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HomeMy WebLinkAboutTQ_Flanders Mit Proposal 3_24_14FLANDERS MILL Wetland and Stream Compensatory Mitigation Plan March 24, 2014 NWO-2013-01559-MTB Upland willow community north side of project site; realigned UT Baxter will be located through this community to restore wetland hydrology. Prepared for: Flanders Mill, LLC 235 Greenhills Ranch Road Bozeman, MT 59718 Prepared by: TerraQuatic, LLC 614 West Lamme Street Bozeman, MT 59715 lbacon@terraquaticllc.com Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 i Contents 1.0 OBJECTIVE 1 2.0 SITE SELECTION 3 2.1. IMPACT SITE ......................................................................................................................................... 3 2.2 MITIGATION SITE ................................................................................................................................. 4 3.0 SITE PROTECTION 4 4.0 BASELINE CONDITIONS 4 4.1. EXISTING CONDITIONS ........................................................................................................................ 4 4.1.1 WETLANDS .......................................................................................................................................... 5 4.1.2. NONWETLAND WATERWAYS ............................................................................................................. 7 4.1.3 HYDROLOGIC CHARACTERISTICS ........................................................................................................ 7 4.1.4 SOIL CHARACTERISTICS ...................................................................................................................... 8 4.1.5 EXISTING VEGETATION ....................................................................................................................... 8 4.1.6 EXISTING WILDLIFE USAGE ................................................................................................................ 8 4.1.7 HISTORIC AND CURRENT LAND USE ................................................................................................... 8 5.0 DETERMINATION OF CREDITS 9 5.1 WETLAND MITIGATION RATIOS (ON-SITE) ........................................................................................ 9 5.2 OFF-SITE WETLAND MITIGATION ....................................................................................................... 9 5.3 MONTANA STREAM MITIGATION PROCEDURE ................................................................................ 11 5.3 WETLAND AND STREAM FUNCTIONAL INCREASE ............................................................................ 11 6.0 MITIGATION WORK PLAN 12 7.0 PERFORMANCE STANDARDS AND MITIGATION MONITORING 14 7.1 PERFORMANCE STANDARDS AND CRITERIA ..................................................................................... 14 7.2 REPORTING FREQUENCY .................................................................................................................... 14 7.3 ADAPTIVE MANAGEMENT PLAN ........................................................................................................ 14 8.0 REFERENCES 17 Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 ii APPENDICES APPENDIX A: Wetland and Nonwetland Waterway (Pre-Mitigation) Delineation Map APPENDIX B: COE Jurisdictional Determination Letter APPENDIX C: Flanders Mill Wetland and Stream Mitigation Map APPENDIX D: Montana Stream Mitigation Procedure APPENDIX E: Flanders Mill Post-Mitigation Functional Assessments APPENDIX F: Mitigation Seed Mixes and Plant Lists APPENDIX G: Project Channels Plans/Profiles List of Figures Figure Number Title Page Figure 1 Flanders Mill, Bozeman, Montana Project Location (Exhibit A) 2 Figure 2 General Land Usage in the Vicinity of the Flanders Mill Project Site (Exhibit B) 2 List of Tables Table Number Title Page Table 4.1 Flanders Mill Wetland and Nonwetland Waterways 5 Table 4.2 Flanders Mill Pre-Construction Wetland Function/Value Ratings and Functional Points, June, 2013 7 Tables 5.1a Flanders Mill Proposed Wetland Impact and Mitigation (On-Site) 10 Tables 5.1b Flanders Mill Proposed Stream Impact and Mitigation (On-Site) 10 Table 5.2 Flanders Mill Post-Construction Wetland Function/Value Ratings and Functional Points, June, 2013 11 Table 7.1 Flanders Mill Mitigation Site Performance Standards and Criteria 15 Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 1 1.0 OBJECTIVE The Flanders Mill project site is the proposed location of a residential housing development and is currently proceeding through the pre-plat meetings with the City of Bozeman. The project site is being developed by Flanders Mill, LLC. The proposed project is 136.75 acres and is located in the east half, west half of Section 3, Township 2 South, and Range 5 East (Figure 1). Elevation range of the project site is approximately 4,030 feet to 4,280 feet above sea level. The hydrologic unit code for this area is 10020008. TerraQuatic, LLC designed the wetland and stream mitigation proposal and WGM provided hydrologic engineering services. The following mitigation proposal will be submitted with the Section 404 application to the U.S. Army Corps of Engineers (COE). The property is bordered by Flanders Mill Road on the west, Baxter Lane on the north, and Ferguson Lane on the southeast (Figure 2). Two city streets will be completed to increase service to the surrounding developments: the south half of the west end of Oak Street will cross the development between Ferguson Lane and Flanders Mill Road and the north end of Ferguson Lane will connect Oak Street to Baxter Lane. Two school properties, a church, the 100-acre Gallatin County Regional Park, and an open space parkland are adjacent to the proposed Flanders Mill project. A NorthWestern Energy electrical power station easement is located along the west-central boundary with access off of Flanders Mill Road. Project design has gone through many revisions to optimize residential living experience and increase wetland function of the riverine and depressional wetland systems. One option was to leave the stream in its current location where it makes two 90 degree turns to circumvent the power station, after which it flows north and adjacent to Flanders Mill Road. Enhancing the current stream corridor with woody species would have had a low success rate as a result of the perched wetland and incised streambed. No enhancement (woody species plantings) would have been possible within the electrical power station easement, however. To optimize parkland experience the developers agreed to invest in realigning the unnamed tributary of Baxter Creek (UT Baxter) to its presumed historical location (based on NRCS hydric soil maps), increase wetland floodplain along the UT Baxter to an average 30 feet wide, increase structural vegetation diversity along all channels and wetlands by planting wetland trees and shrubs, and to establish and protect a 50-foot wide upland buffer along stream corridors and all wetland boundaries were possible. The north end of the realigned UT Baxter south of Baxter Lane will also incorporate and restore hydrology to an upland willow community. The channel will then cross under Baxter Lane and confluence with a Baxter-Border stream reach that was realigned nine years ago and enhanced in a similar fashion. The northern reach of the Baxter-Border stream will also be realigned to remove the channel away from Baxter Lane and out of the borrow ditch. A shallow wetland pond and small lake will also be developed within public parkland and enhanced with woody vegetation. A trail system will circumnavigate both features and include picnic areas and educational kiosks. Wetland credits not met within the Flanders Mill property will be supplemented by off-site wetland credits developed in 2013 as part of a stream enhancement and wetland creation project at the Knoll (BMW, LLC), one-quarter mile northwest of the Flanders Mill project site and within the same stream system. Wetland acreage developed during the Knoll stream enhancement project will exceed pre- disturbance wetland acreage. Both companies, BMW, LLC and Flanders Mill, LLC are owned by the same individual. