A Process for Setting, Managing, and Monitoring Environmental Windows for Dredging Projects: Special Report 262 (2002)

The template for a process for setting, managing, and monitoring environmental windows shown in Box 3-1 was developed through focused discussions that occurred before, during, and after the workshop (see Figure 3-1 for a graphical depiction of the process). The process itself is simple, but its successful execution is more difficult, demanding sustained commitment by all parties concerned. Although any decision to dredge should be based on clearly established need, the proposed process is designed to pertain only to those federal projects that have been preapproved and for which funds have been appropriated. The starting point for this process is not whether to dredge but how and when to dredge.

The proposed methodology works most effectively if it is recognized by all participants as an iterative process allowing for the resolution of environmental windows and related issues that require decisions based on the best available scientific and technological information. It is not the aim of the proposed process to modify the legal basis by which the various agencies (both lead and trustee) participate in shaping dredging projects. Nor does the committee intend to force all projects into a “one-size-fits-all” approach. For example, when threatened and endangered species are involved, the process may need to be applied to a larger area than is typically associated with a single dredging project to avoid cumulative impacts. The committee also believes the proposed process can be applied (after being appropriately adapted to local circumstances) to all major federal dredging projects. Details on each step in the process are provided below. The committee recommends that all

of delineating a “region” must be based on locally acceptable definitions. For example, many areas have existing groups that actively assess environmental issues, such as groups addressing watershed issues, participating on regional dredging teams, or working on a particular estuary’s comprehensive conservation and management plan. These existing groups should help define “regional” and facilitate the rapid identification of regional stakeholder participants. They should be encouraged to evaluate their current membership in selecting the team of core stakeholders and to expand the team as necessary to encompass all relevant groups and individuals and areas of expertise.

Once the Stakeholder Group has been identified, the first action needed is to secure the commitment of all parties to the windows-setting process, including a declaration to provide staff and monetary support as necessary to complete the process on an agreed-on schedule. Senior representatives of each agency or organization must make this commitment. A public statement of policy and support from senior officials will drive the process forward; thereafter, a person with decision-making authority should be obligated to abide by this commitment. It should be noted that participation in the process by government agencies does not imply an abrogation of responsibilities or legal rights under governing laws or regulations.

The stakeholders are convened. The following tasks should be completed during the first meeting or shortly thereafter.

USACE and the local project sponsor should convene the stakeholders identified in Step 1 to accomplish the tasks described below. USACE and the resource agencies should assemble pertinent background material for the stakeholders’ review prior to the first meeting.

Agree on the time period for the evaluation.

A commitment to a set time period for the systematic review and resolution of salient issues is necessary. Once the Stakeholder Group has selected a specific time period, the process that follows will be based on the best available information that can be assembled and considered within that time frame.

Define the specific geographic area(s) of interest or concern within a region.

The specific geographic area or areas of interest or concern within a region should be identified and agreed on. All anticipated federal dredging projects within the region should be enumerated. Ultimately, the areas of interest or concern should be defined by the interests of the Stakeholder Group.

Identify and rank the resources of concern.

The specific resources of concern should be identified, categorized (e.g., listed species), and prioritized according to the consensus of the Stakeholder Group. The prioritization will be subjective and dependent on the collective judgment of the stakeholders.

Conduct a systematic evaluation of proposed dredging projects, as well as existing and potential window applications, and rank the projects in terms of such factors as economic importance and sensitivity to timing.

The Stakeholder Group should conduct a systematic evaluation of projects, existing windows, and potential window applications. The group should categorize the projects in terms of whether significant environmental issues are involved, for example, whether endangered species are migrating through the area or there is a heightened level of uncertainty associated with the project. Factors other than environmental considerations should also be evaluated and prioritized; examples include the economic importance of the project, contractor constraints, the frequency of vessel operations, and navigational safety. This step is important because not all projects will require the group’s attention; a simple sorting of the projects at the beginning of the process will help focus the group’s time and energy. It should be noted that the ranking and prioritization process conducted in this step refers to the application of environmental windows. The process should not be used to prioritize or rank dredging projects. As noted earlier, the template is designed for federal projects that have been preapproved and for which funds have been appropriated.

Form a Science Team whose expertise will make it possible to identify and evaluate the threats to the resources of concern. Select or elect a chairperson. Prepare a charge to the team outlining its assignment, deliverables, and timetable.

