OLYMPIA — Many construction projects can now resume if supervisors can show the state they’re following new safety guidelines amid the COVID-19 outbreak, Gov. Jay Inslee announced at a news conference Friday.

It was unclear how many people will get back to work in coming days, but construction may restart before the expiration of the governor’s current stay-home order on May 4.

The governor and industry representatives outlined a plan to get crews back to work on “low-risk” projects that were under way when he initiated a stay-home order last month. Not all work will be permitted, though.

Tasks on construction sites will have to allow for social distancing, and employers must provide protective equipment, set up plans to mitigate possible outbreaks and meet other safety requirements.

“I would not support any plan that would not protect the people who are providing us our shelter,” Inslee said.

The effort to get construction up and running comes after discussions with six heads of building and development associations, unions and other groups. Those discussions proved “hard-working people of good faith can reach agreements,” Inslee said. The process will likely be repeated with other industries, but it’s too early to say when that will be, he added.

“The day of reopening our economy is not today — it would be way too dangerous,” he said.

On April 14, developers, contractors and construction workers sent Inslee a letter detailing steps they could take to safely resume work, most of which are mirrored in the governor’s plan.

“The governor has given us the opportunity to have a great effect in our industry — he’s put it back in our hands,” Mark Riker, executive secretary of the Washington State Building and Construction Trades Council, said at Friday’s news conference. “It’s our job to do it right. If we do it right, we’ll move to the next step. If we do it wrong, we will be shutting ourselves back down. It won’t be his fault, it will be ours.”

Earlier this week, the governor mapped out some steps for the state to slowly dial back the stay-home order, with some elective surgeries, residential construction and outdoor recreation being the first sectors to recommence.

Inslee on Friday said he hopes to make sure nurses and medical staff have enough personal protective gear for elective surgeries.

An update on hunting and fishing will be coming in the next few days, he said.

As of Friday, the Snohomish Health District has reported 2,268 confirmed COVID-19 cases in the county, with at least 103 deaths. Statewide, there have been 12,753 confirmed cases and at least 711 deaths, according to the state Department of Health.

“Each one of those losses is not a number, it is not a statistic, it is a tragedy in our families,” Inslee said. “We know that the ‘Stay Home, Stay Healthy’ order is working, but we know that it has to continue to avoid a dire fate. And we know that much work remains to be done to control this virus.”

The governor’s announcement came at the conclusion of a week that started with 2,500 people gathering at the Capitol in Olympia to protest his stay-home order, as well as criticism from some conservative state lawmakers and Snohomish County Sheriff Adam Fortney, who called the order unconstitutional.

State law gives the governor wide authority during declared emergencies, including the prohibition of public and private gatherings, imposition of curfews, the closure of stores and the restriction of access to streets, roads and highways — some of which Inslee has done.

Meanwhile Friday, 17 mayors of Snohomish County cities signed two letters, one to Gov. Inslee and another to county residents.

In the letter to the governor, the mayors asked for increased transparency and details on conditions for reopening businesses, outdoor recreation and places of worship. Local leaders also offered to help shape a regional plan and expressed concern that a lack of leadership could lead to non-compliance with the stay-home order.

“We certainly understand the very difficult position that you are in trying to address the simultaneous health and economic crises in our state, and we share your priority of ensuring that we do not see a resurgence of this virus as we reopen,” the mayors wrote to Inslee. “We are also becoming increasingly aware of the very real and tragic circumstances many of our small business owners, workers, and residents face.”

One name not on the letters was that of Edmonds Mayor Mike Nelson.

“Of course we all want these sectors to reopen as soon as possible,” Nelson said in a statement in the Edmonds Beacon. “But this decision needs to be based on public health guidance and medical data to support it if we want our community to truly recover.”

In their letter to Snohomish County residents, the mayors acknowledged the difficulty of social distancing and asked for patience.

“We’ve come so far in slowing the rate of infection and reducing the tragic loss of life,” the letter to residents said. “Let’s see this through to the finish line and become the first region in the country to effectively and lastingly shrink the threat of this deadly virus.”

As the state begins to reopen, transmission of the virus could surge again, leading to more restrictions as the world awaits a coronavirus vaccine, Dr. Chris Spitters, health officer for the Snohomish Health District, said during a Friday media briefing.

“The ultimate end to the COVID-19 saga is population-wide immunity, ideally and most likely obtained through a vaccine,” said Spitters.

He said that a vaccine likely won’t be available for at least a year to 18 months — an estimate that national public health experts have repeatedly floated when discussing a coronavirus cure.

Social distancing could become “part of the new normal for years and months to come,” Spitters said. He cited research recently released by Harvard’s T.H. Chan School of Public Health that suggests periods of social distancing will likely be needed into 2022 to ensure hospitals aren’t overwhelmed by future influxes of COVID-19 patients.

The next rise in cases could come as the weather cools, although researchers aren’t sure yet how the virus’ transmission rate will change with the seasons, Spitters said.

“Most coronaviruses do have a seasonal nature to them, and it’s likely that it will resurge sometime in the fall,” he said. “And then we would cycle through that, likely several times, until we either have sufficient population immunity — to where transmission can no longer occur — or we get a vaccine.”

Herald writer Rachel Riley contributed to this story.

Joey Thompson: 425-339-3449; jthompson@heraldnet.com. Twitter: @byjoeythompson.