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 2 Figure 1. Flanders Mill proposed project site, Bozeman, Montana Project Location Figure 2. General land usage in the vicinity of the proposed Flanders Mill project site. Polygon colors indicate the following areas: dark blue-Flanders Mill project site; aqua-school properties (Site A, Meadowlark School, was constructed in 2013); yellow-parks; dashed orange-potential parkland; purple-church property; and red with blue cross hatch-the Knoll mitigation project site. Flanders Mill Road Baxter Lane Durston Road Oak Street Future Ferguson Lane Future Oak Street N A Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 3 2.0 SITE SELECTION 2.1. Impact Site TerraQuatic, LLC (TQ) conducted the wetland and nonwetland waterway (NWW) delineation during June, 2013 (Exhibit A, Appendix A). The full delineation report is included in the mitigation plan package. The site is currently comprised of 13.33 acres of wetlands (wetlands 1 through 6) and 3,819 feet of streambed (NWW-1 and 2). Proposed permanent impacts total 7.47 acres of emergent wetland and 3,152 linear feet of nonwetland waterways. The Gallatin County Conservation District refers to nonwetland waterway-1 (NWW-1) as UT Baxter Creek. NWW-1 historically arose from an area approximately 800 feet south of Durston Lane (State Engineers Office 1953). The channel crosses Durston Lane at a 90 degree angle and flows north to northwest through the subject property; the substation was not installed until 2001. The stream exits the current northwest side of the Flanders Mill property 1,000 feet south of Baxter Lane, where it crosses under Flanders Mill Road and continues to flow north in the borrow ditch where it crosses Baxter Lane and flows into the Baxter-Border stream. The NWW-1 stream configuration depicted in the 1953 Water Resources Survey was maintained until the NorthWestern Energy substation was installed in 2001. At that time the stream was realigned around the circumference of the station as part of a mitigation agreement. However, there are no protective covenants on this stream reach. The current streambed is approximately two feet wide and is a low-functioning stream with low sinuosity, includes no woody vegetation, and flows have little access to a wetland floodplain adjacent to the stream. Currently the channel receives two sources of surface water: water from a seep along Ferguson Lane and irrigation waste water from the Maynard- Border diversion structure on the south side of Durston enter the tributary. It is suspected that the UT Baxter also conveys groundwater. Impacts to NWW-1 will result from moving the channel from its current location to an area of hydric soils (per NRCS Soil Report, see delineation report). The realigned channel will meander within a 30- foot wide wetland floodplain corridor. At the north end of the property, the stream will cross under Baxter Lane and confluence with a restored reach of the Baxter-Border stream. A woody riparian community will be created along the entire length of the stream (30% cover at maturity), wetland fringe will comprise approximately 25 feet of the stream corridor, sinuosity will be increased, and a 50-foot upland buffer will be created along the corridor where practicable. To satisfy a City of Bozeman request to remove the traffic hazard the Baxter-Border stream (NWW-2) presents because of its location in the Baxter Lane borrow ditch, the stream will be moved 30 feet south of its current location. The City suggested that the entire reach along Baxter Lane (>400 feet) be placed in culverts. To avoid this type of stream impact, the stream will be moved to the south, sinuosity and wetland fringe width will be slightly increased, woody riparian species will be planted along the stream, a small upland buffer will be placed along the corridor, and the stream bank slope will be decreased. At the time of the delineation investigation a majority of the wetlands and stream corridor (wetlands-1 and 6 and NWW-1) were overgrown with a severe Canada thistle infestation, a Priority 2B noxious weed. Most of the driest areas of the central wetland area (wetland-6) were mowed in August to prepare the site for fall herbicide application. Noxious weed treatment, in addition to being a state law, will prepare the site for wetland sod salvage operations during the construction of the realigned Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 4 UT Baxter channel. Desirable wetland sod (e.g. sedge, rush, bulrush species) will be used to create streambanks and wetland floodplain along the channel(s) and around the pond and lake features. The wetland areas are also dominated by field meadow-foxtail (Alopecurus pratensis), a common hayland species. In some areas this species grows to four feet tall and effectively outcompetes more desirable wetland species. In essence, the wetlands are very low functioning with low species diversity. Only the wettest area within a trench that conveys water out of wetland-4, the stormwater pond, has the highest species diversity. 2.2 Mitigation Site Mitigation for loss of wetlands and streambed debits will involve on-site wetland and stream creation, enhancement, restoration (re-establishment and rehabilitation), preservation, and upland buffer creation. Off-site wetland creation from the Knoll project site will supplement wetland mitigation credits. As a result of mitigation efforts within the Flanders Mill project site, wetland and stream function will increase within the project site, as well as stormwater management, vegetation diversity and complexity, and wildlife diversity (e.g. avian and small mammal). A post-construction wetland and stream functional lift has been demonstrated and is presented in Section 5.1 (Table 5.1). 3.0 SITE PROTECTION The wetland and stream mitigation areas will be protected in perpetuity by deed restrictions placed on open space lot(s) that will include all wetlands, stream corridors, and wetland buffers. Protective covenants have already been placed on the Knoll parkland which includes the wetland mitigation site. In addition, covenants will be recorded on all building lots which will regulate the use and maintenance of upland buffers and wetlands. The deed restrictions and covenants will be enforced, along with the maintenance, by one Master Homeowners Association (HOA) that oversees the entire project site. Until the Master HOA is in place (5 to 10 years), Flanders Mill, LLC will be responsible for wetland and stream protection and maintenance. Filed deeds or covenants will be included in the Year-1 mitigation monitoring report. Flanders Mill, LLC owns the project site, currently worth $5.5 million; there are no liens on the property. Total project build out will include approximately 400 residential units. If the COE requires more substantive proof of financial dedication toward completing mitigation construction, monitoring, and maintenance, Flanders Mill, LLC would like the information requested at the time of permit negotiation. 