Many homeowners are unaware that running high-water-use appliances during heavy rain can contribute to sewage backups and potential plumbing issues. The risk is higher for those living in areas with combined sewer systems, where stormwater and household waste share the same pipes. This matters because aging infrastructure in many cities struggles to handle sudden surges of water, and your dishwasher could worsen the problem.
How Combined Sewer Systems Work
Approximately 60% of New York City and an estimated one-quarter of U.S. homes – primarily in older neighborhoods of the Northeast, Midwest, and Pacific Northwest – rely on combined sewer systems. These systems are designed to manage both sewage and rainwater, but heavy rainfall can overwhelm them. When this happens, excess water, including untreated sewage, may be discharged into local waterways to prevent backups.
The Impact on Your Home
According to appliance expert Amy Chernoff, VP of marketing at AJ Madison, using water-intensive appliances like dishwashers during storms adds unnecessary strain to the system. This can lead to backups and overflows in individual homes. Craig Risoli, owner of Mr. Appliance of Staten Island, explains that increased resistance in downstream drainage creates backpressure in household drain lines.
The result? Dishwashers and other appliances may drain slowly, leak, or fail entirely due to the pressure. The problem isn’t necessarily the sewer system itself, but the way drainage behaves under stress.
What You Should Do
The biggest issues arise from appliances that discharge large volumes of water over prolonged cycles, like dishwashers and washing machines. Intermittent water usage (flushing toilets, running faucets briefly) is less problematic. Experts advise postponing these chores during intense storms to reduce strain on both your appliances and your home’s drainage system.
If your home already experiences slow drains or backups during heavy rain, it’s best to delay appliance use regardless of the sewer type. Local municipal maps or a plumbing professional can provide more specific guidance.
Ultimately, awareness of your home’s behavior during storms is key. Appliance professionals can often identify early warning signs during routine service visits. Delaying high-water-use appliances during heavy rain is a simple step that can prevent costly damage and protect both your plumbing and the environment.
