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Let us look at the word "watershed" in order to understand what it is. A watershed is a
drainaige basin surrounding and "shedding" water into a stream, a river, a lake, or wetland.
Also called a catchment area, watersheds captures water such as precipiatation and channels it
to a common outlet flowing from higher elevations to lower ones. The outlet can be the mouth
of a river as it flows into another river or into the ocean. Tributaries are smaller streams or
rivers that empty into larger mainstream rivers of the watershed.

Watersheds vary in shapes and sizes. They can be a few square kilometers, such as one
that drains precipitation into the local Salmon Brook. The watershed can be significantly
larger such as the entire system of tributaries that, with the Salmon Brook, feed into the
Connecticut River and the Long Island Sound.

As water travels from local areas into larger and larger waterways and eventually into the
ocean, they transport fine materials, or sediment, throughout. Sediment is crucial to the life
of the watershed. Sediment and organic matter make up soils. Soils have differing textures,
mineral contents, and water holding and transmitting properties. This determines which plants
grow, how much water runs off the land and how much erosion will occur in areas.

Plant roots slow and absorb runoff, releasing the water slowly into streams, groundwater,
and back into the atmosphere trough transpiration. This vegitation also provide food and
habitats for fish and other wildlife.

Humans put pressure on watersheds as our demands for water, food, housing,
transportation, power, irrigation, and recreation grow. Construction of survaces inpervious to
water such as parking lots and streets prevent the gradual absorption of water in those areas,
forcing direct flows of water via storm drains and dirches. This increased run off can lead to
flooding, erosion, and polluntion.

A watershed is an interconnected land/water system. Polluntants anywhere in the
watershed can be moved with the water and effect larger areas further down in the system.
This means that an oil spill on a mountain can change the water and soil quality for plants and
animals at the mouth of a nearby river.

Natural occurances can also greatly effect the wildlife of a watershed. Flooding can leave
behind stream sand as the receeding water removes the nutrient rich soil. Native plants and
trees thus die off and animals relyant on them for food and shelter suffer. Seasonal flooding
can lead to erosion. Erosion can take away nuntrient rich soil from plants, habitats from
animals, and sometimes even ground out from under our houses.