Hawaii’s rainy season typically runs from October through April, but smart homeowners start their preparation in September. Heavy rains, flash floods, and saturated ground can quickly turn a small plumbing issue into a costly home disaster.

Whether you live in a Honolulu high-rise, a Kailua single-family home, or a cozy cottage in Hilo, proper preparation can help you avoid clogged drains, sewer backups, and water damage. This comprehensive guide walks you through how to prepare your plumbing for the rainy months, with practical tips tailored to our island climate and the unique needs of Hawaii homes.

Why Rainy Season Preparation Matters

On the mainland, winter plumbing prep often means preventing frozen pipes. In Hawaii, our biggest seasonal plumbing challenge is water—lots of it. During heavy rains, stormwater can overwhelm drainage systems, seep into foundations, and even backflow into your home through floor drains or toilets. Because our islands are surrounded by the ocean, salt-rich air accelerates corrosion, making leaks and pipe failures more likely during extended wet periods.

Ignoring rainy season prep can lead to:

• Flooded basements or ground floors
• Sewer backups
• Structural damage from water infiltration
• Mold and mildew growth (which spreads faster in our humid climate)
• Costly emergency plumbing calls during storms

A few hours of preventive maintenance now can save you thousands in repairs later.

Clear Gutters, Downspouts, and Yard Drains

Your home’s first line of defense against water damage is a clear path for rainwater to flow away from your structure.

• Remove leaves, branches, and debris from gutters and downspouts to prevent overflow.
• Check that downspouts extend at least 3 feet away from your home’s foundation.
• Clear yard, driveway, and patio drains—these often clog with dirt and leaf litter.
• For coastal homes, rinse gutters with fresh water to remove salt buildup and prevent corrosion.

💡 Pro Tip: Schedule quarterly gutter cleaning in areas with heavy vegetation or year-round leaf fall.

Inspect and Maintain Sump Pumps

If your home has a basement, crawl space, or low-lying area prone to flooding, a working sump pump is critical.

• Test your pump by pouring water into the pit—it should turn on automatically.
• Clean the pump inlet screen to prevent clogs.
• Inspect the discharge pipe to ensure water is directed away from your foundation.
• Consider installing a battery backup in case of power outages during storms.

If you don’t have a sump pump but your area experiences pooling water during heavy rains, ask a plumber if installation would benefit your home.

Install or Inspect Backflow Prevention Devices

In older neighborhoods and during major storms, municipal sewer systems can become overwhelmed. When this happens, sewage can flow backward into your home’s drains, tubs, and toilets—a health hazard and an expensive cleanup job.

• If you have a backflow preventer, schedule an annual inspection to ensure it’s functioning.
• If you don’t have one, a licensed plumber can install it to protect your home.
• In flood-prone areas, consider additional protective measures like standpipes in basement floor drains.

Check for Existing Leaks

Rainy season in Hawaii often means you’ll use certain fixtures more frequently, and any leaks will worsen under extra strain. Inspect:

• Under sinks for dampness or water stains.
• Toilets for running water or leaks at the base.
• Outdoor spigots for drips or signs of corrosion.
• Water heaters for rust, puddling, or moisture near fittings.

Fixing small leaks before heavy rains prevents more serious water damage and reduces water waste.

Condo and Multi-Unit Building Tips

Living in a shared building means your plumbing prep affects your neighbors too.

• Coordinate with building management to ensure common drains, roof systems, and sump pumps are maintained.
• Learn the location of your unit’s water shut-off valve.
• Report any leaks in common areas promptly—small drips can escalate quickly during storms.
• Ask if your building has a flood response plan and familiarize yourself with it.

Emergency Preparedness

Even the best preparations can’t prevent every problem. Be ready:

• Have sandbags or water barriers ready if you’re in a flood-prone area.
• Keep an emergency plumbing kit with adjustable wrench, plumber’s tape, flashlight, buckets, and gloves.
• Save our emergency number in your phone: (808) 300-0535.
• Store important documents in waterproof containers.

Schedule a Professional Inspection

The best way to avoid rainy season plumbing problems is to schedule a licensed plumber to inspect your system before the storms arrive. At 535 Plumbing, our rainy season inspection includes

• Checking for leaks
• Clearing drains
• Testing backflow preventers
• Inspecting sump pumps
• Verifying that your system can handle heavy rainfall

This proactive approach ensures your home is ready to weather the season.

Call 535 Plumbing Today

Don’t wait until the first big storm to discover your drains are clogged or your sump pump is broken. Just give us a call at (808) 300-0535 and schedule your rainy season plumbing inspection today. Protect your home from costly water damage and enjoy peace of mind knowing you’re ready for whatever the rainy season brings.

Want Peace of Mind All Year?

Join our 535 Plumbing Aloha Membership Plan and get:

• 1 Free Annual Plumbing Visual Inspection
• 1 Free Water Heater Flush Per Year
• Priority Scheduling & Special Discounts
• Ongoing System Monitoring & Maintenance Tips

Let us help you prepare, protect, and prevent plumbing problems—before and after the storm.

Get a Professional Quote for Your Plumbing Emergency

535 Plumbing specializes in plumbing inspections and repairs. Whether you need a routine cleaning or a complex repair, we provide expert plumbing services tailored to your specific situation. Contact us today for a professional assessment and a customized quote to keep your plumbing system in top shape!

Trust 535 Plumbing to Save You Time, Water, and Money

At 535 Plumbing, we specialize in building-wide plumbing maintenance. Our experienced professionals are equipped with the latest tools and techniques to ensure your building’s plumbing and fixtures stay in the best condition possible. From minor fixes to major repairs, we’re committed to providing top-notch service and peace of mind.

Contact 535 Plumbing today to schedule an inspection and take the first step toward reclaiming control over your building’s plumbing. We have the tools and expertise to diagnose and resolve your issue efficiently. Don’t let a simple plumbing problem escalate—take action today to maintain the functionality of your building’s plumbing system. For more plumbing maintenance tips and advice, check out our other guides!

Contact 535 Plumbing Today

535 Plumbing is here to help. We offer:

• Fast and Reliable Service: Get prompt assistance when you need it most.
• Expert Technicians: Our skilled plumbers have experience with all garbage disposal types and plumbing systems.
• Upfront Pricing: No surprises—just honest, transparent estimates.
• Sustainable Solutions: We fix garbage disposals efficiently to save water and reduce your environmental footprint.

If you live on Oahu and are in need of a licensed plumber to help with your plumbing issues, choose 535 Plumbing for the job! Our team of professional Oahu plumbers are highly skilled and our excellent customer support representatives will work with you to schedule your appointments at a time you most convenient. Learn more and schedule an appointment by calling (808) 300-0535, or Visit Our Contact Us Page. Mahalo!