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 VideoVideo 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  Dendritic  Looks like a tree  Most common pattern in PA

Drainage Patterns  Radial  Flows from a high point (volcano, mountain)  Circular

Drainage Patterns  Rectangular  Forms 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

PA Watersheds Methacton 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!

Agricultur e Pesticides/fertilizers – pollute groundwater & causes eutrophication Animal Waste- causes disease/pollutes drinking water Overgrazing- 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 water Landfills- chemicals/pollutants from garbage sink into soil/groundwater when it rains

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