4.0 BASELINE CONDITIONS 4.1. Existing Conditions The Flanders Mill project site has been annexed into the Bozeman city limits. A full delineation report is included in the mitigation proposal package, which includes a wetland and non-wetland waterway delineation map (Exhibit A, Appendix A), photographs, Natural Resource Conservation Service (NRCS) soil map, Montana Department of Transportation (MDT) functional assessments (pre- construction, see also Table 4.2 this report), COE data sheets (including lat/longs of locations), and hydrogeomorphic (HGM) and Cowardin classifications (Table 4.1). General project site conditions and typical wetland and stream characteristics are illustrated in Photos 1 through 4. Wetland number, acreage, HGM class, Cowardin Type, wetland function, hydrologic source and vegetation community are included in Table 4.1. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 5 4.1.1 Wetlands Flanders Mill project site is comprised of 13.33 acres of wetlands comprised of six different wetland systems. Wetland-1 (0.47 acre) is the immediate 3-foot fringe along the UT Baxter (NWW-1) and wetland-2 (0.07 acre) is the fringe along the Baxter-Border stream (NWW-2). Wetland-1 was separated from adjacent wetlands, which are identified as wetland-6 (12.40 acres) because the creek banks are steep and in general 18 inches above surface water level and hydrologic influences are limited by the bank height. For general delineation mapping and compensatory mitigation calculation purposes, the streambed areas (NWW-1 and 2) were removed from the riverine wetland acreage (WL- 1 and 2, respectively), except for functional assessment purposes. Wetland-3 is located in the Baxter Lane borrow ditch, and historically conveyed Baxter-Border stream flows. Table 4.1 Flanders Mill Pre-Mitigation Wetland and Nonwetland Waterways Wetland Acreage HGM Classification1 Cowardin Type2 Wetland Function3 Hydrologic Source4 Wetland Description and Dominant Vegetation Species Category Fx Units WL-1 WL: 0.47 (NWW: 0.25)5 Riverine R/P/UB/PEM III 3.026 Farmers’ Canal and groundwater 3-foot wetland fringe along UT Baxter; reed canary grass, field meadow-foxtail WL-2 WL: 0.07 (NWW: 0.02)5 Riverine R/P/UB/PEM III 0.466 Farmers’ Canal and groundwater wetland fringe along creek; field meadow-foxtail WL-3 0.07 Depressional PEM III 0.18 Groundwater Baxter Lane borrow ditch; field meadow- foxtail, cattail WL-4 0.24 Depressional PEM IV 0.70 Ground and Surface water stormwater pond; cattail, reed canary grass, sparse willow WL-5 0.08 Depressional PEM IV 0.14 Groundwater topographic depression, unknown cause; field meadow-foxtail WL-6 12.40 Depressional PEM III 45.04 Groundwater wetland areas beyond the 3-ft width of WL-was classified as WL-6; field meadow-foxtail and Canada thistle. TOTAL 13.33 (WL only) 49.10 Nonwetland Waterway Bed Length (feet) NWW-1 (UT Baxter Creek) 3,411 NA NA NA NA Farmers’ Canal and groundwater NA NWW-2 (Baxter-Border stream) 408 NA NA NA NA Farmers’ Canal and groundwater NA TOTAL 3,819 1 Hydrogeomorphic Classification; Smith et al.1995. 2 Cowardin et al., 1979: PEM-Palustrine Emergent; R-Riverine; P-Perennial; UB-Unconsolidated Bottom 3Montana Department of Transportation functional assessment results: Category I is the highest functioning wetland and Category IV is the lowest; Functional (Fx) Units are calculated by multiplying total acreage of wetland(s) by rating of each function and value variable rating (Berglund and McEldowney 2008). 4 The major sources of hydrology are listed first (or connected with an “and” statement). 5 Wetland acreage used in pre-mitigation functional assessments includes streambed (NWW) acreage (listed in parentheses). Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 6 Photo 1. General condition and species composition of wetland-6, illustrating a dominance of Alopecurus. Photo 2. Upland willow community adjacent to Baxter Lane; likely a remnant wetland. Hydrology will be restored to this community for restoration mitigation credit by locating new UT Baxter stream channel through this community. Photo 3. NWW-1/WL-1 (approximate 3-foot stream fringe); note lack of sinuosity and woody vegetation. Photo 4. Severe Canada thistle infestation in wetland areas along UT Baxter channel (NWW-1/WL-1) and outside of stream corridor (WL-6). The Baxter-Border stream was moved north of the lane for mitigation purposes in 2004 to compensate in part for Baxter Meadows Subdivision wetland impacts. Wetland-4 (0.24 acre) is a manmade stormwater pond that receives surface water off of Ferguson Lane and collects groundwater. This is the only wetland that is comprised of woody vegetation (primarily willows). Tree-sized crack willows (Salix fragilis) occur adjacent to the stormwater pond and outside of the wetland boundary. Wetland- 5 (0.08 acre) is the only isolated wetland within the project site and is located in a small depression; this wetland has been determined as non-jurisdictional by the COE (Appendix B). Wetland determination data forms are included in the full delineation report. All wetlands are slight variations of palustrine emergent (PEM) wetlands (Cowardin et al. 1979); functional assessments are included in the full delineation report. Two wetlands include a riverine (R), perennial (P), unconsolidated bottom (UB) (WL-1 and 2: R/P/UB/PEM). No federally-listed threatened or endangered species are known to occur within the project site (MNHP 2013; see Appendix F in delineation report). Wetlands-1, 2, and 6 are rated as Category III wetlands (Tables 4.1 and 4.2). Wetlands-3, 4 and 5 are Category IV wetlands. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 7 Pre-mitigation project-wide functional units (FU) total 49.1. Wetland-6 comprises 44.64 (93%) of the total functional units as a result of the large acreage (12.4 acres). In general, wetland function throughout the property is very low primarily because of low vegetation diversity. 4.1.2. Nonwetland Waterways Two nonwetland waterways or 3,819 linear feet occur within the Flanders Mill project site. Both nonwetland waterways are perennial streams. Two other drain ditches within the project site do not have a scoured bed or bank and are 100% vegetated with hydrophytic species. As a result of these characteristics, these features are included within wetland-6 acreage per advice provided by the COE (C. Juhas 2013). 4.1.3 Hydrologic Characteristics The UT Baxter (NWW-1) provides a perennial source of water to the project site and the stormwater wetland (4) provides an intermittent water source. Groundwater is high in the central portion of the project area as well as along the current UT Baxter alignment. As a result of the Baxter-Border stream location within the Baxter Lane borrow ditch, hydrology from this system likely has very little effect on project hydrology. A drain structure that outlets to the Baxter-Border collects ground water from agricultural fields south of Baxter Lane and its borrow ditch location. It is unknown how far this structure extends to the south. The drain structure will be removed during project construction. It is presumed water once collected by the drain structure will naturally collect within the realigned UT Baxter channel. Groundwater monitoring wells have been installed in the proposed locations of the pond, lake and along the northern reach of the new stream alignment to provide data to project hydrologists (WGM). Table 4.2. Flanders Mill Pre-Mitigation Wetland Function/Value Ratings and Functional Points1, June, 2013. Function and Value Parameters Wetland-1 Wetland-2 Wetland-3 Wetland-4 Wetland-5 Wetland-6 Listed/Proposed T&E Species Habitat Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) MT Natural Heritage Program Species Habitat Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) General