Three Washington Cities with New Water Needs Using Shared Mitigation to Offset Impacts in Two Major Watersheds

In December 2010, the City of Lacey submitted to Ecology a mitigation plan for six water right applications, from six different wells located in the Hawks Prairie and east Lacey area with a combined total of 7392 acre-feet per year (AFY) of new water.  Also in December 2010, the City of Olympia (jointly with the Nisqually Tribe) submitted a water right mitigation plan to transfer their 29,209 AFY of surface water rights from McAllister Springs to groundwater rights at a new “McAllister Wellfield”, located about 1.25 miles south of McAllister Springs.  In February 2011, the City of Yelm submitted a water right mitigation plan for one water right application totaling 942 AFY of new water.  Each water right application package had modeled impacts in the Nisqually and Deschutes Basins and McAllister, Woodland Creek and Yelm Creek Sub-basins.  Minimum instream flows in the Nisqually and Deschutes basins are protected by state regulation and are considered a water right.  

Olympia (and the Nisqually Tribe), Lacey and Yelm coordinated their efforts regarding future water supply needs for each entity.  All three cities used the same regional groundwater model and agreed to have their modeling consultants coordinate any changes with each other and to peer-review the model each time it was changed. 

In addition, the Cities combined their planning efforts and financial investment to propose a series of “water-for-water” and “out-of-kind” mitigation actions including recharging reclaimed wastewater and purchasing and retiring existing water rights and land purchases for riparian improvements to address modeled groundwater and surface water depletions that could be expected to occur in the Nisqually and Deschutes Basins and McAllister, Woodland Creek and Yelm Creek Sub-basins. Ecology also invoked the "Overriding Consideration of Public Interest" (OCPI) provision [RCW 90.54.020(3)(a)] since not all mitigation covered year-round pumping impacts from all of the new wells at full build-out.

During the winter and spring of 2012, Ecology approved and permitted Olympia’s water right changes from McAllister Springs to the new McAllister Wellfield and approved all of Lacey’s new water right applications.  Ecology also approved Yelm’s application for new water.  Yelm’s permit was appealed by a small group of local residents living near Yelm and this appeal (Foster v. Yelm) was elevated to the Washington State Supreme Court in May 2015.  In October 2015, the State Supreme Court ruled that Ecology exceeded its authority in issuing a new water right permit where all seasonal stream flow impacts were not offset with “water-for-water” mitigation.

Overall, joint mitigation efforts by neighboring cities or other public water supply entities can serve as a good example for how other municipalities and water systems can effectively and sustainably obtain new water for expected long-term growth in basins that have instream flow rules.  However, due to the October 2015 Washington State Supreme Court decision, only water-for-water mitigation can be used.  Thus the tools available for mitigation to offset future water uses by applicant for water rights in Washington is dramatically narrowed.