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. Watershed Academy

Using the Surface Water Toolbox for Estimating Critical Flow Statistics

February 8, 2018

Julie Kiang, Supervisory Hydrologist, U.S. Geological Survey
Brian Nickel, Environmental Engineer, Water Protection Division, Region 10, U.S. Environmental Protection Agency
Jenny Molloy, Lead Environmental Protection Specialist, Water Permits Division, U.S. Environmental Protection Agency
 

A new Surface Water Toolbox was developed by the U.S. Geological Survey and the U.S. Environmental Protection Agency. The Surface Water Toolbox is a user friendly, downloadable tool for water managers to estimate a wide variety of streamflow statistics. This tool can be downloaded from https://water.usgs.gov/osw/swtoolbox/ and enables users to:

• Estimate critical flow statistics such as 7Q10 for gaged and un-gaged streams;

• Use a variety of statistic tests to evaluate emerging trends and identify anomalies.

Presentation Slides (pdf)

Watershed Academy

  • Watershed Academy Home
  • Learning Modules
  • Webinar Archives
  • Kid's Corner
  • Watershed Resources
Contact Us About the Watershed Academy
Contact Us About the Watershed Academy to ask a question, provide feedback, or report a problem.
Last updated on May 7, 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.