Wildlife Habitat Low (0.2) Low (0.2) Low (0.2) Mod (0.5) Low (0.1) Mod (0.5) General Fish/Aquatic Habitat Mod (0.4) Mod (0.4) NA NA NA NA Flood Attenuation Low (0.1) Low (0.1) NA NA NA NA Short and Long Term Surface Water Storage High (0.8) Mod (0.4) Low (0.3) Low (0.3) Low (0.1) Mod (0.5) Sediment/Nutrient/Toxicant Removal Mod (0.7) High (0.9) High (0.9) High (1.0) High (0.8) High (0.9) Sediment/Shoreline Stabilization Low (0.3) High (1.0) NA NA NA NA Production Export/Food Chain Support Mod (0.6) Mod (0.6) Low (0.3) Low (0.3) Low (0.2) High (0.9) Groundwater Discharge/Recharge High (1.0) High (1.0) Mod (0.7) Mod (0.7) Mod (0.4) Mod (0.7) Uniqueness Low (0.1) Low (0.1) Low (0.1) Low (0.1) Low (0.1) Low (0.1) Recreation/Education Potential (Bonus) NA NA NA NA NA NA Actual Points / Possible Points 4.2 4.7 2.5 2.9 1.7 3.6 % of Possible Score Achieved 38% 43% 32% 36% 21% 45% CATEGORY2 III III IV IV IV III Total Acreage 0.723 0.093 0.07 0.24 0.08 12.40 Functional Units (acreage x actual points) 3.02 0.42 0.18 0.70 0.14 44.64 TOTAL FUNCTIONAL UNITS 49.10 1 MDT Montana Wetland Assessment Method (Berglund and McEldowney 2008); completed forms are included in delineation report, Appendix E. 2 A Category I wetland has the highest function and value parameters and a Category IV has the lowest. 3 Includes streambed area; NWW: 1-0.25 acre and NWW-2: 0.02 acre. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 8 4.1.4 Soil Characteristics Hydric soils were mapped by the NRCS within a majority of the proposed stream realignment area; Blossburg Loam (542A) is the primary mapped hydric soil (SURGO 2013). However hydric soils were not observed at the microscale level during the delineation in areas not classified as wetlands and which are currently planted with agricultural crops. Hydric soils at delineation sample points were also observed in areas that were classified as nonwetland because of insufficient hydrology pre- or post-irrigation influences. 4.1.5 Existing Vegetation Currently wetland-6 is the most diverse wetland in areas of 0 to 12-inch perennial saturation or inundation. These wetter areas include American wild mint (Mentha arvense, FACW), beaked and Nebraska sedge (Carex utriculata and C. nebrascensis, respectively, OBL), hard-stem club-rush (Schoenoplectus acutus, OBL), American-brooklime (Veronica americana, OBL), broad-leaf cat-tail (Typha latifolia, OBL), fringed willowherb (Epilobium ciliatum, FACW), and arctic (Baltic) rush (Juncus arcticus). Invasive agricultural species typically observed in hay meadows and grazing lands, including field meadow-foxtail (Alopecurus pratensis, FAC) and smooth brome (Bromus inermis, FAC) have encroached into the edges of these saturated communities and are also dominant in non- wetland areas. 4.1.6 Existing Wildlife Usage Wildlife observed within the project boundary during the delineation include mule and white-tailed deer (Odocoileus virginianus and O. hemionus), mallard (Anas platyrhynchos), red-tailed hawk (Buteo jamaicensis), Swainson’s hawk (Buteo swainsoni), and sandhill crane (Grus canadensis). A detailed wildlife survey was not conducted in 2013. 4.1.7 Historic and Current Land Use The property has been managed for hayland production and cattle grazing for many years. Alfalfa (Medicago sativa) is currently planted in the northern and southern thirds of the property and is actively irrigated each year. Cattle grazing was conducted most years in the middle third of the property where a majority of the wetlands occur. The hayland grass species Alopecurus comprises the majority of the middle portion of the project site. There is a mitigation site south of the NorthWestern Energy substation easement and includes the stream reach within the easement boundary (Corps File No. 200590029). The mitigation site has no restrictive covenants. The intent of the mitigation plan was to enhance the wetland adjacent to the stream corridor and rehabilitate the streambed. Sinuosity of this stream reach south of the substation was increased and woody plants were installed along the stream, however mortality was high and less than five plants survive. The stream reach included in that mitigation work will be maintained as a wetland, however the bed will be filled to the level of the surrounding wetland to decrease hazard issues. Flood irrigation and wheel-line irrigation have been used on the property for many decades. Because of these practices field meadow-foxtail has proliferated throughout the project area, in wetland and nonwetland areas. In areas that were determined to be nonwetland the hydrology was insufficient to support the development of hydric soils and/or hydrologic indicators were absent for periods long enough to justify classifying the area as wetland. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 9 5.0 DETERMINATION OF CREDITS 5.1 Wetland Mitigation Ratios (On-site) Mitigation for loss of wetlands will include: on- and off-site wetland creation and on-site enhancement, restoration (re-establishment and rehabilitation), preservation, and creation of upland buffer along the stream/wetland floodplain corridor (Table 5.1.A). The wetland and stream mitigation map is included in Appendix C. Mitigation construction will be completed prior to filling any wetland with the exception of culvert and some foot bridge installations to avoid future wetland and stream disturbance. Wetland credits not met (i.e. “Loss” in Table 5.1.A) with on-site mitigation will be met by supplementing with off-site credits at the Knoll project site, which was completed in 2013 (see Section 5.3). Pre-construction (prior to any wetland fill) mitigation ratios will be requested: • creation, 1:1; • restoration (re-establishment), 1:1; • restoration (rehabilitation), 1.5:1; • enhancement, 3:1 (by planting wetland trees and shrubs); • preservation, 5:1; and, • upland buffer, 4:1. One shallow pond (<6 feet) and one deep “lake” (<2.1 deep water surface acre) will be created to enhance public parkland and mitigate for wetland loss. The lake will be the byproduct of gravel removal. The entire shallow pond will occur in upland areas; wetland creation credits will be applied to this feature. The fringe wetland and a 6-foot wide area of shallow water (<1 foot deep) around the lake will be comprised of current wetland (enhancement category) and upland (creation). All non- impacted wetland areas will qualify as enhancement mitigation as a result of extensive woody species plantings. Wetland restoration (re-establishment) of an upland willow shrub community on the north end of the project site will be accomplished by realigning the UT Baxter through the community. Restoration (rehabilitation) credit will occur in areas where the channel will be relocated within a current trench system. Preservation credit is proposed for wetland-4, a very diverse stormwater pond (Exhibit B, Appendix C). The wetland includes shrub and emergent species, and very large crack willows grow in uplands immediately adjacent to the wetland. Raptors use the trees for hunting and home range perches, and sandhill crane nest every year in the shallow area of the wetland. 5.2 Off-site Wetland Mitigation As a result of the Flanders Mill estimated 0.23 acre unmitigated (on-site) wetland loss (Table 5.1.A), the deficit will be balanced by off-site mitigation. A stream enhancement and wetland creation project completed in the Knoll project site 0.25 mile northwest of Flanders Mill will provide the acreage needed to balance wetland impacts. The Knoll site will be delineated each year until it is determined that acreage exceeding that project’s pre-mitigation acreage has been exceeded by at least 0.23 acre. If wetland mitigation acreage in excess of 0.23 acre is needed to meet Flanders Mill wetland loss, we will use all excess mitigation acreage generated at the Knoll project site for compensation. