Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. Healthy Watersheds Protection
  3. Integrated Assessment of Healthy Watersheds

Developing a Watershed Health Index: Introduction

The foundation of a healthy watersheds assessment is compilation of ecological information that is measurable, comparable and consistent across the area of the assessment, and relevant to summarizing the primary attributes of a watershed’s condition. Watershed indicators are first selected, based on the six essential ecological attributes fundamental to the healthy watersheds assessment approach:

  • Landscape Condition
  • Habitat
  • Hydrology
  • Geomorphology
  • Water Quality
  • Biological Condition

A sub-index for each of the six attributes is developed from these indicators. Sub-index values for each watershed are then aggregated up into a single Watershed Health Index value for each watershed.

All sub-index and index values are relative (i.e., "healthier" or "less healthy" as compared to the group of watersheds being assessed). These values are not absolute (i.e., no cutoff value for health is identified). Index and sub-index values are meant for comparing relative differences among watersheds rather than precisely defining healthy vs. unhealthy watersheds.
 

See examples of integrated assessments.

Healthy Watersheds Protection

  • EPA's Healthy Watersheds Program
    • What EPA Is Doing for Healthy Watersheds
    • Technical Elements
    • Learning Exchanges
    • Healthy Watersheds Listserv
    • Program Reports & Publications
  • Information About Healthy Watersheds
    • Basic Information and FAQs
    • Benefits of Healthy Watersheds
    • Land Conservation and Watershed Protection
    • Watershed Protection Projects by State and Region
  • Integrated Assessment of Healthy Watersheds
    • Integrated Assessment of Healthy Watersheds
    • Developing a Watershed Health Index
    • Developing a Watershed Vulnerability Index
    • Preliminary Healthy Watersheds Assessment
Contact Us About Healthy Watersheds Protection
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on June 2, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions
  • Site Feedback

Follow.