Water pressure is determined by the difference in elevation between the water level in our storage tanks and your home or business. The greater the vertical difference, the higher the pressure; the lesser the vertical difference, the lower the water pressure. Since elevations can vary in a neighborhood and even along a street, there is no typical water pressure in town. And even on a daily basis, water pressure can fluctuate about 5-10 psi as the water level in those tanks change. In portions of Cary west of NC 55, daily pressure can temporarily fluctuate up to 20 psi and may not have a noticeable impact on your property's plumbing. Throughout our community, water system operations and emergencies can increase or decrease pressure without warning.
High Water Pressure
Homes experiencing high water pressure may need a pressure reducing valve (PRV) or the one installed may have failed or needs to be adjusted. North Carolina Plumbing Code requires a PRV be installed where the water pressure within the main serving your home or building exceeds 80 pounds per square inch (psi), reducing pressure to protect water pipes and fixtures.
Look for the PRV where your private water line comes into your house, usually just inside the foundation wall in a crawlspace or in a closet located at the front of a residence. We recommend contacting a licensed plumber to assess high water pressure concerns.
Low Water Pressure
Multiple factors can cause low water pressure in your home:
- A sudden drop in water pressure could be due to a line break; contact us immediately to assess potential causes at 311 or (919) 469-4000 outside Cary
- A persistent low pressure flow could be due to your location, PRV setting, or line break; we suggest you contact a licensed plumber or call us if you have questions
- An isolated fixture with low pressure may be due to a build up in the fixture's aerator. Check and clean as needed.