Heavy torrential rainfall on Monday, August 3, 2026, triggered severe flash flooding along Washington Avenue in Hillsdale, submerging portions of the roadway and highlighting the persistent vulnerability of the Pascack Valley corridor to rapid stormwater accumulation. Local police officers closed sections of the road as workers and residents monitored the rising waters, which also heavily impacted low-lying parking lots and streets in neighboring Westwood.
This recurring issue along Washington Avenue illustrates the complex relationship between municipal civil engineering and residential property management in northern Bergen County. The region’s geography—characterized by the Pascack Brook basin and tight, clay-rich glacial soils—creates a scenario where heavy downpours quickly overwhelm local drainage systems. When public storm sewers reach maximum capacity, the water has nowhere to go but upward through catch basins, spilling onto asphalt and eventually encroaching onto adjacent commercial and residential properties.
From a preventative homeownership perspective, events like the August 3 flood underscore the necessity of robust on-site water mitigation systems. During peak storm events, residential perimeter drains and sump pumps are forced to work at maximum capacity. If a municipal storm line surcharges, residential systems that drain directly into the street can experience backflow. Homeowners can mitigate this risk by installing heavy-duty check valves on discharge lines and ensuring that foundation grading slopes away from the home rather than toward it.
To better prepare for future weather patterns, local property owners should assess their own systems. Key questions to ask a licensed drainage professional include whether the home’s current sump pump setup has a sufficient pumping capacity (measured in gallons per hour) to match regional peak rainfall rates, and whether a battery-powered backup system is configured to handle prolonged power outages during severe storms.