In New Jersey, the presence or absence of freshwater wetlands upon land is important in calculating "developability" – so much so that it must be at the top of your due diligence checklist. For preliminary investigations, I use the reliable on-line service called NJ GeoWeb, provided by the New Jersey Department of Environmental Protection (NJDEP).
Wetland regulations in the State of New Jersey are complicated and strict, yet there are several exceptions to the rule. In most instances, using an exception to the rule will require a form of compensation.
As a general guide, in areas governed by the Pinelands Commission, there must be a minimum of 300 feet between a wetland boundary and a septic system and 250 feet between a house and a wetland boundary.
Outside of Pineland Commission areas, the NJDEP requires a distance of 50 feet between development and a wetland. Sometimes, this distance requirement is increased to 150 feet if threatened and endangered (T&E) plant and animal species are dependent on the wetland complex.
You can search NJ GeoWeb by using a physical address or by Block and Lot. Some of the interesting data layers include soils type, wetlands, sewer service and historical satellite imagery. In certain areas, you can view black and white satellite images from the 1930’s.
Using wetland mapping is not a perfect science, but it will give you a pretty close estimate of the wetlands in your target area. Sometimes the mapping is “dead on”. Other times, it is very close or “off the mark” completely, but this is rare.
The only true way to determine the presence or absence of freshwater wetlands is by on-site examination by a trained wetlands scientist. These professionals look at three key indicators: vegetation, soil conditions and wetness.
Certain types of trees and plants inhabit wetlands. Certain soil types are found in wetlands. And, of course, wetlands tend to have water. None of these three factors is conclusive in and of themselves, so scientists use this “Three Parameter Test” for wetlands.
However, if you want to learn wetland conditions using electronic mapping, go to NJ GeoWeb. Here are the steps to take at NJ GeoWeb:
1. Click on “Launch GeoWeb Profile”. The button is located toward the bottom, center of the page.
2. On the top navigation bar, click “Searches”. For your target property, select either “Address Search” or “Parcels by Block/Lot”.
3. Fill in the information requested and hit “Search”.
4. Once the site appears on the screen, use the tools on the right-hand bar to navigate. For example, the hand icon should be clicked to pan the image across the screen. The “+” and “-“ icons should be chosen to increase or decrease the size of the image.
5. After selecting any of the above icons, you will have to move the cursor back to the map to pan, enlarge or reduce the image on the screen.
6. To view mapped wetlands, go to the “Base Layers” navigation box on the left-hand side.
7. Scroll down to “Wetlands (2012)”, which can be found in the “Land” section.
8. Click on the dark blue box next to “Wetlands (2012)” and the wetlands mapping will appear.
9. To view a satellite overlay, instead of a bare map, scroll down to “2015 Imagery (Natural)” and click “Natural 2015”.
Whenever I am evaluating a parcel of land for development, such as building a house, an electronic wetlands map search is one of my first stops. I have found NJ GeoWeb to be very helpful.
If you are evaluating property located in Gloucester County exclusively, try visiting Gloucester County GIS Maps. This resource provides great wetlands information. However, there are far fewer layers.