The Thames River, one of Connecticut's largest tidal rivers, flowing south from Norwich to the Sound.

influence felt furthest inland on the Connecticut River, where twice-daily rises and falls in water level are noticed as far upstream as Windsor Locks. Even the channel buoys swing around to the beat of the tide they lean upstream when the tide is rising and downstream when it falls.

Despite the influence of tide, tidal rivers are not salty, except very close to the coast. Inland rises in river level are caused by the push of the tide backing up and slowing the passage of fresh water - not the influx of salt water. On the Connecticut, for instance, salt water at the surface reaches only as far north as the Route 95 bridge, during normal flow and tide conditions. Along the river bottom, salt water intrudes further, sometimes as far as the East Haddam Bridge - 16 miles inland. North of Haddam, the entire river always runs fresh. This intrusion of salt water is called the salt water wedge, for the wedge-shaped profile of the fresh water-salt water contact.. The salt water wedge forms because salt water is heavier and sinks beneath the fresh water. Salt and fresh waters do not mix as readily as one might expect, and the salt wedge is remarkably

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