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HomeMy WebLinkAbout(22) Current Conditions and Proposed Remediation 05-14-2021 document 4515 Valley Commons Drive #201, Bozeman Montana 59718 P: 406.585.4161 F: 406.585.6919 www.bechtlearchitects.com May 14, 2021 Section 22 - Current Conditions and Remediation Bridger Meadows Nieghborhood Development Preliminary Plat Application Preliminary PUD Application Current Conditions and Proposed Site Remediations. The Bridger Meadows Neighborhood project site is bounded by commercial development off Commercial Drive to the south, bounded by residential development off Birdie Drive to the east, bounded by residential development along Boylan Road to the northeast, bounded by Bridger Creek Homeowners Association Park to the north and bounded by Glen Lake Rotary Club Park to the west. The property is legally described as Northwest1/4 of the Southeast1/4 of Section 31, Township1 South, Range 6 East, Principal Meridian, Bozeman, Montana, Gallatin County. Figure 1: Bridger Meadows Site Location). Figure 1: Bridger Meadows project site is bounded by commercial development off Commercial Drive to the south, residential development to the east off Birdie Drive, Boylan Road to the northeast, Bridger Creek Home Owners Association Park to the north and Glen Lake Rotary Park to the west. Bridger Center LLC purchased the property proposed for the Bridger Meadow Neighborhood in August of 2013. Since its purchase, Bridger Center LLC has been working with City officials and private entities to explore opportunities and requirements to create a distinctive development that looks to implement Bridger Meadows Neighborhood May 13, 2021y 14, 2021 PUD Preliminary Application – Current Conditions and Remidiations Page 2 h:\bridger meadows pud\20-0601 pud prelim plan\(22) current conditions and proposed remediation 05-14-2021.docx design elements in conjunction with Bozeman’s Community Plan goals and objectives. The property has faced many challenges and issues through its various ownerships including development impedements which have included access and, easement issues, improper and/or failed infrastructure on adjacent developments, dumping, and homeless encampments. Since its purchase, Bridger Center LLC has undertaken efforts to address existing conditions known to be detrimental to the property and surrounding neighborhoods with the ultimate intent of creating a exceptional residential neighborhood within the landlocked parcel. A neighborhood that will advance the overall quality of the surrounding areas and district through development of fifteen sixteen single family (R-1) residences two affordable (townhome) housing choices and preservation of 7.15 7.20 acres (60.2% 61% of the total site) into wildlife refuge through the protection of a existing wildlife and of existing riparian habitat with extensive federally protected wetlands areas. As part of the ownership effort Bridger Center LLC has mitigated some of the immediate issues impacting the site. Other improvements will be done as part of the development’s infrastructure development work. Existing conditions that Bridger Center LLC has mitigated and or has plans for as part of the project include cleaning the site, addressing the homeless issues, and addressing water issues. The following is summary recently completed efforts and propsosals to be included in the development process. Water and Wetlands Study Terraquatic LLC has conducted a delineation of wetlands and waters of the U.S. at the subject site. A final report was submitted to the Army Corp of Engineers and is available for review. The delineation was done in compliance with the 1987 U.S. Army Corps of Engineers (USACE) Wetland Delineation Manual of the U.S. (Objective LU-4.1, E-1.1) Phase I Environmental Site Assessment A Phase I Environmental Site Assessment (ESA) has been completed for the subject site. The ESA was completed in accordance with methods outlined in American Society for Testing Materials, Standard Practice for, Phase I Environmental Site Assessments: ASTM Designation E 1527-93. (14a-e) Phase I Environmental Site Assessment 03-2019 – Appendix D Preliminary PUD Application and Preliminary Plat Application for the Phase 1 ESA. Existing Mitigations – Recently Completed Natural resource enhancement and restoration activities have been performed at the Bridger Meadows neighborhood project site. Work already completed includes the removal of approximately 21 cubic yards of trash and debris. Most of the debris that was removed consisted of household trash which was found at several homeless campsites on the subject property, (Photos 1 – HOMELESS CAMP DEBRIS). Disturbed areas have been re-graded and seeded with a wetland/riparian seed mix. Trash that could not be recycled was legally disposed of. Bridger Meadows Neighborhood May 13, 2021y 14, 2021 PUD Preliminary Application – Current Conditions and Remidiations Page 3 h:\bridger meadows pud\20-0601 pud prelim plan\(22) current conditions and proposed