Stormwater Outfalls

Public Works Director Robert McAndrews
Ph: (509)-394-8526

There are approximately 59 individual outfalls within the City to Garrison Creek, Stone Creek, Military Springs (Burlingame Pipe), and Thompson Creek that do not include stormwater treatment prior to their discharge to the waterway. The majority of these outfalls are directly adjacent to paved public roadways that are considered a pollutant generating impervious surfacing (PGIS). To protect water quality, improvements to most of the identified outfalls is recommended with the exception of one biofiltration swale.  These improvements could include oil-water separators, vegetated buffers, bio-infiltration swales, or other small-scale, Washington Department of Ecology approved point-source water quality treatment devices    
The budgetary number for these improvements are estimated at $90,000 per inlet or a total of 
$2,655,000 . Further investigation of each outfall will be necessary to determine the best treatment and the specific improvements will be determined on a case-by-case basis as funding is made available and each outfall or point source is further evaluated.  The annual maintenance cost of each of these improvements is estimated at $1,000 to $2,000 per year with inspection / maintenance schedule occurring annually, at a minimum.  The expected life of these individual water quality systems is between 5 to 20 years (WSDOT, 2014). 

Legislative Pathway

- City Council Meeting: January 12th, 2021 Stormwater Management Plan Finalization
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Plans1 document

  • Stormwater Plan (Page31)
    document seq 0.00
    This document outlines storm outfalls in the municipal system that need additional treatment mechanisms.