The scientists selected for the Science Team should represent the salient federal and state agencies, the relevant port authority, nongovernmental organizations, and academic institutions. Scientific expertise and reputation should be the essential criteria for selection to maintain the confidence of the stakeholders and the integrity of the process. The chair of the Engineering Team should serve as a liaison and adviser to the Science Team.

Form an Engineering Team, including contractors and USACE personnel whose expertise will allow them to identify the most appropriate technological options (i.e., equipment, management controls, or operational procedures) for conducting dredging and disposal activities to meet the resource goals specified by the Science Team and to assess the costs associated with the options identified. Select or elect a chairperson. Prepare a charge to the team outlining its assignment, deliverables, and timetable.

The engineers selected for the Engineering Team should represent the salient federal and state agencies, academic institutions, and dredging contractors, as appropriate. Engineering expertise and reputation should be the essential criteria for selection to maintain the confidence of the stakeholders and the integrity of the process. The chair of the Science Team should serve as a liaison and adviser to the Engineering Team.

The Science and Engineering Teams conduct biological and engineering evaluations of the proposed dredging projects. All potential adverse impacts, along with the biological resources of concern, should be identified. Close coordination between the two teams should be sought, and overlap should be created by having the chairperson of each team serve as an adviser to the other team.

The Science Team identifies biological resources predicted to be adversely affected by each dredging project and provides this information to the Engineering Team.

The Science Team will receive the Stakeholder Group’s recommendations and translate them into scientific questions. The team should first conduct an initial screening to determine the specific life-history stages or habitat areas of concern relative to the expected dredging operations. A general assessment of the species’

vulnerability to various dredging stressors, along with the cumulative impacts, should be calculated. A matrix approach might be used to summarize this initial screening and to focus subsequent efforts. This information should be provided to the Engineering Team.

The Science Team documents the temporal variability of the species in the area and the vulnerable habitats. The Science Team also identifies the acceptable levels of impact (e.g., “takes”) and the specific stressors responsible for the impacts and provides this information to the Engineering Team.

The Science Team should identify all relevant studies and data that can assist in evaluating temporal variations in the vulnerability of particular species and habitat attributes to different stressors, and use this information to identify the specific stressors of concern. This information should be provided to the Engineering Team. Stressors should be defined by type [e.g., total suspended solids (TSS), noise], zone in the water column (e.g., lower water column, surface), magnitude (e.g., critical levels of TSS above which species are affected), and temporal and spatial extents of concern (e.g., how long TSS above the critical level can be tolerated, or how close the resource is to the source of stress). To the degree possible, this evaluation should take into account the cumulative effects of dredging-related stressors and other factors—including fishing, cooling-water intakes, and other dredging projects that can affect the same population—on the resources of concern.¹ Input from the chair of the Engineering Team will be important for ascertaining the current state of knowledge about particular parameters, such as actual levels of TSS around different types of equipment or anticipated noise levels. If time and resources are available within the context of the process, new investigations or summaries might be initiated to fill and identify data gaps. It is also expected that as new information is gleaned (e.g., from monitoring activities), it will be incorporated routinely into the existing body of knowledge.

The Engineering Team, using information from the Science Team on the stressors involved, recommends strategies for reducing the stressors to acceptable levels (e.g., technology, contracting, operational methods, equipment selection). The Engineering Team provides cost estimates for these strategies. The results of the Engineering Team review are provided to the Science Team.

The Engineering Team, with the assistance of the Science Team chair, should review the information on dredging stressors and environmental impacts provided by the Science Team, and recommend the most appropriate mitigating technologies and operational controls for dredging and placement.

For this step to succeed, the potential stressors must be specified and the levels of concern quantified by the Science Team. Technological control methods should then be recommended for achieving the stated objectives relative to zone (e.g., water column, pelagic, benthos) and type of stressor (e.g., suspended solids, entrainment). It must be recognized that the range of feasible technologies may be limited and that technological solutions will probably be only partial ones. The objective is to achieve the most effective dredging operation while meeting the environmental criteria provided by the Science Team. The success of the template will depend on the interaction of the Science and Engineering Teams. The process might work as follows:

• Scientists define the target levels for stressors (e.g., levels of take by entrainment, maximum TSS).

