Underground Irrigation Leak Detection & Repair in Solano, Napa & Sonoma County
A 1/32-inch irrigation leak wastes about 6,300 gallons a month, and it can do that under a lawn that still looks fine. We find it in order: the meter with everything off, each zone run on its own, then a pressure hold on the suspect pipe. The only hole dug is the one over the leak, and the repair is pressure-tested before it’s buried.
Is it the main line, a lateral or a valve?
The meter tells you which half to search.
The main line runs from the meter to the valves and holds pressure all day. Each lateral runs from a valve to its heads and holds pressure only while that zone runs. So with every tap and zone off, a moving meter points to the main line, a valve that won’t close, or the house. A still meter sends the search to the zones, one at a time.
The simple version of the test: read the meter, use no water for two hours, read it again. If the reading moved, water is leaving the system.
Meter, everything off, 2 hours Moves
A Main line
Under pressure all day. The meter moves with everything off, and the wet patch doesn’t follow any zone’s schedule.
B Lateral
Under pressure only while its zone runs. The meter sits still when the system is off; the zone runs weak, heads don’t pop up fully, or one patch stays soggy.
C Valve seep
A valve that doesn’t fully close lets water into its zone all the time. It shows as a puddle at that zone’s lowest head, and the meter creeps.
D Low-head drainage
Not a broken pipe. After each run, the water left in the zone drains out of the lowest head, then stops. A check valve under the head holds it back.
With a check valve under the lowest head, the water is held back and the head stops draining.
Water in the pipe runs downhill, so the lowest head is where a zone drains out. A check valve under that head holds it back.
How do you find a leak without trenching the lawn?
By proving where it is before anyone digs.
Carlos and his crew work in this order:
The meter, everything off
Whether water leaves while nothing should run
Each zone on its own, watched
A weak zone, a soggy patch, a head that won’t pop up
A pressure hold on the capped section
The leak is in that run of pipe
One dig, over the fault
The rest of the lawn stays as it is
The repair
The damaged section cut out and replaced with new PVC and fittings. A seeping valve is rebuilt or replaced; we install Rain Bird anti-siphon valves
A second pressure hold, then backfill
The trench tamped and leveled, the meter read again, every head run
You get it in writing: what failed, where it was, and what was replaced. When a system has more patches than pipe, the answer is a rebuild, not another repair.
3-year warranty on qualifying irrigation and lighting systems.
…diagnosed and fixed a sprinkler issue we'd been dealing with
Andres Rodriguez, Google review, Feb 2026 (opens in a new tab)…checked our sprinklers and found a broken one we didn't know about
Jennifer Murphy, Google review, Mar 2026 (opens in a new tab)
Will my water provider adjust the bill after a leak?
Napa will, once every five years; Vacaville and Fairfield take a request after the repair. Tap your town.
Lit: the six towns we have leak answers for. Elsewhere, ask your provider.
City of Napa Water Division · Checked Sep 2026
Yes, once every five years.
An underground leak of more than 5,000 gallons can qualify for one bill adjustment per address in five years. Apply within 60 days of finding it. The city repairs leaks at or before the meter; leaks after it are yours to repair.
A leak 1/32 of an inch across, running for 14 days:
gallons
Napa’s line is 5,000 gallons, about 24 days of this leak.
- Napa, City of Napa Water Division: Yes, once every five years. An underground leak of more than 5,000 gallons can qualify for one bill adjustment per address in five years. Apply within 60 days of finding it. The city repairs leaks at or before the meter; leaks after it are yours to repair. Checked Sep 2026.
- Vacaville, City of Vacaville: You can ask, after the repair. Repair the leak first, then send the city a Water Loss Adjustment Request. A leak on your side of the meter is yours to repair. The Solano County Water Agency has a rebate on a smart home water monitor, so the next leak shows up on your phone. Checked Sep 2026.
- Fairfield, City of Fairfield: You can ask, on the city’s form. Leak adjustment requests go on the city’s online form: when the leak was found, when it was fixed, and the receipts. No other terms are posted. The Solano County Water Agency has a rebate on a smart home water monitor, so the next leak shows up on your phone. Checked Oct 2026.
- Suisun City, Suisun-Solano Water Authority: Ask your provider. No posted adjustment terms. Call the water authority with the repair receipt in hand. The Solano County Water Agency has a rebate on a smart home water monitor, so the next leak shows up on your phone. Checked Sep 2026.
- Benicia, City of Benicia: Ask the city. A free city water account shows when and where the household uses the most water, so a leak shows up as a jump before the bill does. Checked Oct 2026.
- Windsor, Town of Windsor: Ask the Town. Leak alerts come through the Town’s water portal, and the Town counts runoff and a draining low head as water waste. Checked Sep 2026.
Every provider’s watering hours, side by side: Watering rules by city.
Low heads and the water meter
Low-head drainage, or a valve.
If it drains after each run and stops once the line is empty, it’s low-head drainage: the water left in the zone running downhill. A check valve under the head holds it back. If it never stops, the zone’s valve isn’t closing and needs rebuilding or replacing.
The side of the meter decides.
Vacaville: A leak on your side of the meter is yours to repair. Napa: The city repairs leaks at or before the meter; leaks after it are yours to repair. If water is coming up in the meter box itself, call your provider first. Checked Sep 2026.
Find the leak, dig once.
Carlos starts at the meter and quotes the repair free, in writing.
Call for a free quote(707) 329-8391
