2. Water Cycle
• Water is always on the
move. Rain falling where
you live may have been
water in the ocean just
days before. And the water
you see in a river or stream
may have been snow on a
high mountaintop.
• The water cycle is also
known as the hydrologic
cycle.
– Fun Fact:
• Hydro is Latin for water
3. Where is water?
• Water can be in the
atmosphere, on the land, in
the ocean, and even
underground.
• It is recycled over and over
through the water cycle.
• In the cycle, water changes
state between liquid, solid
(ice), and gas (water
vapor).
4.
5. Stage 1 : Evaporation
• Evaporation is the process
where liquid changes to
vapor form.
• Evaporation turns the water
that is on the surface of
oceans, rivers, & lakes into
water vapor using energy
from the sun.
6. Stage 1 : Transpiration
• Transpiration is the
process when water
evaporates from plants.
• Plants lose water through
their stems, leaves, and
roots.
• A fully grown tree may
lose several hundred
gallons of water through
its leaves on a hot, dry
day.
7. Stage 2: Condensation
• Condensation is the process by
which water vapor in the air is
changed into liquid water.
• The water vapor rises in the
atmosphere and cools, forming
tiny water droplets by a
process called condensation.
• Those water droplets make up
clouds.
8. Stage 3: Precipitation
• Those water droplets that
CONDENSE make up clouds. If
those tiny water droplets combine
with each other they grow larger and
eventually become too heavy to stay
in the air. Then they fall to the
ground as rain, snow, and other
types of precipitation.
9. Stage 3: Precipitation
• Precipitation is the
process where water
released from clouds in
the form of rain, freezing
rain, sleet, snow, or hail.
It is the primary way water
is delivered from the
atmosphere to the Earth.
10. Did you know…
• How many gallons of water fall when 1 inch
(2.5 cm) of rain falls on 1 acre of land?
– 27,154 gallons of water!
• Rain drops are not tear shaped.
– They start out in a ball shape, but as they fall they meet with
air resistance, which starts to flatten out the drop until at
about 2-3 mm in diameter the bottom is quite flat with an
indention in the middle - much like a hamburger bun. When
raindrops reach about 4-5 mm, things really fall apart. At this
size, the indentation in the bottom greatly expands forming
something like a parachute with two smaller droplets at the
bottoms. The parachute doesn't last long, though, and the
large drop breaks up into smaller drops.
11. Wow! That is amazing!
• The world's record for average-annual rainfall
belongs to Mt. Waialeale, Hawaii, where it
averages about 450 inches (38 ft) per year.
• The world’s record for least amount of rain
goes to Antofagasta Region, Atacama Desert,
Chile at 0 inches in one year!
– It takes 6 gallons of water to grow the potatoes for
your order of fries!
– For your hamburger it takes 1300 gallons of water
to produce everything needed!
12. Stage 4: Runoff
• The variety of ways by
which water moves across
the land.
• As it flows, the water may
seep into the ground,
evaporate into the air,
become stored in lakes or
reservoirs, or be extracted
for agricultural or other
human uses.
13. Stage 4: Infiltration
• Some of the
precipitation seeps
into the ground and
becomes a part of
the groundwater.
• Infiltration is the
process by which
runoff soaks into the
ground.
14. Stage 5: Accumulation
The process in which water pools
in large bodies (like oceans, seas
and lakes) Most of the water on
Earth is in the Ocean.
Did you know?
Water stays in certain places longer than
others. A drop of water may spend over 3,000
years in the ocean before moving on to another
part of the water cycle while a drop of water
spends an average of just eight days in the
atmosphere before falling back to Earth.
15. The Water Cycle
• Earth's water is always in
movement on, above, and below
the surface of the Earth.
• Since the water cycle is truly a
"cycle," there is no beginning or
end.
• Water can change states among
liquid, vapor, and ice at various
places in the water cycle, with
these processes happening in the
blink of an eye and over millions
of years.
