Slow the Flow… Save the Lake: Throwing money at Lake Winnipeg won’t help much, but some ditch-digging might

Frontier Centre, Saskatchewan, Uncategorized, Water (historic), Worth A Look (historic)

If you listen to the Selinger government's latest plan to aid Lake Winnipeg, money has the power to scrub phosphorus from the water of Manitoba's largest lake.

On Thursday, the province announced a new "Lake Friendly Accord" intended to leverage $1 billion worth of investment into ways to improve the ecological state of the vast Lake Winnipeg watershed, which stretches from the Rocky Mountains in the west down to the edge of South Dakota and then east into Canadian Shield between Atikokan and Thunder Bay.

The accord emphasizes an effort to co-ordinate the environmental efforts of the many political jurisdictions across the watershed, which includes portions of five provinces and four states and encompasses hundreds of Canadian and U.S. municipalities.

It's a lovely idea, if you believe it's possible to convince the humans in charge of every city, town, rural municipality, farm, factory, cottage, boat and septic field across a vast swath of North America to reduce the amount of phosphorus and nitrogen they allow to flow into their rivers and streams.

All of those waterways wind up in Lake Winnipeg, where the nutrients promote the growth of algae. Along with causing unsightly blooms — a mostly cosmetic nuisance — this algae contributes to the turbidity of the lake, making the underwater environment less hospitable for invertebrates that have evolved to survive in clearer water.

And after all the algae dies, the decomposition process removes oxygen from the lake, making life more difficult for fish and other species that tend to rely on oxygen.

As scientists at Ontario's Experimental Lakes Area first demonstrated decades ago, removing phosphorus from the lake is even more important than removing nitrogen, which blue-green algae can access directly from the air.

Policy-makers are well aware of this, even as many Manitobans remain confused and erroneously believe Lake Winnipeg is contaminated in some way. It can be tough for ordinary people to wrap their brains around the fact a lake can be completely safe for people right now and still be perched on the precipice of ecological disaster.

What form would that disaster take? In even more overfertilized bodies of water such as Africa's Lake Chad and Asia's Aral Sea, the entire food chain essentially collapsed.

Hence the conventional wisdom that preventing nutrients from making their way into Lake Winnipeg is the best means of avoiding a similar calamity in Manitoba.

But the recent work of researchers tasked to do nothing but study Lake Winnipeg's nutrient problem suggests this effort may be futile. All the money in the world may not be able to reduce the flow of nutrients into the lake considering the vast array of sources for the phosphorus and nitrogen.

According to the landmark report by the Lake Winnipeg Stewardship Board, 64 per cent of the nutrients that wind up in the lake come from outside Manitoba.

Within the province, Winnipeg accounts for five per cent of the nutrients and other point sources account for two per cent. All agricultural activity in Manitoba accounts for only five per cent.

Meanwhile, a pair of natural processes — atmospheric deposition on the lake and non-agricultural runoff in Manitoba — accounts for the remaining 24 per cent of phosphorus and nitrogen that winds up in the lake.

Over the past decade, hundreds of millions of dollars have been spent trying to reduce the nutrient emissions of two specific types of nutrient sources: agriculture and the point sources, which include the City of Winnipeg.

But even if every farm in Manitoba and Winnipeg's three sewage-treatment plants suddenly stopped contributing any nutrients by way of magic, Lake Winnipeg's nutrient loads would only be reduced by 12 per cent. The remaining 88 per cent of the nitrogen and phosphorus would still find its way into the lake.

This brutal arithmetic has led researchers at the University of Manitoba, conservation groups and think tanks to propose it may be far cheaper, way easier and immensely more effective to hold back the water instead of holding back the nutrients.

Their idea: Build a series of low-tech dugouts on every available piece of agricultural land across the watershed and change the slope of drainage ditches to allow them to store more water on a temporary basis.

Water in both the dugouts and ditches would then be used to nourish specialty crops, hay or even marsh plants. This growth would scrub out plenty of nutrients before the water is released downstream. The side benefits include less severe flood peaks and more water sources during potential droughts.

But this low-tech idea is meeting resistance in some corners of government where officials have a lot invested in the current nutrient-reduction orthodoxy. And it's hard to blame them, considering they've just spent the past decade ordering farmers and municipalities to spend hundreds of millions to reduce their nutrient outputs in a manner that has so far done very little to save Lake Winnipeg.

Obviously, any nutrient-reduction effort is beneficial. But the benefits to date have been exaggerated.

On Thursday, the province claimed sewage-treatment upgrades in Winnipeg will reduce nutrient loads within the province by seven per cent. This is a meaningless statistic, as Winnipeg contributes only five per cent of the total load into Lake Winnipeg every year.

Within the province, that figure is 14 per cent. Assuming that provincial figure could be cut to seven per cent — which may not be possible — it would only cut the total nutrient load to Lake Winnipeg by 2 1/2 per cent, a tiny amount.

The province also told another white lie, claiming it's paying for a third of the city's sewage upgrade. On Thursday, the province pegged that third at $235 million, which works out to a sewage-treatment upgrade with a $705-million price tag.

There was a time when the upgrade only cost $705 million: 2003. Thanks to construction inflation and scope inflation, that number was revised upward to $1.2 billion in 2005 and then $1.8 billion.

In fact, when the total cost of combined-sewer replacements are factored in, the price tag for Winnipeg's waste-water improvements is expected to wind up somewhere between $4 billion and $5 billion.

And yes, that is all to reduce the total nutrient loads into Lake Winnipeg from five per cent to 2 1/2 per cent. The work has value, but will not come close to sparing the lake from ecological disaster.

So what can be done instead? The province has the right idea when it plans to consult every jurisdiction within the watershed, but the focus should be on water-retention and nutrient reuptake from this stored water — both difficult but achievable goals.

No one's arguing in favour of allowing the city to dump raw sewage into Red River or allowing hog barns to spew liquid manure into drainage ditches, but even if the City of Winnipeg and hog farming did not exist, Lake Winnipeg would still be in trouble.

So let's stop pretending money can serve as a magic phosphorus sponge. The real solutions to the Lake Winnipeg conundrum involve a radical transformation of the watershed into something that resembles a patchwork of swimming pools and storage canals, in a manner that can deliver revenues to agricultural producers and won't cost governments and the private sector a ridiculous amount of money.

This is what scientists are saying right now. Who in government will be brave enough to make this happen?