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SWP Publishes Five Studies  To Support Evidence-Based Decision-Making in the Mara River Basin

The studies  are  the foundation for a  water allocation plan in  Tanzania  

As demand for water continues to grow and climate change makes water availability less predictable, water security is an increasing challenge  around the world. While many countries would like to adapt their water management strategies to respond to this challenge, a common hurdle is a lack of reliable data to support evidence-based decision-making. This problem is particularly true of transboundary water resources that are shared by two or more countries.

One such at-risk water resource is the Mara River Basin, shared by Kenya and Tanzania. The river basin, which supports some 1.2 million people and world-famous wildlife preserves, is  threatened by  factors such as population growth, deforestation, and climate change and variability.

People collect water from the Mara River. The river supports a population of 1.2 million people in Kenya and Tanzania as well as world-famous wildlife preserves, but is under stress due to factors such as population growth and climate change. Photo: SWP.

To confront this challenge, the USAID-funded  Sustainable Water Partnership, implemented by  Winrock International, has been working since 2018 to provide decision support systems in the Lower Mara River Basin.  Together with  Tetra Tech  and  research  partners at the Stockholm Environment Institute (SEI), the IHE-Delft Institute for Water Education and  mWater,  SWP recently published a series of studies that assess  past and present  water demand, water availability and water use in the basin, as well as evidence-based projections for the future.

Completed under field leadership of SWP’s  Sustainable Water for the Mara (SWM) activity,  the studies served as the basis for a water allocation plan for Tanzania’s portion of the river basin. The  eventual goal  in the region is to facilitate a harmonized transboundary water allocation plan between Kenya and Tanzania to jointly manage the Mara.  The WAP  for  the lower Mara River basin in Tanzania  will significantly contribute to a potential transboundary water allocation plan between Kenya and Tanzania.

For more information, view summaries and links to each study below.   

Lower Mara River Basin Water Availability Assessment

This technical report  describes the analytical procedures and results of a water availability assessment for the Mara River Basin using long-term historical  precipitation and discharge  data.  The  objectives of this assessment were: 1) to regionalize average monthly and average annual discharge data, 2) estimate flow duration curves, 3) set up long-term water balances for the sub-catchments within the Mara River Basin, and 4) assess changes in the hydro-meteorological time series data sets.

Lower Mara River Basin Water Demand Assessment  

This water demand assessment presents the outcomes of analyses to estimate  current and  future water demands for  human and economic activities in the Tanzanian  portion of the  Mara River Basin over the next  5, 10 and 20  years.  The  water  demand assessment findings were combined with the  water resource availability  assessment to calculate the water balance  in the basin.

Lower Mara River Basin Water Abstraction Survey Report

This report describes the  findings of a field survey  in the Mara River Basin in Tanzania to estimate current use, including locations, source types, approximate amounts abstracted, and purposes for the water abstractions. Information  from the abstraction survey was  combined with data presented separately on water resource availability, future demand projections, and the reserve to calculate the water balance to be included in a future Mara-wide water allocation plan.

Lower Mara River Basin Future Scenarios

Together with SWP, SEI facilitated  robust decision support (RDS) workshops with stakeholders. Through the workshops, stakeholders identified and discussed different  uncertainties, such as climate change,  land use and  demographics changes  confronting the basin. This report details potential future scenarios identified by local Mara River Basin stakeholders through this process.

Mara River Basin WEAP model

The Water Evaluation and Planning (WEAP) system model of the Mara River Basin was developed as a collaborative effort between  SWP, SEI, and  IHE Delft.  Informed by the water abstraction, demand, and availability assessments along with the stakeholder RDS workshops,  the historical and baseline conditions are representative of researchers’ best understanding of the basin as it has existed and been used historically, as it exists and is used today, and how it will exist and be used into the future, without any major changes.

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Sustainable Water Partnership (SWP)

The Sustainable Water Partnership (SWP) is a five-year, Leader with Associates cooperative agreement that supported U.S. Agency for International Development’s (USAID) thought leadership, innovation and action in global water security. SWP was implemented by Winrock International and its partners Tetra Tech, Stockholm Environment Institute (SEI), the International Union for Conservation of Nature (IUCN), World Resources…