Science Inventory

Healthy Watersheds Integrated Assessments Workshop Synthesis


U.S. EPA. Healthy Watersheds Integrated Assessments Workshop Synthesis . U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/207, 2011.


The Healthy Watershed Integrated Assessment Workshop was a coordinated effort between ORD and OW, with input from across ORD, OWOW, EPA Regions and States. The goal of the workshop was to assess and advance the state of the science of healthy watershed integrated assessments in support of EPA’s Healthy Watersheds Initiative. EPA’s Healthy Watershed Initiative strengthens the application of the anti-degradation clauses of the Clean Water Act. The workshop included presentations and discussions of the Healthy Watersheds Initiative, current state healthy watershed assessment approaches, watershed resilience, a conceptual model for healthy watersheds, implementation issues, and applications of healthy watershed assessments at the local to national scales. Following the workshop, a subset of workshop participants worked together to further refine the ideas discussed during the workshop to produce a synthesis report. Workshop outputs are being used to inform the Healthy Watersheds Initiative and will be posted on the OWOW Healthy Watershed Initiative website.


The U.S. Environmental Protection Agency, in partnership with others, is embarking on the new Healthy Watersheds Initiative to protect our remaining healthy watersheds, prevent them from becoming impaired, and accelerate our restoration successes. In November 2010, a Healthy Watersheds Integrated Assessments Workshop brought together technical experts and practitioners to advance the state-of-the-science on integrated healthy watersheds assessments and to consider the role of green infrastructure (i.e., networks of natural land cover) in maintaining watershed health and resilience. The focus of the workshop was on the technical matters of conducting, and the state-of-the-science supporting, healthy watershed assessments, and not on the policy issue of the approach for watershed assessment appropriate for environmental decision making. This document synthesizes, and builds on, the ideas discussed at the Workshop. It represents the ideas and views of the contributors, and should be considered as a starting point for further exploration. This document is not EPA policy nor is it EPA guidance; rather it reflects the further development of ideas by some of the workshop participants. Watershed function and aquatic ecological integrity are dependent on the interaction of multiple processes and conditions across many spatial and temporal scales. Organizing these multiple processes and conditions into a coherent set of relationships is necessary to better understand the functions that support a healthy watershed, and to guide management actions that sustain ecological integrity of aquatic ecosystems. “Health” can be viewed as a relative measure of the deviation from some “natural” or baseline condition, and it is usually measured by some static indicator(s), such as an index of biological integrity or landscape condition (e.g., connectivity). However, it is the underlying watershed process regimes that generate the necessary dynamic conditions that maintain ecological integrity, so a measure of “health” would more appropriately be based on the extent to which watershed process regimes are modified relative to the baseline, or their natural ranges of variation. Key to protecting healthy watersheds is understanding how particular conditions and process regimes within a watershed should be managed to maintain the ecosystem in some desired state within the natural range of variation. When disturbances, changes, and shocks occur within a watershed, processes may be pushed outside of their natural range of variability. In such cases, the system may recover because its adaptive capacity has not been exceeded, or it could pass a threshold and change into another ecosystem state. Increasing a system’s resilience to pressures includes ensuring that watersheds retain their adaptive attributes such as meander belts, riparian wetlands, floodplains, terraces, and material contribution areas. For example, a disturbance may lead to temporary changes in the timing, volume, or duration of flow that are outside the natural range of variability; but within a resilient watershed, these perturbations will not cause a permanent state change because riparian areas and floodplains help to absorb some of the disturbance. With an understanding of the hierarchical organization of the drivers, processes, and functions of aquatic ecosystems, the appropriate framework for an assessment can be developed. A “tiered approach” is one potential strategy for conducting an integrated watershed assessment that allows users to address the range of management actions for a watershed within the limitations of available time and budget. A truly integrated assessment will include an assessment at the broad or watershed scale since it informs analysis at the subsequent finer scales. A watershed scale assessment can provide information on key processes, stressors, and conditions within the landscape based on broad geographic information and land use patterns. However, a broad scale analysis is limited primarily to issues addressing planning level decisions that deal with land use patterns (e.g., zoning, designations, and policies) and water use as it affects hydroecological requirements (e.g., instream flow, ground water input, lake levels, hydrologic connectivity). Finer scale assessments (i.e., waterbody and local scale) are performed within the context of the watershed scale and can address issues regarding reach and site scale processes, and specific protection and restoration designs. Tiered assessments create efficiency by using existing data for an initial screening. A healthy watershed classification system based on large-scale remote sensing data may then identify where finer scale, more intensive assessments should be prioritized. It may also reveal those development patterns that are most protective of watershed