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HomeMy WebLinkAboutRequest for wetland type change , , _ �� SVOBODA E�OLOGICAL R�S�UR�E� _ - , � � - Providing the Sharper Edge in Natural Resources & Environmenta� Consulting ` = � - � ' � . - , July 25, 2005 � , Lyle Oman ' ' , City of Orono � � ' � PO Box 66 . Crystal Bay NLN, 55359 RE: SER Project Name: 2640 2650 ox Street ; ' � � SER Project No: 2004-0 -03 � : , Project Location: A portion of the SE 1/a of Section 4,T 117N, R 23W, City of • Orono, Hennepin�Coupty, Minnesota Letter Purpose: Request for Wetland Type Change, ' Dear Mr. Oman ' Svoboda Ecological Resources(SER)was askeci-by our client,Judy,Plucker,to review the wetland type that was identified durir�g the site 'visit on June 25 and.July 2,2004 and subsequently stated in the delineation report dated July 14,2004.The wetland types assigned to Basins 1 and 2 in the repoR , were both palustrine (P-) type wetlands exhibiting emergent (-EM-) vegetation with a seasbnally flooded(-C-)moisture regime that is ditched(-d)oEherwise described as Type 3 (PEMCd)wetlands on the National"Wetland Inventory(NWI) maps. Upon further review it_became apparent that the original classification .described by SER_was inaccurate due to the lack of appropriate hydrophytic vegetation and hydrology that normally � accompanies a Type.3 wetland. Specifica'lly, neither narrow-leaf catta'rl(Typha angustifolia, OBL) nor bulrushes (Scirpus spp.,NI)were observed within either of Basins 1 or 2. Instead the dominant plant species,observed was reed canary grass (Phalaris arundinacea, FACW+), which would indicate a Type 2 status as described in the US Fish and Wildlife Service Circular 39 publication. Hydrology was indicative of a Type 2 wetland as well, given that it was without standing water but was waterlogged or saturated in some portions of each basin at the time of the original site visit and during the latest site visit on July 19, 2005. It should be noted that al� observations of this parcel were made during the growing season. See Attachment A for�a description of the plant indicator categories. , Basin 3 was delineated and was included as a revision in the report dated July 14,.2004 but was not 2477 Shadywood Road a Excelsior, MN 55331 � - (952) 471-1100 (Off'ice) a (952)471-0007 (Fax) . assigned a wetland type.This basin,however,exhibits the same vegetation conditions as that of both Basins 1 and 2 described above. SER has determined that Basins 1 and 2 should be reclassified as (P-) type wetlands exhibiting emergent (-EM-) vegetation with a saturated (-B-) moisture regime that is ditched (-d) or Type 2 (PEMBd)wetlands. SER would classify Basin 3 as a Type 2(PEMBd)wetland as well,based on the same conditions as described above for Basins 1 and 2. For a comparison of Type 2 and Type 3 wetlands, refer to the Circular 39 description of these two types published by the Fish and Wildlife Service. Also,below is an excerpt from a technical paper, written by Frank Svoboda, that offers a clarification of the Cowardin classification and Circular 39 Wetland Types 1, 1L, 2, 3 and 7. The full version of this paper is found in Attachment B of this letter. Type 2—Inland Fresh Meadows Inland fresh meadows(Type 2)wetlands have soil that is usually without standing water during most of the growing season but is waterlogged to within at least a few inches of its surface. Vegetation includes grasses,rushes,sedges,and various broad-leaved plants.In northern environments,typical species representatives are carex, rushes, redtop, reedgrasses, mannagrasses, prairie cordgrass and mints. Meadows may be present in shallow lake basins, sloughs, farmland "sags" or may border shallow marshes on the landward side. Table 4(Cowardin et al p.28)includes within its description of Type 2 wetlands as fen and northern sedge meadow. The water regime is described as saturated (B). This description, as used by some plant ecologists and wetland scientists,is specifically limiting and at least in some instances does not suggest that reed canary grass dominated wetlands would fall into this category. Type 3—Inland Shallow Fresh Marshes Inland shallow fresh marshes (Type 3) wetlands have a soil substrate that is usually waterlogged during the growing season and at some times may be covered with as much as 6 inches or more of water. Common vegetation includes grasses,bulrushes, spikerushes,and various other marsh plants such as cattails, arrowheads,pickerelweed, and smartweeds. Common representatives in the North include reed,whitetop,rice cutgrass,carex and giant burreed.Type 3 marshes may nearly fill shallow lake basins or sloughs or may border deep marshes on the landward side. They may also occur as seep areas in agricultural fields resulting from failing drain tile systems or where sand seams are near the surface on hillside