Useful Information About the Water Levels of Lake Michigan
Life has its ups and downs. So does Lake Michigan.
Before the 1980s, you may recall eating in a beautiful setting while the lake waves pounded on the rocks beneath your dining window. The Red Lantern Inn formerly perched upon the shore where the Lake View beach pavilion now sits. This restaurant succumbed to high lake levels which peaked in 1986 when all five Great Lakes experienced record high levels of over 581 feet.
The high water level period ended in 1997. The lake then proceeded to fall to much lower than average levels. We are now experiencing another cycle of high lake levels. In December for 2017, the lake reached the water level of 580.02 feet. That was the highest December record since its record high in December of 1986.
The Great Lakes experience both short term and long-term cycles of rising water levels. Each of the Great Lakes typically exhibits a seasonal rise in the spring primarily caused by an increase in liquid precipitation, increased runoff due to melting of accumulated snow and low evaporation rates.
An increase in evaporation, a decrease in precipitation, and the accumulation of snowpack on the lake primarily cause the seasonal decline of water levels in fall and winter. Significant water level fluctuations require multiple months, seasons, or years of wet or dry conditions.
Some beaches have plenty of beach space and a steady supply of sand and can handle the highs and lows of the lake’s cycles. Therefore, erosion does not affect those areas as heavily during high lake levels, spring storms, or runoff. However, the beaches at Mount Baldy, Central Avenue, Lake View, and Portage Lakefront do not have that steady supply of sand. These areas are particularly vulnerable to erosion from storm waves.
One-fifth of the length of the park's lakeshore is highly vulnerable to lake level changes. Most of this location is to the east of Burns Harbor, areas from Dune Acres to Michigan City.
Long-shore currents readily replenish sand to the beaches. Man-made structures built into the lake such as the Michigan City breakwall exacerbate the erosion issues by preventing the natural movement of sand from the north down to the south end of the lake. This sand starvation affects beaches directly west of the man-made structures.
In July of 2015, high waves and erosion temporarily closed Central Avenue Beach. An eight-foot drop off with exposed pieces of jagged old road resulted from too much water action and too little sand.
In January of 2018, the trail to the beach at Mount Baldy re-opened with a re-routed trail after a storm washed out a portion of the beach. While Mount Baldy’s trail was re-opening, an area of Portage Lakefront had to close due to storm erosion of the cement overlook and stairs.
Visitors can do their part to help minimize this erosion by staying out of the fenced areas so native vegetation has a chance to regrow and stabilize the dunes. In addition to protecting the shore, stabilizing these areas will also help protect the natural resources like rare plants and animal homes.
Changes to Lake Michigan’s level will continue whether it happens abruptly from storms or more subtly by climate change. As park managers and visitors, we must learn how to adapt to the changes the lake brings.
On your next visit to the beach, take a look around. Do you have a lot of beach between the water and the dunes or do you barely have a dry place to lay a towel? The answer might depend on where you visit along the southern shoreline, what time of year you visit, and where Lake Michigan is in her cycle of ups and downs.
