On this map I was so focused on getting everything done and not losing anything in the canal, that I completely forgot about the need to squander money to get the fifth star. By the way. You can use the tunnel that you destroyed to get to the power station. You just need to do an anti-clockwise loop after descending the embankment, so the track crosses over itself. There is just a need to be a bit more mindful of train movements in order to avoid a collision at the crossing point.
