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HomeMy WebLinkAboutApp. E. - Wetland Report 09-24-2019 Melissa Pope Community Development 20 East Olive Street PO Box 1230 Bozeman, MT 59771 November 15, 2018 Re: Results of 2018 Wetland Delineation on Phase 5, Norton East Ranch Subdivision Dear Melissa, This submittal was drafted in response to Chris Saunders’ email sent to Matt Hausauer of C&H Engineering on August 22, 2018. His email requested that Norton East Ranch provide an updated wetland delineation of the preservation wetland area within Phase 5 of Norton East Ranch. The wetland delineation was completed between September 14 and October 5, 2018, using methodology developed by the USACE and other federal agencies for implementation of Section 404 of the Clean Water Act. Delineation procedures involved a review of existing site-specific information and completion of an onsite field investigation based on guidelines for the Routine Determination Method presented in the Field Guide for Wetland Delineation and the Regional Supplement to the Corps of Engineers Mountains, Valleys, and Coast Region. Vegetation indicator status for this investigation was derived from the Western Mountains, Valleys, and Coast 2016 Regional Wetland Plant List. Taxonomic references included Dorn 1984, Hitchcock 1971, Lackschewitz 1991, and Lesica and Husby 2001. Eleven test pits were excavated throughout Phase 5 to determine the wetland boundaries based on conformance with the USACE wetland criteria for plants, soil, and hydrology. The wetland data was entered on the eleven Wetland Determination Data Forms included with this submittal. Photographs taken during the 2018 wetland delineation field investigation are also included. The 2018 wetland delineation boundaries and test pit locations are shown on the enclosed Wetland Delineation Exhibit (EX1) provided by C&H Engineering. Included on the exhibit are the original 2006 wetland delineation boundaries showing the 8.64-acre preservation wetland, the 25-foot upland buffer, and the meets and bounds of the area protected by the Covenant of Dedication signed and recorded on April 11, 2008. The preservation of the non-jurisdictional wetland and upland buffer and the drafting of the Covenant of Dedication protecting the wetland in perpetuity were conditions of the original 404 permit for Norton East Ranch. The preservation wetland is still considered non-jurisdictional based on the lack of a permanent downgradient surface water connection or significant nexus to a water of the US. There have been no unapproved impacts to the mitigation wetland since it was created in 2007. The easement for Laurel Glen Parkway across the mitigation wetland was shown in the Covenant of Dedication. A temporary drain ditch was excavated in January 2015 at the north end of the preservation wetland parallel to the north property boundary to prevent surface water from inundating the Lakes Subdivision to the north (see enclosed Photo 8.0 from March 2015). Several permanent solutions have been implemented sitewide to address the flooding issues. The temporary drainage ditch is no longer necessary and will be abandoned. A sub-surface draintile has been installed at the south property boundary, a temporary ditch and culvert excavated between the historic spring box and preservation wetland has been abandoned and filled, and the dewatering activities have ceased. The following paragraphs detail the flooding issues that have occurred sitewide since construction began in 2010. The wetland boundaries of the original preservation wetland expanded west of Laurel Parkway between 2010 and 2014, as shown on the 2018 wetland exhibit. The recent wetland expansion was the result of three temporary and artificial sources of surface water that occurred after Norton East Subdivision construction began in 2010. The historic landowner prior to Kevin Spencer of Norton E Ranch had installed two drain tiles within the parcel to reduce groundwater levels to facilitate hay cultivation. The underground drain tiles were broken during construction in 2010, which resulted in groundwater surfacing from the underground pipe to an historic spring box located near the south property boundary. The spring box had been abandoned and dry until the drain tile was broken. The outflow from the spring box coupled with dewatering activities created flooding sitewide. A ditch was excavated in upland by the contractors from the south boundary to the west edge of the preservation wetland, continuing north to the adjacent property. The excess surface water resulted in flooding on the property to the north, the Lakes at Valley West, which created a pond and channel in uplands that were slated for development. A temporary drainage trench was excavated in 2015 at the northwest edge of the preservation wetland to divert excess surface water on Norton East property to Aajker Creek before it crossed the boundary to Valley West. The drainage ditch excavation was completed after a meeting between the Lakes owner Greg Stratton, Barbara Vaughn, and Todd Tillinger, director of the USACE, in March 2014. The drainage ditch was intended to be a