Why Your DeKalb Water Bill Suddenly Went Up
A water bill that jumps without an obvious explanation is the most common reason people call us, and the causes fall into a fairly short list. Work through them in this order — it goes from cheapest to most expensive, which is the right direction to search.
1. A toilet flapper
Start here every single time. A flapper that no longer seals lets water trickle from the tank into the bowl continuously, and the fill valve tops it up just as continuously. It is silent, invisible, and can pass a remarkable volume over a month. Food colouring in the tank, twenty minutes, look in the bowl. A flapper costs a few dollars.
2. The irrigation system
If your bill climbed in May or June and the house is dry, this is very likely it. A zone valve whose diaphragm has failed passes water with the controller off. A lateral cracked by winter freeze leaks every time the zone runs. Shut the irrigation supply valve and watch the meter for thirty minutes. If the meter stops, you have your answer. Our page on sprinkler leak detection goes into it further.
3. A water softener stuck in regeneration
DeKalb treats its water with ion exchange softening before it reaches you, but plenty of homes have their own softener as well. When a softener’s control valve fails, it can regenerate constantly, dumping water straight to the drain. Look for continuous flow at the softener’s drain line.
4. Seasonal or household change you forgot about
Houseguests, a new washing machine used differently, filling a pool, a new lawn being established, a hot dry August with more watering, a child home from school for the summer. Compare against the same period last year rather than against last month, and think about what actually changed.
5. A hidden leak inside the house
Run the meter test. Everything off, note the reading, wait thirty minutes, read again. Movement means water is escaping. Then close the main shutoff and repeat to work out whether it is inside or underground. Full method in our meter test guide.
6. A leak in the buried service line
If the meter keeps moving with the house main closed, the leak is in the service line between the curb stop and the house. This one produces no visible symptom in many cases — in DeKalb’s clay till, water can travel sideways into a utility trench or a storm drain and never surface. See underground water line leak detection.
7. An under-slab leak
A supply line under a basement slab can leak into the sub-base and out through the drain tile and sump, which means the bill goes up and literally nothing looks wrong. The clues are a sump pump that runs in dry weather, a warm patch on the floor, or efflorescence on the concrete.
8. A meter or billing issue
Rare, but it happens: a misread, an estimated bill followed by a catch-up actual, or a meter change. The City of DeKalb Utility Division can be reached at 815-748-2050 and will discuss a reading with you. Do this after you have run the meter test, so you arrive with evidence rather than a theory.
A quick decision tree
| What you observe | Most likely cause | Next step |
|---|---|---|
| Bill up only in summer months | Irrigation leak or over-watering | Isolate irrigation, watch meter |
| Bill up year-round, house dry | Toilet, softener, or buried leak | Dye test toilets, then meter test |
| Meter moves with main closed | Buried service line leak | Service line locate |
| Meter moves, main closed stops it | Interior leak | Isolate hot vs cold, then locate |
| Sump runs in dry weather | Under-slab supply leak | Under-slab locate |
| Warm spot on basement floor | Hot-water line under slab | Stop using hot water, call |
What it is worth spending to find out
A leak detection call costs a fraction of a single season of a significant leak, and far less than excavating the wrong part of a yard. If you have run the meter test and it confirms water is escaping, the remaining question is only where — and that is a question worth answering precisely rather than approximately.
Quick answers
Policies on leak adjustments vary and are at the utility's discretion. Contact the Utility Division at 815-748-2050 to ask what their current process is. Having documentation of the leak and of the repair — which our reports provide — generally helps any such request.
Enough to notice. A flapper passing water continuously can waste several hundred gallons a day depending on how badly it is seating. Across a billing period that is thousands of gallons from a part that costs less than a coffee.
Then water is not currently escaping, and you are looking at either intermittent use — an irrigation zone, a softener cycle, an appliance — or a usage change rather than a leak. Try an overnight reading to catch intermittent losses before concluding there is nothing there.
More leak guides
The 30-minute meter test that tells you whether water is escaping, and whether it is inside the house or underground.
Where DeKalb pipes freeze, how to prevent it, and the first five minutes when one bursts.
Four causes, four different fixes, and how to tell them apart before spending money.
Leak line, answered 24 hours
(815) 849-0091Call nowOne call does it. We work out what is likely wrong on the phone, quote before we come out, and book you in on the same call.