AWA Wilderness & Wildlife Defenders: Elbow McLean Dam Concerns, Support for ‘Room for River’ Pilot
January 30, 2015
Important flood-risk management decisions are imminent in the Bow watershed, with long-term impacts to our rivers’ natural ability to buffer floods and droughts, purify water and support important aquatic ecosystems. Please add your voice to request immediate disclosure of cost-benefit analyses for flood mega-projects, and to support ‘Room for the River’ solutions that strengthen river ecosystems and move vulnerable infrastructure and homes in low density areas off flood plains.
– Carolyn Campbell, AWA Conservation Specialist
The proposed Elbow River dam upstream of McLean Creek (also called the McLean Creek site, or MC1) will have major ecological impacts upstream and downstream even if never used in a ‘flood’. The ‘dry dam’ description is misleading: a 19 meter high permanent barrier and a permanent reservoir are proposed. A much larger gate, creating a larger reservoir, will be used for undetermined higher flows.
The food web in the upper Elbow, like other Alberta mountain headwaters, relies on organic debris that enters from land runoff, is trapped by log jams and rocks, and is processed by bacteria, fungi and aquatic insects. The steeper grades move sediment downstream and scour stream beds, which among other benefits provide the threatened bull trout population in that area with clean gravels to aerate their incubating eggs. Dam reservoirs replace productive flowing river and riverside habitat with less productive silty, standing water. They also block movement of materials downstream and movement of fish and other organisms upstream and downstream. Relying on dams in order to retain and build more vulnerable floodplain settlements and infrastructure increases the risk of catastrophic consequences from large storm events that overtop dams.
Our best information is the Alberta government will likely decide in February whether to proceed with design and environmental assessments for the Elbow McLean dam. Cost-benefit analyses have been prepared for this and two other proposed flood mega-projects (Springbank diversion and Glenmore reservoir’s tunnel-to-the-Bow). The government should be transparent about these high-cost projects and release these analyses ahead of its decision.
‘Room for the River’ is an approach now used by the Dutch government, recognizing their historic over-reliance on engineering to avert flood risk. ‘Room for the River’ principles generally seek to: make more room in the flood plain for flood waters to disperse or be channeled; move back vulnerable buildings and other infrastructure from rivers; restore natural flood and drought resilient wetlands and river-side vegetation; minimize reliance on berming river edges and on costly dams subject to catastrophic failure. AWA believes this is the wisest flood-proofing and drought-proofing approach, especially in lower density urban communities and rural areas. The comment period ends on January 31 for a report outlining ‘Room for the River’ pilot project ideas on the Bow and Elbow River mainstems from the headwaters to Calgary. A copy of this report is here.
A copy of AWA’s letter to Alberta Environment and Sustainable Resource Development (ESRD) Minister Fawcett is here.
Please write ESRD Minister Kyle Fawcett, ESRD.Minister@gov.ab.ca :
Please copy firstname.lastname@example.org on any ‘Room for the River’ comments, by January 31.
And please copy AWA at email@example.com on your correspondence. Thank you for defending our vital rivers!