequate to meet project DQOs and make necessary revisions (Step 5.2). When the data collection plan is judged to be adequate, analysis can proceed to the next level and inquire whether restoration goals are being achieved. If goals have not been achieved, the entire approach may need to be re-evaluated (indicated in the flow chart by a branch leading back to Step 2).
Step 5.4: Set Schedule for Continued Monitoring
If restoration appears to be proceeding successfully and is meeting specified goals and milestones, the project will often enter a phase of assessing of water quality standards attainment, for which a program for continued monitoring should be established . This program will typically differ from the initial monitoring program, which has the burden of proving that the restoration technique can work in a given setting. Continued monitoring is designed to ensure that progress is ongoing and backsliding doe s not occur. The continued monitoring of a restoration site can often be incorporated into a state's Watershed Protection Approach.