Each year, Snohomish County is required to prepare two documents. These documents must be submitted to the Department of Ecology by March 31 of the year:
In addition, the county prepares other documents such as the Structural Stormwater Control Programs.
In addition to addressing different time periods (past vs. future), these documents have another important difference. The annual reports are legally-binding documents used by the Department of Ecology to determine permit compliance based on actual performance in the past, whereas the SWMP document is essentially a non-binding informational document used to inform the Department of Ecology and the public about the permit and the actions the county intends to take to comply with it.