[yread]

Its not just that water temperature rises but that there is less of it (ie drought) so the constant amount of constantly hot water from the plant gets mixed with less water left in the river increasing its temperature more

[XorNot]

Well it's got more to do with not wanting to boil the river ecosystem rather then being unable to cool the plant.

[dgellow]

It’s both, higher temperatures also make the cooling less efficient.