As shown in the table above, the daily irrigation need varies widely from day to day and even can be widely different from one year to the next. This is the basis for the magic of Weather Based Irrigation Control. Weather Based Irrigation Control calculates the water lost on a daily basis and then only waters when the site needs it based on this scientific calculation. With the widely varying irrigation need, it is impossible to accurately calculate or "guess" what will be needed during the following week as a manually programmed conroller does. When you guess, you usually guess consistently higher than needed.
In our experience, weather based irrigation is saving 20-40% from historical water usage. As water is expensive, this can add up to significant dollars. In most cases, we are finding a 2 year or less ROI. We strongly believe that all properties should have some form of weather based irrigation. If you don't have it already, we will be proposing it again as a part of our 2013 budget proposal.