Sewer connection moratorium enacted on part of Sammamish; current development unimpacted

By Miki Mullor

The Sammamish Plateau Water District board voted unanimously enact a moratorium on new sewer connection certificates in the northern part of Sammamish. Current development in the permitting process, including Town Center Phase I 400 homes project, are not impacted by this decision. Future development in the Town Center and elsewhere within the affected area will be blocked while the moratorium is in place.

In January, we reported the Sewer District’s warned King County a moratorium is coming, yet apparently no progress has been made.

Sewer moratorium enacted 

The District is legally responsible to supply water and sewer services to customers in portions of Sammamish and Issaquah. It has the authority to regulate the use of its sewer system.  The District is under contract with King County to send its wastewater to Kind County’s regional facilities for treatment and disposal. 

The District’s Resolution 5018 states that the District designed and constructed its local system in Sammamish, since 1970, anticipating a northern connection, known as the “Sammamish Plateau Diversion,” to meet capacity needs.  

We reported details on the northern connection issue in December:

“The second connection to King County’s regional sewer conveyance system referred to as the Sammamish Plateau Diversion is a critical component of both King County’s and the District’s long-term planning, and is key to implementing the District’s Wastewater Comprehensive Plan which has been reviewed and approved by King County,” states the District’s resolution. 

In 2018 the District was informed that construction of the Sammamish Plateau Diversion had been deferred by King County due to funding limitations relating to the operational failure of King County’s West Point Treatment Plant during a storm event in February 2017. No time for reinstatement and completion of the Sammamish Plateau Diversion was provided.

No firm commitment from King County 

The District said that an interim improvement evaluation concluded that there are no simple solutions to meet the District’s regional sewage conveyance needs. “To date King County has not made any firm commitments regarding the Sammamish Plateau Diversion or King County’s participation in the necessary interim improvements,” the District’s resolution states. 

The District’s board has declared a 90 day moratorium on issuance of Certificates of Sewer Availability and for connecting current residents who are requesting transition from a septic system. The District said it may extend the moratorium as deemed necessary while it is seeking “firm commitments” from King County to address the capacity issues in Sammamish. 

The moratorium only impacts new development proposals in the the northern part of Sammamish, depicted in pink in the following map:

Source: Sammamish Plateau Water District

Development applications already submitted are vested and unaffected by the moratorium.

A Certificate of Availability is a reservation of future sewer capacity for a proposed development. Once a sewer certificate is issued, it remains valid as long as it is included in the permit application for the development and the application is still under review by the city. If the developer did not apply for a permit, the sewer certificate will expire after one year. 

The sewer moratorium will not impact any currently planned development in Sammamish or in Unincorporated King County, such as the area north of 244th Ave.  The Sammamish Comment asked the district about the status of Town Center Phase I, the largest development project in Sammamish. The District confirmed three sewer certificates have been issued to STCA, the developer of the project, and those remain valid.  The moratorium may, however, impact any future development in the Town Center or anywhere else in the impacted area, as long as the moratorium is in place. 

The Sewer district has set up an information website for the public at


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1 thought on “Sewer connection moratorium enacted on part of Sammamish; current development unimpacted

  1. Keep in mind the infrastructure is totally fragmented . God forbid a major disaster would ever happen in our area. You go nowhere for help. Just look what took place in Texas. Poor planning from day ONE. You have politicians that have no clue to sit down with experts for a serious discussion addressing the infrastructure. You and I plus others pay for the short comings. Sincerely, H. Maine

    Sent from Mail for Windows 10

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