I have city water. I've had a plumber in to correct my low water pressure problem. The pressure was consistently low at every outlet but did not change if other outlets were opened. He replaced the whole house water filter and the pressure value where the water line first enters the house. He tested and found 60 lbs as the water comes out of the filter to the rest of the house. However, when we turn on any water source, the pressure drops to around 25 lbs. Now if I have one water outlet open and then open another the water pressure at both drops to almost nothing. In other words, the problem is worse and he charged me $1,000.00. He suggested the problem was in the cities water meter. I had them test it and they said it was fine.