The life of a river

April 23, 2011

Altamaha Riverkeeper Sonja Cox on the life of the Altamaha:

Question: Where are the salt water, brackish water and fresh water lines in the Altamaha River?

Cox: The locations of the salt/brackish/fresh water lines will vary with the river stages and tides. You'll see tidal action in the river all the way up to Sansaville Bluff, half-way to Jesup, 60 to 65 miles upriver, though the water there is fresh. In that area there is an immensely valuable and rare freshwater tidal ecosystem that stretches down to the salt water line.

The salt water line has moved inland over the last several decades, due to drought and rising sea level (this line is measured by many people at Fort Pulaski, near Savannah). When the river is low, the salt water line is just below where Lewis Creek joins the Altamaha, and can go down to the Hammersmith area. When the river is really high, it's pushing fresh water out into the ocean so the salt water line is off shore.

Can you describe some of the features found along the course of the river?

At the coast, the river separates into several arms, forming the Altamaha Delta, a vast and ecologically rich system of rivers, creeks, swamps, lakes and marshes that is home to a tremendous number of plant and animal species. The lower Altamaha supports a diversity of life akin to a tropical ecosystem and is known as "The Little Amazon."

On the coast, the ecosystem that is created, influenced and supported by the Altamaha stretches from the north end of Blackbeard Island to the Jekyll Island causeway. When the river gets up, and sheet flows through swamps, its waters stretch out that far - it has a real influence on half the coastline of the state. Depending on the river's flood stage, it covers one-third to one-half of the Georgia coastline all the time. And its economic influence is bigger than that - people from the rest of the state's coast come to the Altamaha Delta and the Golden Isles for commercial and recreational fishing and for other recreation and vacation/hospitality. It's an economic engine for the area and the whole state.

Photo credit Bobby Haven, The Brunswick News

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