Transatlantic freshwater aqueduct

This paper offers a technical and geopolitical reappraisal of a macro-engineering proposal to plumb Earth's freshwater, siphoning some of it from a region of surplus (Amazon River Basin) to a region of shortage (arid northern Africa) via his positively buoyant (subsurface floating) seabed-anchored Transatlantic Freshwater Aqueduct. Two different routes for the pipeline, of length 4,317 and 3,745 km, respectively, have been considered. Pipe diameters larger than 60 m are necessary for "reasonable" low pumping power (i.e., less than 20 GW). Using a bundle of smaller size pipes instead of a larger single pipe might overcome technical difficulties but the advantage of simplifying the construction technology might be exceeded by the disadvantage of consuming more power in operation. To keep the number of pumping stations reasonably small (i.e. fewer than 20) a single pipe of diameter higher than 30 m (or bundles of smaller diameter pipes) is required. The Atlantic Ocean currents may be used to provide the necessary power for pumps. The available power possibly provided by the North Brazil Current ranges between 2 and 9 GW. The North Equatorial Current may provide less than 0.3 GW power while the North Equatorial Counter Current provides the largest power availability, ranging between 2 and about 100 GW. A rough cost estimate of the project is about 20,600 GUSD and 18,400 GUSD, respectively, for two pipeline routes. © Springer Science+Business Media B.V. 2009.