processes and functions, and avoid costly environmental issues such as flooding, ground water contamination, and low flow concerns that cannot be readily resolved with site level actions. Smaller-scale assessments may be used to classify and map specific areas that are important to protecting watershed processes and resiliency, and at the same time identify specific stressors that may threaten or impede the recovery of healthy watershed functions. As tiers of assessment are completed, and results are shared with the public, care must be taken to explain what the data may or may not be telling us. To ensure the appropriate application of assessment results, data has to be accessible in a manner that is appropriate to the user’s goals, objectives, and decision process. Without clear written and visual explanations of the basis and need for strategic and prioritized watershed actions, public support will not be easily achieved. A process-oriented approach of protecting the ecological processes that naturally create and maintain habitats will enhance the traditional site-specific and stream reach surface water quality approach. Further, the protection of ecological processes will benefit from a broader landscape approach of not only maintaining stream buffers, but integrating watershed components such as meander belts, lake shores, riparian wetlands, and floodplains into protection programs. All of this will require aquatic resource managers to work at larger scales with a whole new set of partners concerned with land use planning and management. Land and water protection through non-regulatory and regulatory programs, conducted at all levels of government in partnership with nongovernmental organizations and landowners, is central to implementing the Healthy Watersheds Initiative. However, protection and restoration are often part of an integrated approach, as many states consider opportunities to protect healthy watersheds and restore impaired watersheds with a high recovery potential. A process-based approach that considers watershed resiliency and sustainability is important for restoration success. In addition to restoring natural flows, this could mean adding green infrastructure, removing constraints (e.g., dams), or working to ensure that land-water ecosystems remain dynamically connected. To restore and protect dynamic processes, planning should bring together different interest groups and provide opportunities and incentives to bundle “project” components and achieve a net ecological benefit. Regulatory, technical assistance, and funding program managers should strive to integrate land conservation; wetland, riparian, and floodplain protection and restoration; urban stormwater and agricultural best management practices; channel and shoreline management; and instream ecological flow protection and restoration. Protecting healthy watersheds is cost-effective in the long run. The goal of the Clean Water Act is to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters. Historically, greater emphasis has been placed on the restoration element of the goal. A shift in emphasis from restoration alone, to more of a balance between “avoidance” or maintenance of the integrity of the Nation’s waters and restoration, at all levels of government, would better achieve the integrity goal of the Clean Water Act. Much can be done at very little cost, especially with support and coordination from regional entities and federal agencies. Local and state Healthy Watersheds initiatives can get off to a fast and efficient start by learning from the successes and failures of one another. EPA and other federal agencies should consider working together to emphasize integrated assessments and Healthy Watersheds protection in their research and grant programs, and support a web-based clearinghouse where states are encouraged to post their accomplishments and success stories. A number of research gaps and data needs relevant to Healthy Watersheds have been identified as priorities. In order to increase protection of healthy waters, the following research priorities have been identified: 1) Evaluate core metrics and methods for measurements of healthy watersheds; 2) Conduct cost-benefit analyses to explore the long-term net benefit of protecting healthy watersheds, green infrastructure, and processes sustaining healthy watersheds; 3) Identify characteristics of aquatic ecosystems and their surrounding watersheds that make them resilient to changing land use and climate for use in predictive models; 4) Understand interdependence of existing and proposed stratification frameworks; 5) Develop regional models to predict natural and altered flow, ground water, and thermal regimes; 6) Develop efficient and cost-effective methods for assessing status and trends in geomorphology and material transport; and 7) Explore consistency of assessment results across endpoints and spatial and temporal scales. In order to enhance watershed resiliency, the following significant gaps in out scientific knowledge have been identified: 1) Understand responses of aquatic systems to the effects of climate change; 2) Identify the indicators and develop the sampling schemes needed to monitor and detect changes in condition or drift in reference sites due to climate change; and (again) 3) Identify characteristics of aquatic ecosystems and their surrounding watersheds that make them resilient to changing land use and climate for use in the design of predictive models. Finally, recommendations for improving restoration of degraded waters include: 1) Enhance existing monitoring approaches to include representative systems for Healthy Watersheds evaluation and adaptive management; 2) Use Healthy Watersheds principles when coordinating protection and restoration across multiple scales; and 3) Promote the establishment of partnerships to explore the socioeconomic conditions that favor healthy watershed protection.


ND HWI SYN 11_16_2011.PDF   (PDF,NA pp, 4345 KB,  about PDF)


Record Details:

Product Published Date: 02/24/2012
Record Last Revised: 04/09/2012
OMB Category: Other
Record ID: 239843