217217217
200200200
255255255
000
163163163
131132122
2396553
110135120
1129256
62102130
1025648
130120111
237237237
8011927
252174.59
“The views, opinions and findings contained in this report are those of the authors(s) and should not be construed as an official Department of the Army position, policy or decision, unless so designated by other official documentation.”
Melissa Kropfreiter, PEHydraulic Engineer
Great Lakes Hydraulics and HydrologyUSACE Detroit District10 August 2019
GREAT LAKES WATER LEVELS1
2
Hudson Bay
LakeOntario
Lake St. Clair
St. Clair River
DetroitDetroit River
St. Marys River
Niagara River
Minnesota
WisconsinMichigan
Illinois
Indiana Ohio PENNSYLVANIA
Quebec
Ontario
Diversion Dam
Control Dam
Long Lake
LakeNipigon
Thunder Bay
Diversion Dam
AguasabonRiver
Albany
River
DuluthKeweenawPeninsula Canada
UnitedStates
Sault Ste. Marie
Sault Ste. MarieLake Superior Control Structure
StraitsOf Mackinac
Georg
ian
Bay
Green Bay
Gre
enBay
Chicago Sanitary& Ship Canal
Illinois Waterway
Bay City
Toledo
Cleveland
Toronto
Buffalo
Oswego
Welland CanalNiagara Falls
Cape Vincent
Ottawa River
OttawaLAKE ST. LOUIS
Ogoki Project
Long Lake ProjectControl Dam
Nipigon River
Kenogami River
Ogoki River
Albany
Riv
er
Bas in
Lake Superior
Lake
Mi c
ha
ign
Chicago
Great
in
a
ge
Lake
Hu
ron
LakeErie
Missi
Ri
ssippi
aive
nr B s
Montreal
St. Lawrence River
Lakes
B
as i
n
Milwaukee
Pennsylvania
New York
Rochester
Kingston
St. Lawrence RiverControl structure
Cornwall
Massena
The Great Lakes Basin• 14,000 miles of shoreline• 95,000 square miles of water• 200,000 square miles of land• 8 States & 2 Provinces
MONITORING GREAT LAKES WATER LEVELS
100 years of coordinated water level data
Forecasting since the 1950s
MONITORING GREAT LAKES WATER LEVELS3
Daily Average Water Levels Based on Lake-Wide Average Network• Lake Superior: Duluth, Marquette, Pt. Iroquois, Thunder Bay, Michipicoten• Lakes Michigan-Huron: Harbor Beach, Ludington, Mackinaw City, Milwaukee, Tobermory, Thessalon• Lake St. Clair: St. Clair Shores, Belle River• Lake Erie: Toledo, Cleveland, Port Stanley, Port Colborne• Lake Ontario: Oswego, Rochester, Toronto, Kingston, Port Weller, Cobourg
4
> 1 decade low waterRecord Rise
Record highs
Record lows
GREAT LAKES WATER LEVELS(1918-2019)
5
2012 VS. 2019 ON THE ST. CLAIR RIVER6
WindSet-upStorm Water Level
Undisturbed Water Level
Wind
Lake profile showing wind set-up
HIGH WATER LEVEL IMPACTS 7
• Shoreline erosion• Less beach
• Property damage• Greater impact from seiche
(wind) events• Ice jams produce greater
chance for flooding
Seiche
HIGH WATER PHOTOS8
Courtesy of USCG and the Port of Monroe, MI
ANNUAL WATER LEVELS AND THE HYDROLOGIC CYCLE9
WINTER SPRING SUMMER FALL
Snowaccumulation
Snow melt, rainfall,increased runoff
Increasedsunshine warmslake water
Increasedevaporation
Typical Lake Michigan-Huron Water Level
FACTORS IMPACTING WATER LEVELS10
Inflow from Upstream Lake Ev
apor
atio
n
Prec
ipita
tion
Outflow
Run
off
Net BasinSupply
Net Total Supply
WHAT HAPPENED IN THE LAST YEAR?11
Beginning of August 2018 Level: 602.55 ftBeginning of August 2019 Level: 603.27 ft 0.7 ft rise
0.7 ft rise
August 2018 – August 2019• Wet Fall• Snowy winter• Good ice cover• Wet spring• High NBS
FACTORS IMPACTING WATER LEVELS AUGUST 2018 – AUGUST 2019LAKE SUPERIOR
12
Inflow from Upstream Ev
apor
atio
n
Prec
ipita
tion
Run
off
Net BasinSupply
Net Total Supply4.0 ft
3.8 ft0.2 ft
3.3 ft*
*Pre-Project (unregulated, natural) St. Marys River flows would have been the equivalent of 3.5 ft on Lake Superior
NTS – Outflow = Change in lake level
(Inflow + NBS) – Outflow = Change in lake level(0.2 + 3.8) – 3.3 = 0.7 ft
Outflow
New record highs set in May, June, and July
Projected levels (dashed green line):• Expected to be at historic
record high in August
Forecasted range (shaded red area):• 9 to 13 inches above long term
average levels• Above last year through
October
SIX MONTH WATER LEVEL FORECAST13
1.3 ft rise from August 2018 – August 2019
• Snowy winter• Good ice cover• Wet spring• High NBS
WHAT HAPPENED IN THE LAST YEAR? 14
Beginning of August 2018 Level: 580.57 ftBeginning of August 2019 Level: 581.88 ft 1.3 ft rise
FACTORS IMPACTING WATER LEVELS AUGUST 2018 – AUGUST 2019LAKE MICHIGAN-HURON
15
Inflow from Upstream Lake Ev
apor
atio
n
Prec
ipita
tion
Outflow
Run
off
Net BasinSupply
Net Total Supply6.9 ft
4.6 ft
5.6 ft
2.3 ft*
*Pre-Project (unregulated, natural) St. Marys River flows would have added 2.4 ftto Lake Michigan-Huron
NTS – Outflow = Change in lake level
(Inflow + NBS) – Outflow = Change in lake level(2.3 + 4.6) – 5.6 = 1.3 ft
Within 1 inch of record high in June and July
Projected levels (dashed green line):• Begin seasonal decline in
August
Forecasted range (shaded red area):• 28 to 31 inches above long
term average levels• 7 to 15 inches above last year’s
levels
16
SIX MONTH WATER LEVEL FORECAST
17
LATEST WATER LEVEL INFORMATION
https://www.lre.usace.army.mil/Missions/Great-Lakes-Information/Great-Lakes-Information.aspx
18
LIVING ON THE COAST
https://www.lre.usace.army.mil/Portals/69/docs/GreatLakesInfo/docs/CoastalProgram/Living%20on%20the%20Coast%20Booklet.pdf?ver=2016-06-06-105107-683
19