KfDT Montana Wetland Assessment Method May 25, 1999 



INTRODUCTION 



In 1989. the Montana Dqiartment of Transportation (MDT) and the Montana Dq)artment of FisL Wildlife & Parks (MDFWP) 

 developed a wetland evaluation method to be appbed to highway projects in Montana. Substantial revisions of the method and 

 corresponding field forms were undertaken in 1994 and 1996. The 1996 version (Berglund 1996) was tested for three field seasons at 

 several hundred wetlands. Opportunities to miprove assessment accuracy and evaluator consistency were noted during this period and 

 incorporated into the 1999 revision. These instructions and the correspondmg field forms comprise the 1999 version of this functional 

 assessment method. 



As with previous versions, the 1 999 evaluation method discussed in this report was primarily designed to address highway and other 

 Linear projects, such as pipelines and transmission hnes. However, the method can be appUed to other types of projects, including 

 mitigation projects, at the discretion of the user. It is important to note that this method is intended to evaluate wetland functions and 

 values, and is not to be used to delineate jurisdictional wetland boundaries. Wetland dehneation should be conducted prior to 

 evaluation using the 1987 Corps of Engineers (COE) wetland delineation manual (Environmental Laboratory 1987) or other COE- 

 approved methods. 



The objectives of the revised form are to provide a rapid, economicaL, repeatable wetland evaluation method applicable to Montana 

 that: 



• meets the needs of local regulatory agencies in terms of quantifying jurisdictional wetland fimctions and values with respect to the 

 majority of proposed wetland disturbance-related and mitigation projects in the state, particularly highway projects; 



• minimizes subjectivity and variability between evaluators; 



• provides a means of assigning wetlands overall ratings to facilitate avoidance priorities; and 



• incorporates some of the principles of the hydrogeomorphic (HGM) assessment method to foster use of the revised form as an 

 interim method until HGM is fully implemented in Montana, and as an alternate method once HGM is implemented. As of the 

 writing of these instructions, the Regional Guidebook for Assessing the Functions oflntermontane Prairie Pothole Wetlands in 

 the Northern Rocky Xlountains (Hauer et al. 1 999) has been completed, and a guidebook addressing riverine wetlands will be 

 available in early summer 1999 (Hauer pers. comm.). 



METHODS 



Methods appUed during the substantial 1 996 revisions to the original MDT method are presented in the 1 996 instructions (Berglund 

 1996). Potential revisions to the 1996 version of the method and form were initially discussed at a meeting conducted at MDT during 

 late 1998. Meeting attendees included MDT biologists and primary MDT wetland consxiltants. A draft revised form was presented to 

 the Montana Interagency Group (consistmg of MDT, COE. U.S. Fish & Wildlife Service [USFWS]. Environmental Protection Agency 

 [EPA], Federal Highways Admimstration [FHWA], Montana Department of Environmental Quality [MDEQ]. Natural Resources 

 Conservation Service [NRCS]. and MDFWP for review and comment in early May 1999. The Montana Natural Heritage Program 

 (MNHP) was consulted with respect to formatting for development of an electronic version of the data forms The method and 

 corresponding data form were revised in spring of 1 999 based upon received comments, meeting results, and literature review . 



Primary literature sources referenced during the course of the 1996 method and form development and 1999 revision included 

 Regional Guidebook for Assessing the Functions oflntermontane Prairie Pothole Wetlands in the Northern Rocky Mountains (Hauer 

 et al. 1999), /I Comprehensive Review of Wetland Assessment Procedures (Bartoldus 1999). Oregon Freshwater Wetland Assessment 

 Methodology (Roth et al. \991>), Minnesota Routine Assessment Method for Evaluating Wetland Functions (Miimesota Interagency 

 Wetland Group \996). Draft Hydrogeomorphic Assessment of Riverine Wetlands (Viiwer zad Coo)s. 1996). An Approach for 

 Assessing Wetland Functions Using Hydrogeomorphic Classification, Reference Wetlands, and Functional Indices (Smith et al. 

 1995), Wetland Evaluation Technique (Adamus et al. 1991), the Highway Methodology Workbook (COE 1995). Washington State 

 Wetlands Rating System for Eastern Washington (Washington State Department of Ecology [WDE] 1991), and Washington State 

 Wetlands Rating System - Western Washington (WDE 1993). 



INSTRUCTIONS AND DISCUSSION 



A copy of the five-page 1999 MDT Montana Wetland Assessment Form is provided in Appendrx A. This section of the report 



1 



