Going to add my vote for this as well. It’s possible to track water usage today (as many of us do) via interfaces such as MQTT. But the energy dashboard has taken things to a whole new level with long term statistics and allowing data to be seen daily, weekly, monthly, etc. without having to create separate sensors for each of those data points.
I fully support the idea brought up by others to improve the Energy dashboard by adapting it to be more of a Utility dashboard. Many of us want the dual goals of being more environmentally aware and saving money (nice how those two thing normally go together). If the tools introduced with the energy dashboard were to be extended to other utilities (water in my case - which should be no surprise because I live in drought-stricken Southern California) this task would be made a lot easier.
Also worth mentioning is that the energy dashboard is one of the innovations that makes Home Assistant a true standout over most home automation platforms. The idea of rising above the various integrations to offer meaningful insight into the data. One of the many reasons I enjoy the platform.