temporary solution to allow the Lakes development to proceed until the draintile system on the Norton property could be installed. The drainage ditch at the north property boundary was dry during July 2018 and will be abandoned permanently. The surface water sources that created the westward expansion of the wetland have been terminated. The ditch excavated from the historic spring box near the south boundary to the preservation wetland and the culvert connection between the ditch and preservation wetland at West Babcock have been abandoned. A draintile system has been installed at Fallon Street near the south property boundary to collect groundwater and divert it offsite to Aajker Creek. The location of the 12- inch draintile installed by March 18, 2017, was shown on the Phase 4 plans. A groundwater model showing the zone of influence was completed by Michael Nicklin to obtain the 404 permit authorization. The October 18, 2016, Nationwide 29 permit authorization (NWO-2007-1084-MTH), for the offsite discharge of groundwater from the draintile to Aajker Creek has already been provided to the City. The wetland area west of the west boundary of the preservation wetland developed between 2010 and 2014 as a result of temporary and artificial sources of surface water. The water sources have been terminated. The expanded wetland area exhibits marginal wetland conditions dominated by field meadow foxtail (Alopecurus pratensis – FAC), reed canary grass (Phalaris arundinacea – FACW), Canadian thistle (Cirsium arvense – FAC), field sow thistle (Sonchus arvensis – FACU), and smooth brome (Bromus inermis – UPL). The supporting wetland hydrology no longer exists and the functional value of the newly developed wetland is low based on the lack of structural and plant diversity and water, and the prevalence of invasive species. There is no value to reusing the field meadow foxtail and reed canary grass sod, which are both aggressive dominant species. Any trees and shrubs planted in the expanded wetland area would not survive without artificial irrigation as a result of the termination of the water source. Please contact my office if you require further information. Sincerely, Barbara Vaughn Environmental Engineer, MS Cc: Kevin Spencer, Norton East Ranch LLC Matt Hausauer, C&H Engineering Enclosures: Wetland Determination Data Forms 2018 Site Photos Wetland Delineation Exhibit – EX1 SITE PHOTOS SEPTEMBER/OCTOBER 2018 WETLAND DELINEATION Photo 1.0 View is looking east toward wetland pit SP-2. Photo 2.0 Photo is of SP-3-UPL, dominated by reed canary grass w/o redox or wet hydrology. Photo 3.0 View is looking north at SP-7-Wet, dominated by meadow foxtail and reed canary grass. Photo 4.0 View is looking southeast toward West Babcock and SP-8, upland test pit. Photo 5.0 View is looking northeast at preservation wetland east of Laurel Parkway. Photo 6.0 Photo is looking west at temporary drainage ditch at north boundary in August 2018. Photo 7.0 View is of temporary drainage ditch looking west in October 2018. The Lakes development discharged groundwater produced from dewatering to the ditch during construction on their property in September 2018. Dewatering activities have been terminated. The ditch was dry in July/August 2018. Photo 8.0 The view is looking southeast at fenced boundary between The Lakes and Norton East Ranch in March 2015. The temporary drainage ditch excavated in January 2015 is shown on right (south) side of fence line. Dried out pond left of fence is on The Lakes property. Drainage ditch was excavated to prevent surface water from flooding adjacent Lakes property. Ditch excavation approved by Todd Tillinger of US Army Corps in March 2014. WETLAND REVIEW REQUIRED MATERIALS: NORTON EAST RANCH SUBDIVISION: Phase 5 KEVIN SPENCER, OWNER; February 23, 2018 APPLICATION SETS: Plan sets that include all required items listed on the wetland checklist listed below. • See enclosed 11x 17 Preliminary Plat Map of Norton East Ranch – Phase 5 STATUTE: Enclosed is information required for all activities proposed in or adjacent to regulated wetland areas as mandated in Section 38.30 of the Bozeman Municipal Code. The boundaries of waters of the US were identified within the Phase 5 Norton East Ranch parcel boundaries on October 13 and 14, 2006 using methodology developed by the US Army Corps of Engineers (USACE) and other federal agencies for implementation of Section 404 of the Clean Water Act. The Individual Permit for Norton East Subdivision impacts was authorized on April 28, 2008. The wetland identified in Phase 5, W-5-05 was classified by the USACE as a non-jurisdictional wetland. Non-jurisdictional Wetland-5-05, encompassing 8.68 acres of depression, palustrine wetland, was preserved as part of the mitigation plan. Covenant of Dedication Number 2299907 recorded on May 14, 2008, by Charlotte Mills of Gallatin County, protects in perpetuity the preservation wetland and the Baxter Creek corridor including 50-foot water course setbacks. The areas associated with the ROWs for Laurel Parkway and West Babcock streets were excluded from protection. The Covenant of Dedication is included with this submittal. APPLICATION FEE: WETLAND REVIEW CHECKLIST: 1. The Pre-Application Plat of Phase 5 Norton East Subdivision shows the boundaries of the preservation wetland including the limits of the ROW associated with Laurel Parkway. The development of Phase 5 will not impact the preservation wetland except for the completion of Laurel Parkway, which was authorized in the April 18, 2008, 404 permit, the Covenant of Dedication, and the Master Plan. Elevated boardwalks will be constructed across the wetland to minimize impacts. 