Editing Dam (section)

==== Economics ====
Construction of a [[hydroelectric plant]] requires a long lead time for site studies, [[hydrological]] studies, and [[environmental impact assessment]]s, and are large-scale projects in comparison to carbon-based power generation. The number of sites that can be economically developed for hydroelectric production is limited; new sites tend to be far from population centers and usually require extensive [[power transmission]] lines. Hydroelectric generation can be vulnerable to major changes in the [[climate]], including variations in [[rainfall]], ground and surface [[water level]]s, and glacial melt, causing additional expenditure for the extra capacity to ensure sufficient power is available in low-water years.

Once completed, if it is well designed and maintained, a hydroelectric power source is usually comparatively cheap and reliable. It has no fuel and low escape risk, and as a [[Sustainable energy|clean energy]] source it is cheaper than both nuclear and wind power.<ref>{{cite web|url=http://en.openei.org/apps/TCDB/|title=Transparent Cost Database – Transparent Cost Database|website=en.openei.org}}</ref> It is more easily regulated to store water as needed and generate high power levels on demand compared to [[wind power]].