Someone down thread posted that the private company has proposed several new reservoirs starting in 1992 and they've all been blocked on environmental grounds by the government or by NIMBYs.

For example the Abingdon Reservoir has been in planning for 19 years[1]. It is opposed by GARD[2], the Group Against Reservoir Development. It's hard to see how this is the fault of privatization.

[1]https://en.wikipedia.org/wiki/Abingdon_Reservoir

[2] https://groupagainstreservoirdevelopment.org/