[noselasd]

you can switch turbines on and off , leading water to a turbine or a bypass in minutes

[powcontech]

You can, but I wonder do the operating conditions of the river actually allow it for a great number of plants? Or are they hemmed in by needing to always have a certain flow in the river plus/minus 10%.

[noselasd]

Usually they require a certain flow, the flow will be the same whether it goes through a turbine or bypass ofc.