Irrigation Water Meters: Compare Installation Fees With Sewer Savings

An irrigation meter is worth evaluating only when your utility will exclude enough outdoor water from sewer billing to recover the installed and recurring charges. A second meter does not automatically create savings. Confirm the utility’s eligibility, inspection, backflow, meter ownership, billing unit, and deduction formula before requesting a plumbing quote.

EPA’s WaterSense metering guidance says many utilities estimate sewer charges from the incoming water meter even though landscape irrigation, pools, and other uses may not enter the sanitary sewer. It says some utilities offer a sewer credit or deduction and advises contacting the provider about metering and reporting requirements. Read the EPA guidance. The document is commercial guidance, but the metering principle applies; local residential rules control.

Build the payback worksheet

Record:

Cost or input	Question
Installation	Meter, setter, plumbing, trench, permit, backflow device, inspection
Recurring charges	Second-meter fee, reading fee, service charge, testing
Avoided sewer volume	Utility-approved gallons or CCF excluded each billing period
Sewer rate	Volumetric charge and any sewer cap or winter-average rule
Timing	Seasonal irrigation months and credit start date

Calculate annual net benefit = (deducted volume × sewer rate × eligible months) - recurring charges. Payback is installed cost ÷ annual net benefit, but treat it as a simple screening calculation. Water use, rates, and approval can change.

A hypothetical break-even test

Assume installation costs $1,200, the meter fee is $6 per month, irrigation uses 5,000 gallons per month for six months, and the utility’s sewer charge is $0.009 per gallon. Avoided sewer charge is 5,000 × $0.009 × 6 = $270 per year. Recurring cost is $6 × 12 = $72; annual net benefit is $198; simple payback is $1,200 ÷ $198 = 6.1 years. These are assumptions, not a provider quote. If only 3,000 gallons qualify, annual net benefit drops to $90 and payback extends to 13.3 years.

EPA notes that utilities may use different meter types and that improper sizing can cause pressure loss, inaccurate low-flow measurement, or unnecessary fixed charges. Ask who owns and maintains the meter, how it is read, and whether it must be utility supplied. An outdoor line that also serves a hose bib, pool, or automatic top-off may not qualify as irrigation-only.

The utility bill itself is the baseline for the comparison: EPA’s bill guide explains that fixed and volume charges can coexist and that rate structures may be uniform, tiered, seasonal, or drought-based. Use the bill guide to identify the sewer line and unit before estimating a deduction.

Read the rule before the quote

Some utilities require a separate service connection; others install a deduct meter after the main meter. Confirm whether the sewer deduction is a credit on the next bill or a separate rate class. Ask if the utility charges sewer service on all water use below a minimum, uses a winter average, or excludes only usage recorded after approval. Check backflow testing and annual inspection requirements. The provider’s written answer matters more than a contractor’s generic “sewer savings” estimate.

Use a low, expected, and high irrigation volume in the worksheet. Exclude rain-fed months and account for drought restrictions. Price the meter, excavation, restoration, backflow assembly, permits, and any service upgrade separately. If the payback depends on a future rate increase, mark that as a scenario rather than a promise.

The right next step is a utility confirmation email followed by two itemized quotes. The quote should name the meter location, line served, testing responsibility, and restoration scope. Only then compare the installed cost with the sewer deduction the utility will actually honor.