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Water levels on Lake Huron are constantly changing. They can change within a few hours in response to a storm system, undergo seasonal changes in response to higher evaporation rates in the late fall, winter and spring, and higher precipitation and melting snowpack in spring, to long-term changes that can see Lake Huron fluctuate within a range of about two metres between highs and lows. There are also many other factors that influence water levels on Lake Huron, both human and natural drivers of change.
Long-term changes are determined by the difference between the amount of water coming into the lake, and the amount going out. When several months of above-average precipitation occur with cooler, cloudy conditions that cause less evaporation, the levels gradually rise. This summer on Lake Huron we’re experiencing continuing high water levels, partly due to the high amount of ice cover we had this winter, combined with a wet and cold spring. Although these natural processes are the main driving factor behind water level changes, human activities can have a major influence as well, such as water diversions and human-induced climate change.
Water levels tend to peak each year mid-summer, and begin to decrease as we move into the fall. If you are interested in learning more, the Great Lakes Water Levels Dashboard, found here, is an interactive online tool that allows you to see current and historical water levels all the way back to 1918, along with predictions for upcoming changes.
Fluctuating lake levels are part of the magic of living along the coast, and many coastal ecosystems, such as coastal wetlands, depend on these changing water levels to thrive. The dramatic changes experienced recently underscore our need to be adaptable and flexible to the natural rhythms of the lake. That said, we understand that the higher levels we've been experiencing can be disheartening to many people who have shoreline cottages or visit our beaches. As people made their way to the beach last summer, some arrived wondering where the beach had gone! Particularly in dune areas, the shoreline appeared to be overtaken with dune grasses. This can be frustrating to people who are looking for "towel real estate" during the summer, however dune grass serves an important function! The vegetation and root structure provides some resistance to erosion, and allows for a gradual and sustainable exchange of sand between the dunes and the beach. Removing dune vegetation can accelerate erosion and alter the natural balance, causing beaches to deteriorate over time.
So how can you aid the long term protection of your beach?:
· Leave native dune vegetation, such as Marram grass, to perform its role.
· Hardened structures, like seawalls, revetments and groynes can disrupt sand movement, can diminish the amount of sand available to the beach, and cause issues in other nearby areas of the shoreline. Avoid hardened structures in beach and dune areas (and most coastal areas, for that matter).
· Motorized vehicles, like all-terrain vehicles, can be very destructive to dunes. Use these vehicles on roadways and designated pathways away from the beach.
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