About a week ago we lost water pressure throughout the house and yard (sprinklers). Both hot and cold are affected. My house was built in 1999, copper pipes, we do have water softener (it was without salt for about 2 months), we use city water. The city checked the pressure at the street end and the pressure is normal. The guy tested the pressure in the backflow valve for the sprinklers and it is fine, but said the flow could still be low. He also said maybe the regulator is blocked, but the pipes to home land yard split before the regulator. So wouldn't that mean the flow is blocked before where the pipes split? The city guy said we might need to get a backhoe and dig up the whole front yard to "fix" the pipe, but he can't even identify where the problem is. Any ideas?? What type of professional would I call to find the problem??

If this were my call the first thing I would do is disconnect the water service line ahead of the PRV valve and see if I had pressure and volume up to the valve. Your problem will be solved by the process of elimination. Some where along the line you will find a point where pressure and volume falls off. Start at the meter and work to the PRV valve. Good luck, Tom