Long distance (relatively) water pipelines are not to expensive as long as it isn’t vertical cliffs and unstable slopes on the way, so a catchment at the lower drainage or even a low dam can provide the necessary temporary storage, even if 5-10 miles or more away.

Still not super cheap of course, so then the classic ‘what will this get us for the cost, and does it pencil out as profitable’ (generally a good proxy for worth the time and expense) starts to come into play.

Thinking about it, many hydropower schemes are already built as cascades - that could be retrofitted as pumped storage quite easily, if you can interconnect the dams for reasonably cost.

Nice info! Did a bit of digging and here is a detailed analysis of such a plan (recent) for the Indus River Valley I ran across. Pretty neat [https://www.sciencedirect.com/science/article/pii/S2352152X2...]

Edit: According to the paper, it's economically viable when the output power price (post-pumping and running through the turbine again) can be > 2X the price of the hydropower, which with seasonal variation and spikey but 'free' sometimes power, could definitely help. Preferring something like solar over running a turbine could also help.

The challenge of course is that many times hydropower is nearly free and available in large quantities, as the dams are also used for flood control, so they either toss large quantities of water over the spillways (wasting it), or run it through a turbine - but they can't NOT move the water.