STANWOOD — City Hall is overdue for an update, but its location in a floodplain complicates the project.

Federal requirements for flood-proofing buildings during a major renovation would multiply the cost of an upgrade, adding about $1 million to a project that could cost up to $620,000 on its own, according to city documents.

City leaders have been seeking ways to phase in renovations, but that approach also is running up against floodplain regulations.

Snohomish County has been part of the National Flood Insurance Program since 1984. This means the county has specific development requirements within floodplains. In return, the federal government makes flood insurance available.

One requirement is that any renovation costing more than 50 percent of a building’s value requires the building to be flood-proofed, often by elevating it.

The Stanwood City Hall project runs into its 50 percent cutoff at $192,000. If it costs more than that, the building would need to be elevated about 8 feet in order to meet requirements, Community Development Director Ryan Larsen said. In the mayor’s office, the floor would be where the lights are now.

It would cost more to flood-proof Stanwood City Hall than the price of a full renovation. The city estimates it would need between $750,000 and $1.25 million to elevate the building.

Earlier this year, Stanwood City Council members decided to prioritize renovations and do a smaller scale project that would fall within the $192,000 limit.

The council voted Thursday to reject all four bids the city received for the project. The lowest was $303,000.

Stanwood has applied for a $1 million federal hazard mitigation planning grant to elevate City Hall, and staff hope to hear back in October, Larsen said.

In the meantime, phasing in some of the more pressing updates could allow the city to stay within its budget. City code requires a two-year window between the projects if they are phased in, city administrator Deborah Knight said.

Stanwood City Hall was built in 1939 and has been used as a city hall, police station and jail, and community center and stage. The last time the building got an overhaul was in the 1960s.

Now, the community development department is crammed into a small space, the bathrooms need a remodel, the meeting room lacks any audio or visual equipment, and the flooring, paint, fixtures and furniture are outdated.

Several years ago, the city did some upgrades on the building. Workers removed the chimney, repaired siding, painted the outside and replaced the roof.

Next, city staff and leaders plan to move the community development department to a larger space near the mayor’s office and update the interior of the finance department. Eventually, they hope to put a new meeting room where the community development department is now. They also would like to redo the bathrooms.

“We’re still back in the mid-20th century with this building,” Knight said.

In the long run, city leaders need to determine whether to flood-proof and remodel the building or build a new City Hall outside of the floodplain.

“The council had originally, before the economic downturn, talked about building a new City Hall, but that got shelved,” Knight said.

It’s under discussion again after the Oso mudslide, which killed 43 people and altered the Stillaguamish River in ways that remain uncertain as flood season approaches.

“After that event, the council started talking about whether it made sense to keep the City Hall in a floodplain,” she said.

City leaders are keeping an eye out for potential locations, but Knight expects it will be years before a new building is planned.

Some small renovations — namely relocating the community development department — could be finished by January 2015 as long as they fall within the cost limit, she said. Stanwood City Hall might need to close for one day during the work, but otherwise would be open as usual. Fourteen employees work in City Hall and they see “a steady parade” of customers, Knight said.

Kari Bray: 425-339-3439; kbray@heraldnet.com.