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 10 Creation Restoration (Re-establishment) Restoration (Rehabilitation)Enhancement Preservation Upland Buffer Wetland-1 0.47 0.35 2.26 JD 2.02 0.11 0.59 0.40 6.96 Wetland-2 0.07 0.07 0.03 JD 0.03 0.35 Wetland-3 0.07 0.07 0.00 JD Wetland-4 0.24 0.01 0.23 JD 0.23 Wetland-54 0.08 (0.08)0.00 NJ Wetland-6 12.40 6.97 5.53 JD 0.10 4.17 0.02 1.13 Pond 0 0.97 (JD)0.97 0.65 Lake 0 0.31 (JD)0.31 0.19 UPL Willow3 0 0.27 (JD)0.27 0.02 TOTAL ACRES 13.33 7.47 9.60 3.44 0.38 0.59 4.57 0.25 9.30 1:1 1:1 1.5:1 3:1 4:1 5:1 3.44 0.38 0.39 1.52 0.06 1.45 Nonwetland Pre-Mitigation Debit2 Created Post-Mitigation Waterway (LF1)(LF)(LF) NWW-1 3411 2744 5185 NWW-2 408 408 324 Total Linear Feet 3819 3152 5509 CREDIT4 1. LF: Linear Feet 2. Debit = Streambed LF Impact 3. Cedit (Streambed LF Created) = Total Post-mitigation construction LF - Total Debit LF 4. Stream debit has been exceeded if number is positive. 4. Non-jurisdictional acreage not included in total impact. Table 5.1.B. FLANDERS MILL PROPOSED STREAM IMPACT AND MITIGATION (On-Site) 7.24 RATIO DIVISION MITIGATION CREDITS TOTAL MITIGATION CREDITS +2357 LF Table 5.1.A FLANDERS MILL PROPOSED WETLAND IMPACT AND MITIGATION (On-Site) NET GAIN (+) or LOSS (-) 1. Pre- and Post-Mitigation: acreage prior or after (respectively) to mitigation construction 2. JD: Jurisdictional; NJ: Nonjurisdictional 3. Upland willow community; acreage included in W-1 acreage for functional assessment. -0.23 Wetland Pre-Mitigation Acreage1 Impact Acreage Jurisdictional Status1 Goal Mitigation Acreage Post-Mitigation Acreage1 Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 11 5.3 Montana Stream Mitigation Procedure The project developers are proposing to relocate the perennial UT Baxter Creek to its likely original location based on NRCS mapped hydric soils (SURGO 2013) and topographic characteristics of the property (Table 5.1.B). The Baxter-Border stream will also be moved to satisfy a City of Bozeman request to eliminate traffic hazards; the stream is currently located in the Baxter lane borrow ditch. We are proposing to move the stream 30 feet south of its current position. The project has been presented to the Gallatin County Conservation District and they are amenable to allowing these permit applications to be addressed by the Board. The Montana Stream Mitigation Procedure was used to determine stream credits and debits (Appendix D). Total project channel linear feet (LF) debit is 3,152 LF, total LF credit is 5,509 LF for a 75% increase (Table 5.1.B). Total project debit using the Montana Stream Mitigation Procedure is 21,591; total credits are 652,533, a very large gain. 5.3 Wetland and Stream Functional Increase As a result of mitigation efforts within the Flanders Mill project site, there will be an estimated 46% increase in wetland function within the project site, as well as stormwater management, vegetation diversity and complexity, and wildlife diversity (e.g. avian and small mammal) (Table 5.2). Table 5.2. Flanders Mill Estimated Post-Mitigation Wetland Function/Value Ratings and Functional Points1, February, 2014. Function and Value Parameters Wetland-1 Wetland-2 Wetland-4 Wetland-6 Pond Lake Listed/Proposed T&E Species Habitat Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) MT Natural Heritage Program Species Habitat Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) Low (0.0) General Wildlife Habitat Mod (0.7) Low (0.2) Mod (0.5) Mod (0.7) Mod (0.7) Mod (0.7) General Fish/Aquatic Habitat High (0.8) Mod (0.4) NA NA NA NA Flood Attenuation High (0.9) Low (0.1) NA NA NA NA Short and Long Term Surface Water Storage High (0.9) Mod (0.4) Low (0.3) Mod (0.5) High (0.8) Mod (0.5) Sediment/Nutrient/Toxicant Removal High (0.9) High (0.9) High (1.0) High (1.0) High (1.0) High (1.0) Sediment/Shoreline Stabilization High (1.0) High (1.0) NA Mod (0.6) High (1.0) Mod (0.6) Production Export/Food Chain Support High (0.8) Mod (0.6) Low (0.3) High (0.9) Mod (0.7) High (0.9) Groundwater Discharge/Recharge High (1.0) High (1.0) Mod (0.7) Mod (0.7) High (1.0) Mod (0.7) Uniqueness Low (0.3) Low (0.1) Low (0.1) Mod (0.5) Mod (0.5) Mod (0.5) Recreation/Education Potential (Bonus) High (0.2) NA High (0.2) High (0.2) High (0.2) Low (0.2) Actual Points / Possible Points 7.5 4.7 3.1 5.1 5.9 6.3 % of Possible Score Achieved 68% 43% 36% 57% 66% 70% CATEGORY2 II III IV III II II Total Acreage3 2.894 0.065 0.23 5.35 0.97 2.556 Functional Units4 (acreage x actual points) 21.68 0.28 0.71 27.29 5.72 16.07 TOTAL FUNCTIONAL UNITS 71.75 1 MDT Montana Wetland Assessment Method (Berglund and McEldowney 2008); completed forms are included in delineation report, Appendix F. DARK BLUE indicates an increase over pre-mitigation number or rating; LIGHT BLUE indicates an increase resulting from a new wetland or water resource feature; no color indicates no change; and, ORANGE indicates a decrease. 2 A Category I wetland has the highest function and value parameters and a Category IV has the lowest. 3 Acreage used to assess wetland function differs from acreage in mitigation Table 5.1.A as a result of calculation methods. Impacts and mitigation acreages are based on precise boundaries of each delineated wetland and do not include surface water areas. Functional assessment acreages within this project are based on the entire wetland and water surface area within the “functional” wetland community. 4 Includes streambed area (0.36 ac-approx. 3 feet wide) and restored willow community (0.27) acreage. 5 Includes streambed area (0.03 ac- approx. 4 feet wide). 6 Includes created and enhanced wetland fringe (0.45 acre) and open water (2.10 acres). Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 12 6.0 MITIGATION WORK PLAN Compensatory mitigation will occur in the following areas: • wetland-1/NWW-1 will be realigned through areas that are currently wetland and nonwetland; • hydrology will be restored (re-established) to a nonwetland willow community by constructing a reach of the stream through the community; • an area of wetland-6 that appears to have been part of the historic stream alignment will be restored (rehabilitated) by constructing a reach of the realigned stream through the current wetland; • all wetland areas not impacted by the proposed development will be enhanced with woody species plantings; • a fringe wetland will be constructed around the circumference of a gravel pit (“lake”) located in upland and current wetland areas; • a shallow wetland pond will be constructed in a nonwetland area; and, • wetland-2/NWW-2 will be realigned to meet a City of Bozeman request to remove stream from borrow ditch. 6.1. Stream and Wetland Corridor Construction City of Bozeman Unified Development Ordinance requires that a 50-foot wide watercourse setback be established along all perennial streams and jurisdictional wetlands. The setbacks are extended by the width of adjacent wetlands along a watercourse. The setbacks and nonwetland streambank will be seeded with a parkland upland seed mix comprised of fescue, bluegrass and wheatgrass species (Table F.1). Wetland seed species (Table F.1), wetland channel corridor and enhancement area shrub and tree species (Tables F.1 and F.2), woody species quantities in each stream reach (Table F.3a) and planting enhancement zone (Table F.3b), channel corridor cross-section and schematic diagrams (Figures F.1a and F.1b), and channel reach and enhancement zone schematics (Figures F.2a and F.2b) are included in Appendix F. Shrub and tree species acceptable in Bozeman city parks will be planted in the upland buffer (species not included in this report). Work will commence during summer 2014 and be completed by December 31, 2014. No wetland impacts will occur prior to completion of wetland mitigation construction and planting. Stream and wetland reconstruction will involve stripping and salvaging sod within the 30-foot wetland/stream corridor. The floodplain and stream will be excavated and shaped, and salvaged sod will be placed to meet final grade. Culverts will be installed at the time of stream realignments to avoid future stream disturbance. Any temporary impacts (e.g. fill needed to mobilize equipment through the site) will be removed prior to completion of mitigation construction. 