Watershed Reading

1. Watershed= area of land that drains precipitation to a body of water

2. Depends on topography- Divided by ridges (hills) drainage divides

Video Video 2

3. Drainage Divide One watershed on one side of hill

Other watershed on other side of hill

Ridges determine where water will flow

4. Drainage Patterns

DendriticLooks like a tree

Most common pattern in PA

Drainage Patterns

Radial Flows from a high point (volcano, mountain)

Circular

Drainage Patterns

RectangularForms right angles

Drainage Patterns

Trellis ** What we have Valleys in areas

of soft rocks; ridges (hills) in areas of hard rock

Drainage Pattern Questions

5. Near volcanos & mountains radial

6. Most common dendritic

7. Alternating hard & soft rock trellis

8. Continental Divide Many continents have a

continental divide (imaginary lines that follow ridges). The continental divide in North America separates into 2 major watersheds West side drains into the Pacific

Ocean East side drains into the Atlantic

Ocean

10-12. PA WatershedsMethacton HS is in the Delaware watershed

Susquehanna is the largest PA watershed.

Into what river will all smaller rivers in this area flow?

If we follow the Delaware River out, what body of water will we come to?

Do our actions around the Schuylkill River affect the Delaware Bay?

13. Importance of Watersheds

Habitats to many organisms Collect and store rainfall Water for agriculture, industry and

households Recharges groundwater Wetlands within the watersheds help to

filter out pollutants and absorb water to prevent flooding

• We are connected to others downstream

• Our waterway flows into other waterways.

• Our watershed drains into other watersheds.

• Our mess / our pollution travels downstream.

Watershed Impacts Downstream

Watershed Pollution Nonpoint Source Pollution Cannot be traced to one specific source- generally comes from all of us.

Stormwater Runoff

When rain or melting snow washes over the ground, pollutants such as leaked oil from cars, dog waste and litter gets carried into our waterways.

It is often nonpoint source pollution, so it’s a little bit here and a little bit there, which adds up!

Agriculture

Pesticides/fertilizers – pollute groundwater & causes eutrophicationAnimal Waste- causes disease/pollutes drinking waterOvergrazing- causes erosion more sediment in water clogs fish gills

Urbanizat-ion

Storm water runoff washes all of the following into bodies of water: Pet waste cleaning chemicals Oil Gas Detergents Paints

Mines Heavy metals in runoff acidify the bodies of water

Industry Smog causes acid rain (chemicals released into air)Industrial waste dumped into waterways.

Waste Disposal

Sewage- untreated human waste causes disease & death in drinking waterLandfills- chemicals/pollutants from garbage sink into soil/groundwater when it rains

Solutions