>big lakes are used for recreational boating This is a great point. Many of those reservoirs included recreation benefits in the accounting that led to them be

>big lakes are used for recreational boating This is a great point. Many of those reservoirs included recreation benefits in the accounting that led to them being funded in the first place, so it may not be trivial to impinge on them. >in the west, putting these in water might not make so much sense. OTOH, evaporation is also a big problem there (roughly a couple million acre-feet/year in the Colorado drainage, from memory) so mitigating that would be beneficial.