• Engineers choose appropriate technology to meet the targets using a matrix approach.² Key components of the matrix include impact media, impact character, and equipment control methods.

• Monitoring is used to refine the matrix, as needed.

The Science Team reviews the information developed by the Engineering Team and notes any resulting changes in the expected impacts.

The Engineering Team should provide to the Science Team information regarding improvements or changes in operational approaches to the dredging

project that could reduce the stressors involved below critical levels, as well as any impact these changes might have on the duration of the dredging and disposal activities. The Science Team should consider these modifications in relation to (a) the degree of certainty relative to the threshold levels for each stressor, (b) the extent to which the suggested changes reduce the spatial and temporal extent of the dredging impacts, and (c) whether the changes in approach introduce any new stressors or are likely to result in any indirect effects on the resource that were not considered in the evaluation in b. For instance, a particular technological approach may reduce the level of TSS below that believed to cause acute stress to the species and habitat of concern, and as a result the project may take longer to complete. This may in turn increase the time period when the TSS level exceeds that for chronic impacts as compared with the impact of the original project, or only reduce suspended sediment concentrations (SSCs) below the upper limit of the range of TSS expected to harm the resource. The technique used to minimize SSCs might also involve physical measures (e.g., silt screens) that may be thought to cause some other stress to the resource by, for instance, further limiting access of migrating species through a constrained channel.

Such considerations should be used by the Science Team to weigh the potential advantages of the recommended technological changes against the risk to the resource posed by the project with and without the changes. The Science Team should provide a clear evaluation of the potential risk to the resource of concern under both of the latter scenarios.

The Science Team recommends acceptable dredging periods, that is, environmental windows.

On the basis of its findings in earlier stages of the process, the Science Team should determine the temporal constraints that need to be imposed on dredging activities to protect resources of concern from likely substantial adverse impacts. The environmental windows thus identified will be those periods when dredging and disposal operations can take place without unacceptable impacts on species and habitats and other resources of concern. These windows should be assessed for both technological scenarios considered in the previous step (i.e., with and without technological changes in approach) to identify clearly the changes in window length and timing associated with the implementation of different technological approaches.

In addition, the Science Team should specify the criteria to be used to set the windows. In some cases, windows will be delimited by specific dates (e.g.,

to avoid cropping of anadromous fish eggs and larvae). In other instances, a window may be closed (e.g., based on a documented take of a threatened and endangered species) or triggered (opened, extended, or closed) by physical environmental variables such as water temperature or determination of species activity (e.g., the presence or absence of a species of concern at certain levels of abundance). In cases in which real-time environmental or resource observations are to be used to open or close windows, the Science Team will have to specify the monitoring protocols and data standards to be used to support the decision to open or close a window.

If temporal constraints on dredging activities are not considered necessary to protect the species or habitats of concern, the Science Team should provide a clear recommendation for the window to remain open year round. The Science Team may provide a justification for this recommendation in the same manner used to justify recommendations for specific windows.

Should sufficient information for assessing the effect of dredging activities on local populations or habitats be unavailable, the Science Team should use available studies and information for other systems, together with data concerning the physical environment of the local system, to assess the potential impact of dredging activities on species and habitats of concern (Step B). Because of the uncertainties associated with such inferences, it is unlikely that the Science Team will be able to specify potential conditions and stressors in sufficient detail for review by the Engineering Team. In these cases, the Science Team should recommend windows on the basis of the information for other systems, considering any differences in local conditions that may limit the utility of this information, and state explicitly where the greatest areas of uncertainty lie. The rationale for such recommendations should be summarized and explained to the Stakeholder Group.

A formal consultation under Section 7 of the Endangered Species Act is conducted if listed species may be adversely affected.

A dredging project that has the potential to affect species listed as threatened or endangered under the Endangered Species Act of 1973 (16 U.S.C. 1531 et seq.) may be the subject of an informal consultation during the earliest stages of planning and scientific review. During this phase of the project, the goal of the informal consultation is to identify whether listed or proposed species and critical habitats are in the project area and if so, to eliminate or mitigate the potential impact by modifying the timing, method, or scope of the project in such a manner as to avoid the need for a formal consultation. During this informal process, input

from all sources (e.g., existing data and literature, observers) can be used to positively confirm species in the area, ensure that there is a complete understanding of the potential impacts to these species, and identify the best tools for eliminating or reducing impacts to the maximum extent possible. Once it has been determined that unavoidable adverse effects are likely, a formal consultation is required to determine whether the proposed action is likely to jeopardize the continued existence of the species of concern or result in destruction or adverse modification of critical habitats. During this formal consultation, the information resulting from the informal consultation is useful in developing the Biological Assessment (required for major construction activities) and the Biological Opinion. The Endangered Species Consultation Handbook (published jointly by the National Marine Fisheries Service and the U.S. Fish and Wildlife Service) may be useful to participants not fully familiar with the consultation process.

