Our project has limited turf areas that will require irrigation. We have a small irrigation system supplied by a rainwater cistern sized to provide required volume per LEED requirements. However, under drought conditions, the owner would like to be able to add potable water to the cistern if necessary. I have recommended a hose bibb intake for such conditions as LEED does not consider a hose bibb part of a permanent system. However, the owner has asked if we could instead install an emergency valve to connect to potable water supply to fill the cistern only under drought conditions. My gut is to stick with the hose bibb. Thoughts?