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HomeMy WebLinkAbout022 Current Conditions and Proposed Remediation document 4515 Valley Commons Drive #201, Bozeman Montana 59718 P: 406.585.4161 F: 406.585.6919 www.bechtlearchitects.com February 21, 2022 Section 22 - Current Conditions and Remediation Shady Glen Planend Unit Development Preliminary PUD Application Preliminary Plat Application Current Conditions and Proposed Site Remediations. The Shady Glen PUD project site is bounded by commercial development off Commercial Drive to the south, residential development off Birdie Drive to the east, residential development along Boylan Road to the northeast, Bridger Creek Homeowners Association Park to the north and Glen Lake Rotary Club Park to the west. The property is legally described as Northwest ¼ of the Southeast ¼ of Section 31, Township1 South, Range 6 East, Principal Meridian, Bozeman, Montana, Gallatin County. Figure 1: Shady Glen Site Location Figure 1: Shady Glen Site Location Bridger Center LLC purchased the property 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 design elements in conjunction with Bozeman’s Community Plan goals and objectives. The property has faced many challenges and issues through its Shady Glen PUD February 21, 2022 Preliminary PUD Application – Current Conditions and Remidiations Page 2 various ownerships including development impedements including 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 16 single family (R-1) residences including two affordable homesites (townhouses), and preservation of 7.13 acres, 60.07% of the total site as existing riparian habitat with extensive federally protected wetlands. 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 – 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 Shady Glen 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. Shady Glen PUD February 21, 2022 Preliminary PUD Application – Current Conditions and Remidiations Page 3 Photos 1: Debris and garbage left at the Shady Glen Property by Bozeman’s homeless population. Approximately 1.9 tons of garbage was removed. Shady Glen PUD February 21, 2022 Preliminary PUD Application – Current Conditions and Remidiations Page 4 Flooding Mitigation - Proposed A stormwater ditch traverses Shady Glen along, and outside of, the east and north property lines. 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 intercepted by a french drain from the Village Greens Townhouses. The ditch, including constant flows from the french drain, discharges to a failed detention basin located approximately 50 ft north of the Shady Glen northern property boundary. A. B. Photos 2 -2A & 2B: A. Public Stormwater outfall, discharge from the Village Greens Townhouses. 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 East Gallatin Recreation Area trail and enters the Shady Glen property near its northwest corner. Water flows across the property in a west/southwest direction, (Photo 3A – BRIDGER CREEK HOA DETENTION POND). Numerous aspen trees on the Shady Glen 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 River 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). Shady Glen PUD February 21, 2022 Preliminary PUD Application – Current Conditions and Remidiations Page 5 Photo 3A. Failed Detention basin on neighboring subdivision property to the north. 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 Shady Glen property. C. Dead mature trees in the path of outflow water. 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 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). A. Shady Glen PUD February 21, 2022 Preliminary PUD Application – Current Conditions and Remidiations Page 6 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). Shady Glen PUD February 21, 2022 Preliminary PUD Application – Current Conditions and Remidiations Page 7 Pedestrian Circulation - Proposed The Shady Glen development will provide connections to the existing adjacent trail system which runs along the river through adjacent properties and within the Glen Lake Rotary Park and ultimately connect to newly developed Story Mill Park, Figure 2 – EXISTING EAST GALLATIN RECREATION AREATRAIL SYSTEM. (Goal C-2, Objective C-2.1, & Objective R-1.5). The proposed development will provide an additional pedestrian and bicycle connection to Commercial and Bridger Center Drive through the emergency access leading to direct access to and from the main entrance of Story Mill Park , Figure 2.1, - EXISTING EAST GALLATIN RECREATION AREA TRAIL SYSTEM. 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. Figure 2: The Story Mill Spur Trail is located on 3 sides of the subject site. Figure 2.1: The Story Mill Spur Trail Proposed Connection Route to Story Mill Park.