Great Lakes Water Levels
What are the factors that influence Great Lakes water levels?
What is the “normal” range of Great Lakes water levels?
What about Lakes Michigan-Huron?
Environmental and Socio-Economic Impacts
Climate Variability and the future…
Water levels go up, water levels go down….
Great Lakes Cross Section
Lake Erie
Lakes Michigan
and Huron
St. Lawrence River
Niagara Falls
804 ft
752 ft 925 ft
1333 ft
Lake
St. Clair
212 ft
379 60 223 89 236 150 77 350 33 52 28 35
Distance in Miles
571.0 ft 579.3 ft 601.0 ft
245.4 ft
20.6 ft
Great Lakes Basin Framework Study
Lake Superior
Lake Ontario
What Drives Water Level Change?
Climate Precipitation + Runoff – Evaporation = NBS
Seasonal changes in climate (annual)
Inflows and Outflows Connecting Channel Flows between Lakes
Water-Level Regulation
Diversions (into and out of basin)
Consumptive Uses
Wind and Storm Events (short term)
Great Lakes Water
Balance
Lake water levels are climatically
driven by seasonal changes in
precipitation and evaporation.
Evaporation is affected by surface
water temperature, wind speed, and
presence/absence of ice cover.
Inflows/outflows via connecting
channels between Lakes
St. Marys River
St. Clair/Detroit River
Niagara River
St. Lawrence River
Source: Great Lakes Environmental Research Laboratory
Month
mm
on
th
e L
ak
e S
urfa
ce
-100
-50
0
50
100
150
200
250
Net Basin Supply (P + R - E)
Jan Mar May Jul Sept Nov Feb Apr Jun Aug Oct Dec
Month
mm
on
th
e L
ak
e S
urfa
ce
-200
-100
0
100
200
300
Runoff Precip Evap
Jan Mar May Jul Sept Nov Feb Apr Jun Aug Oct Dec
Hydrological Components
Lake Superior
Hydrologic Values
1948-2006
Courtesy IUGLS
Long Lac/ Ogoki
154 m3/s (5400 cfs).
Chicago Diversion
91 m3/s (3,200 cfs)
Lake Michigan-
Huron
Lake Erie
56% precipitation
40% runoff
4% diversions
----------------------
43% evaporation
57% outflow
39% precipitation
34% runoff
27% inflow
----------------------
31% evaporation
68% outflow
1% Chicago diversion
79% inflow
11% precipitation
10% runoff
----------------------
89% outflow
11% evaporation
Lake Superior
Lake Ontario
79% inflow
15% runoff
6% precipitation
----------------------
93% outflow
7% evaporation St. Marys River
2110 m3/s
St. Clair/Detroit River
5360 m3/s
Niagara River
5780 m3/s
St. Lawrence
7060 m3/s
Diversions and Impacts
Lake Superior Great Lakes
Courtesy IUGLS
Long Lac/ Ogoki
154 m3/s (5,400 cfs).
Chicago Diversion
91 m3/s (3,200 cfs)
Welland Canal
244 m3/s (8620 cfs)
+9 cm (+3.5”)
0
0
Net +9 cm (+3.5”)
+7 cm (+2.8”)
-4 cm (-1.6”)
-12 cm (-4.7”)
Net -9 cm (-3.5”)
+11 cm (+4.3”)
-6 cm (-2.4”)
-4 cm (-1.6”)
Net +1 cm (+0.4”)
Lake Michigan-
Huron
Lake Erie
Connecting Channel
Diversion in
Diversion out
Diversion within
St. Clair River
Sault St. Marie
Control Structures
Cornwall Massena
Control Structures
Basinwide Drop in
GL Water Levels Lake Ontario
Regulation Begins
August 2013 Forecast
Low Water Impacts
Environmental
Shifts in shoreline position/location (loss/gain wetlands)
Loss of hydraulic connectivity (Georgian Bay wetlands/tributaries)
Changes in seasonal magnitude, timing and duration
Altered tributary flows and Lake circulation patterns
Degradation of water quality
Socio-Economic
Commercial Shipping
Recreational Boating/Marina Operation
Coastal hazards (erosion and flooding)
Public Health and Safety (water quality)
Property Access
Glacial Isostatic Adjustment
Glacial Isostatic Adjustment (GIA) in northern Lake Huron and Lake
Superior exacerbates impact of low Lake Michigan-Huron water
levels. Rates are cm/100 years relative to Lake outlet elevations.
IUGLS - Lake Michigan-Huron Water Levels
Long-term change in the head
between Lakes Michigan-Huron and
Lake Erie.
Possible erosion/increased
conveyance in St. Clair River due to
dredging and sand mining?