slopes. Cowardin et al (Table 4, pg 28) describes the water regime as either seasonally flooded (C) or semipermanently flooded (F). The accurate categorization of Type 3 wetlands is most critical since seasonally flooded wetlands containing reed canary grass are eligible for larger de minimus fills(up to 10,000 square feet) than cattail marshes (only 400 square feet). SER appreciates the your time in reviewing our request to re-classify Basins 1 and 2. Please feel free to contact Frank Svoboda or Brian Burgner at (952) 471-1100 if you have any comments or questions regarding this letter. Sincerely, Svoboda Ecological Resources � �� � � Franklin J. Svoboda, CWB, PWS Brian K. Burgner President Wetland Ecologist Cc. Jerry Boldenow LITERATURE CITED Cowardin, L.M., V. Carter, F.C. Golet, and R.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S. Fish and Wildlife Service, FWS/OBS-79/31. 103pp. Shaw, S.P., and C.G. Fredine. 1956. Wetlands of the United States. U.S. Fish and Wildlife Service, Circular 39. 67pp. Attachment A Plant Indicator Categories INDICATOR CATEGORIES* Obligate Wetland (OBL)—Occur almost always (estimated probability >99°Io) under natural conditions in wetlands. Facultative Wetland (FACW)—Usually occur in wetlands (estimated probability 67°Io - 99°Io), but occasionally found in non-wetlands. Facultative (FAC)—Equally likely to occur in wetlands or non-wetlands (estimated probability 34°Io - 66%). Facultative Upland (FACU)—Usually occur in non-wetlands (estimated probability 67°Io- 99%), but occasionally found in wetlands (estimated probability I°Io- 33%). Obligate Upland (UPL)— Occur in wetlands in another region, but occur almost always (estimated probability >99%) under natural conditions in non-wetlands in the region specified. If a species does not occur in wetlands in any region, it is not on the National List. %Reed,P.B. 1988. National list of plant species that occur in wedands:Minnesota. National Wedands[nventory,U.S.Fish and Wildlife Service,St.Pe[ersburg,Florida. Attachment B Clarification of Cowardin Classification and Circular 39 Wetland Types 1, 1L, 2, 3 and 7 Clarification of Cowardin Classification and Circular 39 Wetland Types 1, 1L, 2, 3 and 7 By Franklin J. Svoboda Svoboda Ecological Resources 2477 Shadywood Road, Sutie 100 Excelsior, MN 55331 (952) 471-1100 franks @ gpsinnovations.com Introduction The National Wetland Inventory (NWI) mapping process completed in Minnesota between 1979 and 1982 developed a wetlands inventory map for the state of Minnesota utilizing remotely sensed color infrared photography that was visually interpreted. The interpretation process hierarchically classified wetlands using, at the time, the recently published Cowardin classification system (Cowardin et al 1979). The wetland interpretation and classification process was ground verified using selective plots and locations but was ground truthed to only a limited extent. Consequently, the published NWI paper copies carry the disclaimer that these maps are to be used for advisory purposes only and actual classifications are to be based on ground verification. Visual interpretation from remote sensed imagery has some limitations particularly with regard to the water regime modifier. Year to year variation in precipitation cycles along with the occurrence of precipitation events at the time that the imagery was acquired, even if all acquisition occurred during the spring season, can result in variations in modifier categorization. Accurate classification becomes critical when regulatory decisions are being made with regard to the wetland type and the amount of de minimum fill that is permissible. Also, it is a matter of scientifically accurate consistency with regard to adherence to the various technical publications and regulatory guidance documents. Circular 39 was authored by Shaw and Fredine and published by the U. S. Fish and Wildlife Service (USFWS) in 1956. The intended purpose of Circular 39 was an effort at classifying and inventorying wetlands on a national scale in order to assess the wetland base and related waterfowl production potential. The classification process was never intended to serve as a classification system for wetland regulatory purposes. However, since it was the first national effort of its kind and as wetland regulatory intentions materialized, this was the only method available to differentiate between wetlands of different types. The Board of Water and Soil Resources (BWSR) cross-reference table (8420.0549 subp. 2.) indicates that Circular 39 Type 3 wetlands have a"C" water regime modifier. This is an inaccurate cross-reference and the intent of this technical paper is a clarification of the correct interpretation. There is also a common tendency to refer to bottomland hardwoods as Type 7 wetlands. This is also an inaccurate classification. The