Flash floods occur due to rain even without a lake, but a lake can accelerate and exacerbate the effects. However, natural forces – rain, snow, ice cover, temperature, evaporation – are the most important factor affecting water levels in the Great Lakes. Increasing frequency and duration of droughts and associated low water levels increase nutrient concentrations and residence time in rivers, increasing the likelihood of harmful algal blooms and low oxygen conditions. Increasing rainfall intensity and the impacts of forest fires and fertilisers are increasing sediment, nutrient and pollutant loads in surface waters used by downstream water users7,8 and ecosystems.
When one thinks of climate change, temperature changes, especially warming, are often the first thing that come to mind.
Can lakes cause flooding?
Most lakes have fluctuating water levels, but they don’t usually flood the way rivers do because lakes usually have drainage streams or rivers that drain them. Senior Fellow, Bill Graham Centre, University of Toronto & Associate Professor, Western Michigan University Every fall I take my environmental studies class camping at Sleeping Bear Dunes National Lakeshore on Lake Michigan. But if these upper lakes are directly connected to Lake Erie, the Niagara River and Lake Ontario, why didn’t scientists predict the flooding? With so much water draining through the system and Lake Ontario at the end of the chain, regulators say they have tried to relieve people and property both upstream and downstream of the dam by controlling the amount of water flowing through.
There are more variables that control what happens to a particular river or stream to control flooding because, unlike a lake, the water can come from many different areas.
How do lakes prevent flooding?
Water then flows off the land in quantities that cannot be carried in river channels or retained in natural ponds, lakes and man-made reservoirs. This can help prevent damage, but it is better to combine dykes with other flood protection methods to reduce the risk of dyke failure. The Environment Agency says that while dredging can improve general land drainage, it cannot prevent rivers from bursting their banks due to the enormous volume of water. In an act of successful flood prevention, the federal government offered to buy up flood-prone properties in the United States to prevent repeated disasters after the 1993 Midwest flood.
Can man-made lakes flood?
There are many different sizes of man-made lakes, each intended for domestic or industrial use, e.g. irrigation, stormwater management, energy and resources. Water loss can occur through evaporation (especially in arid regions) and, depending on the reservoir bottom, through seepage (small reservoirs are often lined). Some reservoirs have been known to flood due to a defective or outdated dam, but levels usually fluctuate only slightly. There is wide variation in the size of man-made reservoirs such as large artificial lakes or small pond-like bodies of water.
Seasonal flooding that follows a predictable pattern can be easily contained with an appropriately sized artificial lake that can accommodate the additional runoff.
Can the Great Lakes flood?
Instead, the five Great Lakes are subject to natural seasonal fluctuations, with levels both above and below historic highs over the past four decades. Muskegon on Lake Michigan received 7.45 inches more rainfall than average in the first eight months, while Sault Ste Marie on Lake Superior received about 9 inches more than average during the same period. After the species was discovered in Lake Ontario last fall, scientists and officials are trying to get ahead of a possible invasion before it’s too late. Says Eric Anderson, an oceanographer at NOAA’s Great Lakes Environmental Research Laboratory.