Yes, the Great Lakes is the largest surface fresh-water system in the world with about 20% of the world’s supply. Much of the water is still glacial originated water. Less than 1% of the water in the Great Lakes is “renewed” on an annual basis with precipitation and groundwater, the remaining 99%+ remains a legacy from the last ice age.
There are hundreds of garden keepers at Niagara Falls. Their job is to keep everything looking great> Here you see the American Falls in the background while the grass is being cut. That bare patch, probably caused by foot traffic by the thousands of tourists that are visiting, will be resodded quickly to keep up appearances.