Political Implications of Measuring Water

This week we're going to use Damkjaer & Taylor's (2017) critical review of measures of water scarcity to try and understand how the Water Stress Index (WSI) can shape, inform and misguide the political geographies of water in Africa. 

What makes measuring water political?

Measures of water scarcity inform how water is governed: They determine where and in what ways the management of water is needed based off how much water is 'available' and how much water individuals and communities 'need'. How these needs and availabilities are quantified will inevitably affect water governance strategies. They may, for example, influence the nature and scale of water infrastructures, which may have multi-scalar political consequences.  Measurements of water are political because they quantify the relative power that physical landscapes can hold over human ecologies, and thus form political realities - they render water in Africa calculable and knowable, and assess the competing needs and positionalities of different industries and groups of populations who access water.

Physical metrics of water scarcity

The oldest and most widely used physical metric of water scarcity is Falkenmark's (1989) Water Stress Index (WSI)(Damkjaer & Taylor, 2017; White, 2014). The WSI defines water scarcity as the total water resources available to a population, and is calculated by dividing the total water availability (measured using mean annual river runoff (MARR)) by the total population for a given area (Falkenmark, 1989). The WSI thus implies a universal demand for water, and provides a universal figure of <1000m3 capita-1 year-1to denote water scarcity (Falkenmark, 1989). Countries that exhibit values below this threshold are seen to be water scarce, and thus, according to Falkenmark (1989), cannot meet the water needs of their population. Originally conceived to help prevent famines by measuring water stress in East Africa (Damkjaer & Taylor, 2017), the WSI is widely used across the world, both as a standalone metric and as part of other water scarcity metrics, largely because it is relatively easy to calculate and interpret (White, 2014).

Figure 1 WSI across Africa (Jemmali, 2018)

Despite this, the WSI can dangerously obfuscate the political geographies of water, hiding important spatial and temporal variabilities in water availability and use. By basing freshwater availability off MARR, the WSI hides other key sources of freshwater, including green water storage and groundwater storage, and ignores the varying quality of freshwater that the MARR value will contain because of seasonal variations in precipitation (Damkjaer & Taylor, 2017). As mentioned in the previous post, seasonal variation in precipitation (and thus river runoff) is the defining climatic characteristic across Sub-Saharan Africa (Ziegler et al., 2013). The importance of water storage is therefore crucial and forms important political geographies. 

Further, the WSI hides the uneven geographies of access to water that may exist within a given country, and, perhaps critically, the WSI's assumption that freshwater demands are universal seriously limits the WSI's ability in assessing actual water scarcity. This point is particularly important in Africa, where freshwater withdrawals vary significantly across within countries across the continent. Figure 1 seems to show us that for much of Sub-Saharan Africa water scarcity is not much of an issue, that actually it is the semi-arid regions of north Africa and South Africa that have the biggest problems with water scarcity. Used in conjunction with figure 2, we can see that the most water scarce countries in Africa are those with the highest demands. Water use is higher in these countries because of more advanced agricultural techniques, namely water intensive irrigation, and more developed water infrastructure (Thompson et al., 2000). Indeed, these countries have on average the highest levels of access to safe water and access to improved water sources. Conversely, Niger is listed as a country with no water stress, with very low freshwater withdrawals, and yet only 56% of its population has access to safe drinking water, a figure much lower than the supposedly water stressed countries in north Africa.

Figure 2 per capita annual freshwater withdrawals (m3 ) in Africa (FAO, 2006)

What is also interesting about Figure 2 is that no countries in Africa exceed Falkenmark's (1989) supposed threshold for water scarcity, and most do not even come close. How can the WSI thus be a meaningful indicator of water resources in Africa?