Rhillman: I like where you are going with your flow logging. Have you considered how to report flow that’s not associated with a specific valve? (i.e. a slow leak or gusher, or other sources drawing water through the meter?)
Have you considered publishing your flow rates via MQTT? http://mqtt.org/ this is a very simple and lightweight publish/subscribe framework and would allow integration with other devices. For example, you could publish your rows of data to topic “Rhillman/home/sprinklers” and then have your phone (or another OS controller) subscribe to the same topic to trigger an alert.
It would also be nice to track the actual cost of the water for logging. This can get complicated with tiered water rates, but I’m happy to count all water usage at the highest rate for the billing cycle, and not worry about the cheaper water at the beginning of the cycle.