6.1.1 UT Baxter Creek (WL-1/NWW-1) Wetland mitigation areas associated with the UT Baxter Creek will be connected to the Baxter-Border Stream (WL-2/NWW-2), a jurisdictional waterway. The realigned stream channel will meander within a 30-foot wetland floodplain corridor that will be planted with riparian trees and shrubs. Along most of the corridor there will be a 50-foot upland setback; some areas may be narrowed as a result of street crossings and there may be no “upland” buffer in areas where current wetlands directly abut proposed building lots. Total protected area from stream centerline will therefore average 65 feet or more. Upland buffer credit will be requested for these UDO setbacks within the 25% rule guidelines (upland buffer cannot comprise more than 25% of the total mitigation credits requested). Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 13 Salvaged wetland sod from areas of proposed wetland impact will be used to construct the wetland floodplain along the realigned UT Baxter (Plan/profile, Appendix G). The wetland floodplain along NWW-1 will typically have a nearly flat slope (>10:1). The upland buffer along the stream corridor will have a slope in the range of 4:1 to 3:1. Only sod with a dominance of sedge, rush, or bulrush species will be salvaged. When these sod resources are depleted, any remaining wetland creation areas will be seeded with a wetland seed mix (Appendix F). Containerized wetland shrubs will be planted within the wetland floodplain corridor and all other areas of enhanced wetland (wetland-6) that will not be impacted. Trees species less tolerant of saturated conditions (e.g. aspen and cottonwood) will be planted along the wetland/upland boundary. At this time we are proposing to plant 1,056 containerized woody species of which 96% are hydrophytic species (4% are chokecherry). 6.1.2 Baxter-Border Stream (WL-2/NWW-2) The realigned Baxter-Border stream channel will meander slightly within a seven to 10-foot wetland/streambed corridor (current corridor is approximately 5 feet wide). The wetland floodplain will be seeded with hydrophytic species and approximately 56 shrubs and trees will be planted within the corridor and the base of the upland bank. The Baxter-Border stream watercourse buffer will be limited to 12 feet on each side of the stream corridor because of limited space in the area of realignment. The bank slope will be in the range of 3:1-2:1 because of limited space issues; current slope is 1:1. 6.2 Pond Construction Construction of the wetland fringe around the gravel-extraction pit (“lake”) and the shallow wetland pond will occur at the end of the construction season and after the streams have been realigned. The outer edge of the gravel pit will be sloped in the range of approximately 8:1 to 10:1 to allow soil saturation within 12 inches of the soil surface for several weeks of the growing season. Slopes will increase to approximately 3:1 to a distance safe for recreational use and steepen thereafter to the bottom of the pit. No fish stocking is planned for this feature. Maximum lake depth is anticipated to be 15 feet. The shallow wetland pond will be less than six feet deep and will be sourced by groundwater and limited storm runoff. The feature will provide avian habitat and the public will be encouraged to use this area for bird watching. The lake fringe and wetland pond will be constructed using salvaged sod comprised of hard-stem club- rush (old name: bulrush), American-brooklime, cat-tail, and spike rush. When sources are depleted, the wetlands will be seeded using the wetland seed mix. In addition to wetland shrubs and trees, nonwetland, wildlife friendly species (e.g. chokecherry) will be planted around these features. Upland buffers (50-foot wide) will also be placed around the lake and pond unless they border current wetland areas. 6.3 Maintenance Plan The realigned streams and wetland floodplain corridors will be self-maintained because of the perennial source of groundwater which sustains these systems. The pond and all wetlands along the west side of the project site will continue to be hydrologically supported by groundwater from the Flanders Mill borrow ditch. The pond may be connected to the lake by an overflow swale less than 4 Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 14 feet wide. An overflow feature will likely be incorporated into the lake design to allow any excess stormwater to enter the realigned UT Baxter channel (NWW-1). The existing channel around the circumference of the substation will remain in place and continue to collect groundwater; associated wetlands north of the substation will persist and support shrub and tree plantings. 7.0 PERFORMANCE STANDARDS AND MITIGATION MONITORING Mitigation monitoring will be conducted for five years post-construction. Upon completion of mitigation construction, transects and photo points will be established and a construction completion report will be filed with the COE by February 28 of the following year. This report will illustrate transect and photo point locations and include number and species of woody plantings, final seed mix contents, and a plan view of areas that were vegetated with wetland sod and seed. 7.1 Performance Standards and Criteria For each performance standard there are criteria that must be met by year five post-mitigation construction (Table 7.1). Intermediate criteria have also been established to insure final criteria have been met. Belt transects will assess percent cover of defined community types within a 10-foot wide belt established perpendicular to the stream/wetland corridor and extending into adjacent upland buffer. COE data points will be established in wetland and upland areas. Several transects will be established along the stream/wetland corridors (4 to 6), in the lake wetland fringe (2), the wetland pond (1), and in the restored wetland (re-established) willow community (currently qualifies as upland). Enhancement wetland areas will be monitored for woody species survival. 7.2 Reporting Frequency Mitigation monitoring reports will be submitted to the COE by February 28 of the year following the monitoring event. 7.3 Adaptive Management Plan In the event that on-site and off-site wetland mitigation criteria are not met by year-5 post-construction, we will enter negotiations with the property owner to determine direction. The mitigation areas will require reconstruction or wetland credit will be purchased from an in-lieu fee program. