This study explores the physical changes in rainfall and landscapes leading to major flood events in the Awash Basin, Ethiopia. Climate Change is creating new flood regimes and reshaping the interaction of flooding with rapidly changing communities, heightening risk to vulnerable communities within the basin. Therefore, this study examines the interaction of physical phenomena with societal and economic dynamics across the basin’s upper, middle and lower reaches. Focusing on the extreme wet season in 2020, the study’s multi-dimensional perspective includes analysis of hydroclimatic variables at the basin level including global drivers, flood characterization in selected catchments, and understanding of affected communities at sub-catchment levels.
Ethiopia
REACH Story of Change: Improving water security in Ethiopia through integrated use of surface and groundwater resources
As one of Africa’s fastest growing cities, Addis Ababa’s demand for water has sky-rocketed over recent decades due to population growth, increased per capita consumption, rural to urban migration, and growing water demand from industry. Water supplies across the city are already struggling to meet demand, with regularly interruptions to water services exacerbating inequities. This Story of Change explores the range of methodologies that REACH has applied to examine the implications of climate and population growth for Addis Ababa’s water supply. Of particular focus is a first-of-its-kind dynamic water allocation model which integrates both surface and groundwater resources.
Ensuring sustainable water security through sustainable land management: Research evidences for policy
Land degradation is adversely affecting over 75% of the Earth’s land surface and could exceed 90% by 2050. Likewise, the rate of soil erosion will increase by 66% during the period 2015–2070. Sustainable land management (SLM) practices are key to reducing rates of land degradation and are proven to ensure water security by increasing soil moisture availability, decreasing surface runoff, decreasing soil erosion, increasing infiltration, and decreasing flood discharge. In Ethiopia, over 85% of the land is moderately to very severely degraded at an estimated cost of $4.6 billion annually. This research highlights the importance of developing an SLM-water security policy to make the most of SLM techniques at a local and national scale.
Tracing contaminants of emerging concern in the Awash River basin, Ethiopia
This study focuses on characterization of Emerging Organic Contaminants (EOCs) in the Awash River basin. Characterization of the EOCs was supplemented by chemical analysis of samples from river, boreholes, tap water, and surface water reservoirs. Analyses of environmental isotopes (δ 2 H, δ 18 O, and 222Rn) were used to investigate the exchange of contaminants between surface and groundwater supply sources. The analysis showed new types of contaminants in the water supply sources with potential impact on human and wider environmental health.
Demystifying Heavy Metals and Physicochemical Characteristics of Groundwater in a Volcano-Tectonic Region of Middle Awash, Ethiopia, for Multipurpose Use
This study investigates the concentrations of physicochemical and heavy metal contaminants in the groundwater of the Middle Awash Basin, Ethiopia, to inform targeted water management strategies. After collecting groundwater samples during both the dry (June) and wet (October) seasons of 2021, the study found significant levels of contamination, including extraordinarily high concentrations of total dissolved solids and electrical conductivity. Over half of the groundwater sources were unsuitable for drinking, posing significant health risks to local communities that rely heavily on these sources due to limited access to clean surface water. These findings highlight the urgent need for comprehensive groundwater management and remediation plans in the Middle Awash region to ensure safe and sustainable water use.
Policy and practice recommendations on flood risk management in the Awash basin
In 2020, extreme rainfall triggered massive flooding and severe damage to property in Ethiopia’s Awash river basin. The International Water Management Institute (IWMI) examined climatic and non-climatic drivers of this event and its impacts on different social groups. Recommended action points for practitioners and policy makers include institutional design for coordinated flood management and response, collaboration on operational guidance and improved early warning system, revision of studies based on recent science and data, improving access to data for researchers and research-users, integration of indigenous knowledge into flood risk preparedness and research, and strengthening of Awash-flood related research in Ethiopia’s university and higher education institutions. Gender-responsive interventions to flooding are critical.
Hydrologic Extremes in a Changing Climate: a Review of Extremes in East Africa
This review presents recent research on drivers and typologies of climate extremes across different East African geographies. Droughts and floods remain the major challenges of the region. There are improvements in forecasting these extremes, but further research is required to improve understanding of key drivers and improve information provision for risk-based decision-making.
Environmental isotopes (δ 18O–δ 2H, 222Rn) and electrical conductivity in backtracking sources of urban pipe water, monitoring the stability of water quality and estimating pipe water residence time
In this paper, environmental isotopes and electrical conductivity are used to investigate water quality variations in the urban piped water network of Addis Ababa, Ethiopia. The isotopic signature of the water allows the back-tracking of tap water to its source and also provides insights into pipe water residence time for groundwater-sources supplies. The tracers reveal that 50% of the city relies on groundwater, and that groundwater-sourced water supplies show the highest water quality instability. One important cause of water quality variation in the city is borehole stoppages and reconnection as a result of electricity cuts.
Evaluating the effects of geochemical and anthropogenic factors on the concentration and treatability of heavy metals in Awash River and Lake Beseka, Ethiopia: arsenic and molybdenum issues
This study assesses heavy metal and pollution sources within the Awash River Basin, in Ethiopia. In this region, significant urbanization and industrialization have caused pollutants to enter water bodies on a large scale. After finding high levels of heavy metals across surface water sampling stations, the study advocates for increased efforts towards water security within the Addis Ababa and Awash watershed region.
Evaluating the structures and arrangements of water institutions to include in-stream modeling for water quality management and control pollution: Insights from the Awash Basin, Ethiopia
In sub-Saharan regions, human activities are causing stream water quality to decline. This study assesses stream water quality issues in the Awash Basin of Ethiopia, identifying key sources of land-based pollutants. Applicable models with the capability of simulating the Awash streams are presented, and recommendations towards improved use of water quality modelling for development planning by Awash Basin institutions are made.
