Underground water leak

[UnHandy]

The meter reader says my water usage has skyrocketed and suspects a leak. There's nothing leaking in the house and with everything turned off, the meter is still spinning. I'm suspecting that it's the main pipe to the house. The problem is, it's about 250 yds from the water meter at the road to the house. I don't know where the leak is. I have a pretty decent guess where the line is run but I'm not sure. How can I fix this without spending and arm and a leg?
There is an area of the yard about 25 yards downhill from where I think the pipe runs that has been wet for about a month and a half. There also happens to be a pond near there and I thought it was from the pond but now I'm not sure.
Any advice for the clueless? Oh, and I may be able to borrow a backhoe but even with that, I hate to think about digging the whole yard up looking for a leak. Plus, with me operating the backhoe, there will certainly be leaks after I start digging around the pipe.
Thanks for any help.

[thedcdude]

I think it's pretty clear you're in over your head with this one. Call the utility first, then call a plumber.

[HayZee518]

check for extremely wet spots along the supposed run of pipe. inject a dye after the meter to see where the leak is if it migrates to the surface. other than that professional help is almost always needed.

[Lewis]

this may help

The wet spot is an indicator of a leak but the water is going to take the path of least resistance so it may not be an indicator of the location of that leak. You have several options...
1) you can call a leak detection service and then have a plumber come and dig up the area and fix that section.
2) you can have a replacement of the pipe which would involve a lot of digging
3)you can have a lining company come and line the existing pipe. this should fix the leak and provide you with corrosion control for the future.
4) and there may be a company that can pull a new pipe through.

If it was me I would try the lining company first because it would not involve digging. If there is a company that can pull a pipe through that could work as well but i am not sure if it would lower your water pressure. Try looking in google for pinhole leak. My mom had the same problem with a leak in the main line and she used ePIPE.

Hope this helps...Good Luck