Generally speaking, watering lawns early in the morning is better than during midday. Watering during the day keeps a lot of water from ever making it into the ground, due to evaporation. By watering early in the morning, before it gets warm (especially in the south, like at Johnson Space Center), you end up using far less water for the same effect; this reduces costs and drains on local resources, makes government centers more green, and the change can be made very quickly and simply (just a change to the sprinkler timers or instructions to the groundskeepers). While we're at it, include an override so that if there is a good chance of rain, or if the rain has already started, the sprinkler cycle can be turned off or delayed.
Idea No. 14936