Winnipeg Free Press - PRINT EDITION
Dugouts could change the game
Water holes called cheap solution to flooding, lake pollution
PLUMAS, Man. -- Halfway between Riding Mountain and Lake Manitoba, Lorne Rossnagel raises 600 head of cattle on some of the flattest land on the Canadian Prairies. Five generations of his family have farmed in and around the RM of Westbourne on land criss-crossed by drains that carry water into Big Grass Marsh.
When his great-grandfather immigrated from Poland, the priority in the region was to get rid of water. So many drains were cut in Westbourne and neighbouring Lakeside a century ago that Big Grass Marsh was reduced to a desolate patch of easily windswept silt and highly combustible dried peat.
When Ducks Unlimited arrived to restore the marsh in the 1930s, farmers in the area got an early, first-hand look at the benefits of wetlands restoration, a complex and costly practice often cited as an environmental panacea.
But Rossnagel has done something on his land that's far simpler, cheaper and potentially more beneficial for the province.
For about $25,000, he dug a big hole in the ground to store water. If every other Manitoba agricultural producer follows suit, Lake Winnipeg could be saved and the severity of all but the worst floods could be reduced forever.
"If we had a lot of these, I think we could keep a lot of nutrients out of the system," Rossnagel said, standing at the edge of an unremarkable-looking dugout about 200 metres long, 50 metres wide and eight metres deep. "I love the idea. It's low-tech and it doesn't cost very much."
The practice of storing water is hardly new, as farmers have used some form of dugouts for millennia.
What's new is Manitoba scientists assigned to save Lake Winnipeg believe the solution is to dig more of these holes.
Over the past decade, the public and private sector have spent hundreds of millions of dollars trying to reduce the amount of nutrients -- chiefly phosphorus, but also nitrogen -- that wind up in Lake Winnipeg. These nutrients come from every urban, rural and natural area in the vast Lake Winnipeg drainage basin, which stretches from the Rocky Mountains to South Dakota to northwestern Ontario.
Once in the lake, nutrients promote the growth of unpleasant and occasionally toxic algae blooms. After the algae die, they decompose and deprive the lake of oxygen, upsetting the ecological balance by making the underwater environment inhospitable for fish and invertebrates.
For decades, holding back the nutrients was believed to be the solution to this problem. Now, the province's leading watershed scientists say it makes more sense to hold back the water instead.
"If you want to manage water quality, manage the water," said David Lobb, chairman of the Watershed Systems Research Program, a group of University of Manitoba scientists given five years to solve Lake Winnipeg's eutrophication problem.
After being handed this task in 2010, his group concluded it's pointless to focus on just sewage-treatment plants, hog barns, fertilizers or any other single source of nutrients.
"People focus on things that are of popular interest, like hog barns. But that's not the biggest source of the problem," Lobb said.
The problem is the soil itself, fertilized by decades of nutrient application. Every flood, every snowmelt and every time it rains, nutrients from the soil head toward the lake.
The solution is as elegant as it is simple: Dig holes and alter ditches to store water during the spring. Then either release this water later or pump it back over the farms, using it to nourish orchards, specialty crops, hay or livestock.
"Farmers know they need water, but they drain it like waste," Lobb said. "We have to stop treating water like waste."
Holding water, his group maintains, could slow the drainage process that contributes to flood crests and provide farmers with a means of surviving droughts in addition reducing the amount of phosphorus flowing into Lake Winnipeg. All it would take for this to work on a watershed-wide scale is for farmers to convert one per cent of their land into dugouts, he said.
The challenge is to make this affordable. "We think the only way these retention schemes will have legs of their own is if they are self-propelled by economics," Lobb said.
Agricultural producers are enthusiastic about the idea. Over the past year, 107 holes have been dug across the province, said Lobb, who fears the work is being done before he and his colleagues figure out the best way to build and operate them for the purpose of reducing nutrient loading, mitigating flood crests and making money for farmers.
"We haven't had the opportunity to actually test it," he said. "We're concerned this is getting ahead of us without the science to back it up."
But the U of M working group is optimistic this approach can, over the long term, reduce both nutrient loading and flood crests.
"We're not promising to save the world. I don't think we could have stopped the Assiniboine from flooding in 2011," said soil scientist Don Flaten. "But if we can provide a benefit in eight years out of 10, let's go for it."
Assiniboine alert issued
THE flood outlook for Manitoba remains unchanged, provincial officials said Wednesday.
How much recent rain and snow will change that outlook is still being calculated, they added.
Meanwhile, a flood warning has been issued along the Assiniboine River from Millwood to Virden as river levels are expected to overflow banks.
A flood watch has also been issued for the Assiniboine River from Virden to Brandon, and for the Whitemud River as river levels are approaching the bank and likely to overflow. Flooding in these areas is expected to primarily affect agricultural land.
The province said a high-water advisory has been issued for the Assiniboine River below the Portage Diversion between Portage la Prairie and Headingley due to the increased potential for ice jams.
High-water advisories have also been issued for streams in the Parkland region from the Duck Mountains to Gladstone; the Pembina River, the Swan River and tributaries; and smaller tributaries and drains in southeast and south-central Manitoba.
In North Dakota, the Red River at Fargo has crested. Flows at Grand Forks Wednesday morning were 43,800 cubic feet per second (cfs) and flows appear to be near crest.
In Winnipeg, the Red reached a peak of 18.8 feet above normal winter ice level at the James Avenue monitoring station Wednesday morning. It settled to 18.7 feet in the afternoon. Levels and flows are expected to stabilize in the city during the next 24 hours as operation of the Red River Floodway and the Portage Diversion continues.
Inflows at the Portage reservoir are peaking at more than 16,000 cfs. Flows through the Portage Diversion Wednesday morning were about 8,800 cfs, with 8,100 cfs flows downstream on the Assiniboine River.
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THE Red River is receding at Fargo after cresting early Wednesday morning.
The river crested at 33.27 feet between 2:15 and 3:15 a.m., the U.S. National Weather Service reported.
That represents the 12th-highest flood in Fargo's history, but wound up well below dire predictions made earlier in the spring, when forecasters feared a record flood in Fargo.
The Red's highest recorded level at Fargo remains 40.84 feet in 2009.
The Red was also receding Wednesday at Grand Forks after cresting at 7 p.m. Tuesday.
It is expected to crest at Emerson, Man., at the border some time between May 6 and May 8.
A crest in Winnipeg is expected before Victoria Day. It's expected to crest no higher than 20.5 feet this spring.
Republished from the Winnipeg Free Press print edition May 3, 2013 A6
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