1962 last time major dredging
occurred on St. Clair River
(subsequent maintenance dredging
lower reaches only).
No compensation for St. Clair River
dredging (25 and 27 ft channels).
Level Rationale
0 cm (0.0”) No change
10 cm (3.9”) Post 1962 dredging
25 cm (9.8”) Plus 27-ft channel (1959-1962)
40 cm (15.7”) Plus 1930 mining & 25-ft channel
50 cm (19.7”) All alterations since 1850
Restoration Scenarios
8
2
1 5A
IJC Recommendations - St. Clair River
Recommends further investigation to restore Lake
Michigan-Huron water levels
Recommends that the governments undertake further
investigation of options to increase water levels in Lakes
Michigan-Huron by 13 to 25 cm (about 5 to 10 inches).
Investigation to be funded, undertaken, and concluded as quickly
as possible.
Criteria and Deliverables
Explore options that would provide relief during low water
periods, but not exacerbate future high water levels, and
Provide a comprehensive binational benefit-cost analysis and a
detailed environmental impact study of potential structural
options.
IJC Recommendations - Lake Superior
IJC Endorses Lake Superior Regulation Plan 2012.
Plan 2012 delivers robust performance over a wide range of
possible hydrologic conditions.
Preparing supplemental Orders of Approval to implement Plan
Further study of Multi-Lake Regulation is not warranted.
Climate uncertainties, high cost, institutional requirements, and
environmental concerns.
1973 Regulation of Great Lakes Water Levels and 1993 IJC
Levels Reference Study reached similar conclusions.
IJC Recommendations - Multi-Lake Regulation
IJC Recommendations - Adaptive Management
Endorses implementation of a comprehensive Adaptive
Management approach supported by Science and
Monitoring
Established International Great Lakes – St. Lawrence River
Adaptive Management Task Team to further develop a detailed
adaptive management plan.
Strengthening hydroclimate monitoring and modeling;
Ongoing risk assessment;
Ensuring more comprehensive information management and outreach;
Improving tools and processes for decision makers;
Collaborative regional adaptive management study for addressing water
level extremes; and
Integration of water quality and quantity modeling activities.
Climate Variability and Water Levels
According to the most recent climate models, the climate
in the upper Great Lakes basin during the next 30-70
years is likely to be characterized by:
Increase in storm severity - an increase in precipitation and more
frequent and intense storms (weather variability);
Increase in evaporation - an increase in lake evaporation
resulting from higher surface water temperatures and wind
speeds, lack of winter ice;
Change in seasonal timing - increased water supply during
winter/spring months accompanied by larger decreases in
supply during summer/early fall resulting in slight overall annual
declines.
Future Great Lakes Water Levels
Great Lakes water levels are anticipated to remain below long-term historic mean water levels, but generally within the range of historic water levels. Anticipate more extreme and variable water level events, i.e.
anticipate both low and high water level regimes that may exceed historic thresholds, both low and high.
Lower Lake Michigan-Huron water levels may continue to occur irrespective of St. Clair River compensation. St. Clair River compensation may reduce, but not eliminate potential low water-level impacts on Lakes Michigan-Huron.
Adaptive management is still required to plan for (and respond to) extreme water level events whether or not St. Clair River compensation is implemented.
Questions?
Late Holocene Lake Levels - Lakes
Michigan/Huron
Historicalrecord
Historical average(1819 - 1999)
Nipissing IIphase
Algomaphase
v. 2003
MeasuredInferred
1800 2000
177
178
~160-year fluctuation
~30-year fluctuation
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
Calendar year before 1950
175.0
175.5
176.0
176.5
177.0
177.5
178.0
178.5
179.0
179.5
180.0
180.5
181.0
574
576
578
580
582
584
586
588
590
592
594
1950 1500 1000 500 0 500 1000 1500 2000 2500 3000AD BC
YearCourtesy Todd A. Thompson - Indiana Geological Survey
August 2013 Forecast
Lake Superior Water Level Regulation
Sabin Rule (1916-1941)
Rule P-5 (1941-1951)
Rule of 1949 (1951-1955)
1955 Modified Rule of 1949
(1955-1979)
SO-901 (“Guide” 1973-
1979)
Plan 1977 (1979-1990)
Plan 1977A (1990-present)
Plan 2012 proposed…
181.5
182.0
182.5
183.0
183.5
184.0
184.5
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Wat
er
Leve
l (m
, IG
LD 8
5) Lake Superior Level
Pre-Project
Plan 77A
175.0
175.5
176.0
176.5
177.0
177.5
178.0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Wat
er
Leve
l (m
, IG
LD 8
5) Lake Michigan-Huron Level
Plan 77A and PreProject
St. Clair River Restoration