remediation 05-14-2021.docx Photos 1: Debris and garbage left at the Bridger Meadow Property by Bozeman’s homeless population. Approximately 1.9 tons of garbage was removed. Bridger Meadows Neighborhood May 13, 2021y 14, 2021 PUD Preliminary Application – Current Conditions and Remidiations Page 4 h:\bridger meadows pud\20-0601 pud prelim plan\(22) current conditions and proposed remediation 05-14-2021.docx Flooding Mitigation - Proposed A stormwater ditch traverses the Bridger Meadows property along its eastern and northern property line. This conveyance ditch is located between the Story Mill Spur trail and the terrace area of Boylan Drive, (Photo 2A & 2B – Public Storm Water Outfall). The conveyance ditch accommodates stormwater runoff and groundwater flows created by a french drain from the Village Greens Townhomes. The ditch, including constant flows from the french drain, discharges to a failed detention basin located approximately 50 ft north of the Bridger Meadows northern property boundary. A. B. Photos 2 -2A & 2B: A. Public Stormwater outfall, Discharge South Village Green. B. Stormwater conveyance ditch. The entire stormwater ditch is completely dry upstream of the French Drain outfall. Overflow from the detention basin travels under the Story Mill Spur trail and enters the Bridger Meadow property at the northwest corner. Water flows across the northwest corner of the Bridger Meadows property in a west/southwest direction, (Photo 3A – BRIDGER CREEK HOA DETENTION POND). Numerous aspen trees on the Bridger Meadows property and in Rotary Club Glen Lakes Park in the pathway of this outflow source of water have died due to saturated soil conditions. Mature vegetation in the detention pond area of the neighboring Bridger Creek Subdivision has also died, due to saturated soil conditions. Historic stands of aspen trees all the way to the East Gallatin are slowly succeeding to willow thickets. A variety of willow species are becoming the dominant tree species within these locations, (Photos 3B & 3C – STORM WATER DRAINAGE CHANNEL). Bridger Meadows Neighborhood May 13, 2021y 14, 2021 PUD Preliminary Application – Current Conditions and Remidiations Page 5 h:\bridger meadows pud\20-0601 pud prelim plan\(22) current conditions and proposed remediation 05-14-2021.docx Photo 3A. Failed Detention basin on neighboring subdivision property. B. C. Photos 3B & 3C: B. Outflow water from neighboring subdivision detention basin travels under Story Mill Spur trail onto the northwestern corner of the Bridger Meadows property. C. Dead mature trees in the path of outflow water. In an effort to mitigate the damaging impacts of the groundwater running through the detention basin to the Bridger Meadows property, Bridger Center LLC has offered to reroute much of the water from the french drain and deliver it to the south end of the pond on the Bridger Meadows property. Base flow measurements were taken of the outfall water directly downstream from the French Drain outlet as it enters the stormwater ditch east of the subject site, (Photos 4A through 4E – FLOW MEASUREMENT OF FRENCH DRAIN). The flow was estimated to be about 27.23 gallons per minute. There was no evidence of stormwater flow at the time our base flow measurement for the French Drain water was collected. (Photo 4A – CONSTRUCTION PLANS FOR FRENCH DRAIN). (Goal E-2 & Objectives E-2.1 through E-2.3). Bridger Meadows Neighborhood May 13, 2021y 14, 2021 PUD Preliminary Application – Current Conditions and Remidiations Page 6 h:\bridger meadows pud\20-0601 pud prelim plan\(22) current conditions and proposed remediation 05-14-2021.docx A. B. D. C. E. Photos 4A-E: A. Construction plans for the French Drain (groundwater interceptor from a neighboring subdivision. B. French Drain outfall. C-E. Setting up v-notch weir. Weir was used to collect baseline flow measurements of water exiting the French Drain system. The average measured flow was 27 gallons per minute (gpm) or 0.060 cubic feet per second (cfs). Bridger Meadows Neighborhood May 13, 2021y 14, 2021 PUD Preliminary Application – Current Conditions and Remidiations Page 7 h:\bridger meadows pud\20-0601 pud prelim plan\(22) current conditions and proposed remediation 05-14-2021.docx Pedestrian Circulation - Proposed The Bridger Meadows development will provide connections to the existing adjacent trails system which run along the river, occur on the adjacent properties, and within the Rotary Club Glen Lakes and ultimately connect to newly developed Story Mill Park, Figure 3 – EXISTING GLEN LAKE, STORY MILL SPUR TRAIL. (Goal C-2, Objective C-2.1, & Objective R-1.5). Signage will be posted asking trail users to keep their dogs restrained and on the trails. Typical park signage will also be posted such as no camping, park hours, clean up after pets, and other similar signage. In addition, dog waste stations will be installed at the trail heads to facilitate clean trails. Appendix A, Figure 7: The Story Mill Spur Trail is located on 3 sides of the subject site.