A bunch of little ideas can hold back lots of water

It tells you something about the times when the experts use comparisons to recent flood events to help us understand the severity of the threat we face this spring.

If we get favourable weather between now and spring thaw, it's going to be as bad as 2009. If we don't, get ready for another Flood of the Century, a mere 14 years after the last one.

Instead of occurring once or twice in a decade since 1950, floods of some description have become almost an annual event someplace in Manitoba over the past decade, with significant flooding in 2001, 2002, 2006, 2009, 2010.

On top of last spring's flood, heavy rains at the end of May drowned 665,000 acres of farmland. We even had flash floods in October, after a so-called "weather bomb" settled over the province with monsoon-like rains and high winds. Much of the province's farmland entered winter in a saturated state, which in itself has ominous implications for the spring.

The Interlake is almost filled to overflowing, and farmers in the watersheds south of it fear what will happen to them when it does. Farmers in the already flooding Assiniboine River valley worry about recently announced plans to send more water into the system from Saskatchewan.

In other words, we've got water coming at us from all directions, including from below, with all that saturated soil and above, whatever more the heavens deliver.

And if that isn't enough to make you water weary, there's more to come. The U.S. Geological Survey has predicted a "highly significant chance" for the wet cycle to continue for at least 10 to 15 years and moderate chances for it to continue beyond that.

While we can generally agree on the fact that we have too much moisture in Manitoba at the moment, when it comes to solutions, we quickly divide into camps -- those who want more protection and those who want more drainage.

Predictably, the soggy situation has increased the calls for better dikes, deeper ditches and more drainage. Some even suggest dredging the river to get that water flowing out to sea as quickly as possible.

The Red River Basin Commission, a bilateral coalition of municipal leaders focused on finding long-term water management solutions for the Red River basin, has been raising a different "D" word lately: delay.

What if there wasn't so much water trying to drain through the river system at once?

A soon-to-be released report is the first that takes a serious look at upstream storage as a means to reduce peak flows on the Red River by 20 per cent.

It estimates 885,000 acre-feet of storage, (885,000 acres storing one foot of water), at an estimated cost of $1 billion would be enough to do the job.

A 20 per cent reduction in peak flows would be enough to avoid the 1997 dike breach at Grand Forks.

That seems like a lot of land and a lot of water, not to mention a lot of money, to make a small difference. But small differences can add up to big benefits.

Just ask the farmers living along the Manitoba escarpment west of Miami who have been studying how water, land and humans interact on the landscape for the past 26 years.

The Deerwood Soil and Water Management group turned to small dam structures in the South Tobacco Creek watershed to try to reduce the damage from flash flooding in spring, and after heavy rainfalls. There were many who pooh-poohed the idea, saying such small water-control systems would tie up farmers' land and be of little benefit.

The farmers were proven right. Localized, high-intensity runoff has been reduced by as much as 90 per cent by individual dams. Today, 26 headwater retention structures control water flows across 30 per cent of the 18,000-acre watershed, resulting in a 25 per cent reduction in overall peak flows. It is saving local municipalities and property owners millions in downstream erosion damages.

There are added benefits. The stored water can be used for back-flooding pastures or irrigation. It also serves as a nutrient sink, measurably reducing the nutrients lost into waterways, which can later become a problem with eutrophication in lakes.

That alone justifies public investment into putting this in place. Would it alone solve Manitoba's excessive water situation? Probably not.

But when the sandbagging is over and the cleanup is done, instead of searching for the next big D idea to deal with Manitoba's extra water, maybe it's time to consider a bunch of little ones.

Laura Rance is editor of the Manitoba Co-operator. She can be reached at 792-4382 or by email:

laura@fbcpublishing.com

Republished from the Winnipeg Free Press print edition February 5, 2011 B9