The stormwater manual provides guidance on how to design and maintain stormwater controls, including the control of runoff, and stormwater holding ponds. If you are not using the standards in this manual, indicate whether you are following a different manual approved by the Department of Ecology.
For more information on Ecology’s stormwater manual, visit: https://ecology.wa.gov/Regulations-Permits/Guidance-technical-assistance/Stormwater-permittee-guidance-resources/Stormwater-manuals.