The Science Team prioritizes the recommendations for windows and provides this information to the Stakeholder Group in areas where multiple windows for varying species are recommended.

It is likely that more than one species’ life-history stage or habitat will be considered by the Science and Engineering Teams using the above process for any given project reach. The result may be restrictions on dredging or technological approaches that effectively limit the sponsor’s capability to complete the project in a cost-effective manner. Thus when the Science Team recommends for multiple resources individual windows that are not concurrent, it should provide an assessment of the relative importance of implementing those restrictions based on the suite of affected resources within the project reach. The Science Team should consider (a) the vulnerability of the population to the expected impact; (b) the degree of protection provided by restricting dredging and disposal activities to the window; (c) the level of uncertainty associated with both of these factors; (d) the cumulative effect of dredging and disposal activities in this reach and other factors affecting the resource of concern, including fishing, cooling-water intakes, and other dredging projects that affect the same population; and (e) the diversity of resources protected by any given window. The team should base its assessment on available data concerning the resource in the particular reach, information from other areas, and its members’ best professional judgment in the absence of data. The Science Team should provide the Stakeholder Group with a prioritized list of windows, along with a supporting rationale that reflects the relative utility of the various windows in protecting resources of interest to local communities, regions, and the nation.

The Stakeholder Group reviews the alternative strategies— including windows—identified by the Science and Engineering Teams and endorses a plan of action.

This is the most difficult step in the process; it is also the most critical. The conclusions of the scientific and technical experts must be explained to the stakeholders and affirmed or supported by the decision makers. Briefing the Stakeholder Group will be the last formal action of the Science and Engineering Teams. Stakeholders will then have an opportunity to discuss the scientific conclusions presented, as well as economic and societal considerations, such as the consequences of choosing a particular environmental window for the recreational use of the area or the overall economics of the dredging project. The final product from the Stakeholder Group should be a consensus recommendation for the implementation of environmental windows. During Step 1 of the process, the Stakeholder Group should have selected two or three structured decision-making tools to evaluate; the most appropriate of these tools should be selected.

Actual implementation of the consensus recommendations will occur through applicable regulatory and interagency review processes (e.g., National Environmental Policy Act, Coastal Zone Management Act, 401 certification, Essential Fish Habitat consultation). Agencies involved in these processes should integrate the work of the scientists and stakeholders into their assessment of proposed projects. There should be no surprises; if there are, it may mean a key player was not at the table, or his or her participation in the process was compromised in some manner.

A final task of the Stakeholder Group is to determine how each member should be informed of unexpected developments that may result should a departure from the agreed-on recommendations occur. Again, there should be no surprises or post-consensus side agreements, as these would erode the trust and open communication needed to make the process successful on a sustained basis. An ad hoc committee may be useful for resolving disputes and revising the recommendations.

The recommended plan is implemented.

Dredging projects are now performed. The work should include monitoring intended to (a) test the assumptions on which the windows were based, (b) test

the expected performance of the dredging option selected, and (c) provide basic information for better discussions in the future.

The Stakeholder Group reviews the season’s dredging activities to evaluate monitoring data and to identify changes that can be incorporated to refine future dredging and disposal activities.

It is imperative for the efficacy of the process that follow-up reviews of both the implementation of the recommendations and the specific environmental windows be conducted. The validity of key assumptions and expectations will have a bearing on how they feed into the next iteration of the process. The final step should be scheduling of the next iteration, which is essential to maintain continuity.

The process that has been presented in this chapter is based on adaptive management. In other words, as new information is acquired and experience is gained, it is fed back into the process. Each project should be viewed as a tool for improving the process. Successful stakeholder processes place responsibility on the participants for demonstrating leadership in effecting such improvements.