DEC Freshwater Wetlands Classification System (6 NYCRR Part 664.5)

The New York State Department of Environmental Conservation (DEC) classifies wetlands according to their respective functions, values, and benefits. Of the four classes of wetlands, Class I wetlands are the most valuable and are subject to the most stringent standards.

	Class I – must have one of the following 7 characteristics	Class II – must have one of the following 17 characteristics	Class III - must have one of the following 15 characteristics	Class IV
Cover Type		(1) it is an emergent marsh in which purple loosestrife and/or reed (phragmites) constitutes less than two-thirds of the covertype	1) it is an emergent marsh in which purple loosestrife and/or reed (phragmites) constitutes two-thirds or more of the covertype; (2) it is a deciduous swamp; (3) it is a shrub swamp; (4) it consists of floating and/or submergent vegetation; (5) it consists of wetland open water;	A wetland shall be a Class IV wetland if it does not have any of the characteristics listed as criteria for Class I, II or III wetlands. Class IV wetlands will include wet meadows and coniferous swamps which lack other characteristics justifying a higher classification
Ecological Associations	1) Classic kettle hole bog	(2) it contains two or more wetland structural groups; (3) it is contiguous to a tidal wetland; (4) it is associated with permanent open water outside the wetland; (5) it is adjacent or contiguous to streams classified C(t) or higher under article 15 of the environmental conservation law	6) it contains an island with an area or height above the wetland adequate to provide one or more of the benefits described in section 664.6(b)(6);
Special Features	2) Resident habitat of an endangered or threatened animal species 3) Contains an endangered or threatened plant species 4) Supports an animal species in abundance or diversity unusual for the state or region	(6) it is traditional migration habitat of an endangered or threatened animal species; (7) it is resident habitat of an animal species vulnerable in the state; (8) it contains a plant species vulnerable in the state; (9) it supports an animal species in abundance or diversity unusual for the county in which it is found; (10) it has demonstrable archaeological or paleontological significance as a wetland; (11) it contains, is part of, owes its existence to, or is ecologically associated with, an unusual geological feature which is an excellent representation of its type;	7) it has a total alkalinity of at least 50 parts per million; (8) it is adjacent to fertile upland;* (9) it is resident habitat of an animal species vulnerable in the major region of the state in which it is found, or it is traditional migration habitat of an animal species vulnerable in the state or in the major region of the state in which it is found; (10) it contains a plant species vulnerable in the major region of the state in which it is found;

DEC Freshwater Wetlands Classification System (continued)

	Class I – must have one of the following 7 characteristics	Class II – must have one of the following 17 characteristics	Class III - must have one of the following 15 characteristics	Class IV
Hydrological / pollution control features	5) it is tributary to a body of water which could subject a substantially developed area to significant damage from flooding or from additional flooding should the wetland be modified, filled, or drained (6) it is adjacent or contiguous to a reservoir or other body of water that is used primarily for public water supply, or it is hydraulically connected to an aquifer which is used for public water supply	12) it is tributary to a body of water which could subject a lightly developed area, an area used for growing crops for harvest, or an area planned for development by a local planning authority, to significant damage from flooding or from additional flooding should the wetland be modified, filled, or drained; (13) it is hydraulically connected to an aquifer which has been identified by a government agency as a potentially useful water supply; (14) it acts in a tertiary treatment capacity for a sewage disposal system;	11) it is part of a surface water system with permanent open water and it receives significant pollution of a type amenable to amelioration by wetlands
Distribution and Location		(15) it is within an urbanized area; (16) it is one of the three largest wetlands within a city, town, or New York City borough; or (17) it is within a publicly owned recreation area.	12) it is visible from an interstate highway, a parkway, a designated scenic highway, or a passenger railroad and serves a valuable aesthetic or open space function; (13) it is one of the three largest wetlands of the same covertype within a town; (14) it is in a town in which wetland acreage is less than one percent of the total acreage; or (15) it is on publicly owned land that is open to the public.
Other	(7) it contains four or more of the enumerated Class II characteristics. (not determined to be duplicative of each other).

Go to the Wetlands section of the Natural Resource Inventory.