Outdoor watering is limited to a maximum of 15 minutes per station per day. For most irrigable areas and most irrigation systems, 15 minutes is too long and will result in more than incidental runoff which is prohibited. The time frame was put in place to not only accommodate residential users, but also larger commercial and recreational areas that may need longer to cycle through each station. The combination of 15 minutes per station and no more than incidental runoff should be self-limiting. If someone can water 15 minutes without creating runoff then they can do that. If runoff is created at 5 minutes, then that should be the end of the watering time for that station.