Union County, NJ: flood zone, zoning and property lines by address
Free, no account. Or open the New Jersey map and tap a lot.
Towns in Union County: Elizabeth, Union, Plainfield.
Flood zone by address
ParcelSheet reads FEMA's National Flood Hazard Layer at the lot: the zone, whether it is a high risk area where lenders ask for flood insurance, and the base flood elevation where FEMA lists one. FEMA's countywide study for Union County has 49 FIRM panels, the newest effective September 2006; no coastal V zones are mapped in it.
The official panel and any Letter of Map Amendment are at FEMA's Map Service Center. An elevation certificate for an Union house comes from a licensed surveyor and is often on file with the county or city building office.
Property lines
The parcel outline, parcel number and mapped size come from the New Jersey statewide parcel map (NJ Office of GIS cadastral layer with the MOD-IV tax list), so an Union lot shows the same lines the municipal tax maps draw. Union County covers about 65,771 acres of land and 1,690 acres of water.
Mapped lines are approximate. The Union County Board of Taxation keeps the parcel record (Union County website); every county's office is on the state's county boards of taxation list; a licensed surveyor sets the true corners.
Zoning
In New Jersey zoning is set by each municipality, not by the county: in Union County, Elizabeth, Plainfield each zone the land inside their limits. ParcelSheet shows the use code on the lot's parcel record and the municipality it sits in; the municipal zoning office has the district, the uses it allows and the lot size it needs. The Union County website lists the county's municipalities.
ADU and guest houses
The New Jersey Municipal Land Use Law (N.J.S.A. 40:55D) lets each municipality allow an accessory dwelling unit on a lot with a house. Whether an Union lot can add one depends on its district; the municipal zoning office has the rule. ParcelSheet shows the mapped lot size and the ground's slope, the first two things the question turns on.
Septic and soil
ParcelSheet reads the USDA soil survey at the lot: the soil's name, its septic absorption rating and whether it is prime farmland. Union County is soil survey area NJ039, Union County, New Jersey, last updated August 2026, on Web Soil Survey.
A new or changed septic system in Union County needs a permit from the Union County health department under the NJDEP septic rules (N.J.A.C. 7:9A), which tests the soil on the lot itself.
Setbacks
Setbacks in Union County come from the zoning district: the front, side and rear distances a house must keep. ParcelSheet does not draw setback lines; the municipal zoning office gives them for the lot's district, and Elizabeth and Plainfield for land inside their limits.
Hazards that apply
- Wetlands and wildfire. ParcelSheet shows the National Wetlands Inventory near an Union lot and the Forest Service wildfire hazard rating at it.
Questions
Is my house in a flood zone in Union County?
Type the address in the box above and ParcelSheet reads FEMA's flood zone at the lot's center. FEMA's countywide flood map for Union County has 49 panels, the newest effective September 2006. A lender or insurer uses the official FIRM panel; FEMA's Map Service Center has it.
How do I find property lines in Union County?
Open the New Jersey map, type the address, and the parcel outline from the county Board of Taxation shows on the map with its parcel number and mapped size. Mapped lines are approximate; only a licensed surveyor sets the true corners.
What is my property zoned in Union County?
Zoning in Union County is set by each municipality (such as Elizabeth, Plainfield), not by the county. ParcelSheet shows the use code on the parcel record and names the municipality; the municipal zoning office has the final word.
Can I build an ADU in Union County?
The New Jersey Municipal Land Use Law (N.J.S.A. 40:55D) lets each municipality allow an accessory dwelling unit, and each sets its own rules. In Union County ask the municipal zoning office for the lot's district first; ParcelSheet shows the lot size as mapped so you can see the room you have.
Do I need a septic permit in Union County?
Yes. A new or changed septic system in Union County needs a permit from the Union County health department under the NJDEP septic rules (N.J.A.C. 7:9A). ParcelSheet shows the USDA soil survey's septic rating at the lot, from survey area NJ039 (Union County, New Jersey).
Next to Union County: Essex County, Hudson County, Middlesex County, Morris County, Somerset County.
The New Jersey map · All New Jersey counties · Flood zones explained · FIRM panels and LOMAs · All 50 states