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The Watershed

The Long Island Sound Watershed

To consider the future of Long Island Sound requires looking well beyond the wetlands and water of the Sound itself. The composition of water that enters the Sound reflects activities in the entire watershed.

What, exactly, is a watershed? It is the entire land and water area that drains into a stream, river, lake, estuary, or ocean. One watershed is separated from another by a drainage divide where runoff water moves in opposite directions towards the adjacent watersheds.

Picture the Connecticut and Housatonic Rivers. They both flow from north to south. They run parallel to each other. And they both empty into the Long Island Sound. Yet they never run into one another. Why is this? Because there is a divide, a system of ridges, hills, and mountains between the two. When the rains come, the runoff goes one way or the other.

A watershed is usually named by the dominant water source it drains into. The Long Island Sound watershed comprises all the land and water area that feeds into the Sound from Connecticut, New York, Massachusetts, Rhode Island, Vermont, New Hampshire, and Canada. Still smaller watersheds make up big ones, and the Sound watershed is comprised of nine major watersheds and innumerable smaller ones.

The largest of these component watersheds is the basin of the Connecticut River, which begins its journey in Canada, forms the boundary between New Hampshire and Vermont, and bisects both Massachusetts and Connecticut before emptying into Long Island Sound. On its way, the Connecticut River picks up water from 11,263 square miles -7,208,320 acres. The Housatonic and Thames River basins together add another 3,500 square miles of watershed. No major rivers from Long island drain into the Sound, but rivers are not a requirement to be part of a watershed. Numerous small creeks and streams on the North Shore empty into the Sound. Also, the surface water and groundwater from a strip of land between the coast and the moraine on the North Shore flow to the Sound. This region contributes 210 square miles to the Long Island Sound watershed.

A watershed can be large or quite small. The pond in your backyard may drain only one acre. The Long Island Sound watershed drains over ten million acres. For those that live in the Long Island Sound waershed, a clean Long Island Sound begins in your own small watershed – your backyard.

Remember, everyone lives in a watershed.

It's important to keep in mind that the water quality of any stream or lake in the watershed is controlled by the upstream watershed. That is, conditions on the lands that make up the watershed determine the cleanliness of the water body into which they drain. Take a walk, look up the stream, and see what's happening on the land in your own neighborhood. Here is where the efforts of every resident of the watershed - whether on the coastline or as far away as Vermont or Canada - can have a direct effect on keeping Long Island Sound healthy.

Watershed associations

Watershed associations are one type of organization devoted to protecting the environment. The watershed might be a large one, like the Connecticut River watershed, or a smaller but just as important one, like the Mianus River watershed at the border of western Connecticut and New York state.

Successful watershed associations -

  • have recognized the need for protection of the watershed
  • have taken the time to understand and identify significant issues and devised a plan to address them
  • have involved local, state, and, where applicable, federal natural resource officials in the plan development.
  • have put together resource maps of the watershed for visual display of information
  • have enlisted the most sought-after work force available volunteers
  • have conducted an energetic public information and education effort
  • have fought for their rights to restore, improve, and protect the quality of their watershed

Some danger signs for watershed health

  • Erosion from development sites or streambanks that can carry nutrients and sediments, clog rivers and wetlands, and damage fish habitat
  • Trash on the landscape that will end up in rivers, streams, and the Sound
  • Fallen trees and limbs that can block streams and cause flooding
  • Frequent and prolonged algal blooms that indicate a nutrient enrichment problem in natural waters
  • Dead fish and wildlife that indicate pollutants or low oxygen levels in the water
  • Pipes that might be illegal pollution sources spilling into natural waters
  • Odors that might indicate a failed septic system
  • Intrusion on watershed wetlands needed to purify stormwater runoff
  • Closed beaches and shellfish beds that indicate pathogen contamination
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