16. Surface Water
Clear Creek near IH-45
and 518.
• Surface water is
any water that is
on the surface of
the Earth.
• This includes
rivers, streams,
creeks, lakes, and
reservoirs.
17. What is a watershed?
The land area that drains into a
particular water body. All land is in a
watershed and everybody lives in a
watershed.
During a rainstorm, the water that
flows over the land as runoff collects in
channels such as streams, canals,
rivers, etc. The land area that drains
water is called a watershed.
18. Watersheds
• So, a watershed is the area
of land where all of the
water that falls in it and
drains off of it goes into the
same place (in our case,
Clear Creek).
• The word watershed is
sometimes used
interchangeably with
drainage basin or
catchment.
• The watershed consists of
surface water -- lakes,
streams, reservoirs, and
wetlands--and all the
underlying ground water.
Clear Creek tributary near
Blackhawk Road.
20. Clear Creek Watershed
Drainage Area:
197 square miles
Watershed Population
(Harris County):
118,026
Open Stream Miles:
154 miles
Primary Streams:
Clear Creek
Turkey Creek
Mud Gully
Kemah
You are here!
21. All About the Clear Creek
Watershed
Clear Creek tidal area. Near
IH-45 and FM 518.
• The Clear Creek watershed
is located in southern
Harris County.
• The watershed
encompasses portions of
Harris, Galveston, Brazoria
and Fort Bend counties; 16
cities including Houston,
Brookside Village,
Pearland, Friendswood,
League City, Pasadena,
and the Clear Lake Area
communities.
22. Environment of the Clear Creek
Watershed
• Clear Creek between Clear
Lake and the City of
Friendswood is in a natural
state.
• Its bottom elevations are
below sea level and subject
to tidal influences.
• A number of natural and
recreational parks have
been developed along the
creek.
• Much of the channel
upstream of this line also
supports heavy vegetative
growth.
Clear Creek from Challenger Seven
Memorial Park
23. Flooding in the Clear Creek
Watershed
• Flooding occurs
frequently along
various reaches of the
main channel and its
tributaries.
• Storm surge has also
caused flooding within
the watershed and has
the potential to extend
upstream from Kemah
to I-45.
24. From an aerial view, drainage patterns in a
watershed resemble a network similar to the
branching pattern of a tree.
Tributaries, flow into streams.
Streams eventually empty into a
large rivers. Like other branching
patterns (e.g. road maps,
veins in a leaf, the human nervous
system), the drainage
pattern consists of smaller channels
merging into larger ones.
29. Ground Water
• Below a certain depth, the ground that is permeable enough
to hold water is saturated with water.
• The upper surface of this zone of saturation is called the
water table.
• The saturated zone beneath the water table is called an
aquifer, and aquifers are huge storehouses of water.
30. Ground Water
• Groundwater is the part of precipitation that seeps down
through the soil until it reaches rock material that is
saturated with water.
• Water in the ground is stored in the spaces between rock
particles (no, there are no underground rivers or lakes).
• Groundwater slowly moves underground, generally at a
downward angle (because of gravity), and may eventually
seep into streams, lakes, and oceans.
Unsaturated soil
Saturated
soil
31. Aquifers
• Aquifers are underground
reservoirs.
• Almost no bacteria live in
aquifers. Many pollutants
are filtered out as the water
passes through the soil on
its way to the aquifer.
• To tap the groundwater in
an aquifer, wells are dug
until they reach the top
layer of the aquifer, the
water table.
• When a lot of water is
pumped from an aquifer, or
when there is a dry spell,
the water table sinks lower.
32. Aquifers
•
•
•
Wells can be drilled into the aquifers and water can be pumped out.
Precipitation eventually adds water (recharge) into the porous rock of
the aquifer.
The rate of recharge is not the same for all aquifers, though, and that
must be considered when pumping water from a well. Pumping too
much water too fast draws down the water in the aquifer and eventually
causes a well to yield less and less water and even run dry.
