Several options are available to reduce the impacts of reduced cooling water for thermoelectric power generation, increases in water temperature and lower flows for hydropower generation. These include  switching from freshwater to seawater  or air cooling;  replacing once-through cooling systems with recirculation systems;  replacing fuel sources for thermoelectric power generation;  increasing the efficiency of hydro and thermoelectric power plants;  relaxing discharge temperature rules to allow warmer water to enter rivers;  installation of screens to stop algae or jellyfish blooms clogging intakes;  reducing power production and managing demand; and  changing reservoir operation rules . Shreshta et al.  show that changing reservoir operation rules can offset reduced water availability under RCP8.5 until 2050, but is insufficient by the 2080s. van Vliet et al.,  showed that a 10% increase in hydroelectric generation efficiency can compensate for reduced water availability in most regions. Higher efficiency thermoelectric plans offset impacts under lower climate change scenarios but are shown to be inadequate under RCP8.5 by the 2080s; whereas a switch to seawater and dry  cooling provides a net increase under this scenario. However, these technologies can increase costs. Increasing the temperature of water discharged from the power station can have negative environmental impacts .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report