Small dams are great. Per dollar they can store a lot more water than large dams (partly due to compacted earth vs concrete construction), they don't incur larg

Small dams are great. Per dollar they can store a lot more water than large dams (partly due to compacted earth vs concrete construction), they don't incur large water transport costs and evaporation/salination, and they reduce regional flooding (again, because they store more water per dollar) and improve on-farm water security. In terms of liters stored per hectare, there are more opportunities for small-scale dams than large dams. Like in Australia, every farm should have its own system of dams. Scale matters. Like all things, there's a "right size" for everything. We've been focusing almost exclusively on huge dams, but neglecting small [property scale] dams. At a smaller scale there are many advantages: significantly more 'edge' for beneficial biotic interactions (edges between biomes are more productive than either biome on its own), the topsoil can be economically removed during dam construction to avoid methane release and wasted biomass (impossible in a huge scale dam), runoff and on-farm erosion is reduced by strategic dam placement within the landscape, and the water can be directly used on the farm with no transaction overhead or canal network (just a simple system of gravity fed pipes). http://www.fao.org/docrep/012/i1531e/i1531e.pdf http://www.fao.org/docrep/012/i1531e/i1531e.pdf >significant flood control+reservoir dams will certainly be rebuilt I wouldn't necessarily adopt such a pessimistic attitude. Your analysis is predicated on the idea that A) the society will have the resources to rebuild thousands of [often economically futile] dams, and B) the society will neglect to account for the ecological and indirect economic costs of building a dam (reduced forestry yield due to phosphorus deprivation from salmon runs, increased insurance cost due to delta erosion, etc) versus the water resources and flood control abilities, which are constantly degrading due to silt buildup. http://news.nationalgeographic.com/news/2014/08/140826-elwha-river-dam-removal-salmon-science-olympic/ http://news.nationalgeographic.com/news/2014/08/140826-elwha...