2. Phase 5 development will avoid impacts to the preservation wetland. Trail crossings will be constructed using elevated boardwalks. The Laurel Parkway has been partially constructed as a gravel road. The roadway will be completed as part of Phase 5 development. The parkway was excluded specifically on the Covenant of Dedication. 3. A majority of the original wetland delineation information and boundaries defined for the non-jurisdictional preservation wetland was obtained from the Norton East Ranch Property Wetland Delineation Report drafted by Morrison-Maierle, Inc. Environmental Services Group in October 2006. Morrison-Maierle, Inc. completed the delineation of waterways and wetlands on a 245.6-acre parcel owned by Norton Properties, LLC, on October 13 and 14, 2006. The May 9, 2016, Waters of the US Delineation Report, characterizing the wetland boundaries at the discharge point of a drain tile from the Norton Property to Aajker Creek is included with this submittal (see project history in No.7). The October 18, 2016, permit amendment letter from the USACE authorizing the construction of the discharge pipe is included with this submittal. 4. The site plan shows the delineated wetland boundary for the preserved non- jurisdictional wetland W-5-05, the property boundary, existing and proposed structures, streets and hardscape including sidewalks and pathways, watercourses and drainageways on and within 100 feet of the property. The preserved non-jurisdictional wetland (W-5-05) within the Phase 5 Norton Ranch boundaries will not be directly or indirectly impacted by the proposed activities. No 404 permit will be required. 5. No fill material will be placed into a jurisdictional wetland or waterway as part of the Phase 5 Norton East Ranch development. Elevated boardwalks will be used to minimize impacts to the preserved non-jurisdictional wetland. The footings will be constructed to minimize the affected area. 6. Copies of the original 404 permit and subsequent amendments are enclosed with this submittal. The only water of the US onsite, W-5-05, will not be impacted by the development for the Phase 5 plat submittal except for the completion of Laurel Parkway, which has already been addressed in the Covenant of Dedication. No 310 or 404 permits will be required for development of Phase 5 associated with the proposed pre-application plat submittal. 7. Norton East Ranch Subdivision was originally permitted under Reference Number NWO-2007-1084-MTH, authorized on April 28, 2008. Morrison-Maierle, Inc. Environmental Services Group completed the original delineation of waterways and wetlands on the 245.6-acre parcel owned by Norton Properties, LLC, on October 13 and 14, 2006. The 2008 permit authorized 0.75 acres of impact located within the property boundaries of the Norton Ranch East Subdivision. An additional 0.25 acres of offsite impacts were necessary to provide access to the subdivision through the extension of West Babcock and Fallon streets across the 64-acre parcel owned by Joe Billion. Mitigation for 1.0 acre of wetland impacts was provided by the enhancement and preservation of 8.68 acres of a non-jurisdictional wetland (W-5-05), maintenance of a 25-foot upland buffer (1.92 acres) around the perimeter of a majority of the preservation wetland, and the preservation of 4.0 acres of the Baxter Creek riparian corridor, which includes 50-foot watercourse setbacks. A March 8, 2011, letter from the USACE authorized the extension of the permit deadline to December 1, 2011, to allow for the completion of the tree and shrub installation. A permit amendment authorized October 18, 2016, allowed the installation of a drain tile south of Fallon Street. The drain tile was installed in April 2017 to divert excess groundwater flow from a broken subsurface drain tile that had been installed in the 1970’s to Aajker Creek. Water from the broken drain tile flooded the adjacent Valley West property at the north boundary where the preservation wetland W-5-05 terminated. Before the drain tile was installed in 2017, surface water from the broken drain tile on Norton East accumulated in a pond located on Valley West property. Following a meeting with Todd Tillinger of the USACE, a trench was excavated at the northwest edge of the preservation wetland to divert surface water west from Norton East property to Aajker Creek before it crossed the boundary to Valley West, The drain tile installed at Fallon Street in April 17 currently diverts groundwater to Aajker Creek near the south property boundary and is expected to prevent the overland flow of surface water across the homesites on Norton East and Valley West property.