EPA released a draft report February 28, 2011, prepared by the National Center for Environmental Assessment within the agency’s Office of Research and Development, for public comment through April 14, 2011. 76 Fed. Reg. 10,892 (2/28/11). The draft report investigates the issues and challenges associated with identifying, calculating and mapping indicators of the relative vulnerability of water quality and aquatic ecosystems in the United States to the potential adverse impacts of long-term climate and land use change.

In preparing the draft report, the center gathered a set of more than 600 indicators of water quality and aquatic ecosystem conditions, along with data-sets from EPA, other federal agencies and organizations to use as a test model for identifying challenges and best practices for calculating the vulnerability of watersheds nationwide. Specific stressors to watersheds addressed in the draft report include (i) pollution, (ii) introduction of alien species, (iii) blocked migration routes, and (iv) fragmentation of habitats due to human development. The report and its appendices may be downloaded at http://www.epa.gov/ncea.