Stormwater Master Plan

The City is updating its Stormwater Master Plan. A Stormwater Master Plan is an important strategic document for maintaining clean water and healthy ecosystems in Lake Oswego.

The Master Plan document will prioritize the installation and design of projects to improve stormwater drainage and infrastructure throughout the city. The City currently manages more than 130 miles of stormwater pipelines and 4,637 catch basins, with many nearing their expected end-of-life.

The Stormwater Master Plan will include the following components:

Research and collect data on the public stormwater system, including flow data,
Evaluate existing areas of deficiency and other issues in the public stormwater system,
Model the current public stormwater system to determine potential future areas of deficiency and other issues with the public stormwater system,
Develop a prioritized master list of public stormwater projects and associated cost,
Determine sources of funding the capital projects and staff required to maintain the public system.

Timeline

The City issued a Request for Proposals for a Stormwater Master Plan in September 2025 with the contract awarded to Hazen & Sawyer in January 2026. Data collection will take place in 2026 and 2027. It is expected that the Master Plan will be completed in 2028.

Opportunities for public input and involvement will be updated and made available on this project page.