MDT Montana Wetland Assessment Method May 25. 1999 



evenly distributed, vegetated classes must be within 20% of each other in terms of their percent composition of the AA (refer to the 

 percentages listed under #10). 



The third variable is the maximum duration of surface water (any water above the ground surface that is available to wildlife; not 

 necessarily open water) covering at least 10% of the AA. The 10 percent criterion should be considered a rule of thumb and is 

 intended to be applied primarily at smaller (e.g., less than 1 or 2 acres), rather than larger sites. For example, 9 acres of surface water 

 should not be dismissed at a 100-acre AA sunph' because this 10 percent guidance is not met. The intent of this criterion is to allow 

 consideration of significant surface water amounts within an AA relatrv'e to wildlife habitat while disallowing insignificant surface 

 water amounts. The fmal call will depend on the specific situation at hand and is therefore left to the evaloator. Abbreviations for 

 surface water durations are as follows: P/P = pennanent/perennial; S/I = seasonal/intermittent; T/E = temporary/ephemeral; and A = 

 absent where: 



Permanent/perennial: Surface water is present throughout the year except during years of extreme drought. 



SeasonaL'intermittent: Surface water is present for expended periods, especialK' earh' in the growing season, or may persist 



throughout the growing season, but may be absent at the end of the growing season: or surface water does 

 not flow continuoush', as when water losses from evaporation or seepage exceed the available streamflow. 



Temporary/ephemeral . Surface water is present for brief periods during the growing season, but the water table is well below the 

 surface most of the year; or surface water flows briefly in direct response to precipitation in the immediate 

 vicinit}' and the channel is above the water table. 



TTie final variable is degree of disturbance at the AA as determined under #12. This will determine the habitat features rating. 



iiL Rating. Determine and circle the general wildlife habitat rating and functional pwDints for the AA by apphing the results of i and ii 

 to the matrix provided in the data form. 



14D. General Fish / Aquatic Habitat: This field assesses general fish and aquatic habitat at the AA based upon the presence of 

 certain groups offish and habitat features. Assess this fiinction onh,' if the \K is used by fish or the existing situation is "correctable" 

 such that the AA could be used by fish (e.g., fish use is precluded by perched culvert or other barrier, etc.). If the AA is not or was not 

 historically used by fish due to lack of habitat (includmg duration of surface water), excessive gradient, etc. (e.g., the AA does not have 

 the opportunity to provide habitat for fish), circle NA where indicated on the data form and proceed to the next function. 



Variables assessed to determine a rating for habitat qualitv include duration of surface water, structural cover, shading, and habitat 

 availabiht>'. Presence of surface water is an obvious critical component offish habitat. Seasonally flooded areas can be important 

 nursery and foraging areas for fish (and can result in "high"' habitat quaht)' ratings using this assessment); however, longer duration of 

 surface water generally results in higher ratings because surface waters of such duration are available to fish for greater periods and 

 varieties of life stages. Flow or w ater level stabiht>- is an important habitat component for a variet}' of Montana fish species (Raleigh 

 1982. Raleigh et al 1984, Raleigh et al. 1986, McConneU et al. 1984, Hickman and Raleigh 1982, Marcus et al. 1984, Inskip 1982. 

 Stuberetal. 1982). 



Abundant structural cover and well-vegetated streambanks and shorelines are also important habitat components for se\'eral Montana 

 fish species (Raleigh 1982. Raleigh et al. 1984, Raleigh et al. 1986. McConneU et al. 1984, Hickman and Raleigh 1982. Inskip 1982, 

 Stuber et al. 1982, Krieger et al. 1983, Edwards et al. 1983). Structural cover such as submerged logs and vegetation, other wood}' 

 debris, floating-leaved vegetation, and large rocks provides resting areas, refiige fi"om predators, hiding areas for predators, and 

 functions as a substrate for insect larva; an important food source for many fish species. High water temperatures that result fix)m 

 removal of streamside vegetation can render habitat as unsuitable for fish that are sensitive to higher temperatures, such as bull trout. 

 Vegetation along streams, ponds, and lakes also provides insect habitat an important food source for man) fish species. 



Although the physical habitat attributes of a site may be attractive to fish, use of the area may be significanth' reduced or precluded due 

 to the presence of inadequately-sized culverts, dikes, continual sources of degradation, or other causes. Consequenth. such potential 

 "habitat modifiers'' are also considered in the assessment. In addition to the presence of undersized culverts, dikes, and other such 

 structural habitat modifiers, the method considers whether a waterbody within the AA is hsted on the MDEQ list of Waterbodies in 

 Need of Total Maximum Daily Load (TMDL) Development (MDEQ 1999) with listed "probable impaired uses" that include ^^■arm 

 water fishery, cold water fishery, or aquatic life support. Fish use and aquatic habitat quaht}.' of such listed waterbodies have been 

 determined by MDEQ to be "impaired". The impaired waterbodv' Ust is lengthy and d\-namic and is not included as an appendix to this 