NWI paper maps do not use the water regime modifier "E" because it was difficult to interpret from the inherent limitations imposed by the remote sensed imagery. Therefore, most if not all Type 3 wetlands were given the designation "C". However, the following discussion will examine and clarify the differences between Circular 39 Types l, 1L, 2, 3, and 7 and the appropriate Cowardin water regime modifying terms. Circular 39 Wetland Types Type 1/1L—Seasonally Flooded Basins or Flats Type 1 wetlands are characterized by soil that is covered with water or is waterlogged during variable seasonal periods but is usually well drained during much of the growing season (italics added for emphasis). These wetlands may be found in upland depressions as well as in overflow bottomlands, i.e. river and stream floodplains. Within floodplains, flooding may occur in late fall, winter or spring. In upland contexts, basins or flats may be water filled during heavy rain events or following spring snow melt. Vegetation types vary greatly according to the season and the duration of flooding. Included within Type 1 are bottomland hardwoods as well as some herbaceous growths. Where the water has receded early in the growing season, smartweeds, fall panicum, tealgrass, chufa, redroot cypress and weeds (such as marsh elder, ragweed and cockleburs) are likely to occur. Shallow basins that are submerged only very temporarily usually develop little or no wetland vegetation (Shaw and Fredine 1956, p30). Since Circular 39 was developed for national application, the description of Type 1 wetlands covers a broad range of geographic contexts hence the reference to winter flooding. Cowardin et al (p. 28) in Table 4 describe Type 1 wetlands as seasonally flooded basins or flats, wet meadow, bottomland hardwoods and shallow freshwater swamps. The water regimes are described as temporarily flooded (A) or intermittently flooded (J). The Minnesota Department of Natural Resources (DNR), within the regulatory framework of the Protected Waters and Public Wetlands framework has added the Type 1 L designator to more clearly clarify the Circular 39 classification method and to allow an accurate distinction to be made between bottomland hardwoods, seasonally flooded non-vegetated or herbaceous vegetated basins and hardwood swamps. The distinction on the basis of hydrology is clear and it was the intent of the DNR to differentiate between forested bottomland hardwoods and non-forested wetlands. Type 2—Inland Fresh Meadows Inland fresh meadows (Type 2) wetlands have soil that is usually without standing water during most of the growing season but is waterlogged to within at least a few inches of its surface. Vegetation includes grasses, rushes, sedges, and various broad-leaved plants. In northern environments, typical species representatives are carex, rushes, redtop, reedgrasses, mannagrasses, prairie cordgrass and mints. Meadows may be present in shallow lake basins, sloughs, farmland "sags" or may border shallow marshes on the landward side. Table 4 (Cowardin et al p. 28) includes within its description of Type 2 wetlands as fen and northern sedge meadow. The water regime is described as saturated (B). This description, as used by some plant ecologists and wetland scientists, is specifically limiting and at least in some instances does not suggest that reed canary grass dominated wetlands would fall into this category. Type 3—Inland Shallow Fresh Marshes Inland shallow fresh marshes (Type 3) wetlands have a soil substrate that is usually waterlogged during the growing season and at some times may be covered with as much as 6 inches or more of water. Common vegetation includes grasses, bulrushes, spikerushes, and various other marsh plants such as cattails, arrowheads, pickerelweed, and smartweeds. Common representatives in the North include reed, whitetop, rice cutgrass, carex and giant burreed. Type 3 marshes may nearly fill shallow lake basins or sloughs or may border deep marshes on the landward side. They may also occur as seep areas in agricultural fields resulting from failing drain tile systems or where sand seams are near the surface on hillside slopes. Cowardin et al (Table 4, pg 28) describes the water regime as either seasonally flooded (C) or semipermanently flooded (F). The accurate categorization of Type 3 wetlands is most critical since seasonally flooded wetlands containing reed canary grass are eligible for larger de minimus fills (up to 10,000 square feet) than cattail marshes (only 400 square feet). The difference in hydrological regimes is discussed in the next section. Type 7—Wooded Swamps Wooded swamps (Type 7) wetlands have a soil substrate that is "waterlogged to within a few inches of its surface" (Shaw and Fredine 1956, pg 22) during the growing season and often can be covered with as much as 1 foot