FINAL REPORT - International Joint Commission

Table A-1: Constraints Applied to Each Plan
Constraint 58-DD A + B + D +
6,230 m3/s (220,000
ft3/s) ice formation
Yes.
Yes.
Yes.
Yes.
ANNEX 3
J+ limit in winter
570 m3/s and
1,420 m3/s (20,000
and 50,000 ft3/s) >
75.2 m (246.7 ft).
During ice mgmt –
700 m3/s (25,000
ft3/s). Outside of ice
mgmt – 700 m3/s
(25,000 ft3/s), unless
Lake Ontario > 75.5 m
(247.7 ft), then
1,400 m3/s
(49,400 ft3/s).
During ice mgmt – 700 m 3 /s
(25,000 ft3/s). Outside of ice
mgmt – 700 m3/s (25,000 ft3/s)
unless Lake Ontario > 75.5 m
(247.7 ft) then 1,420 m3/s
(50,000 ft3/s). J limit rarely comes
into play outside of ice mgmt due
to plan stability of releases;
sometimes required during fall
drawdown in high lake years.
Usually 400 m 3 /s
(14,000 ft3/s) but
700 m3/s (25,000
ft3/s) if Lake Ontario
level > 0.3 m (1 ft)
above target.
Limit to min. level
at Long Sault or
Saunders HW in
winter
Yes. Incremental
down to 71.8 m
(235.6 ft) at Long
Sault.
Yes. One hard
constraint at 71.8 m
(235.6 ft).
Yes. One hard constraint at
71.8 m (235.6 ft) at Long Sault.
Yes. Progressive
constraint down to
71.2 m (233.6 ft).
With Ice Qmax =
9,340 m3/s
(330,000 ft3/s)
Yes.
Yes.
Yes. A specific rule that limits
flows through Coteau Control
Structure to maximum of
2,500 m3/s (88,300 ft3/s) based
on local inflows and maximum
Beauharnois capacity.
Yes.
Qtrm after ice
Qmax = 9,900 m3/s
(349,500 ft3/s)
Yes. Set at
9,500 m3/s
(335,500 ft3/s).
Yes. Set at
9,900 m 3 /s
(349,500 ft3/s).
Yes. A specific rule that limits
flows through Coteau Control
Structure to a maximum of
2,500 m3/s (88,300 ft3/s) based
on local inflows and maximum
Beauharnois capacity.
Yes. Set at
9,500 m3/s
(335,500 ft3/s).
2nd qtrm after ice
Qmax = 10,300 m3/s
(363,800 ft3/s)
Yes. Set at
10,000 m3/s
(353,000 ft3/s).
Yes. Set at
10,000 m3/s
(353,000 ft3/s).
Yes. A specific rule that limits
flows through Coteau Control
Structure to a maximum of 4,000
m3/s (141,200 ft3/s) based on
local inflows and maximum
Beauharnois capacity.
Yes. Set at
10,000 m3/s
(353,00 ft3/s).
Open water with
Seaway Qmax =
10,700 m3/s
(377,900 ft3/s)
Yes, if Lake Ontario
level > 75.8 m
(248.7 ft).
Yes.
Yes, if Lake Ontario level ? 75.7 m
(248.4 ft), else the lessor of
11,500 m3/s (406,100 ft3/s) or
channel capacity.
Yes, if Lake Ontario
level > 0.77 m (2.5 ft)
above target,
otherwise 9,910 m3/s
(350,000 ft3/s).
Open water closed
Seaway Qmax=11,500
m3/s (406,100 ft3/s)
Yes.
Yes.
Yes.
Yes.
Qmax < max hydraulic
channel capacity
Yes.
Yes.
Yes.
Yes.
Iroquois HW < 75.6 m
(248.0 ft)
No rule applied,
but there were no
occurrences in the
stochastic case.
No rule.
Yes. A specific rule is applied that
supercedes all other constraints.
No rule applied, but
there were no
occurrences in the
stochastic case.
Perfect ice indicator
forecast
Yes.
Yes.
Yes.
Yes.
“Fair” St. Louis
forecast
Yes.
Yes.
Yes.
Yes.
Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows
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