Estimation of the transboundary economic impacts of the Grand Ethiopia Renaissance Dam: A Computable General Equilibrium Analysis

Employing a multi-region multi-sector computable general equilibrium (CGE) modeling framework, this study estimates the direct and indirect economic impacts of the Grand Ethiopian Renaissance Dam (GERD) on the Eastern Nile economies. The study contributes to the existing literature by evaluating the impact of the dam under three different climatic and hydrological scenarios, taking into account both the transient GERD impounding phase and the long-term operation phase in a global CGE setting. The results demonstrate the significance of the GERD in generating basin-wide economic benefits and improving welfare in the Eastern Nile basin. During the impounding phase, the GERD benefits mainly Ethiopia and to some extent Sudan. GERD impounding inflicts economic costs, however, on Egypt, especially if it occurs during a sequence of dry years, and depending on the level of water withdrawal in Sudan. The negative effects of the GERD on Egypt[U+05F3]s economy are reversed when the GERD becomes operational. In that case, the GERD generates substantial economic benefits and enhances economic growth and welfare in all the Eastern Nile countries. Instituting a basin-wide power trade scheme would substantially boost Egypt[U+05F3]s economy and thereby further increase the economic value of the dam

Climate change effects on water allocations with season dependent water rights

Appropriative water rights allocate surface water to competing users based on seniority. Often water rights vary seasonally with spring runoff, irrigation schedules, or other non-uniform supply and demand. Downscaled monthly Coupled Model Intercomparison Project multi-model, multi-emissions scenario hydroclimate data evaluate water allocation reliability and variability with anticipated hydroclimate change. California\u27s Tuolumne watershed is a study basin, chosen because water rights are well-defined, simple, and include competing environmental, agricultural, and urban water uses representative of most basins. We assume that dedicated environmental flows receive first priority when mandated by federal law like the Endangered Species Act or hydropower relicensing, followed by senior agricultural water rights, and finally junior urban water rights. Environmental flows vary by water year and include April pulse flows, and senior agricultural water rights are 68% larger during historical spring runoff from April through June. Results show that senior water right holders receive the largest climate-driven reductions in allocated water when peak streamflow shifts from snowmelt-dominated spring runoff to mixed snowmelt- and rainfall-dominated winter runoff. Junior water right holders have higher uncertainty from inter-annual variability. These findings challenge conventional wisdom that water shortages are absorbed by junior water users and suggest that aquatic ecosystems may be disproportionally impaired by hydroclimate change, even when environmental flows receive priority