Landscape Health Protects Us All
Written by C. Lacombe
Protecting the Elbow River and the people who live by it, drink it and enjoy playing in and around it requires a slightly different focus, according to a life-long lover of the Eastern Slopes of Alberta’s Rockies.
“I find one of our great ironies is that when we talk about water management, we focus on our rivers and lakes. When in fact, by the time water is in rivers and lakes, most of the important water management decisions have been made because they are land use decisions,” says Kevin Van Tighem, author and former Park Superintendent, Banff National Park.
Kevin Van Tighem addresses ERWP AGM tour participants June 19. Photo: Mike Murray
He asserts that all the land west of Calgary is “a giant green, living reservoir.” Most of the water that ends up in our streams, rivers and lakes comes from the mountains and foothills of the Eastern Slopes of the Canadian Rockies. He compares the region to a giant sponge. He says over 80 percent of the water that comes down the Elbow River originates as snow. When we change the landscape’s condition, we change the way the land receives, retains and releases snow over the seasons.
For example, when logging clears large patches of land, it accumulates more snow because snow doesn’t get caught up in trees to blow away or evaporate. On the upside, this stores more water during the winter, but that water comes all at once during the short spring melt period and, potentially, as a flood.
Conversely, if forestry took small patches of forest, snow would accumulate in the exposed areas, but still have some shade to slow its melt. The water would infiltrate the ground in the spring, find its way to aquifers and to the rivers later in the summer when we need it.
A change in forestry practices can have a large effect on the amount and timing of water and water movement.
So Van Tighem asks, “Do we want to pay for services and help forestry be viable and improve our water supply? Or do we want the status quo; which means we’ll be bailing out our basements more frequently than we would otherwise?”
Van Tighem says that logging is increasing in the Elbow River valley, so we need to have this discussion now.
Another example he offered is Off Highway Vehicle (OHV) use. Part of the challenge as he sees it is that Alberta did not regulate OHV activity when it began. Much of the OHV traffic and damage takes place in what Van Tighem
called the living sponge. “If you compact it, slice it, allow it to wear down, it loses its capacity to hold water and it releases water faster.
It (OHV recreation) didn’t come with any planning or development and has resulted in linear slashes through that green, living sponge.” The lack of planning means that many of the pathways through the forests are excellent rills for moving water off the landscape quickly causing erosion that eventually leads to larger gullies.
“As those cuts erode, they open up the existing water table and create leaks. All these lovely little creeks you can walk along all summer long are bleeding wounds – that’s ground water draining out quickly instead of slowing moving down to the rivers.”
These were two examples Van Tighem offered, but he expressed some astonishment that 40 years of human activity now looks as though we designed our activity to dry out the foothills landscape.
“Everything we do is the perverse opposite of what we would do if we managed the watersheds strategically.”
He then points out that our water management focus that turns our attention to the behavior of rivers, leads us to speculate about the use of dry dams instead of landscape restoration.
“You can build your dry dam, but if you haven’t made the headwaters healthy, the rate at which dry dams accumulate sediment and the frequency with which extreme flows will challenge them increase. There is still a sick landscape feeding a dysfunctional water supply down to those dams.” He then enumerates some of the other challenges with dry dams such as debris accumulation, fish displacement and stranding.
“Any time you muck around the natural flow process of rivers, you really affect the ecosystem. What really troubles me is that we have a sick watershed and rather than make it healthy, we want to make it sicker by doing the technological dam fixes that are just another part of it,” he says with some frustration.
He also mentions that the proposed dry dams may look as though they solve downstream problems, but they can actually increase problems. They create new flood plain where it didn’t exist before, undermine adjacent slopes and deepen channels. They also run the risk of failing during a large flood event and causing much more damage.
He suggests that instead we mimic the original dry dam builders – beavers. Beavers build many small dams that capture spring flood waters. If any one should fail, only a small surge moves downstream. He says he spoke to an engineer that says we have many places where roads cross creeks. We could construct those creek crossings as dry dams with spillways and save both the roads and the upstream watershed. We could also stop killing all the beavers.
“Instead of building something huge and dangerous on a major river, we should be looking at existing stream crossings and how we can design them differently,” he says.
This would contribute to a healthier landscape in the headwaters by holding small amounts of water in many places where it has time to release sediment, infiltrate to the water table and support the local ecosystem. It also protects downstream water users and ensures a more natural slow release of snowpack storage for summer needs.
“Our decisions are the things that choose our future for us. We could be choosing to make those headwaters all that they were and even more in terms of healthy, green, wet, well-watered, nurturing places,” he says.
Download this article: pdf July 2015 ERWP Newsletter - Kevin Van Tighem (1.17 MB)