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

20

QUESTIONS?Melissa Kropfreiter

(313) 226-6443Melissa.A.Kropfreiter@usace.army.mil