The utility uses a winter average, sewer average, or wastewater average to set sewer charges for part of the year.
Some utilities use winter water use to estimate sewer charges because outdoor irrigation is lower. High indoor use or leaks during the averaging window can raise sewer costs later.
Check first
Find the months used for winter averaging or sewer averaging.
Check indoor water use, toilet leaks, softener cycles, and guest stays during those months.
Compare sewer charges before and after the average is applied.
Look for irrigation or outdoor water that should not be part of the average.
Practical savings moves
Fix indoor leaks before the averaging window when possible.
Track gallons per day during winter average months.
Avoid unnecessary indoor water waste during the averaging period.
Ask the utility how leak adjustments apply to sewer averages.
Avoid these mistakes
Do not assume summer irrigation always raises sewer charges if winter averaging is used.
Do not ignore a winter leak because the summer bill is when the impact appears.
Do not compare sewer bills without knowing the averaging rule.