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 15 Table 7.1. Flanders Mill Mitigation On-Site and Off-Site Performance Standards and Criteria (2015-2019) Method Areas Timing Criteria Potential Contingency Plans Flanders Mill On-Site Mitigation Delineation All creation and restored (re-established) wetland areas; enhancement and preservation wetland areas will not be delineated. Note: Regarding the wetland fringe around the lake, only the creation area will be delineated; the enhancement zone will not require delineation. Years 2 and 4 (2016 and 2018, resp.). Any areas not meeting wetland acreage in former years will be redelineated in 2015. During Years 1 and 3 wetland boundaries will be reviewed in the field to check wetland development progress. Year-5: creation and restored (re-established) wetland areas must meet positive hydrology and vegetation criteria. Investigate potential to increase water flow into the project site; Adjust topography to increase saturation; Reseed or sod area to meet hydrophytic vegetation criteria; No action will be taken if hydric soils have not developed by Year-5. Belt Transects Plant Cover Belt transects will be established and assessed in the following areas: - WL-1/NWW-1 corridor; - WL-2/NWW-2 corridor; - Restored willow community; - Lake fringe creation zone; and - Wetland pond All years Plant Cover Years – 2-3: 70% plant cover for all seeded and sodded areas, including upland buffer areas. Year-4/5: 95% plant cover Year 5: 75% woody species survival rate Reseed areas of insufficient hydrophytic emergent/grass species; reseed upland buffer when cover is insufficient. Replant woody species if mortality is >25%. COE Data Points An upland and wetland data point will be established along all belt transects. All Years Years – 2-5: Positive hydrology and vegetation criteria must be met; positive hydric soil criteria not necessary Investigate potential to increase water flow into the project site; Adjust topography to increase saturation; Reseed or sod area to meet hydrophytic vegetation criteria; No action will be taken if hydric soils have not developed by Year-5. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 16 Method Areas Timing Criteria Potential Contingency Plans Photopoints Four directional photos at each belt transect. All Years All Years: photos must illustrate vegetation maturation wetland mitigation and buffer. Reseed areas of insufficient hydrophytic emergent/grass species; reseed upland buffer when cover is insufficient. Replant woody species if mortality is >25%. The Knoll Off-Site Wetland Mitigation Delineation Knoll stream enhancement and wetland creation site Every Year until created wetland acreage results in >0.23 acre or whatever excess acreage may be needed to compensate for loss at the Flanders Mill on-site mitigation site Wetland area must meet positive hydrology and vegetation criteria. Reseed areas of insufficient hydrophytic emergent/grass species; reseed upland buffer when cover is insufficient. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 17 8.0 REFERENCES Berglund, J. and R. McEldowney. 2008. MDT Montana Wetland Assessment Method. Prepared for Montana Department of Transportation, Helena, Montana. Post, Buckley, Schuh, & Jernigan, Helena, Montana. 42pp. Brinson, M, R. D. Rheinhardt, F. R. Hauer, L. C. Lee, W. L. Nutter, R. D. Smith, and D. Whigham. 1995. The Guidebook for Application of Hydrogeomorphic Assessments to Riverine Wetlands. Wetlands Research Program Technical Report WRP-DE-11. U.S. Army Corps of Engineers Waterways Experiment Station, Vicksburg, MS. Consortium of Pacific Northwest Herbaria. 2013. University of Washington Herbarium, Burke Museum Burke Natural History and Culture, University of Washington, Seattle, Washington: Montana State University Herbaria (MONT). Site accessed June 2013: http://www.pnwherbaria.org/data/search.php Cowardin, L., V. Carter, F. Golet, and E. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. FWS/OBS-79/31. USDI Fish and Wildlife Service. Washington, D.C. Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1. Vicksburg, MS: U.S. Army Engineer Waterways Experiment Station. Site accessed December 2012: http://el.erdc.usace.army.mil/wetlands/pdfs/wlman87.pdf. Environmental Protection Agency and U.S. Army Corps of Engineers (EPA and USACE). 2007a. Clean Water Act Jurisdiction following the U.S. Supreme Court's decision in Rapanos v. United States & Carabell v. United States. Issued June 5th. Washington, D.C. Environmental Protection Agency and U.S. Army Corps of Engineers (EPA and USACE). 2007b. Memorandum for Director of Civil Works and U.S. EPA Regional Administrators. Washington, D.C. Juhas, C. 2013. USACE Project Manager, Personal telephone communication, June, 2013. Lesica, P. 2012. Manual of Montana Vascular Plants. B. Lipscomb (ed.), Botanical Research Institute of Texas, Fort Worth, Texas. Lichvar, R. W. 2012. National Wetland Plant List. Western Mountains, Valleys, and Coast 2012 Final Regional Wetland Plant List. ERDC/CRREL TR-12-11. Hanover, NH: U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory. Lichvar, R. W., N. C. Melvin, M. L. Butterwick, and W. N. Kirchner. 2012. National Wetland Plant List Indicator Rating Definitions. ERDC/CRREL TN-12-1. Hanover, NH: U.S. Army Corps of Engineers, Engineer Research and Development Center, July 2012. Montana Natural Heritage Program. 2013. Montana Species of Concern, Flanders Mill Project Site. Montana State Library Natural Resource Information System, University of Montana, Helena, Montana. Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 18 Smith, R.D., A. Ammann, C. Bartoldus, and M.M. Brinson. 1995. An Approach For Assessing Wetland Functions Using Hydrogeomorphic Classification, Reference Wetlands, and Functional Indices. Wetland Research Program Technical Report WRP-DE-9. U.S. Army Corps of Engineers Waterways Experiment Station. Vicksburg MS. State Engineers Office. 1953. Water Resources Survey, Part II: Maps Showing Irrigated Areas in Colors Designating the Sources of Supply. Helena, Montana. U.S. Army Corps of Engineers (USACE). 1990. Regulatory Guidance Letter, 90-07. Clarification of the Phrase “Normal Circumstances” as it Pertains to Cropped Wetlands. September 26, 1990: http://www.usace.army.mil/Portals/2/docs/civilworks/RGLS/rgl90-07.pdf U.S. Army Corps of Engineers (USACE). 1995. Wetlands Delineation Manual, Part III: Characteristics and Indicators of Hydrophytic Vegetation, Hydric Soils, and Wetland Hydrology: Hydric Soils. Environmental technical Services Co., Austin, Texas. U.S. Army Corps of Engineers (USACE). 2005. Technical Standard for Water-Table Monitoring of Potential Wetland Sites. ERDC TN-WRAP-0502. June 2005. U.S. Army Corps of Engineers (USACE). 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0), ed. J.S. Wakely, R. W. Lichvar, and C. V. Noble. ERDC/EL TR-10-3. Vicksburg, MS: U.S. Army Engineer Research and Development Center. U.S. Army Corps of Engineers (USACE). 2013. Wetland Jurisdictional Determination (Flanders Mill). Letter from Helena Regulatory Branch, Todd Tillinger. U.S. Department of Agriculture (USDA). 2006. Natural Resources Conservation Service Field Indicators of Hydric Soils in the United States, A Guide for Identifying and Delineating Hydric Soils, Version 6.0. U.S. Department of Agriculture (USDA). 2011. Natural Resources Conservation Service Wetland Identification No. 1 Normal Circumstances: Wetland Identification Challenges Associated with Disturbance/Atypical Situations. U.S. Department of Agriculture (USDA). 2013a. Natural Resources Conservation Service Climate Information – Wetlands Retrieval for Montana, Gallatin County, WETS Station : Bozeman Montana ST UNIV, MT1044. Site accessed June, 2013: http://www.wcc.nrcs.usda.gov/ftpref/support/climate/wetlands/mt/30031.txt U.S. Department of Agriculture (USDA). 2013b. Natural Resources Conservation Service Soil Survey Geographic (SSURGO) Database for Gallatin County Area, Montana. Site accessed May, 2013: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx . U.S. Fish and Wildlife Service (USFWS). 