New rescue mission for Stanley Park’s ‘Incredible Shrinking Lake’

The latest ideas for preventing a beloved lake in Stanley Park from turning into a swamp will go before the public next month.

A consultant for the  Vancouver park board will present several possible plans for saving Beaver Lake at an open house meeting in November, the date of which had not been scheduled as of Oct. 16.

The lake has been shrinking for decades and could soon cease to be recognizable as a lake.

Consultants AquaTerra Environmental will be seeking comments from the public on the plans.

The ‘Incredible Shrinking Lake’

Lakes do shrink over time, filling in and eventually transitioning from lake to swamp to dry land. What’s unusual about Beaver Lake is that this process has taken place in just a few decades.

When the Stanley Park causeway was constructed in 1938, the lake’s surface covered 6.7 hectares. By 1997, it covered just 3.9 hectares.

The lake has also been getting shallower. More than 70 per cent of its surface is now covered by waterlilies and other plants, and past estimates have suggested there could be no open water left by the year 2020.

“Older visitors to the park have said they would even come here for ice skating,” said Robyn Worcester, conservation programs manager for the Stanley Park Ecology Society. “You couldn’t do that now.”

Humans are the primary cause of Beaver Lake’s shrinkiage, Worcester said.

The construction of the causeway and the gravel trail encircling the lake reduced the amount of rainwater that ends up in the lake and increased the amount of sediment in the water that does make it.

Similarly, the introduction of invasive fragrant pond lilies has hastened the build-up of sediment on the lake’s bottom and overgrown its surface.

The lake, and the creek that flows out of it, is one of only a handful of freshwater habitats in the city of Vancouver. It is home to several species considered at risk in southern British Columbia, including coastal cutthroat trout, blue dasher dragonflies, and great blue herons.

If Beaver Lake disappeared, “it would be a loss of biodiversity for the city of Vancouver,” Worcester said.

A plan for restoration

Past studies of the Beaver Lake problem have come to differing conclusions about what should be done to solve it. A 1985 report recommended dredging the lake at a cost of up to $218,000 — worth roughly $425,000 today.

[pullquote align=”right”]We’ve known it was a problem since before 1985. We’ve known it was getting worse.[/pullquote]In 1999, a similar study recommended against dredging, taking the approach that the park board should try to limit future damage to the lake, rather than try to actively reverse it.

AquaTerra’s recommendations won’t be known until the open house, but dredging is “certainly an option,” said Alan Duncan, an environmental planner for the park board.

He said he believes the public will be more receptive to future plans for restoring the lake.

After the 2006 windstorm that blew down trees across Stanley Park, many people “rediscovered” the park’s interior, Duncan said. Because of the storm, both elected officials and the general public are now more aware of the need to actively maintain the park’s environment.

‘It’s going to be expensive’

The current study of Beaver Lake is part of the Stanley Park ecological action plan, which grew out of the park board’s and ecology society’s responses to the storm.

“Beaver Lake was number one on the list,” Duncan said. “We’ve known it was a problem since before 1985. We’ve known it was getting worse.”

The city allocated $500,000 in its 2012-14 capital plan for the implementation of the ecological action plan. Of that total, $300,000 is scheduled to be spent in next year’s budget.

Nearly all of it will be used for work on Beaver Lake, but it likely won’t be enough to cover the cost of the consultant’s proposal, regardless of what that proposal entails.

“We don’t know what it’s going to be, but we’re anticipating it’s going to be expensive,” Duncan said.

He said he expects whatever work the consultant suggests to be “phaseable.” This would allow work to begin on one part of the project while the park board seeks additional funding for the rest.

Updated Nov. 7: The park board has scheduled two open houses with the Beaver Lake consultant. The first is scheduled for Thursday, Nov. 21, at the Coal Harbour Community Centre from 4 to 8 p.m. The second is scheduled for Saturday, Nov. 23, at the West End Community Centre from noon to 4 p.m. More information is available on the project website.