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Freshwater Wetlands Mapping

NYS Article 24 Freshwater Wetland Maps

The Freshwater Wetlands Act (Article 24 of the Environmental Conservation Law) requires DEC and the Adirondack Park Agency (for areas inside the Adirondack Park) to map all those freshwater wetlands that are subject to jurisdiction of the law. The law requires that the maps show "the approximate location of the actual wetland boundary." DEC will refine that approximate boundary by doing a field delineation for landowners when they need more precise information, such as when they are planning to conduct work near a wetlands area.

How Wetlands are Mapped

Wetlands are mapped using a variety of information sources, such as aerial photography, soil surveys, other wetlands inventories, and field verification. The mapped wetlands are then depicted on NYS Department of Transportation 1:24,000 planimetric quadrangle base maps. DEC then complies with a series of administrative steps to provide public notice. These steps include distributing of a set of draft wetland maps to appropriate local government clerks; sending a letter by certified mail to affected landowners and local governments; and publishing a legal notice in two newspapers and in the DEC Environmental Notice Bulletin. DEC then provides a public comment period to receive comments on the maps, and conducts any follow-up field visits to ensure the accuracy of the maps. After these steps are all complete, the maps are finalized and copies are filed with the local government clerks and notice is again provided to landowners and local governments and in the newspapers.

The original wetland maps were filed in most counties between 1984 and 1987. Filed maps exist for all counties except for the portions of these six counties located within the Adirondack Park: Franklin, Fulton, Herkimer, Saratoga, St. Lawrence, and Washington. In addition, the wetland maps have been amended at various locations to correct errors and to reflect changes in the wetlands resource.

Wetland Map Amendments

Wetlands are a changing natural resource and their boundaries will vary over time. Sometimes, the boundary changes are minor and the maps do not need to be amended to reflect the minor differences. However, when boundaries change substantially, which can happen over longer periods of time, the maps need to be revised to accurately reflect the new wetland boundary.

Wetland maps can be inaccurate for other reasons, as well. Improved technology has also given us the ability to detect wetlands that were missed when the agency did most of the wetlands mapping in the 1980s. Using new and better aerial photography, computer based geographic information system capabilities and digital soil surveys, biologists are able to inventory wetlands that meet the legal definition of wetland, but are not shown on the regulatory maps.

The science of wetlands also has matured in the past 20 years. The old perception that all wetlands are marshy and have open water has been placed in a new context. We now know that only about 14% of our wetlands fit this cattail-marsh-with-a-duck image. Most of our wetlands are shrub or forested swamps, and many lie along rivers and streams in the floodplain riparian zone. In the past, many of these critical wetlands were missed in the mapping process.

Finally, amendments might occur when technical corrections to the maps are needed. These may include renumbering wetlands, correcting notification deficiencies, changing wetland classifications, or updating symbols. Typically, amendments are not undertaken solely to do technical changes; these most often are included as part of other resource-based amendments.

Map amendments may consist of adding entirely new wetlands; adjusting the boundaries of existing mapped wetlands; deleting areas that no longer meet the statutory definition of wetland, either because they are too small or do not support wetland vegetation; extending the regulated adjacent area of the wetland beyond 100 feet (perpendicular to the wetland) which may be needed to protect the integrity of the wetland; or making other technical changes to the maps. Amendments range from a single amendment on one quadrangle to a comprehensive re-mapping of entire quadrangles or counties. Wetland map amendments have been done in many counties around the state.

An amendment is officially started when notice of the wetland map amendments is provided to landowners, the public, and local officials in the same manner as that required for the original wetlands maps (See How Wetlands are Mapped) Once an amendment has been officially begun, the wetland(s) subject to the amendment become regulated and the property owners are required to obtain a permit to conduct regulated activity in that wetland(s).

Where Amendments Have Occurred
A list of completed map amendments can be found in the Wetland Map Amendment List (pdf file, 26 KB).

The following amendments are underway:
  • Cattaraugus County, Maps 11 and 18
  • Chenango County, Maps 23 and 24
  • Erie County, Map 2, Wetland TW-50
  • Erie County, Map 3, Wetland TE-38
  • Erie County, Maps 9, 10, 13 and 14, Wetland LA-17
  • Niagara County, Maps 5, 7, 14, and 15
  • Orange County, Maps 4 and 13
  • Saratoga County, Maps 8-9, 11-25, 27-28
  • Seneca County, Maps 7-8, 10-11
  • Ulster County, Map 24

What The Wetland Maps Show

The NYS Article 24 Freshwater Wetland maps show the approximate location of the wetland boundary and the unique alpha-numeric (e.g. AB-12) wetland identification number assigned to each wetland. The maps show roads and hydrography (such as steams and ponds), but do not show the regulated wetland adjacent area nor the wetland classifications. Also, they do not show the topography, contours, or elevational data.