2013. National Wetlands Inventory: Montana. ESRI Shape, NAD83, Projection Albers Equal-Area. Site last updated May 22, 2013. Site accessed July 2013: http://www.fws.gov/wetlands/Data/Mapper.html . Flanders Mill Wetland and Stream Mitigation Proposal March 24, 2014 19 Western Regional Climate Center (WRCC). 2013. Bozeman Montana ST UNIV, Montana Station (241044), 1892-2013. Site accessed: June 26, 2013, http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?mt1044 . 1 APPENDIX A __________________________________________________________________ Wetland and Nonwetland Waterway (Pre-Mitigation) Delineation Map: Exhibit A __________________________________________________________________ APPENDIX B __________________________________________________________________ COE Jurisdictional Determination Letter __________________________________________________________________ APPENDIX C __________________________________________________________________ Flanders Mill Wetland and Stream Mitigation Map: Exhibit B __________________________________________________________________ To review mitigation in detail, please select the following hyperlink: FINAL FLANDERS MILL SUBMITTAL\Flanders Mill WL_Stream Mitigation Map.pdf APPENDIX D __________________________________________________________________ Montana Stream Mitigation Procedure __________________________________________________________________ Table I-c. Debits Worksheet Factor Impact NWW-1 Impact NWW-2 Impact Area 3 Impact Area 4 Impact Area 5 Impact Area 6 Stream Type*0.60 0.60 0.00 0.00 0.00 0.00 Stream Status 0.25 0.25 0.00 0.00 0.00 0.00 Existing Condition 0.25 0.25 0.00 0.00 0.00 0.00 Dominant Impact 2.50 2.50 0.00 0.00 0.00 0.00 Cumulative Impact^ Location of Mitigation 0.00 0.00 0.00 0.00 0.00 0.00 Comparative Stream Order of Mitigation Site 0.00 0.00 0.00 0.00 0.00 0.00 Type of Legal Protection for Mitigation Site 0.10 0.10 0.00 0.00 0.00 0.00 Sum of Factors (SFi)6.85 6.85 0.00 0.00 0.00 0.00 Linear Feet Impact* (LFi)2,744.00 408.00 0.00 0.00 0.00 0.00Mitigation Timing 1.00 1.00 0.00 0.00 0.00 0.00 SFi X LFi X Mitigation Timing 18796.00 2795.00 0.00 0.00 0.00 0.00 21,591.00 *For bank stabilization projects, impacts include the entire length of the bank being protected not just the footprint of the structure or revetment. Total Debits = Σ (SFi X LFi X Mitigation Timing) = 3.15 Table 2-b. Stream and Riparian Credit Factors Worksheet FACTORS NWW-1^ /East Side NWW-1^ /West Side NWW-2^^ /South Side NWW-2^^ /North Side a Buffer Width 0.63 0.63 0.17 0.25 b Remove Disturbance to Riparian Buffer*0.50 0.50 0.50 0.50 c Fence around Buffer 0.00 0.00 0.00 0.00 d Re-vegetate Riparian Buffer 100.00 100.00 100.00 100.00 e Micro Topography in Floodplain 0.00 0.00 0.00 0.00 f Addition of Woody Debris in Floodplain 0.00 0.00 0.00 0.00 g Management of Invasive Species 0.50 0.50 0.50 0.50 h Removal of Riprap below ordinary High Water 0.00 0.00 0.00 0.00 i Removal of Floodplain Fill (Berms or Impervious Materials)0.00 0.00 0.00 0.00 j Restoration of Channel Morphology 1.00 1.00 0.50 0.50 X Addition of water leases 1.00 1.00 1.00 1.00 Total Sum of Factors (SFm) a-j and X 103.63 103.63 102.67 102.75 Linear Feet Impact* (LFm)2,744.00 2,744.00 408.00 408.00 SFm x LFm 284360.72 284360.72 41889.36 41922.00 p Reach 3 Reach 3 Reach 4 Reach 4 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 10 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 10 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 0 00 Total Riparian Credits = Σ (SFm x LFm x RM) = 652,532.80 *Grazing and haying removed ^^North side no upland buffer, too close to Baxter lane. South side there is some buffer area available. ^Stream average 4 ft width, 13 feet of wetland, 50 feet of upland buffer=83 feet each side Project Name: Flanders Mill Corps #NWO-2013-01559-MTB Debits Linear Ft A 21,591.00 3,152.00 Credit Linear Ft B 652,532.80 5,509.00 =Stream and Riparian Credits Excess Credits 630,941.80 Table 3. Mitigation Summary Worksheet Total Debits = Stream and Riparian Debits Total Credits TRUE Proposed Stream and Riparian Credits > Debits (B> A) APPENDIX E __________________________________________________________________ Flanders Mill Post-Mitigation Functional Assessments __________________________________________________________________ APPENDIX F __________________________________________________________________ Mitigation Seed Mixes and Plant Lists __________________________________________________________________ Table F.1 Flanders Mill Mitigation Herbaceous, Shrub and Tree Species Plant Lifeform Upland Bank and Buffer1 Wetland1 Herbaceous Species (SEED) Durar Hard Fescue (Festuca breviplia [trachypylla], FACU) VNS Tufted Hairgrass (Deschampsia caespitosa, FACW) Turf Type hard Fescue Sodar streambank wheatgrass [streamside wild rye] (Elymus lanceolatus, FACU) Flat-stem Blue Grass (Poa compressa, FACU) Revenue slender wheatgrass [slender wild rye] (Elymus trachycaulus, FAC) Sheep Fescue (Festuca ovina, UPL) VNS Fowl Bluegrass (Poa palustris, FAC) Fowl Mannagrass (Glyceria striata, OBL) Tyndall Spring Triticale (Triticale sp,) Shrub Species (CONTAINERIZED) Choke Cherry (Prunus virginiana, FACU) Red-osier dogwood (Cornus sericea [alba], FACW) Alder (Alnus sp., not determined at this time, FACW) Peach-Leaf Willow (Salix amygdaloides, FACW) Bebb [Gray] Willow (Salix bebbiana, FACW) Yellow Willow (Salix lutea, OBL) Choke Cherry (FACU) Tree Species (CONTAINERIZED) Quaking Aspen (Populus tremuloides, FACU) 1 Names in [brackets] are from Lichvar, R. W. 2012. Figure F.1a. Typical Cross-section of Stream Wetland Corridor Planting Guide Figure F.1b. UT Baxter and wetland corridor schematic. Table F.2 QUANTITY OF WOODY SPECIES PLANTINGS Species Total Species 1 2 3 4 5 6 Total Species A B C1 C2 C3 D E Aspen 88 12 12 12 18 24 10 16 1 1 3 2 1 5 3 Alder 31 5 5 5 7 10 0 6 0 0 1 1 0 2 1 Cottonwood 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dogwood, Red-Osier 104 16 16 16 24 32 0 21 1 1 4 2 1 7 4 Bebb willow 251 37 37 37 55 74 12 49 2 3 10 5 2 16 10 Booth Willow 251 37 37 37 55 74 12 49 2 3 10 5 2 16 10 Peachleaf Willow 35 5 5 5 7 10 4 6 0 0 1 1 0 2 1 Yellow willow 256 37 37 37 56 76 12 50 2 3 10 5 2 16 10 Chokecherry 42 6 6 6 10 13 0 9 0 1 2 1 0 3 2 TOTAL 1056 154 154 154 232 312 50 212 8 12 43 23 10 72 43 Tables F.3a and b. QUANTITY OF PLANTINGS PER WETLAND STREAM REACH AND WETLAND ENHANCEMENT ZONE F.3a F.3b RATIO %T PLANTS REACH RATIO %T PLANTS ZONE 1 0.154 155 1 UT BAXTER 0.2 0.04 9 A 1 0.154 155 2 0.3 0.06 13 B 1 0.154 155 3 1.0 0.21 45 C1 1.5 0.231 232 4 0.5 0.11 22 C2 2 0.308 310 5 0.3 0.05 11 C3 50 6 BB STREAM 1.5 0.32 67 D 6.5 1 1056 1.0 0.21 45 E 4.8 1.00 212 T PLANTS - TOTAL PLANTS "RATIO" IS A MATHEMATICAL ESTIMATE OF PERCENT EACH AREA REPRESENTS OF THE TOTAL AREA WETLAND ENHANCEMENT ZONE (SEE FIGURE F.2b) 1056 STREAM REACH (SEE FIGURE F.2a) WETLAND ENHANCEMENT ZONE PLANTINGS 212 STREAM WETLAND CORRIDOR REACH PLANTINGS Figure F.2a. Stream Wetland Corridor Reach Planting Quantities Figure F.2b. Wetland Enhancement Zone Planting Quantities APPENDIX G __________________________________________________________________ Realigned Stream and Wetland Corridor Plan/Profile __________________________________________________________________ To review plan/profiles in detail, please select the following hyperlink: FINAL FLANDERS MILL SUBMITTAL\WGM Plan_Profiles Project Plan View: this files will be emailed to the USACE Proejct manager to enable viewing of layers within this pdf. Bank Flow of UT Baxter Creek. Base Flow of UT Baxter Creek. High Flow of UT Baxter Creek. Cross-section of UT Baxter Creek. Baxter-Border Ditch (now refered to as stream) cross section. Cross-section of Substation Drain Ditch (“west side stream”).