A computer-implemented method generates a set-point temperature for an evaporative cooler supplying cooled water to a chiller. Under the control of one or more computer systems configured with executable instructions, an achievable temperature for water supplied to the chiller by the evaporative cooler is generated based at least in part on an outside wet bulb temperature. A set-point temperature for the water supplied to the chiller by the evaporative cooler is then generated. The set-point temperature is the greater of the achievable temperature and a minimum temperature for water that can be used by the chiller without causing damage to the chiller.