Flood Cleanup and Water Damage Restoration in Trenton, NJ

New Jersey's capital grew up at the falls of the Delaware, the spot where the river drops about 8 feet across the fall line and turns tidal for the rest of its run to the bay. That location made Trenton an industrial city, and it also put it in the path of the river's biggest floods. A second waterway, Assunpink Creek, cuts through downtown in a channel near the Trenton Transit Center, and in a hard tropical downpour it can rise faster than the Delaware does.

This page is from The Restoration Job, a no-cost referral service rather than a contractor. Call (888) 317-9980 and we'll connect you with an independent restoration provider that serves Trenton, whether the problem is river water in a South Ward basement, a burst pipe in a West Ward twin or a ceiling leak in a downtown office.

The Delaware at Trenton: Crests from 1904 to 2006

The National Weather Service puts flood stage for the Delaware River at Trenton at 20 feet. The highest crest on its list is 30.3 feet on March 8, 1904, followed by 28.6 feet on August 20, 1955, when the remnants of Connie and Diane soaked the basin; the city's weather records show 14.55 inches of rain that month. Then came three floods in less than two years. The river reached 23.4 feet in September 2004 and 25.33 feet on April 4, 2005.

The June 2006 flood was worse still, cresting nearly 8 feet over flood stage, the fourth-highest level recorded at Trenton. More than 1,000 people were evacuated from low-lying parts of the city, and debris in the river forced the water filtration plant to shut down for a time. River floods like these arrive with some warning, since the crest builds over a day or more upstream, which gives residents near the water time to move belongings and shut off utilities before it peaks.

Assunpink Creek and the Night of Ida

Flash flooding is the other half of Trenton's risk. On September 1 and 2, 2021, the remnants of Ida stalled over central New Jersey. The NWS Mount Holly office recorded Assunpink Creek at Trenton cresting at 12.59 feet, in its major flood category, and parts of the city were evacuated. The Delaware rose only to minor flood stage that night; the damage came from the creek and from streets and storm sewers that could not drain the rain fast enough.

Upstream, Mercer Lake was built as a federal flood control project to protect Trenton from the Assunpink, but a storm of Ida's intensity can still overwhelm the lower creek. Homes near the creek corridor and in low blocks of the South and East wards are the most exposed.

Old Housing, Old Pipes and Shared Walls

Trenton is an old city, with about 34,000 housing units, historic districts such as Mill Hill and the State House area, and many attached homes on narrow lots. Older buildings bring familiar leak sources:

• Galvanized and lead-era supply lines that corrode from the inside and fail at joints.
• Cast-iron drain stacks that crack, letting wastewater seep into walls and ceilings below.
• Basement boilers and water heaters that leak slowly for weeks before anyone notices.
• Party walls, so water from one home can show up next door.

With roughly one in eight units vacant in the 2020 census, a leak in an empty building next door can go unnoticed until it stains a shared wall. Plaster walls also hold water differently than drywall; they can look sound while the lath behind them stays wet, so a moisture meter is more reliable than a visual check.

Cleanup After Delaware or Assunpink Floodwater

Floodwater from the Delaware or the Assunpink is contaminated and should be treated that way. A sensible sequence after the water drops:

• Stay out of a flooded basement until power to that level is off, and do not restart a boiler or water heater that was submerged until it is inspected.
• Photograph water lines on walls and damaged contents before anything is thrown out.
• Remove soaked carpet, padding, drywall and insulation; river silt left behind should be shoveled out and surfaces cleaned and disinfected.
• Dry the structure with air movers and dehumidifiers and confirm with moisture readings before rebuilding.

For a home with standing water, our page on flood cleanup outlines what providers typically do, and the sewage cleanup page covers backups through floor drains, which often happen in the same storms.

Humid Summers and Mold in Trenton Basements

Trenton averages about 45 inches of precipitation a year, with July the wettest month, and summers along the river are humid. A basement that took on water in a late-summer storm can show mold growth on wood, drywall paper and stored cardboard within a few days if it isn't dried. Older masonry foundations also wick ground moisture, so many basements in the city stay damp even without a flood. Running a dehumidifier, keeping stored items off the floor and fixing gutters and downspouts that dump water next to the foundation all help. Where growth is already visible across a large area, professional mold remediation with containment is usually the safer route than scrubbing it yourself.