of water. Type 7 wetlands often occur along the edges of sluggish streams, on floodplains, on flat uplands and in very shallow lake basins. In the North, trees include tamarack, arbor vitae, black spruce, balsam, red maple, and black ash. Northern evergreen swamps frequently have a thick ground cover of mosses. Deciduous swamps frequently contain beds of duckweeds, smartweeds and other herbaceous plant species. Hardwood swamps frequently are associated with Type 6, shrub swamp wetlands. Table 4 (Cowardin et al 1979, pg 28) states that Type 7 wetlands include all water regimes except permanently flooded. This description is inconsistent with the more specific description of Shaw and Fredine (1956) that describes a Type 7 wetland as having waterlogged soil to within a few inches of the surface throughout the growing season. Wooded swamps (Type 7) are frequently mischaracterized as bottomland hardwoods (Type 1L), however there are significant differences in the hydrological regimes between the two. The nature of these differences is discussed in a subsequent section. Cowardin Water Regime Modifiers The purpose of water regime modifiers is to provide a better description of the variations in hydrology that occur in wetlands on a seasonal and annual basis. These descriptions are general in nature because wetland hydrology is extraordinarily dynamic. Hydrology is the most variable component of wetlands and can vary substantially within a single basin weekly, monthly, seasonally, annually and over decades. Extraordinarily wet or dry periods, whether short or prolonged, do have dramatic effects on the presence or absence of water in any given wetland. Whether a wetland has naturally occurring hydrology or whether it is partially or completely drained affects its behavior as a component of the landscape, its appearance, the vegetation that inhabits it, and the effectiveness of the functions that it performs. Wetlands may also have artificially induced hydrology due to stormwater inputs or interconnections to other wetlands via ditch or tile drain systems. Careful consideration of each wetland within the overall context of the landscape is necessary to understand which water regime best fits along with the special modifiers that describe alterations to wetlands. One special modifier class that is missing is the "stormwater pond" category. This is a commonly occurring condition in urban landscapes and should be added. Stormwater ponds may have been specifically constructed for that purpose or, in the past, previously existing wetlands were used to treat stormwater and now function as stormwater ponds rather than "natural" wetlands. Descriptions of the modifiers are taken from Cowardin et al (1979, pgs 21 — 22) and from Santos and Gauster (1993, pgs 30— 32). Descriptions within the parentheses are terms used on the NWI key and the longer description is the one used by Cowardin et al. (1979). Where a parenthetical term is excluded, the two terms are the same. Modifier "A" Temporarily Flooded (Temporarv) Surface water is present for brief periods during the growing season but the water table usually is well below the soil surface for most of the season. Temporarily flooded wetlands usually have plants that are characteristic of both uplands and wetlands. This modifier description is most appropriately assigned to Type 1 and 1 L wetlands but clearly does not fit the Type 7 Hardwood Swamp wetland type. Table 4 (Cowardin et al 1979, pg 28) is inconsistent by including this regime in the Type 7 category. Modifier "B" Saturated Soil saturation occurs to the surface for extended periods during the growing season but surface water is seldom present or evident. Many sedge and rush wetlands fit into this category. This modifier also aptly fits the water regime that occurs in the hardwood swamps that are present in parts of Minnesota in hardwood swamps such as black ash swamps and in coniferous swamps such as white cedar, tamarack, and black spruce swamps. This modifier also describes Type 2 wetlands as described above and includes fens and sedge/rush dominated wetlands. ModiFer"C" Seasonallv Flooded (Seasonal) Surface water is present for extended periods especially early in the growing season but is absent by the end of the season in most years. When surface water is absent, the water table is often near the surface. Santos and Gauster (1993, pg 31) add that the water table, after flooding ceases, is very variable, extending from saturated to a water table well below the surface. This accurately describes the situation that frequently occurs within reed canary grass wetlands where there is saturation to the surface or even several inches of inundation after snow melt. In most years, by the end of May, surface water is no longer evident in many of these basins. During June, the water table continues to