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HomeMy WebLinkAboutBC_Bozeman_20216_Engineering_Comments_Response_090420 September 4, 2020 Griffin Nielsen, Engineer II Lance Lehigh, Engineer III City of Bozeman – Engineering Department 20 East Olive Street Bozeman, MT 59715 Reference: Billings Clinic Bozeman Campus Master Site Plan Development Review Response to City Engineering Division Comments Application No. 20216 Project No. 15063.03 Dear Griffin and Lance: Below are the responses to items from the memorandum addressing the City comments on the Billings Clinic Phase Master Site Plan Application No. 20216 dated August 25, 2020. City comments are shown in bold font. Sanderson Stewart responses are below in red. Any additional information for reference has been attached to this memorandum or included with the Master Site Plan resubmittal. General 1. Bozeman Municipal Code (BMC) 38.230.100.A.12.: As presented, the phasing plan is difficult to follow given the complexity and scale of the development. Please provide a detailed phasing plan accompanied with exhibits that show how the development intends to build out. The phasing plan should clearly show sanitary sewer, water, storm, street, buildings, trails, and other critical infrastructure that is needed to support the development. Please see the revised Master Site Plan that provides additional detail for Phase 1 improvements and future improvements. The plan shows the proposed Phase 1 sanitary sewer, water, storm, street, building and trail improvements as well as anticipated improvements for future development in the four defined areas. It is noted on the Master Site Plan that all future on-site and off-site proposed street and utility improvements are to be further evaluated at the time of future development based upon specific future development requirements and will be reviewed and approved by the City at that time. All future improvements will need to be meet City requirements. Legal 1. Bozeman Municipal Code (BMC) 38.410.060.: Please provide a standalone existing survey, which identifies all easements, right-of- way, property lines, etc. In addition, provide a separate exhibit identifying all proposed easements that would be provided with the master site plan (i.e. utility, public access, public street and utility). A copy of the plat for Minor Subdivision 221F is included in the master plan drawings which shows all the existing easements on the parcel. An exhibit has also been included showing all the proposed easements. 2. BMC 38.410.060.: All public easements must be provided with the master site plan submittal in a clean draft format for review. Easements will be deemed inadequate if they are not in a final draft format (signatures are not required for the draft review). Easements must be stamped by a licensed professional surveyor. If for any reason a public easement must be modified based on review of subsequent site plan submittals, the applicant must request a release and reconvey of any portion of the dedicated easements. The following easement have been identified in the application: a. Public Street and Utility easement for all proposed internal streets. b. Public Utility easement along the street frontage per 38.410.060.B.2.a. c. Public Access easement for the shared use path along East Valley Center Road. Easements in final draft format have been attached for review for the Public Street and Utility Easements, the Public Utility Easements and the shared use path along East Valley Center Road. 3. BMC 38.410.060.: A ten-foot minimum front set back easement, using the City’s standard language must be provided allow along dedicated streets for the extension of dry utilities. The application is unclear if the utility easement has been included along all street frontages; including Davis Lane, North 27th Ave., Street A, Street B, and Honor Lane. Ten-foot minimum easements for dry utilities have been included on all the street frontages as requested. 4. BMC 38.410.060.C.1.: The proposed water main extending along the East Valley Center frontage must reside within a minimum 30-ft water main easement. The applicant is advised that at no point may the water main be less than 9 feet from the edge of the easement. A 30-foot water main easement has been provided for the water main extension along East Valley Center Road with the water main offset a minimum of 9 feet from the edge of easement. 5. Provide a copy of the “40 Wide High-Pressure Gas Line Easement” which crosses the southwestern portion of the property. A copy of the 40-foot wide high-pressure gas easement is attached for review. 6. BMC 38.410.060.: The applicant is advised that the City does not allow the construction of half streets. Honor Lane must be constructed along the property’s southern boundary as a 60-ft local street. The applicant will need to coordinate with the southern property owner to obtain the required Right-of-Way (ROW) for the construction of the 60-foot local street. The City will accept either dedicated ROW or a public street and utility easement. The applicant may contact the Engineering Department to receive a copy of a utility easement template. It is acknowledged that the City does not allow the construction of half streets and will coordinate with the adjacent landowner to have an additional 30 feet of right-of-way dedicated on the “Bus Barn Property” at the time that Honor Lane needs to be improved. The applicant plans to provide 30 feet of right of way along the southern property line of Zone D as part of this master plan. 7. BMC 38.270.030.C.: The applicant is advised that onsite concurrent construction will not be granted with the master site plan application. The construction of the overall campus is intended to be phased on a building by building basis and could change depending on the needs of the development. The applicant must submit onsite concurrent construction requests with each phase of the development. It is acknowledged that concurrent construction requests will not be granted for this master site plan and concurrent construction requests will need to be submitted with each phase of development or concurrent construction be approved via a future PUD application. It is understood that concurrent construction is approved for Phase 1 of this development. 8. BMC 38.410.080.E.: A pubic drainage easement(s) must be provided for the stormwater facilitates supporting drainage from public roadways, which include Westlake Road, the expansion of North 27th Avenue, Davis Lane, and other proposed public roadways. The property owner(s) are responsible for the maintenance of these facilities. Public drainage easements for the drainage facilities supporting drainage from the streets have been included for review. 