Water Analysis - Part I

Had an interest in water. Did some research. Here's some excerpt of my research:

1. Current Status

1.1. Global Distribution of Water


There is roughly 1.4bn km3 of water on Earth, of which 35m km3 (2.5%) is freshwater.

Of the total amount of water used globally, 65% is from surface water (rivers, streams and lakes). Just over 20% of water used globally is from groundwater.

1.2. Global Water Demand-Supply Balance

In aggregate, there is sufficient fresh water to meet global demand.

We only need10.5m km3 of freshwater to adequately supply the current 6.5 billion global population.

According to United Nations World Water Development Report, 2007 – providing universal access to the basic minimum of 50 litres a day per person would mean re-distributing just 1% of the amount of water used currently.

§ Key Issues
Hence, the key issue is not insufficient water globally but insufficient water locally. If we could export water to places where it is needed, then the problem will be solved.

But the water demand-supply balance is a very location-centric issue. Essentially, there is insufficient water supply in areas where we demand water. Particularly, the concentration of water demand in a smaller geographical area has increased stress on water supply.

In these areas particularly, the supply of water is falling even as demand for water is rising.
Moreover, the volatility/variance in water supply has also increased

At the core of it, it is a question of distribution of freshwater resource given spatial and time variations in its natural delivery – i.e. matching demand to supply.
Where we can’t effectively match demand to supply, the solution is to decrease demand and increase supply.

§ Measures of Water Deficiency
There are two measures of water deficiency as defined by the UN:

a) The absolute standard
Water stressed: <1700m3/person
Water scare: <1000m3/person

b) The relative standard – ratio of water demand relative to supply
High relative water stress: Demand/Supply >40%
Medium-high water stress: 20%> Demand/Supply > 40%


1.3. Global Water Supply

§ Overuse
Sharp falls in groundwater levels (in India, Australia, China and parts of the US, in particular) and natural reservoirs (for example, the Aral Sea) illustrate the unsustainable nature of water consumption patterns.



§ Pollution
Pollution has further reduced the available resource.
As one measure of river pollution, we can look at the Biological Oxygen Demand (BOD) of water. This is a chemical procedure for determining the rate of uptake of dissolved oxygen by the biological organisms in water. The higher the BOD reading, the worse the level of pollution.


§ Climate Change
Climate change will affect the volatility of water supply – where, when, how much and how water falls,

One of the main impacts of global warming is on glacial river flow. If the glacier disappears then so does the river (at least in the dry season).


In Australia, shifts in rainfall patterns (attributed to climate change) saw inflows into dams decreased by between 30% and 70%, according to the Australian Water Services Association. Brisbane came close to running out of water before rain late last year, according to the Australian Water Association.

It might also affect the overall level of water available in the system
1.4. Global Water Demand

3 main sources of water demand
1) agricultural demand – 70%
2) industrial demand – 22%
3) domestic demand – 8%

§ Increase in Population
Increase in population will naturally increase the overall water use.

§ Increased Water Usage per Capita
Not only has population been increasing but water usage per capita has increased too. This is natural given that water is a normal good and as GDP per capita increase, its consumption per capita will rise.

Growth in water usage has significantly outstripped population growth for three broad reasons:
(i) Rising real incomes have increased the demand for food and more water intensive food groups
(ii) Growth in industrial processes has added to greater demand for water
(iii) Tech advances & urbanization make it more convenient for people to use in greater quantity


§ Intensity of Demand
Rural/urban migration is increasing the stress on the supply/demand balance for two reasons:
(i) Increased water usage due to increased accessibility to water
(ii) a greater concentration of consumers in a smaller geographical area typically places increased pressure on neighbouring water resources (i.e., local water tables)