recede until by August, the water table may be two or more feet below the surface. Many of these areas are used for livestock pasturing and for harvesting meadow hay. Wetlands with a "C" modifier that consist predominantly of reed canary grass should be categorized as either Type 1 or Type 2 depending on the length of time that water is present. This modifier is the most difficult to specifically assign to a Type 1, Type 2 or Type 3 category as it could apply to any of the three. Modifier "D" Seasonal Well-Drained (No comparable Cowardin cate�orv) Santos and Gauster(1993, pg 31) describe this modifier as applying where surface water is present for extended periods especially early in the growing season. The water table, after flooding ceases falls well below the ground surface. This modifier would appear to apply to floodplains and bottomland hardwood forests (Type 1L) as described above. Modifiers "C" and "D" seem to overlap to a certain extent and could also apply to reed canary grass wetlands as well. Modifier "E" Seasonal Saturated (No comparable Cowardin cate�orv) Surface water is present for extended periods especially early in the growing season, and remains saturated near the surface for most of the growing season (Santos and Gauster 1993, pg 31). This modifier would appear to apply to fens, sedge and rush meadows, some Type 6 shrub swamps, Type 7 Hardwood Swamps and Type 8 bogs. Some reed canary grass wetlands might fall into this category but most seem to be dried out by early to mid-summer. Modifier"F" Semipermanentiv Flooded (Semipermanent) Surface water persists throughout the growing season in most years. When surface water is absent, the water table is usually at or very near the land surface (Cowardin et al 1979, pg 22; Santos and Gauster 1993, pg 31). This modifier applies to Type 3 cattail marshes and may also apply to some hardwood swamps such as black ash, conifer bogs and Type 6 alder shrub swamps. Modifier"G" Intermittently Exposed Surface water is present throughout the year except in years of extreme drought (Cowardin et al 1979, pg 22; Santos and Gauster 1993, pg 31). Type 4 wetlands fall into this category. Modifier"H" Permanently Flooded (Permanent) Water covers the land surface throughout the year in all years. Vegetation is composed of obligate hydrophytes (Cowardin et al 1979, pg 22). Modifier "J" Intermittentiv Flooded The substrate is usually exposed, but surface water is present for variable periods without detectable seasonal periodicity. Weeks, months, or years may intervene between periods of inundation. The dominant plant communities may change as soil moisture conditions change. According to Cowardin et al (1979, pg 22) "Some areas exhibiting this regime do not fall within our definition of wetland because they do not have hydric soils or support hydrophytes." Some of the areas in agricultural fields that have been flooded during the spring and early summer of 2003 and 2004, following periods of intense and persistent rainfall, may well fall into this category and may not in fact be subject to regulation as a wetland. Modifier "K" Artificially Flooded (Artificial) The amount and duration of flooding is controlled by means of pumps or siphons in combination with dikes or dams. Water and wastewater treatment facilities are included under this category. This definition does not appear to include stormwater ponds. Modifier "Z" Intermittently Exposed/Permanent (No comparable Cowardin categorv) Exhibits features of both Intermittently Exposed and Permanent water regimes (Santos and Gauster 1993, pg 31). Modifier"W" Intermittently Flooded/Tem�oraiy (No comparable Cowardin cate�orv) Exhibits features of both Intermittently Flooded and Temporary water regimes (Santos and Gauster 1993, pg 32). Modifier"Y" Saturated/Sem�ermanent/Seasonal (No comparable Cowardin cate�orv) Exhibits features of the Saturated, Semipermanent and Seasonal water regimes (Santos and Gauster 1993, pg 32). Modifier"U" Unknown (No com�arable Cowardin cate�rv) The water regime is not known (Santos and Gauster 1993, pg 32). Discussion Type 1/1L The description provided for Type 1 wetlands and the reference to the absence of wetland vegetation in basins that are only flooded very temporarily raises a regulatory question. One of the criteria for a jurisdictional wetland is the presence of hydrophytic vegetation (1987 Manual pp 16 - 26). Type 1 wetlands often are found in agricultural fields and often are determined to be jurisdictional on the basis of an aerial 35mm slide review; the quality of the slides is poor under the very best of circumstances. . The determination of regulatory jurisdiction is based on normal circumstances or as defined by the COE, being agriculturally cropped 51 out of 100 years (i.e. by inference lacking sufficient hydrology for either 5 or 12.5 percent of the