Sturgeon Lake, center of thriving wildlife refuge, is on death spiral

by: PAMPLIN MEDIA GROUP: CHRISTOPHER ONSTOTT - Melody McCart kayaks around Sauvie Island's Sturgeon Lake taking depth samples for the West Multnomah Soil & Water Conservation District. The lake's bottom is filling with sediment, reducing its footprint.Sturgeon Lake is choking to death — slowly but surely.

For decades, the future has appeared dim for the largest lake on Sauvie Island, one of the biggest freshwater islands in the country.

That’s because a chronically congested creek that feeds into the lake has stymied the steady ebb and flow of clear water needed to flush out incoming sediment.

As a result, the nearly 3,200-acre lake’s muddy bottom is gradually rising, shrinking the footprint of the island’s idyllic north-end centerpiece. Analysts predict the water mass will be halved in 50 years, on path to become an emergent wetland. It’s already on its way.

Sturgeon Lake’s depth varies depending on the tides. In rainy seasons, the water can rise to 3 or 4 feet, while in summer it comes closer to 20 inches. Just before the rains return in the fall, the lake often transforms into a mudflat.

This shift is creating a suitable habitat for bacteria and algae to thrive, but not the waterfowl and salmon that have historically used Sturgeon Lake as a haven.

Rising water temperatures, a hobbled ecosystem, bugs — by many accounts the prospects don’t look pretty.

Naturally, that’s a concern for conservationists, who have already spent tens of thousands of dollars to kick-start plans to reverse course. A coalition intent on finding a solution, including the West Multnomah Soil & Water Conservation District and the Oregon Department of Fish & Wildlife, is weighing the merits and costs of specific strategies.

So how did it get to this point?

An island split in two

In 1949 the U.S. Army Corps of Engineers, a federal agency that builds dams and canals and manages flood protection and other public works projects, installed an 18-mile levee that frames the southern half of Sauvie Island. The goal was to make a large swath of land free from perennial flooding and viable for growing crops.

The Sauvie Island Drainage District Levee split the island in two, turning its flood-prone south side into prime — and lucrative — farmland. The northern half, including Sturgeon Lake, remained a designated critical habitat for salmon, migratory birds and other wildlife.

Over time, Sauvie Island became a popular nature refuge, increasingly rare as modernization radiates outward from the Portland metro region. The Oregon Department of Fish and Wildlife estimates nearly 1 million people come to Sauvie Island a year, making it one of the most visited locations in the state. The popular Crater Lake National Park only draws half as many guests.

Island businesses reaped the benefits of the region’s strong interest in organic Sauvie Island produce, flowers and outdoor opportunities, such as The Pumpkin Patch farm’s massive Halloween corn maze. Hunters and birders take advantage of the sprawling wildlife refuge, about half the size of the entire island. Bicyclists trek to the island from many miles away.

The island’s levee-created transformation, however, bears a hefty burden for Sturgeon Lake’s slow demise.

“There is a generation that thought they could engineer their way into anything,” says Scott Gall, rural conservationist for the West Multnomah Soil & Water Conservation District. “And now we are sort of going the other way, to realize we need to work with nature.”

Now the Army Corps is helping finance and implement a plan to undo the damage caused by this dramatic shift of the more than 25,000-acre island’s natural order. The West Multnomah Soil & Water Conservation District is leading the restoration partnership along with other agencies with vested interests in saving Sturgeon Lake, including hunting advocacy group Ducks Unlimited and the Oregon Department of Fish and Wildlife, which owns and manages the wildlife refuge.

A feasibility study is under way, as experts narrow down a large list of fix-its brainstormed in January. Gall says he expects a final project plan in a year or so. Correcting the dilemma of the disappearing lake has been a long-time coming — with numerous starts and stops — and he says it now must be done right.

“There’s been people talking about restoration of Sturgeon Lake for at least the last 30 years,” he says. “We’re not going to jump in too hastily.”

Prior fix set back by massive flood

Oregon State University’s Water Resources Research Institute prepared an environmental assessment in 1987 that concluded Sturgeon Lake has been shrinking in size and shape since the mid-1800s, mostly because of human activities, including diking, damming, land draining and dumping of dredged sediment.

The lake naturally fills with water streaming from both the Columbia River and the Multnomah Channel. But over time, manmade low-water levels meant to facilitate nearby farming plugged Dairy Creek, which flows from the Columbia. In the 1950s and 1960s, sediment dredged from the Columbia River to sustain ship traffic was placed near the creek’s entrance, further slowing the water flow.

So, Sturgeon Lake began filling with more water from the sediment-laden Multnomah Channel, rather than the comparably clear Columbia River. At a rate of 3 millimeters per year, lots of muck flows in, but little flows out.

“We see the lake slowly filling in,” says Jim Adams, Army Corps of Engineers project manager for the Sturgeon Lake Restoration Project.

Juvenile salmon that would normally swim into the lake from Dairy Creek mostly avoid the path. Those that do not, however, have a very tough time surviving the journey.

“It’s a long, tortuous kind of route,” Adams says.

The first iteration of the Sturgeon Lake Restoration Project occurred in 1989. A new channel was created to bring more clear water into the lake. The attempt showed promise until a disastrous 1996 flood once again filled up that water path with deposits, undoing the effort.

Long-time island resident Joe McFarland, 70, has witnessed the lake’s undoing since he moved next to Dairy Creek at age seven.

He fondly thinks of Sturgeon Lake as one of the family.

“We used to water ski on the lake all the time,” McFarland says.

For years, he would kayak through the creek and its conduits into the lake. But as time passed, it became more and more difficult to do his usual loop.

Considering prior attempts to save the lake, even he wonders if it has gone “past the point of no return,” especially considering a presumed multimillion-dollar restoration price tag.

“I kind of wonder if it’s too late. It might just not be possible to save the lake system,” he says.

Finding a solution

Conservationists hope that’s not the case.

In the expansive wildlife area around Sturgeon Lake there live at least 275 species of birds, 37 mammal types and a dozen varieties of reptiles and amphibians, according to an Oregon Department of Fish and Wildlife report in April 2012. That’s not to mention the numerous species of fish and plant life in the lake, and as many as 300,000 Canada geese that stop there during the Pacific Flyway migration. Many presumed solutions are under consideration as scientists continue to study the lake’s shifting hydrology.

The underlying answer is simple in concept, but difficult in implementation: improve the interaction between the clear Columbia River and the muddy Sturgeon Lake.

Following a January brainstorming session with stakeholders, Gall says around 25 improbable ideas — including dredging the lake completely and removing the large levee — were quickly tossed aside in favor of simpler and less costly solutions.

When the project’s direction comes into focus later this year, it will likely be similar to the late-1980s fix, the one thwarted by the 1996 flood, where a path from the Columbia River would be dug out to bring more water to Sturgeon Lake. Other options outlined include shoreline alterations, creek dredging and ramping up periodic maintenance efforts.

The hope is that one or many of these fixes will re-establish a safe haven for endangered salmon, protect the necessary open water areas for waterfowl to thrive and keep the island’s popular wildlife area a thriving destination for its many fervent fans.