Water Supply for Building Permits and Subdivision Approvals

The state legislature adopted new rules (ESSB 6091 (PDF)) to resolve uncertainty related to a Supreme Court decision from October 2016 (known as the Hirst decision (PDF)), which affected the use of wells for residential use mostly in rural areas of the county. The law became effective on January 19, 2018 and guides how the county can approve building permit and subdivision applications.

New Snohomish County Planning & Development Services (PDS) procedures for ALL building permits requiring a drinking water supply are as follows:

Applicants must provide proof of adequate potable water supply, which can be demonstrated by submitting one of the following:

1. Documentation from an approved water purveyor with capacity to serve the proposed building or development stating its commitment to provide adequate potable water. (Water purveyor map)
   (An “approved water purveyor” means the operator of either: a Group A system with a water system plan or a small water system management program approved by Washington State Department of Health (DOH), or a Group B water system with design report approval from DOH, as these systems are defined in WAC 246-290-020); or
2. Documentation from the Washington State Department of Ecology ("Ecology") of an issued water right permit for uninterruptible potable water with adequate capacity to serve the proposed development. (Note: An application for a water right is not acceptable proof of adequate potable water); or
3. Documentation of an adjudicated water right for uninterruptible potable water with adequate capacity to serve the proposed development (this would be very unusual); or
4. Documentation from the Snohomish County Health Department (likely to be engineered drawings) approving an alternative potable water source, other than a permit exempt well; or
5. Declaration of intent to use a permit-exempt well. This could be a verbal or written confirmation, a ‘start card’ from Ecology, or a well log from the Health Department. In addition to requirements regulated by Ecology and the Snohomish County Health Department which continue to apply, permit exempt wells are now regulated differently by the county depending upon which Water Resource Inventory Area (WRIA) the well will be located in. See details below:

WRIA-specific requirements for permit exempt wells (Find your WRIA)

If you are located in:

WRIA 3 or WRIA 4 (Upper and Lower Skagit, includes Carpenter/Fisher Basin) (WAC 173-503) – A mitigation plan approved by Snohomish County will be required prior to issuance of county permits. 

WRIA 5 (Stillaguamish Basin) – Applicants must:

1. Comply with the water usage limits established in the in-stream flow rule (WAC 173-505-090), generally limited to less than 5,000 gallons per day annual average. (Note: Water meters are not required); and
2. Submit a letter from an approved water purveyor (PDF) stating that the purveyor cannot provide water to the applicant’s site. If the purveyor can provide water to the site in a timely and reasonable manner (RCW 70.116.060), hook-up to the public system is required.

WRIA 7 or WRIA 8 (Snohomish, Cedar/Sammamish Basins) (WAC 173-507, WAC 173-508):

1. Water for domestic use is limited to 950 gallons per day (gpd) annual average, but may be curtailed to 350 gpd under declaration of a drought. (Note: Water meters are not required);
2. Record a document with the Auditor on the property title establishing water usage conditions as per (i) above. Recording fees will apply. (Note 1: a pre-drafted form will be provided by PDS. Note 2: A recording number from the County Auditor will be required to be submitted to PDS prior to building permit issuance);
3. Manage stormwater on-site to the maximum extent practicable, maximizing infiltration – provided the soils, slope, water table depth and other site conditions would safely allow for infiltration of stormwater. Low Impact Development techniques (LID) is required even for projects below the 2,000 sq.ft. hard surface threshold in the county’s drainage code (SCC 30.63A). Stormwater infiltration and use of LID should be shown on the Storm Water Pollution Prevention Plan (SWPPP); and
4. Submit fee of $500 in addition to other permit fees.

New procedures for Subdivisions are as follows:

The county is currently reviewing the new state legislation and will provide guidance for subdivisions – coming soon.

 More resources are available here:

 Ecology Washington - Water Supply 

 Ecology Washington - Protecting Stream Flows 

 Drinking Water & Wells