Hoover Dam question

[ljossberir]

When you build the Hoover Dam, it automatically puts a Hydro plant in your other cities (at least in the ones on the same continent).

I have a question about this. Normally, you would have to build a factory in any city before building any kind of powerplant. So if the Hoover Dam puts Hydro Plants in your cities without factories, do they still get the benefits of the Hydro plant? Is it worth it to build factories in these cities afterwards, will that still increase production?

 

[Theoden]

The hydro plant from Hoover Dam will only give it's benefit if a factory is present. This also counts if you had build the plant manually and then sold the factory.
This definately makes it more worthwhile building factories in half-good cities becasue it will mean +100% production when the factory is finished without having to build the hydro plant manually afterwards.