GBA 2020 - Fall Update GBA UPDATE Fall 2020 As a key component of our strategy and short-term action, we are convening a water levels web symposium on October 24, 2020, with Georgian Bay Forever. Speakers will include senior scientists and key officials involved in both: water levels data gathering and forward predictions; and the various water levels control boards and other water levels control structures in the system. The purpose of this gathering will be to hold discussions aimed at achieving consensus where necessary and providing more clarity on: ≥Water-level fluctuation cycles and their predictability ≥ How water levels control structures in the system are managed ≥Whether we have all the data we need to understand water levels and, if not, what data and data-collection approaches should be prioritized ≥ How existing and to-be-collected data can be rationalized and presented to better inform decision-making ≥What improvements could be made to coordinate between control boards and their coordination with other water levels control structures in the system to better address extreme high and low water levels This symposium will provide GBA members who attend with a better understanding of: ≥ The primary drivers of water levels in M-H and what happened recently to increase water levels from the extreme lows of 2013 to the current extreme highs ≥ The various predictions on future water levels that look at historic trends and climate change impacts ≥ How water levels data is gathered and what improvements may be needed Continued from page 1 Human Engineered Influences/Control Points in the Great Lakes From north to south, the primary human interferences in the system are: Name Description/effect and the AFR* in 000’s ft3/sec Governed by Long Lac / Ogoki Diverts most of the natural flow that used to go to James Bay to Lake Superior for four hydro dams and one pulp & paper mill 6 Ontario Power Generation (OPG) + agreement with six First Nations Control works on the St. Mary’s River Connecting channel between Lake Superior and M-H. Hydro dams, locks, compensating works, fish runs 75 International Lake Superior Board of Control Chicago Diversion Diverts water for water supply purposes from the Lake Michigan watershed into the Upper Mississippi River basin at Chicago 3 US Army Corps of Engineers (USACE) St. Clair River Historical dredging for commercial shipping channels, shore hardening, shifts in sand bars and changes in conveyance 189 No controls Welland Canal Bypasses Niagara Falls for commercial shipping and diverts water from Lake Erie to Lake Ontario 9 St. Lawrence Seaway Management Corp. Niagara River Minor works in the river and a diversion for hydro power; no impact on water levels other than possible adjustment of Black Rock Channel 205 International Niagara Board of Control and USACE Moses Saunders Dam From Lake Ontario to St Lawrence River. Hydro Dam. Shipping interests re: limiting St Lawrence River flow rate + impact of Ottawa River. No flooding of Montreal 262 International Lake Ontario-St. Lawrence River Study Board Sources: IJC and USACE Continues on page 7 Source: International Joint Commission *AFR = average flow rate