growing season). The Wetland Conservation Act (WCA) determines normalcy as agricultural cropping for 6 out of 10 years (MnRules 8420.0110, Subp 53; 8420.0122 Subp.l, A and B). Typically, normalcy on agricultural lands is determined by the review of the aforementioned low quality 35mm aerial slides and judgments are made as to whether an area is cropped or if the crops are subject to hydrological stresses. The process is highly subjective and can be biased by excessive precipitation that may occur early in the crop growth cycle. Field examination of these areas may indicate the presence of smartweed and some of the other indicated species in seasonally abnormally wet years whereas in normal years, hydrophytic vegetation is absent. It is highly probable that the process of determination of Type 1 wetlands as jurisdictional in many cases is extending beyond the legitimate definition of Type 1 wetlands and the intent of the 1987 Manual. Does a Type 1 basin need to be flooded for 5 percent of the growing season (the lower definitional bound for jurisdictional hydrology) or 12.5 percent (the upper definitional bound for jurisdictional hydrology) in order for hydrophytic vegetation to develop? In practice, the St. Paul District of the Corps of Engineers (COE) (also applied in practice under the Wetland Conservation Act) applies the 5 percent hydrological definition but if that is too short to allow the development of hydrophytic vegetation under normal conditions than the absence of hydrophitic vegetation would make those Type 1 wetlands non-jurisdictional. Type 1L—bottomland hardwoods—poses an equally difficult regulatory question. Tools for the evaluation of hydrology for non-cropped areas are much more data intensive and are also subject to precipitation event variability. Measurement tools for the determination of precipitation normalcy are a combination of evaluating annual precipitation and comparison to a 30-year rolling average along with extensive near ground surface early season hydrological monitoring. If the water levels are within 12" of the surface for less than 8.5 days in the general latitude of the Twin Cities (5 percent of the growing season), than the area is not wetland. If water levels are within 12" of the surface between 5 percent and 12.5 percent of the growing season (21 days in the general latitude of the Twin Cities) according to the 1987 Manual (Table 5 pg. 36), the area may be wetland but usually is not. However, the standard practice of the St. Paul COE is to declare any areas that exceed the 5 percent criteria to be judged jurisdictional wetlands. Areas with water levels within 12" of the surface in excess of 12.5 percent of the growing season are wetlands. No one has ever undertaken a scientific study to evaluate the relationship between the hydrological requirements and the presence of various wetland or non-wetland plant species. This is a critical, yet unanswered question. Some studies have been completed examining soil types and hydrological responsiveness but the link between plants and hydrology has yet to be made. Given the annual cost of jurisdictional decisions in terms of"lost land" opportunities, perhaps such a study would be prudent. The implications of regulatory misinterpretation are enormous in that it is likely that hundreds of acres of Type 1 wetlands are avoided or mitigated for each year when legitimately these areas are non-jurisdictional and could be developed. Avoidance or impact and mitigation can cost developers and ultimately, homebuyers, millions of dollars annually just in the developing seven-county Metropolitan Area. Mitigating a non jurisdictional Type 1 wetland impact at a 2:1 ratio reduces the usable land base unnecessarily. For every 50 acres of non-jurisdictional impact, 100 acres are removed from the land supply. At an average cost of$100,000 per acre, the cost to developers and ultimately to homeowners is $10,000,000 in just one year for just 50 acres. Type 2/3 Type 3 wetlands create the greatest classification difficulty from the perspective of de minimus qualification. A Type 3 wetland that is seasonally flooded (C) is typically characterized by reed canary grass whereas a Type 3 semi-permanently flooded wetland is more likely characterized by a growth of cattails. The reed canary wetlands are generally dry by late spring to early summer. By late summer, the water tables have receded to well below the surface (> 18 — 36"). In contrast, Type 3 cattail wetlands still contain water above or very near the surface during normal growing seasons. The WCA permits the use of de minimus filling of Types 1, 2, 6 and 7 wetlands. Clearly it is not the intent of the WCA to allow the application of the de minimus criteria to fens since the WCA specifically addresses fens as a special category for protection. Therefore, the Type 2 