Coho Water Resources
Integrated Water Resource Management
Puget Sound Tribe
Since 2015 Coho has been retained by the Natural Resources Department of a tribal government to conduct a multi-faceted investigation of a Puget Sound watershed. This investigation has produced findings to guide the tribe’s decisions about protecting salmon habitat in the watershed and ensuring the integrity of the tribe’s water supply. Products and efforts to date include:
Basin Hydrology: Developed a hydrogeological conceptual
model of the basin characterizing the hydraulic continuity between
groundwater and surface water and how groundwater production
might affect important salmon streams. Determined whether there
should be concern for saline intrusion from the nearby estuarine
setting.
Groundwater Supply: Evaluated the existing groundwater
supply. Determined how to secure existing sources. Identified potential new groundwater sources to
support the economic growth of tribal enterprises.
Reclaimed water: Some wastewater is currently reclaimed and put to
beneficial use. Investigated how the rest may be used, including aquifer storage, land application, and increased surface storage.
Identified measures consistent with federal (EPA) and state
(draft WAC 173-219 rule) reclaimed water policies.
Land use development: Provided guidance for avoiding adverse
impacts on groundwater (e.g. Critical Aquifer Recharge Areas) as the tribe further develops their
economic enterprises.
Prioritized land parcels for preservation or critical designations.
