Coal, oil, natural gas, wind, solar, and hydroelectric: which of these require a steady supply of water?
The answer is "All but wind and solar."
And if we don't grasp just exactly what that means and start making the right moves we will be in a world of hurt in fairly short order.
Hydroelectric power obviously depends on water, but it depends on consistent water, both in the moment and throughout the year. The mountain west, which set its water sharing compact in 1922 at the beginning of a historically wet period, already has trouble with reduced output from some of the major dams. Pakistan has a lot of water at the moment, displacing fully 10% of the populace, but this isn't the sort of thing that benefits hydroelectric stability over the long haul; climate change means we'll have more extreme weather, both wet and dry.
What do you see when you drive by a large coal fired power plant? Giant piles of coal, the trains that bring the coal, and huge cooling towers, perhaps with clouds of steam condensing if it's cool out that day. Take away the regular supply of water needed to handle the waste heat from such a plant and there won't be any electricity made. During the drought in Georgia a few years ago a power plant in Alabama serving 19,000 homes was at risk for shutdown due to the low outflow from Lake Lanier.
We don't have a lot of oil fired power left in this country but examine a diesel generator and you'll find water there, too – a closed loop leads from the engine block to a radiator with a fan. This works up to a certain size, several megawatts of output, then they too need cooling towers.
More and more of our electricity generation is done with natural gas and this gets us coming and going. The plants are more thermally efficient, so less water is needed per megawatt, but the gas feeding them is starting to come from shale or coal bed methane, and these are unregulated environmental disasters in the making. We may be able to get natural gas safely from shale, but given that regulators are not even permitted to know what's in hydraulic fracture fluid at this point, the idea that this is a no risk method of production is not believable.
Wind turbines run on what is known as the Weibull curve; plenty of power spring and fall, less in the winter, and much less in the summer when it's needed most. Even so, their water use is limited to what's in the cooler on the back of that well paid wind energy technician's truck. And his is a job that can never be offshored.
Solar, both photovoltaic and thermal, is much the same. Photovoltaic uses no water, while solar thermal needs a working fluid and that might be water depending on how things are done, but it's a closed system just like the cooling setup for a diesel generator.
If we're going to repair our economy, and by this I mean inflating the number of jobs for Americans, rather than inflating some banker's year end bonus, we have to have both a national industrial policy and the power available to execute our plan. A focus on wind, solar, and hydroelectric where it makes sense addresses both of those concerns and must be the foundation of any recovery plan.