Recycling Water  

Part One: The Challenge of Diminishing Water Supply


Water and currency in Botswana are interchangeable; the same word Pula applies to both. This is not surprising. Botswana is water-scarce and the founding fathers understood its critical importance in 1974 when the Pula was introduced on 23rd August 1976


Special Correspondent

While energy can be generated in various ways to meet rising demand, water cannot because it is a finite and diminishing resource. And as demand increases but supply diminishes due to climate change, water can only become scarcer and more expensive.

The impact of increasingly expensive water on the socio-economic fabric will be profound. The vital importance of water should be reflected in the manifestos of every political party running in the coming elections. This feature is mindful of the need to influence the content of manifestos by making the case for water recycling. This is the only strategy available that can actually increase the supply of water.

Let us start by appreciating the supply side of water. Long term precipitation is 417mm per year generating 242 billion cubic metres (cumecs) per year. As the population grows, the supply of water does not, hence the trend line in the graphic of renewable water per capita is negative.



How do we use our limited water supply in Botswana? Fairly recent data suggests that total consumption has been around 200 million cumecs for a few years, which means that the overall consumption of water is an average of 80 cumecs per capita. Making an international comparison is not straightforward because it reflects the extent of water conservation or recycling. In the advanced industrialised nation of the UK where recycling is widespread, for example, per capita water consumption is 139 cumecs per year. In the USA where recycling is limited, water consumption is much higher at 1370 cumecs per person per year. In South Africa, the per capita water consumption is 288 cumecs per person while in Rwanda it is only 19 cumecs per capita, one of the lowest in the world.

Looking at the use of water in Botswana, about 80 million cumecs is used in agriculture, about 4 million by industry and 106 million cumecs in municipal use, and this includes domestic use.

Being a finite resource, the supply and demand for water is subject to the laws of economics. As every economist knows, when demand increases but supply remains static or reduces, price will increase. The classical demand-supply theory provides a framework for understanding how prices are determined in a market-based on the interaction between consumers’ demand and producers’ supply.

Applying this theory to water in Botswana, especially in the context of increasing demand and diminishing supply due to global warming, helps to forecast future price trends, elasticity of demand, and the opportunity cost associated with water use. The demand for water in Botswana is influenced by population growth, urbanisation, agricultural needs, industrial use and climate conditions. As these factors drive higher water consumption, the demand curve for water shifts to the right. Increased population and urbanisation lead to higher domestic water consumption. Agriculture, a major water consumer, will require more water to sustain crop and livestock production, especially with potential droughts and the recent policy to induce domestic production.

As industries grow, their water requirements increase, adding to overall demand. The supply of water in Botswana is constrained by natural availability, infrastructure and climate change impacts. The diminishing supply due to global warming causes the supply curve to shift to the left. Water resources in Botswana are limited, and over-extraction depletes aquifers and surface water sources. Inadequate infrastructure for water storage, treatment and distribution limits the efficient supply of water. Global warming exacerbates water scarcity by reducing rainfall and increasing evaporation rates. Given the increasing demand and diminishing supply, the equilibrium price of water is expected to rise. According to the classical demand-supply theory, when demand increases and supply decreases, the price of the commodity (water) will increase until a new equilibrium is reached. The elasticity of demand for water measures how responsive the quantity demanded is to changes in price.

In Botswana, the elasticity of demand for water is likely to be inelastic due to its essential nature. Since water is a necessity for households, agriculture, and industry, significant price increases may lead to only small reductions in quantity demanded. While higher prices might incentivise some conservation efforts, the overall demand is less sensitive to price changes, indicating inelastic demand. The opportunity cost of water refers to the benefits foregone from using water in one application over the next best alternative use. In Botswana, this is particularly relevant due to the competing needs of different sectors. Allocating water to agriculture means that less water is available for industrial uses, which might have higher economic returns.

Drinking and sanitation

However, water has a high resource value when used in farming than energy production. Water used for domestic purposes, such as drinking and sanitation, is critical for public health but reduces the amount available for agricultural irrigation. Maintaining water for natural ecosystems can enhance biodiversity and long-term sustainability, but this may conflict with immediate economic uses like farming and industry. The price elasticity of demand for water in Botswana can be evaluated considering the inelastic nature of demand for essential resources. Demand is typically inelastic as water is essential for drinking, cooking and sanitation. Even substantial price increases may result in only marginal reductions in household water consumption.

Agricultural water use is considered as moderately inelastic. Farmers need water for irrigation but may adjust usage slightly with price changes by adopting more efficient irrigation techniques. With industrial water use, elasticity may vary. Some industries might be able to invest in water-efficient technologies or substitute processes while others might have less flexibility. Applying the classical demand-supply theory to water in Botswana indicates that future prices of water are expected to rise due to increasing demand and diminishing supply. The inelastic nature of demand for water, combined with high opportunity costs, underscores the need for efficient water management and conservation strategies. Policies that promote water recycling, efficient use, and investment in infrastructure are crucial for mitigating the socio-economic impacts of water scarcity in Botswana. These measures can help balance the demand-supply dynamics, stabilise water prices, and ensure sustainable water use for future generations. It will be interesting to see how the political parties cover the life-critical issue of pula in the forthcoming election.