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
Lakes Michigan Lake Lake Superior and Huron Niagara Falls St. Clair Lake Erie 601.0 ft 579.3 ft 571.0 ft
Lake Ontario
245.4 ft 212 ft 925 ft 752 ft St. Lawrence River 20.6 ft
1333 ft 804 ft
379 60 223 89 236 35 150 77 28 52 33 350
Distance in Miles Great Lakes Basin Framework Study 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)
Source: Great Lakes Environmental Research Laboratory 300 Great Lakes Water Runoff Precip Evap 200
Balance 100
0 Lake water levels are climatically -100
mm onmm the Surface Lake driven by seasonal changes in -200 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec precipitation and evaporation. Month 250 Evaporation is affected by surface Net Basin Supply (P + R - E) 200
water temperature, wind speed, and 150 presence/absence of ice cover. 100 50 0 -50
mm onmm the Surface Lake Inflows/outflows via connecting -100 Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec channels between Lakes Month
St. Marys River
St. Clair/Detroit River
St. Lawrence River
Hydrological Components
Lake Superior Hydrologic Values 56% precipitation Long Lac/ Ogoki 1948-2006 40% runoff 154 m3/s (5400 cfs). 4% diversions ------Lake Ontario 43% evaporation 57% outflow 79% inflow 15% runoff 6% precipitation ------Lake Michigan- 93% outflow Huron 7% evaporation St. Marys River 39% precipitation 2110 m3/s 34% runoff 27% inflow ------31% evaporation 68% outflow St. Lawrence 3 1% Chicago diversion 7060 m /s
Lake Erie Niagara River 5780 m3/s 79% inflow St. Clair/Detroit River 11% precipitation 5360 m3/s 10% runoff ------89% outflow 11% evaporation Chicago Diversion 91 m3/s (3,200 cfs) Courtesy IUGLS Diversions and Impacts
Lake Superior Great Lakes
+9 cm (+3.5”) Long Lac/ Ogoki Connecting Channel 0 154 m3/s (5,400 cfs). 0 Diversion in Net +9 cm (+3.5”) Diversion out
Diversion within
Lake Michigan- Sault St. Marie Huron Control Structures
+11 cm (+4.3”) -6 cm (-2.4”) Cornwall Massena -4 cm (-1.6”) Control Structures Net +1 cm (+0.4”)
Welland Canal Lake Erie 244 m3/s (8620 cfs) St. Clair River +7 cm (+2.8”) -4 cm (-1.6”) -12 cm (-4.7”) Net -9 cm (-3.5”)
Chicago Diversion 91 m3/s (3,200 cfs) Courtesy IUGLS Lake Ontario Basinwide Drop in Regulation Begins GL Water Levels 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 Restoration Scenarios Long-term change in the head between Lakes Michigan-Huron and Level Rationale Lake Erie. 0 cm (0.0”) No change 10 cm (3.9”) Post 1962 dredging Possible erosion/increased 25 cm (9.8”) Plus 27-ft channel (1959- conveyance in St. Clair River due to 1962) dredging and sand mining? 40 cm (15.7”) Plus 1930 mining & 25-ft channel 50 cm (19.7”) All alterations since 1850 1962 last time major dredging occurred on St. Clair River 1 5A (subsequent maintenance dredging 2 lower reaches only).
No compensation for St. Clair River 8 dredging (25 and 27 ft channels).
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
IJC Recommendations - Multi-Lake Regulation
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 - 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
178
181.0 ~160-year fluctuation 594 Measured ~30-year fluctuation 180.5 Inferred 592 Nipissing II 180.0 177 phase 590 179.5 588 179.0 1800 2000 178.5 586 Algoma 178.0 phase 584 Historical record 177.5 582 177.0 580 Historical average 176.5 (1819 - 1999) 578 176.0 175.5 576 v. 2003 175.0 574 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Calendar year before 1950
1950 1500 1000 500 AD 0 BC 500 1000 1500 2000 2500 3000 Year Courtesy 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… Plan 77A and PreProject
184.5
Lake Superior Level 184.0
183.5
183.0
182.5 Pre-Project
182.0
Water Level (m, IGLD 85) IGLD (m, Level Water Plan 77A
181.5 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
178.0
Lake Michigan-Huron Level 177.5
177.0
176.5
176.0
175.5 Water Level (m, IGLD 85) IGLD (m, Level Water 175.0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 St. Clair River Restoration