Economic valuation of benefits and costs associated with the coordinated development and management of the Zambezi river basin

Abstract

The Zambezi river basin is of utmost importance to its riparian countries in terms of energy, food production and natural resources. Even though there is no legal agreement on the sharing of Zambezi waters, an assessment of basin-wide economically efficient allocation policies will provide valuable information at a time where water managers and policy makers in the region are negotiating the establishment of a unified river basin institution, called the Zambezi Watercourse Commission (ZAMCOM). That institution would be responsible for, amongst other things, the design of allocation rules. In this study, basin-wide allocation policies are derived fron a hydroeconomic model that considers the largest existing and planned hydraulic infrastmcture and irrigad an schemes in the basin. Our results illustrate that the economic value of water varies spatially, driven primarily by large changes in elevation and on the locations of existing or proposed dams. This observation may have implications for future decisions about the siting of expansions in irrigated agriculture. For example, some of the planned irrigation schemes in upstream countries are not economically sound if the power stations that are in an advanced planning phase are implemented. This study also reveals that the economic value of the three largest storage infrastructure (Kariba, Itezhitezhi, Cahora Bassa) is around US$443 million/year.

Opportunities from low-resolution modelling of river morphology in remote parts of the world

“…Most of them focused on the biological, ecological and economical effects (biodiversity, fisheries, wetlands, etc.) of these reservoirs (Bowmaker, 1960;Attwell, 1970;Hall et al, 1977;Du Toit, 1984;Dunham, 1989;Beilfuss and Davies, 1999;Beilfuss et al, 2001;Scodanibbio and Mañez, 2005;Tilmant et al, 2012;McCartney et al, 2013). Fewer works addressed morphological changes correlated to the dams' impacts on sediment and water discharges (Guy 1981;Suschka and Napica, 1986;Beilfuss and Davies, 1999;Davies et al, 2000;Basson, 2004;Ronco et al, 2010;Brown and King, 2012;.…”

Using stochastic dual dynamic programming in problems with multiple near‐optimal solutions

“… Figures correspond to scenarios of future developments as reported in Tilmant et al . [] and Tilmant and Kinzelbach [].…”

“…The penalty for not meeting these requirements is set at 30$per 1000 m 3 , a price within the range given in Tilmant et al . [] for the valuation of environmental benefits.…”

“…It has then been extended to long‐term hydropower scheduling [e.g., Gjelsvik et al ., ; Homem‐de Mello et al ., ; Bezerra et al ., ], where the planning horizon extends over several years. Furthermore, its ability to assess the marginal value of water at each stage and place in the basin [ Tilmant et al ., ] has made it useful for the hydroeconomic analysis [ Harou et al ., ] of large river basins. SDDP enables tackling varied issues including risk assessment [ Tilmant and Kelman , ] or cost assessment of noncoordinated irrigation development among riparian countries [ Tilmant and Kinzelbach , ], the restoration of a flow regime through the coordination of multiple reservoirs [ Tilmant et al ., ] or the integrated assessment of possible future developments in the Blue Nile River Basin [ Goor et al ., ; Arjoon et al ., ].…”

Hydroeconomic optimization of reservoir management under downstream water quality constraints

“…While hydroeconomic optimization models have been widely applied to water quantity management problems (e.g. Heinz et al, 2007;Pulido-Velázquez et al, 2006;Tilmant et al, 2012) and water quality management problems (e.g. Cools et al, 2011;Hasler et al, 2014), only few studies have addressed optimization of coupled water quantity-quality problems (Ahmadi et al, 2012;Karamouz et al, 2008).…”