When I log in to the website and try to download the CSV of my water history, there is a glitch in how that screen is generated that slides the link to download the CSV into the X-axis label area. And the link becomes unselectable. I've tried this in Safari and Chrome on Mac OS X and get the same result.
I've only had my Rachio for 2 days, so I don't have much data to look at right now. But I thought I'd report the glitch in case you were not aware.
I grabbed a screen shot of the problem, but don't see an option to attach that here. I can email it to someone if interested.