A master plan is a support document to the comprehensive plan that details existing conditions of infrastructure, determines population growth as outlined by Portland State University Population Research Center, and recommends improvements and upgrades to the system to support the anticipated growth of a community. Master plans should be revisited every 7 to 10 years or after completion of the high priority/near term projects.

The master plans allow the city to develop a capital improvement plan, set system development charge fees for development, and prepare rate analysis reports to support timely delivery of system improvements as required by community growth. Master plans are prepared by the city and its consultants with input from the community. Once a final draft is completed, the master plan is then reviewed by the Planning Commission who in turn recommends adoption by the City Council.