When the Rockaway runs high, the ground beside it fills up too. Houses on the river side of Jackson Avenue and the streets just off it sit on flat, low lots where groundwater can rise to the level of the basement floor after a long storm or a fast spring melt. That water pushes in at the joint between wall and slab, through cracks in an old floor, or up through a floor drain. Interior perimeter drains with a sump are the standard fix, and a battery backup pump matters on a street where storms and power outages tend to arrive together.
The riverbank itself is changing. The county hazard plan describes a 200 to 300 foot stretch of the Rockaway beside Jackson Avenue, across from Mott Place, that has eroded over time, and the borough has sought money for engineering and state permits to stabilize it. A bank that moves closer to the road and the houses can change drainage on nearby lots. If your yard slopes toward the river, keep downspouts and sump discharge from emptying onto the bank, where added water makes erosion worse, and route them toward a stable part of the property.
Some houses near the river are very old. The borough's Revolutionary era survivors include the Jackson houses, and many others date to the 1800s. Those homes tend to have stone or rubble foundations, shallow cellars, and no footing drains. Repointing, a drain at the base of the wall, and a membrane to guide seepage work better than surface sealers on stone. Before committing, ask the contractor whether your lot is in the mapped flood hazard area, since that affects flood insurance and any work that adds space or changes grading.
Worth knowing in Jackson Avenue riverfront
A 200 to 300 foot section of the Rockaway River beside Jackson Avenue, across from Mott Place, has eroded, and the borough budgeted for design and NJDEP permitting to stabilize it.
morriscountynj.govBy 1760 Rockaway Village had a grist mill, a saw mill and a forge on the Rockaway River, and the three Jackson houses survive from the Revolutionary period.
rockawayborough.orgThe borough has 8 repetitive loss properties and 1 severe repetitive loss property in the flood zone, none yet mitigated.
morriscountynj.gov
Questions from Jackson Avenue riverfront homeowners
My Jackson Avenue basement gets water when the river is up, even without rain. Why?
The river and the groundwater under nearby houses rise together. When the Rockaway stays high, water can push up through the slab and the wall joint. An interior drain and sump pump handle that kind of water.
Can I pipe my sump toward the river?
Be careful. Water dumped onto an eroding bank speeds up the damage, and work near the river can need state approval. Ask the contractor for an outlet on stable ground and check with the borough engineer.