Download Conflict over water resources: case study Colorado River Basin

Conflict over water resources:
Case study Colorado River Basin
LO: explain how the water is being
managed in the Colorado River basin
Water scarcity hotspots
According to the International Water Management
Institute environmental research organisation global water
stress is increasing, and 1/3 rd of all people face some sort
of water scarcity. Agricultural uses dominate in the
growing need for food.
Aral Sea faces environmental catastrophe,
although recent attempts to reduce impacts
of river diversions for especially cotton
production
Egypt imports > 50% of its food because of
physical scarcity
Ogallala aquifer provides
1/3 all US irrigation water,
but is seriously depleted:
the water table is
dropping by about 1m/yr.
As a ‘fossil’ reserve,
formed probably from
past glacial meltwater
flows, it is effectively a
finite resource
Severe water scarcity N China,
leading to South North transfer
scheme-see later slide
R Ganges: physical stress from
pollution and over abstraction
Australia; diversion ¼ of
all water away from
Murray Darling Basin for
agriculture
Much of sub Saharan Africa suffers from
economic scarcity from especially
poverty but also lack of infrastructural
development . Some 1 bn people
involved1
Little/no water scarcity
Physical water scarcity- not necessarily dry areas but those where over 75% river flows are used by agriculture, industry or domestic
consumers
Economic water scarcity- less than 25% rivers used, and abundant supply potential but not reaching the poorest people .
Approaching physical water scarcity – More than 60% river flows allocated, and in the near future these river basins will have physical
scarcity
Water conflicts
Population growth
Consumer demand
Industrial growth
Agricultural demand
DEMANDS?
SUPPLY?
Rising
Diminishing
DIFFERENT
USERS?
Conflicting
demands
•International conflicts i.e. basin crosses
national boundaries
•Internal conflicts ie within a country
•Conservation versus exploitation
Reductions because of:
•Users abstracting/polluting
upstream
•Deteriorating quality
•Impact of climate change
PRESSURE POINT- ie need
for management.
This is shown spatially as a
‘hotspot’ of conflict, see
map on next slide.
Pressure and hence tension
and conflict may be over
surface flow and/or
groundwater supplies
Dams and diversions and
loss of wetlands are
particularly contested.
Present and potential water conflict hotspots
•
•
As water supply decreases, tensions will increase as different players try to access common water supplies
Many conflicts are transboundary in nature, either between states or countries
River basins currently in dispute
River basins at risk in the future
Tigris-Euphrates
Iraq + Syria concerns that Turkey’s
GAP project will divert their water
Colorado: disputes
between the 7 US
states and Mexico it
flows through. The river
is so overused, that it no
longer reaches the sea!.
90% abstracted before
reaches Mexico
Large International drainage basins
Ob
Lake
Chad
Mekong
Ganges
Okavango
La Plata
Zambezi
Insert Figure 2.11
Orange page 47
Note: although there have been rising tensions globally,
many areas demonstrate effective management to
diffuse the situation and create more equitable and
sustainable demand-supply balance, such as the
Mekong River Committee,& the Nile River Initiative
Nile hotly disputed between
Ethiopia and Sudan ,who
control its headwaters, and
Egypt .
The Aral Sea, an inland
drainage basin, once the
world’s 4th largest inland
lake has shrunk sine the
1950s after the 2 rivers
feeding it: the Amu Dayra
and Syr Darya were
diverted for irrigation.
By 2007 the sea was 10%
of original volume and
split into 2 lakes. The ex
soviet states are in
conflict: Uzbekistan ,
Turkmenistan and
Kazakstan.
Colorado river basin:
Geographical location
Name the states
who share the
River basin
During the past 50 years this once free flowing
river has been tamed by a gigantic plumbing
system consisting of
• 14 major dams and reservoirs.
• hundreds of smaller dams.
• a network of aqueducts and canals that supply
water to farmers, ranchers and cities.
Today, this domesticated river
provides…..
• electricity (from hydroelectric plants at major dams)
• water for more than 25 million people in 7 states
• water used to produce about 15% of the nation's
produce and livestock
• multi-billion recreation industry of
–
–
–
–
–
whitewater rafting
boating
fishing
camping
hiking
• enjoyed by 15 million people a year.
Why is it
like this?
Why is there conflict over the water
resources?
Why would these people all have
different views?
Solutions?
Glen Canyon and Lake Powell
Take away this tamed river and…..
• Las Vegas, Nevada would be a mostly uninhabited
desert area.
• San Diego, California (which gets 70% of its water
from the Colorado), could not support its present
population.
• California's Imperial Valley (which grows a major
portion of the nation's vegetables would consist
mostly of cactus and mesquite plants.
Three major problems are associated
with use of this river's water:
• the Colorado River basin includes some of the driest
lands in the US.
• Legal pacts in 1922 and 1944 allocate more water to
the states in the river's upper basin (Wyoming, Utah,
Colorado and New Mexico) and lower basin (Arizona,
Nevada and California) and to Mexico, than now flows
through the river, even in years without a drought.
• because of so many withdrawals, the river rarely makes
it to the Gulf of California.
http://news.bbc.co.uk/2/hi/americas/7506405.stm
http://news.bbc.co.uk/2/hi/americas/7507701.stm
Colorado River drought
• The south-western US is
suffering its eighth
consecutive year of
drought. There are
concerns that the
Colorado River, which has
sustained life in the area
for thousands of years,
can no longer meet the
needs of the tens of
millions of people living in
major cities such as Las
Vegas and Los Angeles.
http://news.bbc.co.uk/2/hi/americas/7506405.
stm
Colorado River case study…..
1. Where is the case study located
2. Why is there an issue? (who are the different
users?/ what do they want water for?)
3. What was done about it?
4. When did this happen?
5. Who has benefited?
5 key points from this case study