Photography after dark can be fun especially with a subject that reflects back many light sources, just watch your exposures and keep your ISO as low as possible to preserve detail.
You can start in the gloaming that time between daylight and dark where you can go roaming as the traditional old Scots ballad would have it, though making pictures as the light fades into darkness.
Once dark, you are working with much slower shutter speeds and higher ISO's (though still trying to keep them as low as possible) and wide open apertures. Some scenes can be rendered much more moody and atmospheric to dramatic effect.
With other you can get mysterious effects like houses illuminated in the dark but seemingly suspended in midair. In all cases the reflected light in the ripples on the surface of the water add interest as well as tone, texture and depth to each image. The full set of photos can found here.