Ideas to create a connected smart water meter out of a "dumb" water meter
Especially relevant in Cape Town now (not only to measure/manage usage but also to alert for water leaks). Many houses are fitted with water meters with no connectivity capability (eg. Bluetooth or Wifi) but instead of buying a brand new smart meter for R1,500 plus (about $100) you could consider one of these Hall effect sensors or an IR sensor to measure from the existing meter that you already have.
Two types of sensors are given at http://bit.ly/2FtmB1b.
A possible solution built around the Hall effect sensor and MQTT messaging is given at https://devpost.com/software/smart-water-meter. It may sound a bit complicated but if you get one right, it can be replicated for a family member or two as well. By hooking into a home automation hub such as OpenHAB or Home Assistant (HASS) you get a lot more info and control than just the water flow. You can set alerts, compare to weather and other information you are monitoring in the house. It becomes way better than just a stand-alone smart water meter!