Water–Food–Energy Nexus Tradeoffs in the São Marcos River Basin

Pedro Henrique Bof,Guilherme Fernandes Marques,Amaury Tilmant,Marcelo Olivares,Ana Paula Dalcin

doi:10.3390/w13060817

Pedro Henrique Bof, Guilherme Fernandes Marques + Show 3 more

Open Access

https://doi.org/10.3390/w13060817

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Abstract

Given its potentialities and characteristics, energy generation, food production, and water availability have a strong interdependency and correlation. Water is needed to produce energy and food, while energy is required to produce water and food. This nexus brings several challenges when scarce water resources must be allocated among competing uses, often in the form of unexpected tradeoffs. Addressing those challenges requires knowledge about the water–food–energy nexus and the associated tradeoffs to support water allocation and management decisions. Those tradeoffs are still not properly understood in the uncertain and stochastic context of water availability. When not properly accounted for, the results are conflicts, loss of investments, environmental impacts, and limited effectiveness of sectoral policies, all of which undermine a country’s development model relying on water and energy security. This paper addresses the competitive uses of recent irrigated agriculture expansion and existing hydropower production in a Brazilian watershed with water conflicts, assessing the economic tradeoffs and water values between energy and irrigated agricultural production under uncertainty. An explicitly stochastic hydro-economic model is used to determine water’s economic value and its variation in space and time. Results indicate that the agricultural benefits outweigh the potential energy losses, and the best course of action should explore an economically compensated reallocation strategy, upon negotiation among users, rather than imposing water supply cutbacks to the agriculture sector.

Highlights

The separation between both curves indicates economic tradeoffs to energy due to reduced inflows, as water is shared with irrigated agriculture
Comparing the economic arrangement with the energy arrangement indicates that the total hydropower benefits are reduced by 5.64% (R$27 million per year) for the 90%
The following specific conclusions are possible, addressing the three key points of investigation proposed in the beginning: How much benefit could the energy sector potentially lose when water is shared economically with the agriculture sector? Losses can reach up to 4.6% in hydropower benefits (R$29.6 or US$7.65 million/year), but 90% of the time, losses are around 5.6%

Summary

Introduction

In Brazil, recent conflicts between water users from different sectors have been registered in [1] with hydropower generation and industrial consumption; in [2] with irrigation, hydropower projects, and other social demands in the São Francisco River Basin; in [3] with hydropower and urban water supply sectors in the Billings and Barra Bonita multiple-use reservoirs; in [4] with irrigators in Campos dos Goytacazes, Rio de Janeiro, Brazil; in [5] with local government, society and business people in the São Luiz do Tapajós hydropower plant and in [6] between two states that share the waters of the basin in the Piranhas-Açu River Basin These examples highlight an increasingly common problem shared by many regions globally, with water systems struggling to adapt to new conditions [7,8]. Food production demands water for irrigation which reduces firm energy yields for hydropower and flows for thermal plants cooling downstream while securing flows for long-term hydropower projects, restricting future irrigated agriculture expansion upstream of the power projects [11]

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