Groundwater and resilience to drought in the Ethiopian highlands

Abstract

During drought, groundwater is often relied on to provide secure drinking water, particularly in rural Africa where other options are limited. However, the technology chosen to access groundwater significantly affects local water security. Here we examine the performance of springs, hand-dug-wells and boreholes in northern Ethiopia through direct high frequency monitoring of water-levels (n=19) and water quality (n=48) over an 18 month period and gathering information on community impacts of declining water access during the El Niño 2015/2016 drought. We found that shallow boreholes equipped with handpumps were the most reliable water supply, recovering within hours to daily abstraction throughout all conditions. Recovery and performance of most hand-dug-wells and springs declined significantly throughout the extended dry season, although in specific aquifer conditions they were reliable. All sources types had negligible measured contamination from Thermo-tolerant Coliforms through the extended dry season, but were contaminated during the rains marking drought cessation. Boreholes were least affected, median 10 cfu/100 ml, compared to 190 and 59 cfu/100 ml for hand-dug-wells and springs respectively. Many communities who relied solely on springs, wells or rivers experienced severe water shortage in the El Niño drought with mean daily collection times up to 12 h and volumes collected reducing to 3-5 litre per-capitaper-day. This led to reports of violent conflict, missed meals, reduction in school attendance and farm activity and increased health impacts. From this study there is a clear case for improving resilience to drought by installing boreholes equipped with handpumps where feasible even if collection times are >30 min.

Drinking water quality from rural handpump-boreholes in Africa

“…This study provides an assessment of the baseline drinking water quality from rural HPBs in Sub-Saharan Africa across a range of different climates and aquifer geology. The results from this study across three countries in Africa show that the majority of drinking water from rural HPBs is found to be of good quality, based on health-based criteria, and certainly better quality than most alternative sources available in rural Africa which confirms earlier smaller scale assessments (Parker et al 2010, Pritchard et al 2016, Macdonald et al 2019. There are no strong links between either dry season length, aquifer geology and water quality based on an assessment of results using 14 parameters with health-based drinking water criteria.…”

“…Compared to surface water sources or shallow hand-dug wells, HPBs usually tap deeper aquifers that are more resilient to inter-annual climate variability (Chilton and Foster 1995, Macdonald et al 2009, Lapworth et al 2013, Taylor et al 2013. For many rural communities in Africa, HPBs are an integral part of household drinking water supply and are often the only source in the dry season, or longer periods of drought (Calow et al 2010, Macdonald et al 2019.…”

Comparative performance of rural water supplies during drought

“…Groundwater is typically a resilient water resource [5][6][7] , but few studies have directly compared the performance of different rural water supply technologies accessing groundwater during drought. One recent field study compared a small sample of springs, boreholes and hand-dug-wells in rural Africa and found that boreholes equipped with hand-pumps were more resilient than springs and hand-dug-wells 8 .…”

Regarding Groundwater and Drinking Water Access through A Human Rights Lens: Self-Supply as A Norm

“…25). Studies have pointed to the importance of public health messages for treating drinking water from wells and boreholes in connection with the first major rains after dry seasons and drought [60]. Education of those who are drilling and constructing the wells, as well as those who are commissioning their construction, are equally important.…”