Irrigation Meter vs Main Meter — How Alpharetta Homeowners Save on Sewer Charges
If you have an irrigation system, you're probably paying sewer charges on water that never enters the sewer. A separate irrigation meter fixes that.
Fulton County's water billing has a structural quirk that costs irrigation users substantial money: the sewer charge is calculated based on water meter readings rather than actual sewer discharge. Water that goes to your lawn and evaporates or soaks into the ground is charged sewer fees as if it had entered the sanitary sewer. For homes with active irrigation systems, that's hundreds to thousands of dollars per year in sewer charges on water that never reached the sewer.
The fix is a separate irrigation meter — a second water meter that measures only the water going to irrigation. Water measured on the irrigation meter is exempt from sewer charges. This guide covers how the program works, what it costs, and whether it pencils out for your specific situation.
How Fulton County's billing actually works
Your monthly water bill has two main components:
Water charges — based on actual water usage measured at your main meter. You pay per thousand gallons consumed, with tiered rates that increase for higher usage levels.
Sewer charges — also based on the main meter reading. The county assumes that water entering your home eventually leaves through the sewer, so sewer charges scale with measured water usage.
The assumption is reasonable for water used inside the house — that water enters the sanitary sewer and the cost of treating it is real. But it's wrong for water used outside the house. That water never enters the sewer system, but the bill treats it like it did.
For typical Alpharetta households without irrigation, the misalignment is small — most water use is indoor and does enter the sewer. For households with active irrigation systems, the misalignment can be substantial — easily 30-50% of total water usage during summer months.
How a separate irrigation meter solves this
A separate irrigation meter installed on the irrigation supply line measures only the water going to the irrigation system. Water measured on this meter is billed for water consumption but exempt from sewer charges.
Setup requires: a second meter pit installed on the irrigation supply line, the meter itself supplied and installed per Fulton County specifications, coordination with Fulton County to add the meter to your account and begin separate billing, and pre-installation contact with Simone Rolland at (404) 612-0883 — the county contact for irrigation meter setup.
After installation, the county reads both meters. Your bill shows usage and charges separately: main meter water and sewer charges, irrigation meter water charges only. The sewer-charge avoidance is automatic.
What it costs in 2026
Approximate Fulton County program cost for installation: around $2,385, including the meter, the pit, the connection, and the county's setup fee. Specific cost varies by site conditions and may have updated since this writing — confirm with Simone Rolland before commitment.
Beyond the program cost, there may be additional plumbing work depending on your specific irrigation supply line configuration. Most homes have a simple supply line from the main to the irrigation system that can accommodate a meter pit without major modification. Some configurations require additional plumbing.
Payback period — does it make sense for you?
Payback depends on three factors: your annual irrigation water usage, the current sewer rate, and the current main water rate.
Quick calculation:
- Estimate your annual irrigation water usage. The simplest method is comparing your winter month bills (essentially no irrigation use) to summer month bills (heavy irrigation use). The difference is roughly your irrigation usage. Multiply by 12 to get an approximation of annual irrigation gallons.
- Apply the current sewer rate to that irrigation usage. The current Fulton County sewer rate is published on the county water services site.
- Annual savings = irrigation usage × sewer rate
- Payback period = installation cost / annual savings
For typical Alpharetta households with active irrigation on a half-acre lot: annual irrigation usage 50,000-100,000 gallons; sewer rate roughly $7-9 per thousand gallons; annual sewer savings $350-$900; payback period 2.5-7 years.
For larger irrigated lots, higher-usage households, or commercial properties: payback period can be 1-3 years. For minimal-irrigation households or properties without irrigation systems: not worth installing.
When to install — and when not to
Install when:
- You have an active in-ground irrigation system used multiple months per year
- Annual irrigation usage exceeds 30,000-40,000 gallons
- Your payback calculation produces a period of 5 years or less
- You plan to remain in the home for at least the payback period
Don't install when:
- You don't have an irrigation system or irrigation use is minimal
- You're planning to sell within the next 2-3 years
- Your lot doesn't permit the additional meter pit installation without major plumbing work
The pool fill credit alternative
Worth knowing for pool owners: Fulton County also offers a one-time pool fill credit for sewer charges on the water used to initially fill a residential swimming pool. The credit is a one-time event, not annual, but for pool owners filling a new pool it's worth claiming. Documentation requirements similar to the leak adjustment credit — call Fulton County for current submission process.
What we do on irrigation meter installations
Our scope on these projects is the plumbing work that connects the new meter to your existing irrigation supply. The meter itself, the pit, and the county-side coordination are handled through the Fulton County program. We coordinate with the county program staff and with you on scheduling so the plumbing work happens at the right time relative to the county's installation visit.
Typical scope includes: identifying the existing irrigation supply line, planning the location for the meter pit, doing the plumbing connection work that ties the new meter into the irrigation system, pressure testing the connection, and restoring service.
The work usually takes a few hours and coordinates with the county's installation visit.
Common questions
"Do I have to use a specific contractor?" No — the meter and pit are county-supplied, but the connecting plumbing work can be done by any licensed plumber. We do these regularly and can coordinate with Fulton County's program staff on scheduling.
"What if I already have irrigation but no separate meter?" Then you're paying sewer charges on your irrigation water. The irrigation meter program addresses exactly this situation.
"Will the meter affect my irrigation system performance?" No — the meter measures flow but doesn't restrict it. Irrigation system performance is unchanged.
"Can I install this myself?" The meter and pit installation is done by Fulton County's program. The connecting plumbing work requires a licensed plumber for the regulated portion.
Next steps if you're interested
Three steps:
1. Run your payback calculation. Use your actual bills from winter (low usage) and summer (high usage) to estimate annual irrigation gallons. Apply the current sewer rate. Confirm payback period meets your threshold.
2. Contact Fulton County's irrigation meter program. Simone Rolland at (404) 612-0883 is the program contact. They'll confirm current pricing and schedule the meter installation.
3. Schedule the plumbing connection work. Once you've coordinated with the county, schedule us to do the plumbing tie-in. Call (773) 207-0518.
The savings start with the first billing cycle after installation. For active irrigation users, this is one of the best single investments you can make in reducing water bills.
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