Jump to main content or area navigation.

Contact Us


Basic Information

Overview of WARSSS components

What are sedimentation problems?
High erosion and destabilized streambanks commonly release excess sediment, causing turbid water and silt deposits that can harm aquatic life and reduce recreational uses of our waters. Excess sediment impairments are among the most common river and stream water quality problems reported by state monitoring programs. Assessing sedimentation problems is difficult and tools are limited.

What is WARSSS?
Watershed Assessment of River Stability and Sediment Supply (WARSSS) is a three-phase technical framework of methods for assessing suspended and bedload sediment in rivers and streams. WARSSS is a watershed approach to sediment assessment that focuses on

  • natural variability in sediment dynamics
  • geologic versus anthropogenic sediment sources
  • erosional and depositional processes
  • prediction of sediment loads
  • streamflow changes, and
  • stream channel stability and departure from reference condition.

Why was WARSSS developed?
The U.S. Environmental Protection Agency supported the development of WARSSS by Dr. David L. Rosgen because there is limited guidance on assessing sediment impairments. WARSSS can be used to analyze known or suspected sediment problems, develop sediment remediation and management components of watershed plans, develop sediment TMDLs (Total Maximum Daily Loads), and other uses. This web-based assessment tool was designed for scientists who need to assess sediment-impaired waters in planning for their restoration.

About PDF Files...
Many of the documents listed on this site are PDF files. Viewing a PDF file requires use of Adobe's free Acrobat Reader software.  *EPA's PDF page  provides information on downloading the software.

How can users begin WARSSS?
The simplified flowchart (PDF, 19 kb, 1p.) illustrates the major components of the WARSSS assessment framework. The detailed flowchart (PDF, 47 kb, 1p.) allows closer study of the steps involved in each assessment phase. Readers may review the fundamentals of river hydrology and sediment dynamics at Introduction to Sediment and River Stability or proceed directly to Using WARSSS.

Jump to main content.