Concern about underground street walls bringing vehicle weight restrictions to Pioneer Square

Anywhere in Pioneer Square, you can feel the history. But descend beneath the sidewalks and you step back in time.

Underground passageways date to the rebuilding from the Great Seattle Fire of 1889.

“They raised the street level and that’s how you ended up with these walls. They raised the street elevation but they maintained the old buildings, so you get an areaway,” said Lorelei Williams of the Seattle Department of Transportation.

Walls that hold up the street are formed of brick and mortar, and even pieces of timber.

“They have all sorts of things that got wrapped up into the construction of them,” Williams said.

Though the walls have stood more than a century, SDOT says they are slowly deteriorating and need closer monitoring.

(Seattle Underground Tour

Engineers also want to relieve some pressure on the walls to preserve them longer. So the city plans new load restrictions on First Avenue between Railroad Way South and Marion Street.

In early May, vehicles weighing more than 10,000 pounds will have to stay in the left lane, where the ground is more solid and where buses drive now.

This all came up when city engineers tried to figure out where to put bus stops after the Alaskan Way Viaduct closed and buses returned to First Avenue in Pioneer Square.

“We said we can’t continue to carry this load,” Williams said.

Although King County Metro buses used to stop more places on First Avenue, engineers found only two spots where they now feel comfortable letting them pull over to the curb.

This summer, the city will also take away or move commercial load zones across Pioneer Square, creating a new headache for businesses that have already endured a lot of construction.

“It’s just going to pile on a little bit more, but we’re going to be able to get through it by working one on one with businesses and making sure that they can get the goods that they need,” said Lisa Howard of the Alliance for Pioneer Square.

Some deliveries might have to be done in alleys, or a block away.

Parking and load zones for regular cars won’t be affected.

The city has already repaired the street walls in the worst condition. In areaways designated historic, some walls could be retrofitted.

Other areaways might be filled in.

The city is just starting an assessment to figure that out, but officials say there is not a safety risk.

“We don’t have a safety concern right now, and that is part of the reason for the action,” Williams said. “By taking the loads off and preserving them we’re avoiding that safety concern.”

The city is beginning an outreach to Pioneer Square businesses and residents.

Although the underground street walls are city property, they must be accessed through private property.

By Graham Johnson, KIRO 7