2022 Drainage Manual Update
We’re updating the DDECM per Department of Ecology requirements. The updated version will become effective on June 30, 2022.
In addition to incorporating minor staff- and industry-requested changes, nine significant changes were included in this update:
Watch this short video to learn about the proposed updates:
Changes summaries:
2021 changes in a Word document track changes format:
Ecology Requirements:
For Questions:
Shannon Peterson - Water Resources Utility Planner
360-867-2069