designation must apply to the "C": modifier Type 3 wetland. Further, Type 3 wetlands in excess of 2.5 acres in incorporated areas and in excess of 10 acres in unincorporated areas are protected under the DNR protected waters statute. In the DNR wetland inventory and classification process, the Type 3 wetlands were clearly dominated by cattails hence the inference that reed canary grass wetlands were Type 2. Type 7/Type 1L Inconsistencies in technical descriptions regarding the hydrological regime of these two wetland types from a scientific perspective become only a matter of discussion between scientists. However, when wetland types are applied from a regulatory perspective, accuracy in definition becomes crucial because certain activities may be permitted in one wetland type and prohibited in another. At present, Wetland Types 1L and 7 are subject to the same wetland regulatory requirements and exceptions. However, that may not be always the case and therefore it is important to note the crucial yet subtle differences between the two types. The majority of bottomland floodplain forests in many years have water tables several feet beneath the soil surface. The language "throughout the growing season" is quite specific in Circular 39. A careful consideration of the species described in the listing provided by Shaw and Fredine (1956) indicates that the habitat requirements of the species listed include the typical presence of a near surface high water table whereas the description of a Type 1L forested wetland describes the term "bottomland hardwood", a rather vague non-specific term but tree species generally included in this category are elm, cottonwood, green ash, and silver maple. Bottomland hardwoods do not include the species described as associated with hardwood swamps. Type 7 wetlands are persistently wet under all but the driest conditions whereas Type 1/1L wetlands are generally dry except under the wettest of conditions. The distinction is significant. In general, the Board of Water and Soil Resources cross-reference classification (Mn Rules 8420.0549 subp. 2.) are generally accurate but the designation of PEMC as a Type 3 wetland poses some problems. Where the Type 3 wetland is comprised of cattails, a de minimus exemption of 400 square feet applies but where the wetland is reed canary grass, also a Type 3 designation should technically apply based on the above discussion. The reed canary grass wetlands do not fit well into the "C" modifier category nor do they fit into the "B": modifier either. As a matter of standard practice, it would seem best to designate reed canary grass wetlands as Type 2 wetlands regardless if the modifier is "B" of"C". The difference is important in that a de minimus exemption of anywhere from 2000 square feet to 10,000 square feet might be applicable. Also being accurate with regard to wetland type is important when designation of the regulatory wetland type is done based on if the deepest part of the basin or the dominant vegetation is the wetland type that determines allowable fill. This requirement often over-regulates the reed canary grass fringe and eliminates the possibility of applying the 2000to 10,000 square foot de minimus in many cases where a very small percentage of the overall basin is cattail but because the deepest part of the basin criteria is applied, only 400 square feet of de minimus fill may be used. In general, while this may seem to be an arcane discussion, in reality it is crucial in order for the regulated community to rightfully claim the wetland exemptions that the law permits. Conversely, it entitles the landowner to rightfully claim useable land for development purposes. A clear understanding and accurate interpretation of the classification system is necessary in order for the exemptions available under the de minimus categories to be appropriately applied. Literature Cited Cowardin, L.M., V. Carter, F.C. Golet, and R.T. LaRoe. 1979. Classi�cation of Wetlands and Deepwater Habitats of the United Staets. U.S. Fish and Widlife Service, FWS/OBS- 79/31. 103pp. Environmental Laboratory. 1987. 1987 U.S. Army Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1, U.S. Army Engineer Waterways Experiment Station. Viscksburg, Mississipii. 100pp + app. Minnesosta Board of Water and Soil Resources. 2002. Board of Water and Soil Resoruces Wetland Conservation Act Rules Chapter 8420. Office of Revisor of Statutes. St. Paul, Minnesota. 151 pp. Santos, K.M. and Joan E. Gauster. 1993. User's Guide to National Wetlands Inventory Maps (Region 3) and to "Classi lcation �Wetlands and Deepwater Habitats of the Unitied States". U.S. Fish and Wildlife Service National Wetlands Inventory Region 3. Bloomington, Minnesota. 38pp. Shaw, S.P. and C. G. Fredine. 1956. Wetlands of the United States. U.S. Fish and Wildlife Service, Circular 39. 67pp.