Manuel López-Ibáñez sent me this article by Tom Adelstein about open source software for the water industry:

1) Bulk Meter Flow and Operations (BMFO) - a web-based application to manage water meter readings.

2) DC Maintenance Management System (DCMMS) - the system provides a web-based application to record and analyze customer complaints and repairs in water supply networks.

You can find the full article in the Linux Journal