Stormwater Policy Objective: After Maximizing Prevention and Source Control Strategies, Use Best Management Practices to Reduce Impacts Until Restoration is Possible

Management of stormwater through BMP’s has proven to be an ineffective long-term strategy.  It should be considered an interim approach and used only to the extent prevention and source control of stormwater cannot be utilized in the short term. Given that, even with aggressive implementation of this policy, existing stormwater problems will continue for some time to come, jurisdictions need to properly manage stormwater runoff that does occur.  Some management strategies are more effective than others.

Many of these strategies are identified in the Department of Ecology Stormwater Manual for Western Washington (2005).  While portions of the manual are not consistent with the approach taken in this policy, many others, such as those relating to maintenance of stormwater catch basins, outline techniques for more effective management of stormwater runoff.  All jurisdictions throughout the region should adopt standards established in the Manual to the extent they do not conflict with the policies outlined above.  The Manual should be updated on a regular basis to reflect emerging strategies and BMPs.

Of particular concern is the need to utilize advanced treatment where feasible.  New, emerging treatment techniques show great promise to remove pollutants from runoff.   More research is needed to test and advance BMP’s in this area.  Traditional treatment techniques, such as the use of street sweepers, should be pursued as well.

Click on the links below for further discussions of individual objectives:

Preserve Natural Hydrological Processes on a Landscape or Watershed Level

Prevent Impacts from New Development on a Site-Specific Scale

Source Control

Restore Hydrologic Processes and Water Quality in areas Where Development has Caused Harm

Mitigate Fully for Any Loss of Hydrologic Functions which Result from New Development

Overarching Mechanisms to Achieve Objectives

To comment or for more information, contact Bruce Wishart, (360) 754-9177.