Doug Jackson from Canberra, Australia, wrote in to share his watering system controller board, which he built in response to local laws that his commercial system couldn’t accommodate.
I live in Australia, or more specifically in an inland region called the A.C.T, where our government have implemented an ODDS and EVENS watering regime. Under the system if you live in an odd numbered house, you may water on an odd day of the month. Likewise, if you live in an even numbered house, you may water on an even day of the month. Everybody may water on the 31st.
This system, along with the mandatory replacement of sprinklers for dripper systems has sucesfully reduced the load on the cities limited inland water supply so that more drastic measures were not required.
Unfortunately, this system was unable to be implemented on my commercial water controller, it wanted to water on a Monday, or a Wednesday, so I was breaking the law, and subjecting myself to a potential fine every other week… So I had to build my own controller.