Impact/Purpose:

This research project sets out to design and conduct an assessment of the long-term ecological consequences of alternative watershed management choices. As the first project to be done at this scale using predictive ecological endpoints, we will seek to identify the appropriate components of such an analysis. We will use experience gained in the conduct of this analysis to identify key research and data needs for future analyses. We will extend this analysis beyond previous and ongoing studies in two ways: by incorporating biological endpoints, primarily properties of fish communities, and by introducing the concept of sustainability of ecological state under future scenarios contrasted with the present state of those same ecological resources. Requirements that are identified during the course of this study will permit the recommendation of specific capabilities that should be incorporated in a general modeling system currently under development to support environmental assessments. Finally, the analysis is intended to be of value for establishing environmental management choices that will be beneficial and those that would be detrimental to the sustainability of ecological resources. Specific objectives are listed below:

1. Develop watershed-based modeling systems to forecast the effectiveness of alternative management plans in meeting sediment-related, nutrient-related, pathogen-related, and toxics-related criteria and standards, and biologically-based criteria and standards; and

2. Develop and maintain a comprehensive technical support capability that directly links environmental TMDL exposure research activities and products for the EPA Office of Water, EPA Regional Offices, and the States to be used for implementation of policy, regulatory development, remediation, and enforcement needs.

Description:

To effectively manage watersheds, the assessment of watershed ecological response to physicochemical stressors such as nutrients, sediments, pathogens, and toxics over broad spatial and temporal scales is needed. Assessments at this level of complexity requires the development of multi-media, multi-stressor, and multi-pathway modeling systems. Such modeling systems will enable the evaluation of alternative management options and the identification of acceptable management choices that will ensure the sustainability of specific, selected ecosystems. The goal of this ERD research program is to develop watershed-based modeling systems to forecast the effectiveness of alternative management plans in meeting sediment-related, nutrient-related, pathogen-related, and toxics-related criteria and standards, and biologically-based criteria and standards. The approach consists of characterizing landscape hydrologic and subsurface inputs to surface water; simulating instream hydrodynamic and water quality conditions; forecasting aquatic ecosystem responses to watershed inputs, in particular fish population and communities; and integrating modeling systems across media, stressors, and pathways. Through this work we will develop and maintain a comprehensive technical support capability that directly links environmental TMDL exposure research activities and products for the EPA Office of Water, EPA Regional Offices, and the States. This work will also support ongoing activities as part of the National Science and Technology Council's Integrated Science for Ecological Challenges (ISEC), a cross-agency initiative aimed at improving scientific understanding of ecosystem responses to various stresses. ISEC-related activities will focus on assessment at the regional scale through the development of exposure models that combine stressor distributions with ecological resource distributions.

Record Details:

Record Type:PROJECT

Start Date:10/01/2001

Completion Date:09/30/2002

OMB Category:Other

Record ID: 56087

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Project Information:

Progress :Most of the models required for the analysis exist in a relatively mature state. A contract task to obtain data to be used for initializing the models, provide boundary conditions, and to parameterize the models was initiated in FY 2001. A preliminary fish response model, including hydrology and suspended sediments has been tested on a set of data at the watershed scale (Contentnea Creek, North Carolina). A basin-scale assessment of the impacts of anthropogenic stress on fish communities also has been completed. A cooperative agreement with a STAR grant recipient has been established to provide future scenarios of population and landuse characteristics (e.g. impervious surfaces).

To date, the following APMs have been delivered:

2000: APM 599 Key -- Peer-reviewed draft TMDL implementation protocol/prototype approach for estimating loadings of sediments to be used by OW regions and states in implementation of CWA ?303. (Carousel)

2000: APM 643 Reporting -- A research brief on simulation plan for modeling of nitrogen for Lower Mississippi River Basin to be used by the national and international scientific community and by EPA program offices. (Carousel)

2001: APM 125 Reporting -- Complete Total Maximum Daily Load (TMDL) modeling application and sampling procedures for sediments in streams. (Hayter)

2001: APM 126 Reporting -- Complete the joint selection by the Office of Water and the Office of Research and Development of Total Maximum Daily Load (TMDL) models to be recommended for use for nutrients, toxic organic chemicals, toxic metals, pathogens, and carbon (oxygen-demanding materials) in streams, rivers, lakes, and estuaries.

(Carousel)

Relevance :In evaluating both current and envisioned ecosystem assessment needs it is clear that the watershed, due primarily to its containment of the hydrologic cycle, is the fundamental unit of analysis. Thus, this task addresses watershed-based ecosystem science and technology development with the additional objective of merging those constructs with site-scale assessments in the interest of providing continuity among regulatory assessment tools for various purposes both within and outside the Agency. The Agency does not now have available predictive tools for evaluating watershed management options dealing with multimedia, multi-stressor environmental insults over multiple spatial scales. Such technology systems would provide a sound scientific basis for under-pinning a variety of pending regulatory decisions in the management of ecosystems, watersheds, and surface waters. This research is intended to produce methodologies to aid regulatory decisions in all these areas using a unified approach that integrates advances on each specific regulatory front by bringing the latest advancements in the underlying science together in a modeling system.

This work will significantly contribute to the development of TMDLs. This program will directly support the mandates under the Clean Water Act, Section 303(d) to carry out the increasingly complex array of exposure and risk assessments necessary in developing scientifically defensible regulations for TMDLs. Additionally, the inclusion of ecological endpoints in this project is significant. In the past regulations that have been implemented to protect ecological resources have done so with implicit connection to the natural communities of organisms. This analysis begins to make this connection explicit. This research will contribute to improved methods for watershed ecological risk assessment and to the management of watersheds for long-term sustainability.

Clients :Office of Water, Regions

Project IDs:

ID Code :12551

Project type :OMIS