Watersheds and Wetlands

CHAPTER 1

Chapter 1

Lesson 1.2 Watersheds Pennsylvania’s Watersheds

Watersheds & Wetlands

PA Academic Standard for Environment & Ecology 4.1.10.A

Describe changes that occur from a stream’s origin to its final outflow.

Learning Objectives

• Students will identify Pennsylvania’s major watersheds and their related river systems and delineate these watershed boundaries.

• Students will describe changes in a river by tracing the river’s flow back to its headwaters and identifying major tributaries.

Watersheds

• What is a watershed? Definition: drainage basin; region drained by, or one that

contributes water to, a stream, lake, or other body of water

• Watersheds are surrounded by topographic highs called divides.

Definition: any ridge between two streams along which precipitation runs off

• Example:

The Continental Divide runs through Canada, the United States, Mexico, and into Central America. It creates the separation between water that drains into the Pacific Ocean and water that drains into the Atlantic Ocean.

Continental Divide

Pennsylvania’s Watersheds• All of the water that drains from Pennsylvania will

eventually make its way to the Atlantic Ocean.• Pennsylvania is organized into 104 watersheds, which

are further divided into basins and sub-basins.

Pennsylvania’s Watersheds

• Great Lakes Basin (Erie & Genesee)• Ohio River Basin• Susquehanna/Chesapeake Basin• Potomac Basin• Delaware Basin

Covering almost half of the state, the Susquehanna River Basin is PA’s largest watershed

Headwaters: New York State’s Otsego Lake

Mouth: Chesapeake Bay

The watershed in which you live, the Delaware River Basin, drains into the Delaware Bay

Major tributaries include the Lehigh River and the Schuylkill River.

Water from this basin provides much of NYC with it’s drinking water.

Ohio River Drainage Basin

Pa’s second largest watershed

(Largest overall)

Drains 34% of PA

Potomac River Drainage Basin

Joins the Susquehanna River at the Chesapeake