MDT Montana Wetland Assessment Method May 25, 1999 



distance from the project determined by A. B, and C above (see Figure 1. Panel #6). 



If wetlands are contiguous with > 20 acres of open water (e.g., Flathead Lake), include open water in the AA to the 

 estimated deep water line (>6.6 feet) or to a point that is double the wetland shoreline width, whichever is greater 

 (see Figure 1 , Panel #1). 



Where wetlands are contiguous with flowing non-wetland water bodies (rivers, streams, irrigation canals): 



For fringe wetlands (cumulative width along both banks < 3x bankfuU channel width) adjacent to a channel with a 

 bankfiill width 2 150 feet (e.g., Missouri River), onh' include the actual wetlands in the AA to a distance fix)m the 

 project determined by A, B, and C. Do not include the channel in the AA unless the wetlands extend into it (see 

 Figure 1, Panel #s 9, 12. 16, 18). 



For all nonfiinge wetlands (cumulative width s 3x bankfiiU channel width) or those fringe wetlands adjacent to a 

 channel with a bankfiill width < 150 feet (e.g.. Link Blackfoot Rrv'er), include the entire channel in the AA to a 

 distance from the project determined by A, B. and C (seeFigm-e 1, Panel #s 10. 11. 13. 14. 15. 17, and 18). 



10. Classification of AA: Enter the HGM class(es) (Smith et aL 1995) pertaining to the AA in column 1. HGM classes apphcable to 

 Montana are riverine. depressionaL slope, mineral soil flats, organic soil flats, and lacustrine fringe. A ke\' to these classes is provided 

 in Appendix C. Class descriptions are provided in Smith et al. (1995). 



For columns 2-6, enter the systems, subsystems, classes, water regimes, and special modifiers that apply to the AA using the Cowardin 

 et al. (1979) classification system. Only the riverine, lacustrine, and palustrine svstems apph' to Montana. A classification hierarchy 

 showing systems, subsystems, and classes from Cowardm et el. (1979) is included in Appendix C. For column 7, enter the estimated 

 percentage of the AA that corresponds to each Cowardin class. 



Vegetated classes are distinguished on the basis of what species constitute the uppermost layer of vegetation and cover more than 30% 

 of the substrate (Cowardin et al. 1 979). For example, an area with 50% areal coverage of trees over a shrub layer with 60% areal 

 coverage would be classified as a forested wetland; an area with 20% areal coverage of trees over a shrub layer with 60% areal 

 coverage would be classified as scrub-shrub wetland. When trees or shrubs alone cover less than 30% of an area but in combination 

 cover 30% or more, the wetland is classified as scrub-shrub. When trees and shrubs cover less than 30% of an area but the total 

 vegetative cover is 30% or greater, the wetland is assigned to the appropriate class for the predominant life form (e.g., emergent) 

 below the shrub layer. Vegetated classes likely to be encountered are defined below: 



Aquatic bed class: Any areas of open water dominated by plants that grow principalh' on or below the water surface for most 



of the growing season. Vegetation is non-persistent and includes submerged or floating-leaved rooted 

 vascular plants, free-floating vascular plants, submergent mosses, and algae. 



Emergent class: Vegetated wetland characterized by erect, herbaceous hydrophytes (e.g., sedges, rushes, grasses, bukush, 



cattail), excluding mosses and Lichens. 



Scrub-shrub class: Vegetated wetland dominated by woody vegetation less than 6m (20 ft) tall. Species include shrubs, young 



trees, and stunted trees and shrubs. 



Forested class: Vegetated wetland characterized by woody vegetation that is 6m (20 ft) tall or taller. 



Moss-lichen class: Wetland where mosses or lichens cover substrates other than rock and where emergents. shrubs, or trees 



make up less than 30% of areal cover. 



11. Estimated Relative Abundance of Similarly Classified Sites within Major Montana Watershed Basin: 



Circle the estimated relative abundance of sites that are similar in composition to the AA and occur within the same major Montana 

 watershed basin (Appendix A) using the following definitions: 



Rare estimated < 10% of wetlands in basin similar to AA 



Common estimated 10-50% of wetlands in basin similar to AA 



Abundant estimated >50% of wetlands in basin similar to AA 



