Lake Erie Water Levels
What you need to know
Since the last glaciers retreated more than 10,000 years ago, Great Lakes water levels have varied dramatically. The difference between the amount of water coming into a lake and the amount going out is the determining factor in whether the water level will rise, fall, or remain stable. When several months of above-average precipitation occur with cooler, cloudy conditions that cause less evaporation, the levels gradually rise. Likewise, prolonged periods of lower-than-average precipitation and warmer temperatures typically result in lowering of water levels.
Why do water levels fluctuate?
There are three kinds of water level fluctuations: short-term, seasonal, and long-term.
Some water level fluctuations are short-term and are due to winds or changes in barometric pressure. These short-term fluctuations, usually lasting from a couple of hours to several days, can be very dramatic and due to storms or ice jams. Storm surge or wind-set up is when high winds from one direction can push the water level up at one end of the lake and make the level drop by a corresponding amount at the opposite end. When the wind subsides abruptly the water level will often oscillate back and forth like a pendulum until it stabilizes again. Similar to water sloshing back and forth in a bowl, this phenomenon is known as a seiche. Lake Erie is most susceptible to storm surges and seiches due to its east-west orientation in an area of prevailing westerly winds and its generally shallow western end.
Seasonal fluctuations range on average from 12 to 18 inches from winter lows to summer highs. The Great Lakes are generally at their lowest levels in the winter months. In the fall and early winter, when the air above the lakes is cold and dry and the lakes are relatively warm, evaporation is greatest. As the snow melts in the spring, runoff to the lakes increases. Evaporation from the lakes is least in the spring and early summer when the air above the lakes is warm and moist and the lakes are cold. At times, condensation on the lake surface replaces evaporation. With more water entering the lakes than leaving, the water level rises.
Long-term fluctuations occur over periods of consecutive years and have varied dramatically since water levels have been recorded for the Great Lakes. Continuous wet and cold years will cause water levels to rise. Conversely, consecutive warm and dry years will cause water levels to decline. Long-term fluctuations are shown on the hydrograph under Tracking Water Levels below. A hydrograph is a plot of water levels versus time. Global warming and a phenomenon known as the ‘greenhouse effect’ could cause significant changes in long-term lake levels. Although debatable, most predictions indicate that global warming would cause prolonged declines in average lake levels into the future. Besides natural climatic variability and potential man-made climate change, other factors can affect long-term fluctuations, including changes in consumptive use, channel dredging or encroachment and movement of the earth’s crust.
Tracking Water Levels
A hydrograph is a plot of lake levels versus time. This Hydrograph shows monthly average water levels from 1985 to 2000.
Monthly means and Daily Averages
Daily and Monthly mean lake-wide average water levels for Lake Erie (1918-2019)
Quarterly Climate Impacts and Outlook
New record high water levels were set for in May on Lake Erie. Levels in June were the highest beginning-of-month levels ever recorded on Lake Erie.
Water Level Forecasts
Army Corps of Engineers Weekly Great Lakes Water Level Update
How do water levels impact the Erie Community?
Presque Isle State Park’s manager and a Pennsylvania DEP chief talk about water levels at the peninsula.
This interview was taken from the Erie Times-News. See the full article here.
IMPACTS OF HIGH WATER LEVELS
Increased sediment transport in the nearshore zone
Alterations to stream and river mouths
Damage to coastal infrastructure
Flooded marinas, docks, boat launches
Shrinking beaches in areas often used for recreation
Increased impacts from storms
Increase in coastal wetland habitats associated with drowned river mouths; some wetland areas may experience erosion
Where to go for more information..
The information on this page was taken from the U.S Army Corps of Engineers, NOAA-GLERL, the Great Lakes Sea Grant Network, and other sources listed below.