Primary purpose
To assess wetland functions in the Section 404 regulatory program as well as other regulatory, planning, and management situations.
Expertise needed
A geologist/hydrologist and a botanist/ecologist experienced in wetlands.
Applicable habitat types
Nontidal wetlands in the glaciated Northeast and Midwest.
Categories assessed
Ten functions are addressed: biological; hydrologic support; groundwater; storm and flood water storage; shoreline protection; water quality maintenance; cultural and economic; recreational; aesthetic; and educational.
Procedure
The Hollands-Magee Method consists of: an inventory sheet, models, and narrative. The user(s) visits a wetland area and completes the inventory sheets by selecting the conditions that best describe various ecological, special, topographical, geological, hydrological, and socio-economical elements. Information from the inventory sheet is used in the models which (a) identify the evaluation elements, (b) assign weights (e.g., 0-5) to each element, (c) list conditions for each element, (d) assign weights (e.g., 0-5) to each condition and (e) provides a possible range and mean score for each function. Scores for each element condition are multiplied by the weight and summed to derive a score for each function. The ten functions may be assigned weights or ranked to facilitate comparisons with other wetlands. Finally, a narrative is prepared describing the generalized aspects of the wetland that gives rise to function based upon best professional judgement.
Key Terminology
Element: definition not provided.
Function: definition not provided.
Function score: definition not provided.
Output
Measure of function of a wetland site relative to the functional model mean score and/or scores for other wetlands in a defined area.
Estimated time to assess 1 acre site
3-4 hours: Office preparation (step 1) and field evaluation (step 2)
Comparison of habitat types
Can directly compare nontidal wetlands within New England, some midwestern states, and possibly other areas.
Use as guide to design
The Hollands-Magee Method models should not be used as a guide to design; however, individual variables (elements) may provide useful information. It is not the intended purpose for the procedure; therefore, it contains properties that limit its application for this purpose. For example, the Hollands-Magee Method uses opportunity variables, but does not set upper limits on those opportunities that could potentially reduce function (e.g., a fetch >2000 ft is assigned a high score in the shoreline protection function). In some circumstances, a wetland may have eroded to the point that it no longer has the capacity to dissipate erosive forces. An upper limit on the opportunity must be defined to insure that the existing or planned wetland can predictably have the capacity to provide a function. Also, the Hollands-Magee Method does not provide validated threshold values for many variables. Some of the variables may provide useful information. Users can refer to the elements to determine which conditions increase or decrease function. This can be translated into design criteria with explicit measurements (e.g., design a shrub-swamp, associated with a lake > 6 ft. deep, located where fetch is over 2000 ft). Finally, the design criteria for some variables may be unsuitable and the overall rating of function may be misleading for the reasons given above.
Contact persons
Garrett Hollands, ENSR, 155 Otis Street, Northborough, MA 01532
phone: (508) 393-8558; fax: (508) 393-5104; e-mail: ghollands@ensr.com
Dennis Magee, Normandeau Associates, 25 Nashua Road, Bedford, NH 03102
phone: (603) 472-5191; fax: (603) 472-7052; e-mail: nai@nh.ultranet.com
Related procedures
Normandeau Associates modified the Hollands-Magee Method and used it in New England and NY during the late 1980’s-1990s. The Rapid Assessment Procedure (Magee and Hollands 1998) is the recent modification of the Hollands-Magee Method that incorporates concepts from the HGM Approach (Smith et al. 1995).
Extent of use/field testing
The Hollands-Magee Method was applied by IEP, Inc. (1975-1981) to 22 townwide wetland assessment/mapping projects in Massachusetts, New Hampshire, and Maine. IEP and Normandeau Associates modified the method for application on the Crandon zinc/copper mine project in Wisconsin. The method was approved for Wisconsin NR 203 - state water quality certification. Normandeau Associates also modified the Hollands-Magee Method (1985) and used it in New England and NY during the late 1980’s-1990s. Over time, numerous consultants have applied the Hollands-Magee Method to over 1,000 routine local, state, and federal wetland permit projects (estimated > 20 projects during the last two years).
Proposed future revisions
The Rapid Procedure (Magee and Hollands 1998) is the current revision.
Key Reference
Hollands, G.G., and D.W. Magee. 1985. A method for assessing the functions of wetlands. Pages 108-118 In J. Kusler and P. Riexinger (eds.), Proceedings of the National Wetland Assessment Symposium. Association of Wetland Managers, Berne, NY.
Complete method available from Garrett Hollands (see contact person information).