A suddenly high water bill usually comes from one of three things: the rate or billing period changed, the household used more water, or water is leaking after the meter. Compare the gallons on this bill with the same month last year before assuming a leak, because gallons show use and dollars do not.
Check the bill itself first. A longer billing period, or a catch-up bill after an estimated reading, can raise the total with no change in daily use. The North Texas Municipal Water District, Frisco’s wholesale supplier, raised its rate on October 1, 2026, and Frisco says water and sewer rates go up starting in January.
If the gallons really did rise, look at what changed. Irrigation is the usual seasonal swing, and a controller left on a summer schedule keeps watering after the weather cools. Guests or a pool refill add up fast.
If nothing explains the gallons, test for a leak. Turn off every fixture, the ice maker and the sprinklers, then watch the leak indicator on the meter, or read the meter before and after two hours of no use, as EPA WaterSense advises. Any movement means water is escaping. The most common silent culprit is a running toilet. Dripping faucets, a broken irrigation line, the buried line from the meter to the house, and a slab leak are the others.
One honest limit: the meter test shows that water is leaking, not where. If the meter still moves with the house shutoff closed, suspect the service line or irrigation, especially with water standing in the meter box. If it stops, the leak is inside or under the house, and a slab or underground leak needs professional leak detection to locate. A leaking drain line will not move the meter at all.