Pumping and distribution without storage
Strictly speaking, I don't think there are actual dangers. You are mainly talking about drawbacks. More specifically, in the case of a power outage, water to customers will be cut. Ditto in the event of pump malfunction. There will also be a pressure fluctuation in the network between the pumping and shutdown phases. In the event of overspeed at pump outlet, there is no "buffer," so you run the risk of dislodging the biofilm and that means increased turbidity and bacteria. In winter, there is also the risk that you won't be able to run the pump under certain conditions, so how can you ensure consistent water supply?
Thank you for the very edifying answer.
But what do you mean by "buffer"? Also, I have a concern about the pump system: the fact that the network curve varies with demand causes a variation in the operating points of the pumping network;
Can this have a detrimental impact on the pump?
The reservoir will provide water with a relatively constant pressure for a given point in the system (with the exception of pressure drops caused by a large draw, for example). This is not the case with a pump that generates greater pressure differences. A reservoir will store the water and distribute it with fewer variations than a simple network pump. For the pumping system, that will depend on the operation of the network. Obviously, if the pump is working outside its nominal curve, it will have a shorter service life. Depending on the start and stop settings, if the network is subjected to a large linear load and equally large draws, the pump may experience frequent starts and stop, which will wear it out prematurely. A tank holding a certain quantity of water under pressure downstream of the pump would limit continuous starts and stops, which would also level out the pressure on the network.