To mark World Water Day 2021, Professor Julien Harou, FutureDAMS Research Director, discusses early applications of the FutureDAMS approach for assessing and planning development in complex human-natural systems with stakeholders.

Development in Africa will require exploiting natural resources in river basins for example with new dams and irrigated areas, but at what cost to nature and those who depend on ecosystems for their livelihoods? Here Dr Harou, describes how partnerships with water planners in some of East Africa’s large coastal river basins has led to new approaches for balancing development interventions.

Development, but with what consequences?

Major river basin development decisions require careful planning: investments are large, decisions can be irreversible and infrastrucuture has a long life-time, so there is a strong argument for ensuring an appropriate balance of benefits and assessing resilience to future climate change. This article describes work in two coastal river basins in Kenya and Tanzania that are essential national reservoirs of energy, food and ecosystem wealth.

Tanzania’s Rufiji basin supports extensive socio-economic and environmental services and is targeted for major development via hydropower infrastructure (e.g., the new Julius Nyerere Hydropower Project – JNHPP) and investment through the Southern Agricultural Growth Corridor of Tanzania (SAGCOT). In Kenya’s Tana river basin, in addition to hydropower and irrigated agriculture, ecosystem services include seasonal floodplain fish catch, flood recession agriculture, reservoir fisheries, estuary fisheries, floodplain cattle grazing, and sediment transport through the delta to the coast. Maintaining flood flows is important for Tana basin habitat regeneration and biodiversity needs, informal agriculture and livestock grazing.

In both cases planners should ask the question: will new water storage dams or operations of existing ones aimed at energy and food production displace essential ecosystem services their associated livelihoods?

Achieving balance in developing river basins

Map of the Tana Basin showing where benefits and impacts occur and how they relate to water flow.

The approach in both projects used river basin simulation models to quantify how water availability across the basin and over time impacts the provision of energy, food and ecosystem services. Artificial intelligence search algorithms then help determine which combined development interventions create the most synergistic interactions between natural and built assets, and most appropriately trade-off their services.

In Tanzania  the project found that development that prioritises energy production adversely affects environmental performance downstream of the JNHPP, although part of the negative impacts can be minimised through release rules designed to replicate the natural variability of flow, without major sacrifice of hydropower. In Kenya’s Tana River basin work showed how controlled releases from multi-reservoir systems can be optimised to consider both provisioning ecosystem and engineered services at different locations and in different seasons.

An interactive visual approach to intervention design

In both case studies projects involved local partners and aimed to enable stakeholder-involved water planning. The work in Tanzania was part of a NERC Future Climate for Africa Umfula project which worked alongside Jomo Kenyatta University and the Rufiji water board. In Kenya UoM was part of the IUCN-led WISE-UP project which included University of Nairobi and Kenyan water management agencies.

A challenge of river basin design with stakeholders is communicating how large number of possible combinations of development interventions combine to produce cumulative impacts for different sectors and regions. A new UoM website used interactive online graphics to allow the many objectives and impacts of water development to be considered concurrently. This allows the implications of different development strategies for diverse stakeholders to be better understood. A WISE-UP project website gives an introductory summary of this visualisation tool, and two descriptions of the Kenya and Tanzania studies show examples of how the interactive graphics can be interpreted to assist stakeholders in understanding river basin water-energy-food-environment development interventions.

FutureDAMS is further developing this approach and applying it to the case study regions. See our case study pages for more information.

Image: Tana River watershed ©2014CIAT/GeorginaSmith
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