Protecting a Basement or Garden Apartment From Flooding
In dense Hudson County buildings, the lowest unit floods first. Here are the practical steps owners and tenants can take to keep water out of a below-grade apartment.
Why the lowest unit always floods first
In the older multifamily buildings that fill Union City and the surrounding Hudson County towns, the lowest unit is often a finished basement or garden-level apartment, and it is the most flood-prone living space in the building. Water follows gravity, so when the street drains back up, when groundwater rises, or when a storm pushes water down the steps, the below-grade unit is where it collects first and deepest. A unit that sits even partly below the surrounding grade is fighting against water on every side.
The density of these neighborhoods makes it worse. Crowded blocks with a lot of paved surface shed rainwater fast, and the storm drains can be overwhelmed during a heavy downpour, sending water that has nowhere else to go down the steps and into below-grade units. A basement apartment that has never had a problem can take on water in a single severe storm that exceeds what the local drainage can handle.
Knowing that the lowest unit is the most exposed is the starting point for protecting it. The goal is to keep water from reaching the unit, to give any water that does reach it a way out, and to be ready to respond fast when a storm exceeds the defenses. None of it is exotic, and most of it is inexpensive compared to the cost of a flooded apartment.
Keep water away from the building
The most effective flood prevention happens outside the unit, by keeping water away from the building in the first place. The drainage that carries rainwater off the building is the first line of defense: when it clogs or overflows, that rainwater runs straight down against the foundation and toward any below-grade openings. Keeping it clear and making sure runoff is carried well away from the building, rather than dumping it next to a basement window or stairwell, prevents a lot of below-grade water.
Stairwells and areaways that lead down to a basement unit deserve particular attention, because they funnel surface water straight to the lowest door. A drain at the bottom of an exterior stairwell has to be kept clear, since a clogged stairwell drain during a downpour turns the stairwell into a pool that pours under the door. Where the grade allows, small berms or properly pitched surfaces that direct water away from a below-grade entrance make a real difference.
The grading around the building matters as well. The ground should slope away from the foundation so water runs off rather than pooling against the walls and seeping toward below-grade units. Low spots and settled areas that trap water near the building are worth correcting. In a dense neighborhood where you cannot control what the whole block does, controlling the water immediately around your own building is what is within reach.
Give water a way out and a way to be stopped
Even with good water management outside, a below-grade unit needs defenses for the water that gets close anyway. A working sump pump is the most important of these. If the unit or the building has a sump, test it periodically to make sure it actually runs, and consider a battery backup, because the storms that flood basements are exactly the ones that knock out the power a sump pump needs. A sump pump that fails during the storm that needed it is a leading cause of a flooded below-grade unit.
For buildings prone to sewer backups, a backwater valve is worth serious consideration. When the municipal sewer surcharges during heavy rain, which happens in dense neighborhoods where the system serves a lot of buildings, a backwater valve keeps contaminated water from flowing back up through the lowest drains into the basement unit. Given how hazardous and expensive a sewage backup in a living space is, this is a high-value protection for at-risk buildings.
Inside the unit, simple choices reduce the loss when water does get in. Keeping stored belongings off the floor on shelving, avoiding irreplaceable items in the below-grade unit, and being mindful of where electrical and mechanical equipment sits all limit the damage from an inch or two of water. None of this prevents a flood, but it makes the difference between a manageable cleanup and a devastating one.
Have a response plan before the storm
Because no defense is perfect against a severe enough storm, the last piece is being ready to respond fast. The faster water is pumped out and the unit is dried, the less is lost, so knowing in advance who to call saves precious time. Keep the number of a 24/7 restoration crew somewhere both the owner and the tenant of a below-grade unit can find it immediately, because the middle of a flooding storm is not the time to start searching.
Owners of buildings with below-grade units should think through the response ahead of a storm: where the shutoffs are, how to reach the tenant, and how quickly a crew can get there. Tenants in a basement or garden apartment should know how to reach the owner or super fast and should report rising water immediately rather than waiting to see how bad it gets. In a below-grade unit, a fast call when water starts coming in is the most valuable response there is.
Empire Water & Fire Restoration serves Union City and the surrounding Hudson County towns around the clock, and we respond fast to flooded basement and garden apartments. Take the preventive steps above, save 551-366-1904, and call the moment water starts coming into a below-grade unit. The speed of the pump-out and the drying is what keeps a flood from ruining the lowest home in the building.
The lowest unit in a Hudson County building floods first, but most of that risk can be managed: keep water away from the building, keep the stairwell drains and the sump pump working, consider a backwater valve, and have a fast-response plan ready before the storm. A little preparation keeps a basement apartment from becoming a total loss.
Call 551-366-1904 to put a damage assessment on the calendar this week.