Lethbridge residents may have heard some talk about drought recently. Most of us are aware that our water supply is pumped out of the Oldman River which flows out of its watershed in the mountains to the west. Some of us may even know that upstream reservoirs hold back water from melting snow and spring rains, to make our water supply more reliable year-round, and so support an extensive industry of irrigated agriculture and various other water users. Most of us don’t fully understand the minutiae of the water licensing system, and we expect that provincially regulated water managers are working to serve our best interests. We expect that the legal system of water sharing that we’ve developed over the last 100-plus years should work sustainably. So, when we hear rumors that we’re in a drought, we trust that our government is following best practices and enforcing regulations meant to protect the public good. Mostly we look at the sky and think it would be nice if it would rain during this hot spell just to cool us down a bit. We continue to water our grass without much thought. As we drive over the bridge we might glance at the river and notice the weir seems taller than usual. Life goes on. No big drought announcements in the news, no mention of drought on the news tab of the City of Lethbridge website.
But an alert needs to be sounded! The river through Lethbridge has dipped to alarmingly low levels over the last few days. The reason? Because government owned and operated dams on the Oldman, Waterton, and St. Mary rivers are holding back flow in hopes of supplying as many license-holders as possible through the coming hot, dry summer. In particular, the stored water is needed to supply the major irrigation districts who are licensed to take a whopping 60% of the average year’s natural flow, followed by municipalities like Lethbridge that expect to take 2%. This means that in dry years, when flows are lower than average, the water allocated to be taken out is proportionally even higher. Keep in mind that the natural river environment does not, and cannot, hold a water license to keep water flowing in the river channel for ecosystem health. The aquatic environment is supposed to be protected by the Water Act, the stated purpose of which is “to ensure a healthy environment and high quality of life in the present and the future”. Dewatering the river to this extent stresses aquatic and riparian wildlife but also impacts natural systems far beyond the river; for example, approximately 85% of all prairie wildlife species rely on riparian areas during at least part of their life cycles.
The Water Act lays out a framework for water management planning and requires a strategy for the protection of the aquatic environment. Since the exact amount of water needed to keep the aquatic environment healthy was still being studied during the drafting of the Water Act in the early 1990’s, the Ministers and Directors responsible were entrusted to set a discretionary Water Conservation Objective (WCO) for ‘environmental protection’. It was arbitrarily set at the lowest amount of water they were prepared to offer to sustain the river. Below this guideline, the critical flow that defines the very bottom of the bucket is called the Instream Objective (IO); this flow is only deep enough to keep intake pipes submerged and effluent diluted to minimum water quality standards. As such, the IO is barely enough flow to prevent fish stranding, and it is certainly not adequate to support the health of the aquatic ecosystem. To find targets for sustainable water management, the exact flows for keeping the whole river ecosystem healthy were determined by a technical team of experts back in 2003. These environmental flows, or Instream Flow Needs (IFN) were higher than the WCO and mimic a more natural range to support whole ecosystem function. However, fully protecting these IFN flows was considered impractical since so many water licenses still needed to be honored. There were some early attempts to develop an impact rating system to find workable compromises, but since then, Alberta’s IFN science has been set aside, and water users have effectively been prioritized at the expense of the natural ecosystem.
If you noticed that the river seems low, you’re right. Daily river flow through Lethbridge has been below the WCO since April. Daily flows in May barely achieved the IO and have even failed this danger threshold for multiple days at a time, and there is no rebound in sight. Natural flows this spring would have been below average, but these conditions would have been up to 14-fold higher through Lethbridge than what the river has experienced so far this spring. Keep in mind that this is occurring during a critical period when prairie rivers need to recharge their water tables to fuel the whole ecosystem through the dry summer.
This isn’t sustainable river management. Instead of buffering the system responsibly and managing river flow sustainably, our reservoirs are being filled with little regard for the way that the river needs to function downstream. The consequences include deterioration of water quality, channel degradation, and chronic stress to wildlife and habitat, as well as the loss of aesthetic and recreational opportunities for people who value our river as more than just an irrigation ditch. We face a paradox: by ‘saving water’ too effectively and by dwelling on maximizing our efficient use of all the water we can ‘save’, we are allowing only a dribble to flow downstream. This approach threatens our river ecosystem and the life-support services that a healthy river provides.
Explore the streamflow situation for yourself at https://rivers.alberta.ca/
Submitted by Lori Goater, M. Sc., P. Biol.
on behalf of the Southern Alberta Group for the Environment (SAGE),
a leading voice for a healthy & environmentally sustainable community.
