Water and Sanitation: An Introduction

As Sean Fox illustrates with figure 1, thus far, the population has continued to grow at an exponential rate. In 1804, the population reached 1 billion. 211 years later, in July 2015, the population was estimated to be at 7.3 billion. The population has increased seven-fold since 1804. With this population explosion, came an exponential increase in the level of urbanisation. However, population growth, coupled with higher concentrations of populations in urban areas has combined to create a strain on resources. Supply of resources, including water and services such as sanitation are struggling to keep up with demand. This is how the water and sanitation crisis was born.

Falkenmark et al. (1989) described water scarcity as conditions such that, renewable freshwater resources are below 1000m³/person/year. Charles Vörösmarty et al. posit that water scarcity occurs when a ratio of estimated annual freshwater demand to availability exceeds 0.4.

Here, Jonathan Chenoweth illustrates the correlation between GDP per capita (PPP US$) and total renewable water resources for the year 2000. As shown, there tends to be a positive correlation; as GDP increases, so does total renewable water resources. The scarcity paradigm questions whether there is a direct link between water scarcity and access to water.

Chenoweth explores a plethora of parameters that influence whether scarcity translates into access. These factors may be physical, socio-economic or political. He concludes that socio-economic development is the primary determinant of a country’s ability to meet its population’s basic needs, not the natural environment.

As shown in figure 1, the detonation of the population bomb led to rapid urbanisation. It is for this reason that I have a particular interest in Africa’s urban environments, especially megacities. Chenoweth’s assertion has also inspired me to focus this blog around what is referred to as the ‘economic water crisis’. In the following posts, I will address these issues:

1. Indicators of national scarcity
2. The link between scarcity and access
3. The reality of the water and sanitation crisis in urban Africa
4. The distribution of water and sanitation resources within Africa’s megacities