Conflict over water resources and management: Case study Colorado River Basin

LO: explain how water use in the Colorado river basin is causing

conflict and how it is being managed

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.

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

Egypt imports > 50% of its food because of physical scarcity

Australia; diversion ¼ of all water away from

Murray Darling Basin for agriculture

Aral Sea faces environmental catastrophe, although recent attempts to reduce impacts

of river diversions for especially cotton production

R Ganges: physical stress from pollution and over abstraction

Severe water scarcity N China, leading to South North transfer

scheme-see later slide

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 Much of sub Saharan Africa suffers from

economic scarcity from especially poverty but also lack of infrastructural

development . Some 1 bn people involved1

DIFFERENT USERS?Conflicting demands

Water conflicts

SUPPLY?Diminishing

DEMANDS?Rising

•International conflicts i.e. basin crosses national boundaries•Internal conflicts ie within a country•Conservation versus exploitation

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 suppliesDams and diversions and

loss of wetlands are particularly contested.

Population growthConsumer demandIndustrial growth

Agricultural demand

Reductions because of:•Users abstracting/polluting upstream•Deteriorating quality•Impact of climate change

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

Insert Figure 2.11 page 47

River basins currently in dispute

River basins at risk in the future

Large International drainage basins

Zambezi

Orange

Okavango

La Plata

Mekong

Ganges

Ob

Lake Chad

Nile hotly disputed between Ethiopia and Sudan ,who control its headwaters, and Egypt .

Tigris-Euphrates Iraq + Syria concerns that Turkey’s GAP project will divert their water

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: 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

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

Case study river: The Colorado River

• https://vimeo.com/63943253

Why is this river causing conflicts? Who may these conflicts be between?

Colorado river basin:Geographical location

Name the states who share the River basin

Locational context

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.

Why is the dam needed?

• Economic growth• Population growth• Power generation (HEP)• Tourism

How could the dam be termed a ‘multi purpose scheme’?

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?

Case study detail:

Watch the following video and make notes on… • Why is the management needed?• What has been done to manage the river• What conflicts have occurred? Why are there these

conflicts?• Case study detail

• https://www.youtube.com/watch?v=BE1RbFJTZdI• https://www.youtube.com/watch?v=JAHHu6tbtow

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.stmhttp://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

Lake Mead image analysis

Foreground - Hoover Dam

Foreground – Water intake towers

Foreground – Hydro electricity power cables

Background – Hills of Nevada

Background – Steep sided gorge

Middle distance – Lake Mead reservoir

Middle distance – Drop in water levels obvious due to white line (chemical weathering by water)

What are the impacts of this scheme?

Environmental ImpactsIt is impossible to manage a river so much and not create some

environmental problems. Problems include:

The Colorado River used to carry about 90 million tonnes of sediment (alluvium) a year down to its mouth. However, the majority of this now gets trapped behind dams, damaging the delta and wetland ecosystem at the river's mouth.

Salinity in the lower Colorado has increased changing the ecosystem.The number of fish shrimps and sea mammals have all reduced around the

mouth of the river.Evaporation rates have increased behind the river's many dams. About 15%

of water is evaporated.The deep water in the reservoirs behind the dams has reduced the

temperature of the river in many areas.

Read page 138-140 (Red textbook)Explain why the following people would conflict with each other over this management of water in

the Colorado:

Stakeholders Reason for conflictThe US Government and the Government of MexicoPeople who live in the upper part of the basin and people who live in the lower part of the basinEnvironmentalists and water managersFarmers and other water users Native Americans and other water users

Examples of management questions

• Choose a water management scheme you have studied. Explain why the scheme was needed (6)

• Choose a water management scheme you have studied. Explain the effects of the scheme (6).

Question from June 2014 paper

4 marks for SPAG

Mark scheme

Peer assessment

Example of a conflict question

June 2013

Mark scheme

Peer assessment