Oregon's Source Water Assessment Results and Maps

Maps of the groundwater and surface water drinking water source areas and potential contaminant sources identified within those drinking water source areas are available as GIS data layers and in a print-ready format. Due to security reasons, the agencies are restricting access to the GIS layers with latitude/longitude readings of wells, springs and intakes. Maps and assessment results can be downloaded here or are available on the Oregon Geospatial Enterprise Office's data clearinghouse web site under Drinking Water. If you do not find what you are looking for or would like individual maps, data layers or data queries at a local or regional scale, please contact DEQ's GIS Specialist at 503-229-6883 or by email.

• Memo on available data
• Instructions on how to view source water areas using DEQ's Facility Profiler
• Maps:
  • Surface Water Drinking Water Source Areas in Oregon (Updated: Nov. 28, 2012)
    Download: [PDF] [GIS Layers ZIP 2.1 MB]
  • Groundwater Drinking Water Source Areas in Oregon (Updated: Nov. 28, 2012)
    Download: [PDF] [GIS Layers ZIP 22 MB]
  • Potential Contaminant Sources (as of Oct. 2005 - note there are not ongoing resources to update source water assessments)
    Download: [GIS Layers ZIP 1.9 MB]
  • Groundwater 2-Year Time-of-Travel zones for Drinking Water Source Areas
    Download: [GIS Layers ZIP 4.9 MB] (Updated: Feb. 29, 2012)
• Maps by County
• Potential Contaminant Source Results - June 2005
• Source Water Assessment Report Summaries for Individual Surface Water Systems
  Full reports are available from your public water system. 
• Example Source Water Assessment Reports:
  • Surface Water System: Seaside Water Department
  • Groundwater System: City of Veneta, City of Irrigon
• Source Water Assessment Methodology


• Updating and Enhancing your Source Water Assessment:
  • Oregon’s Source Water Assessments were completed between 2000 and 2005. Communities are encouraged to "enhance", update and refine the State's Source Water Assessment results through further research and local input as they move forward in developing protection strategies. Updating the assessment is important if a water source is added or removed; significant development within the source water area occurs; land use changes within the source water area are made; or remediation of contaminant sources is completed. Information available through improved state and federal databases and GIS layers should also be added to the assessments.  Additionally, future federal rules such as Chemical Monitoring Reform, Alternative Monitoring, Ground Water Disinfection, and Enhanced Surface Water Treatment Rules may affect source water assessments. Assessments may need to be updated to reflect changes occurring as a result of these new rules. DEQ and OHA can assist with technical aspects of the assessment updates to the extent that funding and resources are available.
  • How to Update/Enhance your Source Water Assessment
• Additional DEQ GIS Data