Several stretches of the Willamette River in downtown Portland are poised for a makeover in the coming decade.

The river is cleaner than many people think. Between 1997 and 2011, the city's Bureau of Environmental Services spent $1.4 billion upgrading its wastewater and storm water system to cut down on sewer overflows into the river. The so-called "Big Pipe" project dramatically improved water quality in the Willamette.

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Now, the Oregon Department of Environmental Quality and the Oregon Health Authority both say the Willamette is clean enough to swim in, though they suggest you might want to shower afterward.

The city, nonprofits and private property owners have pitched four big projects that take advantage of the improved water quality, creating new habitat for fish and new opportunities for swimming and boating.

Here's a rundown on the changes on the horizon for the Willamette in central Portland.

Zidell Yards Redevelopment

Zidell Companies, located next to the aerial tram in Portland's south waterfront, grew into a Portland institution after World War II. It helped dismantle warships and build barges.

Related: Portland’s Toxic Graveyard For World War II Ships

The company recently completed a $20 million environmental clean-up of its 33-acre riverfront property. It announced last year it is closing its barge building business and planning a mixed-use development it calls Zidell Yards on the site.

The last barge Zidell has built is scheduled to leave the company's slipway June 16.

"That will go down the river, and then we're all of a sudden developers. We are in the real estate business," said Alan Park, a development manager with the company.

Park said Zidell's plan for redeveloping the area includes transforming the old barge slipway into an area where people can picnic, swim and watch shows or concerts.

He said the company is actively pursing a permit for a new dock that will connect to the Willamette Greenway trail. The company hopes to break ground on the redevelopment in July 2020.

Swimming Beaches

Portland activist and swimwear shop owner Willie Levenson has pushed the city for years to do more to facilitate swimming in the Willamette. Levenson is the self-described "ringleader" of the nonprofit The Human Access Project.

"If we can get people in the water, they will naturally care more about the outcomes of how they are acting in the watershed," Levenson said.

Mayor Ted Wheeler has embraced Levenson's cause, joining his group for a morning swim on several occasions.

Swimmers gather on a dock on the Willamette River in Portland. Courtney Belasco / OPB

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Over the years, Levenson has partnered with local businesses and Multnomah County jail inmates to remove concrete and debris from several potential beach sites in the city's urban core.

Wheeler's 2017-2018 budget includes $158,000 to continue that work.

The money has been earmarked to transform one site, a sandy spot under the Marquam Bridge — known as Poet's Beach — into a "pop-up" summer swimming beach.

The funds would be used to provide a swimming area buoy line, signage, trash cans, bicycle parking, lifeguards and life vests. The swimming beach would be open to the public from July to September.

The beach would be a pilot project, and the mayor hasn't committed to funding for future years.

New Portland Boathouse

On the east side of the river,the nonprofit Portland Boathouse has been a home for Portland rowers and paddlers since 2004.

It has an indoor training facility and storage for racing shells, dragonboats, outrigger canoes and kayaks. It's a home for the Rose City Rowing Club and the Wasabi Paddling Club, among other groups.

The Boathouse's lease on its property expires in August 2019, and it's searching for a new home.

The boathouse hopes to move to a site on the Oregon Museum of Science and Industry's nearby campus and is planning to privately raise more $3 million for a new "River Center," in partnership with OMSI, according to president Bernie Thurber.

Thurber told the City Council Wednesday that the group's investment in the river center is contingent on the city investing in "a dedicated dock specifically designed for light watercraft use."

The Holman dock, which the boathouse currently uses, is crumbling, Thursber said. The dock also became a sore point for paddlers trying to launch after it became a magnate for sunbathers, swimmers and day drinkers.

Restoring The Eastbank Crescent

Plans for the new river center at OMSI tie in with the city's long-term plan to remake a 1,000-foot-long stretch of riverbank between the Hawthorne and Marquam Bridge planners call "the Eastbank Crescent."

Much of the Willamette River in Portland is relatively hostile to fish: it's a deep, dredged channel, hemmed in by concrete walls.

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But in the Eastbank Crescent, there’s a shallow spot with slower moving water that’s an important resting spot for migrating salmon smolts. Portland’s Bureau of Planning and Sustainability has proposed a major habitat restoration project for the crescent.

It has proposed peeling back layers of concrete and dirt to make the slope of the bank more gentle, adding snags and logjams for fish, and planting native plants and trees along the shore.

They’ve also proposed building a new designated dock for light water craft in the area and creating temporary floating docks for summer swimmers, in part to minimize conflict between the two groups of users.

The bureau said summer swimming is likely to have a relatively minor impact on salmon because the fish migrate during the colder months.

The plan doesn't have any funding at this time, and there isn't a timeline for it either.