The electric generator and the water tanks are outside the restaurant. 

You can find them beside the sea dock, right behind the garden plots. Both areas will provide your venue with basic supplies such as power and water.

Tap on those areas when you find a lack of production to expand and improve the tanks or the generators and don't forget to visit the research section regularly to reach a higher power and water cap.

There may be pending actions to be completed before you can expand the electric room or the water tanks. Read the instructions carefully in the dialog window to find the next step!