Quick Answer:
If your water pressure falls while using faucets after nearby sewer work, first check several faucets and both hot and cold to be sure it’s a real, house-wide drop. Look at visible shutoff valves at the service entry and the pressure-reducing valve or well pump settings. If the change started right after the sewer crew worked nearby, ask the contractor whether a supply line could have been disturbed and request a pressure test and correction.
Why This Happens
- Work near the main or service trench can move soil, bump fittings, or accidentally hit a water supply line, causing a partial cut, kink, or joint failure that reduces pressure.
- Workers may have partially closed a valve at the property edge or at the meter and not fully reopened it.
- If your home has a pressure-reducing valve (PRV) or a private well pump, settings or damage to those components can change pressure during or after nearby excavations.
- Nearby sewer work can also lead to New leaks after sewer cleaning if lines are stressed or supports shifted; that can change system pressure.
Step-by-Step What to Do
1. Confirm the pressure drop is real
- Test multiple fixtures: turn on a faucet in the kitchen, a bathroom cold and hot, and an outdoor hose spigot. Note whether both hot and cold are low and whether the problem is at many fixtures or just one.
- Check at different times of day—if pressure only drops when multiple fixtures run, this can be normal demand rather than a supply fault.
2. Inspect visible shutoff valves and the meter area
- Find the main shutoff near your service entry and any visible sectional valves. Make sure none are partially closed—valves that are half turned reduce pressure.
- If there’s a meter or utility box, look for tags or notes left by the crew; workers sometimes close valves and forget to fully reopen them.
3. Check the PRV or well pump settings if applicable
- If your house has a PRV (usually found on the water line after the meter), inspect visually for leaks or signs of tampering. Don’t force adjustments yet.
- For private well systems, check the pump controller or pressure tank gauge for obvious faults or empty tank condition.
4. Ask the contractor about the work and request a pressure test
- Contact the sewer contractor or municipal crew that worked nearby and describe the timing and symptoms. Ask whether they excavated near the supply line or shut any service valves.
- Request a simple pressure test and that they correct any damage. If you suspect the supply line was disturbed, document the issue (time, which fixtures affected) and insist on a repair or involve the utility if appropriate.
What Not to Do
- Avoid repeatedly adjusting the PRV or the main water shutoff without first confirming the cause — improper handling can worsen supply issues or create leaks.
- Do not dig around the service entry or attempt to repair a suspected cut supply line yourself; buried supply lines and connections can be hazardous and require proper tools.
- Call a professional when pressure drops across the whole house, pressure fluctuates rapidly, or you suspect a cut supply line during nearby work; a pro can safely test and repair supply damage.
When to Call a Professional
- If low pressure affects the entire house or both hot and cold lines after your checks.
- If you find a visible leak, an open trench nearby, or suspect the supply was hit during sewer work.
- If the PRV or well system gauge shows abnormal readings and you’re not comfortable adjusting or testing them yourself.
- If the contractor denies responsibility but evidence suggests the work caused the issue—get a licensed plumber or utility technician to diagnose and provide a repair estimate.
Safety Notes
- Shutting and opening the main valve should be done slowly to avoid water hammer; if you’re unsure, wait for a pro.
- Avoid digging or probing near recent sewer work without proper locating—there may be other buried utilities that can be dangerous if struck.
- If you suspect a major service rupture (large leak, no water at all, mud or water coming from a disturbed area), stop using water and contact the contractor, utility, or a licensed plumber immediately.
Common Homeowner Questions
- Why is only one faucet low when others are fine?
A single low fixture usually means a local issue—a partially closed supply stop, an aerator clog, or a fixture valve problem. - Can sewer crews legally dig near my water line?
Yes, with permits many crews can work near utility lines, but they should take care and notify affected homeowners if they need to close valves. - How quickly should a contractor fix a damaged supply line?
Promptly—if their work caused the damage, they should arrange repair or allow a licensed plumber to assess and correct it right away.
More in this topic
For more related fixes and similar symptoms, see Post-Snaking Main Line Problems.