Been dealing with one house that is halfway down a steep bank, approximate 60' drop from road level (where main is...) The garden is a stepped terrace. They've had to lay the pipe so that it is 750mm from inner apex of each step. Glad I wasn't digging that one... The other alternative was to bring a pipe up 40' from the main below, but the lower main has pressure reduction on it due to it being at the bottom of a massive hill!