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freshwater monitoring

Freshwater Monitoring

Washington Master Sample

The sampling design described on page 12 of the Quality Assurance Monitoring Plan makes use of a common set of random sites. These sites can be used for comparable, complementary monitoring among separate monitoring organizations and across geographic scales. The Plan’s master site list (387,237 points) is available at Ecology's GIS Internet page. The list was generated with help from the U.S. EPA, Corvallis, Oregon, who used a Generalized Random Tessellation Stratified (GRTS) survey design for linear resources.

For all surveys, users should evaluate the list in order of SITEID. Each site should be evaluated to determine its size class and its target class before moving up the list. Stop when enough sites are available to satisfy your study objectives. Be sure to check around to see if others are monitoring with the same site list for your region of interest (e.g. WRIA) . You may be able to save expenses by sharing data and not repeating efforts. In order to determine the site weight (length of stream that it represents in the survey) map lengths will need to be measured for each stream subpopulation (e.g. size class within a region).  This is based on EPA's master sample design description (PDF). 


If you have questions, please contact Glenn Merritt, (360) 407-6777,


Watershed Health Data