Hi geeks,

Having fun with my house renovation project. This time, I'm planning to build fence and I need to dig fence posts. However, I know that there (under ground) I have waste water, water mains, and gas tubes. I don't want to damage any of these. 

How can I found location (+/- 50cm) and depth of these communications? I know where each point goes into earth, but I don't want to dig along their way (still can accidentally damage tube). Which companies can provide this info? I went to city council and printed plans there, but they have only waste water plan. I still need to know where gas and water mains go.