Allegheny River Watershed

Allegheny River Watershed

The Allegheny Rvier Watershed occupies 11,747 square miles in the states of New York and Pennsylvania. The Allegheny River is over 315 miles long, contributing about 60% of the Ohio River's flow at Pittsburgh, Pennsylvania.

Unique Species to the Watershed

The Allegheny River and its tributaries are one of the most biologically diverse watersheds in New York State. The Allegheny River flows through the only area in New York State that was not glaciated during the last ice-age. The geologic history of the watershed, as well as its connection to the Ohio and Mississippi Rivers, has led to its diverse plant and animal life. Species such as the Streamline Chub, the American Paddlefish, Mountain Brook Lamprey, Gilt Darter and the Pocketbook (Mussel) are only found within the Allegheny River Basin in NYS. Several other species, such as the Hellbender, are only found in one other watershed in addition to the Allegheny River Watershed in New York State.

Where Does the Water Go?

The Allegheny River originates from a small mountain small spring in Potter County, Pennsylvania. From its headwaters, the Allegheny River flows 130 miles before reaching the Onoville Marina Park on the Allegheny Reservoir. From the Allegheny Reservoir, the river flows for almost 200 more miles before reaching its confluence with the Monongahela River in Pittsburgh, Pennsylvania. The confluence of the Allegheny River with the Monongahela River forms the Ohio River. The water then flows down the Ohio River to the Mississippi River (the largest river by volume in the United States), before eventually flowing into the ocean at the Gulf of America in Louisiana. 

Triple Continental Divide

The headwaters of the Allegheny River are located on the only "Triple Continental Divide." east of the Mississippi River A continental divide is a boundary line that seperates major river systems. On a mountain in Potter County, Pennsylvania, raindrops falling in the same general area will land in one of three watersheds ...

• The Allegheny River Watershed, which flows into the Ohio River, then the Mississippi River, and eventually flows into the Gulf of America. 
• The Genesee River Watershed, which flows into Lake Ontario, then the Saint Lawrence River, and eventually flows into the Atlantic Ocean
• The Pine Creek-Susquehanna River Watershed, which flows into Pine Creek, then the Susquehanna River, and eventually into the Chesapeake Bay and Atlantic Ocean 

Allegheny River Watershed Land Use

The land use in a watershed generally determines the overall health of the watershed. Threats to water quality within a watershed may include agricultural runoff, industrial pollution, urban runoff, failing sectic systems and inadequate wastewater treatment systems. Forested areas in a watershed act as a natural filtration system. Trees are highly effective at filtering water, as their root system acts as a natural filter - absorbing nutrients (such as phosphorus and nitrogen), and capturing pollutants such as heavy metals, pesiticides, and petroleum hydrocarbons. The process in which trees act as natural filters by absorbing contaminates is known as Phytoremediation.

Allegheny Reservoir Watershed Characteristics

The Allegheny Reservoir Watershed is a sub-watershed to the Allegheny River Watershed. The primary land-use in the Allegheny Reservoir Watershed is forest lands. There is some human development within the watershed, with the largest population centers being the city of Bradford in Pennsylvania and the cities of Olean and Salamanca in New York. Due to the hilly topography of the watershed, the farmland is limited to the more gently sloped valleys created by rivers and creeks, such as the Allegheny River and the Great Valley Creek. Some environmental threats to the watershed include - agricultural runoff, failing septic systems, urban runoff, and inadequate wastewater treatment systems. 

Allegheny Reservoir Land-Use Table

Mississippi River Watershed

The Allegheny River Watershed is a subwatershed to the Mississippi River Watershed. The Mississippi River Watershed is the largest watershed in the United States and the third largest watershed in the entire world, with a drainage basin that is over 1,245,000 square miles in size. From the Appalachian Mountains to the Rocky Mountains, parts of 31 US states and 2 Canadian provinces help to make up the watershed, totaling 41% of the contiguous United States and 15% of North America.