Six potential sites for a new regional municipal jail are in Seattle and the Eastside area, a multi-city planning group announced Nov. 20.

The possible locations include three spots in Seattle and one each in Shoreline, Bellevue and unincorporated King County just north of Redmond.

State law requires cities to have a municipal jail because some misdemeanor offenses require incarceration. Many cities in King County – including Covington, Maple Valley and Black Diamond – have a contract with King County for jail space, but that arrangement is scheduled to expire in less than five years.

A potential one-year extension is on the table, but county officials claim the county jail doesn’t have the capacity to house its own felony jail population beyond then. That means cities will have to collectively build a new jail or construct separate buildings of their own.

Twenty-three municipalities, including the ones that use the largest number of municipal jail beds — Bellevue, Kirkland, Redmond, Seattle and Shoreline — have banded together as the North-East Cities (NEC) municipal jail-planning group to formulate concepts for a new 640-bed facility that would house misdemeanor inmates. A preliminary estimate of the construction cost is $174 million.

Another group of cities, known as South Corrections Entity and comprised of Auburn, Des Moines, Federal Way, Renton and Tukwila, is working on a separate plan for its members.

NEC group has decided to move forward with environmental reviews and public input for its possible sites.

One option under consideration would create an annex to the county jail in downtown Seattle. That option is “attractive” because it would “take advantage of some of the support functions” of the existing facility, said Catherine Cornwall, senior policy advisor to Seattle Mayor Greg Nickels. “They already have a kitchen, they already have a booking facility, and they already have a medical staff.”