Protecting drinking water at its source is very cost-effective because it can cost 40 times more to treat contaminated water than to protect it at its source, pointed out senior water engineer Don Dobson with Urban Systems.
He was speaking at the Okanagan Water Stewardship Council meeting late last week about whether the Okanagan should embark on a Water Management Plan, and what role source water protection should play.
He noted that source protection high up in watersheds also protects the main stem lakes like Okanagan Lake lower in the watershed, which Rob Birtles of Interior Health pointed out is the basin’s largest reservoir lake.
He was discussing one method of protecting domestic water sources, by excluding everyone from the watershed, instead of permitting forestry, logging, range use and recreation.
“But there’s no way we could exclude people from using Okanagan Lake,” he commented, adding, “It’s all about trade-offs. What are we willing to trade off for the use of that area?”
He favours a multi-barrier approach to achieving safe drinking water, but admits the struggle is how best to protect water quality for the future, to achieve sustainability.
Dobson agreed that exclusion from watersheds, to protect our water sources, would not totally solve the problem. Studies have shown than watershed sources of e-coli are about a third from people, a third from cattle and a third from wildlife, so even if you exclude two-thirds, you can’t exclude wildlife.
Bob Hrasko, manager of the Black Mountain Irrigation District, added that you can’t teach people about watersheds when you exclude them.
However, he said such activities as timber harvesting must be done with the fact it’s being done in a domestic water source in mind. “We need to manage and control the risks,” he said.
He said there was “carnage up there (in the Mission Creek watershed) this spring and I’m not sure what to do about it.”
Whole swaths of Mission Creek’s riparian areas high in the watershed were washed out in this year’s high runoff and rain, he reported, so turbidity in their water did not diminish as usual after the spring freshet was over.
The costs for that district to treat water this year were far higher than usual because of that, and he said the sediment then drops out in Kelowna where the creek flattens out, so the creek bed will be higher there now.
A flight over the creek high up in the watershed revealed many places where huge washouts occurred this spring, and much of it is almost inaccessible to try and get in to stabilize banks. Some is areas are very rugged and steep terrain.
Hrasko believes more substantial setbacks along creeks, where activity is carefully controlled, would make a critical difference in water quality, as well as protecting the big lake.
He noted that a 170-metre setback from waterways would only remove a very small portion of the watershed from other uses, yet it would provide 90 per cent protection.
“A lot happens in the watershed we don’t control, from cattle and wildfire to 4x4ing, biking and partying. We must control pollution at its source,” he said.
He noted that in Europe they are buying back corridors along waterways in order to protect drinking water. while here much of that riparian area is already Crown-owned land.
However, Ken Cunningham, resource manager for this region for the forest, land and natural resource operations ministry, said it won’t work to take a single approach to riparian areas no matter what the terrain. Instead, it’s more about identifying and managing problem areas, he said.
Jason Schleppe of Ecoscape Environmental Consultants Ltd., suggested zoning areas of the watershed where it’s sensitive to disturbance so activities can be controlled there.