Transcript watershed notes.ppt

WATERSHEDS
AND POLLUTION
What is a Watershed?
 A watershed is simply: an area of land where runoff collects and
then is a water supply to a large lake or river.
 It is also known as a Drainage Basin
 Watersheds consist of surface water & groundwater.
Groundwater: underground water
- aquifer reservoirs,
water table
Surface water:
- runoff, streams, rivers,
- Lakes reservoirs
Groundwater link
 http://www.brainpop.com/science/earthsystem/groundwater/
Are we in a watershed?
http://cfpub.epa.gov/surf/state.cfm?statepostal=TX
Click the link and find your watershed
What is a Watershed?
 The larger the body of water, the larger the watershed.
Mississippi River Watershed
Colorado River Watershed
Watershed- an area of land that drains into
a stream, river or lake.
 Divide – A ridge of land that separates one watershed from
another.
 Tributary – A stream or river that flows into a larger body of
water.
Russian Dolls and Watersheds?
 Russian Dolls – each large doll has a smaller doll inside
 Watersheds – each large watershed is formed by many
smaller watersheds.
 In Texas there are approximately 210
watersheds!
What local watershed are we part of ?
Who Lives in a Watershed?
Everyone!
Major US Watersheds
Lower West Fork Trinity
River
How are Watersheds Different?
 Each watershed has its own unique
characteristics
 Climate – rainfall, temperature, etc.
 Geology – elevation, slope, soil,
underlying rock, etc.
 Vegetation – grass, trees, desert
 Land Use by Humans – forests, wetland,
agriculture, urban
Why Should We Care About
Watersheds?
 Because what we do in a watershed
affects our water quality and our lives!
 It affects our water for drinking, and industrial use
 It affects flooding and coastal erosion
 It affects our health
 It affects the health of ecosystems
 Healthy ecosystems = Healthy environment = Healthy,
happy people 
Surface and Groundwater
 Surface water
- Water that is found on Earth’s surface. EX:
streams, lakes, ponds or oceans.
 Reservoir –
A lake that stores water for human use.
 Groundwater –
Water that is located
underground.
 Aquifer – any underground layer of rock or sediment
that holds water.
Human Impact
 Much of what human’s do every day can have an
impact on the groundwater in the surrounding areas?
 Take a moment and discuss with your shoulder partner
how you think this might happen. Are the effects
positive or negative?
Cone of Depression:
wells can drain groundwater and lower the water table
Groundwater Contamination:
wastes and chemicals can seep through the soil into
groundwater.
Runoff of Fertilizers
 Runoff of fertilizers used in commercial farming and
even for private use can cause algal blooms to appear
in otherwise fresh groundwater.
Improper Chemical Disposal
 Most people do not know how to properly dispose of
items that are hazardous to the groundwater supply.
Things such as oil, batteries, paint, and grease can
pollute groundwater if not disposed of correctly.
Roadway Runoff
 What gets left behind on the roads anyway?
 After a rain storm, all of the grease, oil, rubber,
gasoline, and trash has the potential to become
part of the runoff that makes its way into the
nearby groundwater.
Industrial Pollution
 Industrial Pollution is one of the leading causes of
groundwater pollution from illegal dumping, to runoff.
Protecting our water supply -Cities must
consider
1. type of liner,
2. type of trash and
3. the maximum amount that the landfill can hold
when properly planning a landfill that will not pollute
ground water!
.
 Open pits no longer acceptable- we now line bottoms.
 Complex impermeable bottom layers to trap contaminants
 Daily deposits are covered by layer of dirt.
 Methane gas and leachate monitoring wells
Sanitary Landfill
Fracking :
there are many people concerned that the natural gas wells in
this area can cause water pollution because of the fracturing (fracking) process needed
to drill into the Barnett shale .
Click here for an
article from
Discovery:
http://news.discovery.com/earth/
groundwater-fouled-by-frackingcontamination-natural-gas120509.htm
Summary
 What is a watershed and how does it affect
Earth’s water supply?
 Supplies water to area rivers and lakes that
we use in our homes.
 What is the relationship between
groundwater and surface water in the
watershed?
 Both groundwater and surface water are
needed to supply the rivers and lakes in a
watershed.