Drawing on ground water and releasing it into the atmosphere isn't great if the demand exceeds the aquifer's ability to recharge. Discharging heated water into

Drawing on ground water and releasing it into the atmosphere isn't great if the demand exceeds the aquifer's ability to recharge. Discharging heated water into a retention pond might allow it to recharge the aquifer (although some would evaporate), and form a less open loop. Or, discharging it into sewers might offset fresh water needs at a downstream treatment plant, and the temperature differential may or may not be important. Sometimes, reclaimed water from treatment plants can be used for cooling as well, and that's better than pulling fresh water directly.