How do you map an entire piped water system, not just its water points?
Record the system as connected assets: sources, pumps, tanks, pipes, valves, meters and taps, each linked into the network it belongs to. You then have a model of the system rather than a scatter of points on a map.
A utility cannot plan from a dot map. Deciding where to extend the network, which pump failure will cut supply to which neighbourhood, or what a rehabilitation will actually cost all require knowing how the parts connect. Modelling the system is also what turns maintenance history into something useful: a valve that fails repeatedly matters more when you can see how much of the network sits behind it.
How to do it
Create the asset system that represents the scheme you are mapping.
Add the major assets first: sources, treatment, pumps, tanks and the main lines.
Trace the pipe network so assets are connected rather than merely nearby.
Add distribution assets such as valves, meters, taps and connections as you survey them.
Record the attributes you will actually manage on, such as capacity, material, diameter and installation date.
Build a system dashboard so operators can see the network, its faults and its performance in one place.