I just received my unit and was reading thru the documents to understand how to set it up before I start plugging in wires and configuring. On the page at http://support.rachio.com/article/116-watering-time-features it says
you can now adjust the amount of water you wish to save by a percentage amount. This feature is explained in more detail in this article
and gives a link to the page http://www.support.rach.io/article/246-adjust-water-amount but that page does not exist. Is this feature no longer supported?