Because of the scale of the map and aerial photography used to produce the wetland boundaries, an on-site field delineation often is necessary to determine the actual location of the wetland on the ground. Interested landowners can contact the Regional Office where the wetland is located if this information is necessary.

Where To View The Wetland Maps

Three online mapping options can be used to view the current regulatory wetland boundary which includes amendments underway.

  • DEC Environmental Resource Mapper
  • NYS Interactive Mapping Gateway - Click on the 'VIEW ORTHOIMAGERY' button on the upper left of webpage to use.
  • Where to Get Wetland Map Information Section (the next section) contains some links to maps of amendments underway.

Paper maps of the filed maps and amendments underway are available at these locations for wetlands within their jurisdiction:

  • DEC Regional Offices
  • Clerk's office for each county, city, town and village
  • Adirondack Park Wetland Maps can be viewed at the Adirondack Park Agency, P.O. Box 99, Rte 86, Ray Brook, New York 12977, 518-891-4050.

Where To Get Wetland Map Information

Where to get wetland maps.
DEC regional office staff and many local government clerks are willing to photocopy portions of wetlands maps for interested parties. This includes portions of filed maps as well as for maps for wetland amendments underway. Contact the County, City, Town, and Village Clerk's offices for the area where the wetlands are located.

However, paper copies of the full size wetland maps must be ordered. Draft proposed amended maps are available for larger scale or county wide amendments These maps can be ordered from either BT Images, Inc. 7098 Distribution Drive, Suite F, Louisville, KY 40258, phone (502) 933-1555, or Syracuse Blue Print Company, Inc., 825 East Genesee Street, Syracuse, NY 13210, phone (315) 476-4084. Maps can be ordered online from BT Images (http://www.btimages.com/commerce/default.asp), or you can download and mail an order form to Syracuse Blue Print Company, Inc. (http://www.syracuseblueprint.com). Order forms are also available at all NYSDEC regional offices.The wetland maps are produced by county. Only the portion of the county that is located on a given quadrangle map will appear on that county's wetland maps. In order to get complete quadrangle coverage, it is necessary to purchase the number of quadrangle maps that represent the number of counties on that quadrangle map.

Wetland amendments are underway in the counties shown below. Some maps of wetland amendments are also available for viewing and printing from the DEC website. In some counties, these are large scale amendments which affect multiple wetland maps. In the case of large scale amendments you will find several large files, each of which represents an individual quadrangle map. These large files are only able to be printed on a large format plotter designed to print 24" x 30" maps.

  • Cattaraugus County, Maps 11 and 18
  • Chenango County, Maps 23 and 24
  • Erie County, Map 2, Wetland TW-50
  • Erie County, Map 3, Wetland TE-38
  • Erie County, Maps 9, 10, 13 and 14, Wetland LA-17
  • Niagara County, Maps 5, 7, 14, and 15
  • Orange County, Maps 4 and 13
  • Saratoga County, Maps 8-9, 11-25, 27-28
  • Seneca County, Maps 7-8, 10-11
  • Ulster County, Map 24

How to obtain digital wetlands data.
Digital wetlands boundary data are available for the NYS Article 24 Freshwater Wetland maps showing wetlands outside the Adirondack Park. These data represent the current regulatory wetland boundary which includes amendments underway. These data represent the boundaries, associated wetland identification numbers and classification codes. No other map information is included. These data are available at no cost from the Cornell University Geospatial Information Repository (CUGIR), the distribution center for all DEC data. These data are in Arc Export format and must be used with geographic information system (GIS) software (such as ArcGIS, MapInfo, etc.).

The digital wetlands boundary data are provided for GIS resource analysis at scales equal to the 1:24,000 scale of original mapping or smaller scales (e.g., 1:100,000 scale). Additional data layers are needed in order to visualize roads, streams, political borders and other features found on an official NYS Article 24 Freshwater Wetlands map. Possible sources for the additional data include CUGIR and the New York State GIS Clearinghouse, among others.

Other Wetland Maps

National Wetland Inventory (NWI) Maps
The National Wetlands Inventory (NWI) maps were produced by the U.S. Fish and Wildlife Service (USFWS). The NWI maps contain information on the location and characteristics of wetlands and deepwater habitats. Wetlands are classified using the method described in the Classification of Wetlands and Deepwater Habitats of the United States, published by the U.S. Fish & Wildlife Service.

The National Wetlands Inventory uses 1:24,000 U.S. Geological Survey (USGS) base maps. The inventory is not complete for New York, although over 800 of approximately 980 total quadrangle maps are available. The NWI, on paper, can be ordered by contacting:

Cornell Institute for Resource Information Systems
302 Rice Hall
Ithaca, NY 14853-5601
607-255-6520

The NWI digital data can be downloaded at no cost from the U.S. Fish and Wildlife Service. NWI wetlands can be viewed from the Wetland Mapper on the USFWS website.




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