Watersheds

Additional Resource Information of Mount Desert Island, Maine.

Terrain

Streams

Ponds

Wetlands

Groundwater

Concerns

Watersheds are often defined in simple terms as drainage basins supplying streams with water.

When first introduced into English in the early 1800s, the word "watershed" referred to the ridgeline dividing two valleys. We still use it in a metaphorical sense to describe events from which there is no turning back. By 1840 it came to mean the slope leading away from such a ridgeline or divide, and by the 1880s it was synonymous with "valley" itself.

Watersheds are natural water receiving, storing, and distributing systems; driven by solar energy and gravity; governed by climate and terrain; modified by human land use and development. Providing water and dissolved nutrients to absorptive tissues of plants and animals, they make life possible in both terrestrial and aquatic environments. Without a reliable supply of water throughout the growing season, photosynthesis would not take place, plants would not grow, browsers and carnivores would not eat, and both nature and the human economy would come to a standstill.

In Maine, watersheds divide the landscape into regions centering on major river systems including those of the Saint John, Saint Croix, Penobscot, Kennebec, Androscoggin, and Saco rivers, as well as a number of smaller coastal rivers and embayments. Since every acre of land in Maine is owned by some person or group, and is likely to be managed for a variety of uses, the functioning of Maine's natural watersheds is modified by the practice of forestry, fisheries, and agriculture; construction and operation of hydroelectric dams; roadbuilding; urban and rural development; and activities related to tourism and outdoor recreation, including hunting, trapping, fishing, hiking, camping, wildlife watching and photography, and boating.

The Maine landscape is managed by a partnership between people and nature. If that partnership sometimes fails to produce the results we desire, the cause is often due to our not fully understanding the influence we hold over natural systems, or the responsibility we have to uphold our end of the bargain. When, for example, the Mississippi River ignores levees people erect to keep it in its appointed channel, overflowing into its natural floodplain, we tend to view the resulting flooding as a "natural" disaster, but in fact it is a disaster of our own making resulting from hundreds of years of land use based on less than a full understanding of how watersheds and aquatic systems function in nature.