9. BMC 38.410.060.: The applicant must obtain the property permitting for the placement of the shared use path in the East Valley Center ROW from the Montana Department of Transportation or the shared use path must be placed within a public access easement on the subject property. The shared use path has been mostly relocated out of MDT ROW and the project is currently being reviewed and permitted through MDT. An easement for the shared use path is included for review. Traffic Impact Study 1. BMC 38.210.060.A.12.: The traffic impact study (TIS) needs to be stamped and signed by a professional engineer. The attached TIS is stamped and signed by a PE. 2. BMC 38.210.060.A.12 and 38.230.100.A.12.: There are a number of recommended improvements identified with the TIS. If the intention is for these improvements to be completed beyond Phase 1, they must be clearly identified with the master site plan and the timing supported by the TIS. The TIS provides limited detail on the timing for required improvements between the completion of Phase 1 to the projected full build out year of 2040 to the City’s transportation system associated with the development. The applicant is advised to meeting with the engineering department to discuss details. Either the TIS should be expanded to identify at which phases warrants will be met with respect to future growth or a condition will be placed on the master site plan requiring warrants to be checked with each individual phase. The Design team has met with the City staff and the TIS author has meet with the City Transportation Engineer. Both identified the best plan of action is to show detail and requirements to the impacts at the time of Phase 1 and recommend update traffic letter be completed for future development after Phase 1 until full build-out of the entire site. This process will ensure improvements are implemented at appropriate times and will also ensure the area improvements are planned/constructed together with the City’s TMP projects likely through CIP funding. 3. Provide details on the proposed internal street sections and their capacity to support the proposed demand for the full buildout of the development. Please included details on Westlake Road and associated public roadway improvements with the project (Street A, Street B, Honor Lane, etc.) The design team has meet with the City staff to discuss the specific roadway sections and further detail is provided in the TIS for the internal streets. Details for the proposed street cross sections have been included in the Master Site Plan. 4. It is unclear in the TIS on the AM and PM splits. Provide the methodology used for obtaining the AM and PM splits. The TIS author met with the City staff and further described the process for finding, reviewing, and analyzing the AM and PM peak hour splits. 5. The associated trip distribution within the TIS needs to be expanded given the scale of the development, which should include critical intersections in order for the City to accurately assess the capacity of the system. The applicant must coordinate with Taylor Lonsdale (City of Bozeman transportation engineer). The TIS author met with Taylor Lonsdale and discussed the project extents, distributions, and impacted intersections. Requested minor edits from Taylor have been implemented in the revised TIS. 6. Several assumptions were made for trip distributions based on "simple inspections of existing traffic patterns within the project area". These assumptions could be could have negative operational impacts on the transportation system. The applicant needs to provide additional narrative within the TIS on the assumed distributions along with a better visual graphic showing the distribution in order to validate the data. The TIS author met with Taylor Lonsdale and discussed methodology and robust process that was undertook to determine future traffic growth, distribution, and patterns. Additional narrative and graphic info have been included in the revised TIS. 7. Multimodal transportation, such as bike lanes and pedestrian facilities were not addressed in detail. The TIS should include detail on multimodal transportation to address circulation within the proposed campus as well as impacts/needed improvements to the City’s surrounding non-motorized transportation network. The applicant must coordinate with Taylor Lonsdale (City of Bozeman transportation engineer). The TIS author met with Taylor Lonsdale and discussed the multimodal transportation aspects of the project. For conservative measures, multimodal trips were not reduced from the site trip generation but information on the sidewalk, trail and bike connections have been added to the report along with updated site graphics. Transportation 1. BMC 38.400.010.: Westlake Road must be upgraded to meet minimum local street standards from the western property boundary to the intersection of East Valley Center Road. Timing of this improvement must be clearly identified. The City requires that all public infrastructure within and directly adjacent to a phase be completed with the proposed phase. a. Westlake Road must be realigned, such that it intersects with East Valley Center Road at an angle greater than 75 degrees, per 38.400.030. and has a length of tangency at the intersection of 100-ft per Table IV-2 from the City Design Standards and Specification Policy Manual (DSSP), which can be found on the engineering departments webpage. The design requirements for Westlake Road are acknowledged. The applicant proposes to construct Westlake Road to a local street standard from east Valley Center Road to the west edge of the property frontage upon development of the future Parking Structure #1 or as otherwise required by future development within Zone “A” as noted on the Master Site Plan. Westlake Road is not required from a transportation standpoint for the Phase 1 development, but the applicant acknowledges that Westlake Road will need to be developed to a local street standard in the future. BMC 38.400.010. and 38.410.060.: Honor Lane, the proposed future local street along the southern property boundary appears to split between the subject property and the property to the south. The applicant is advised that the City does not allow the construction of half streets. Honor Lane must be constructed along the property’s southern boundary as a 60-ft local street. The applicant will need to coordinate with the southern property owner to obtain the required Right-of-Way for the construction of the 60-foot local street. The City will accept either dedicated ROW or a public street and utility easement. Timing of this improvement must be clearly identified. The City requires that all public infrastructure within and directly adjacent to a phase be completed with the proposed phase. It is acknowledged that the City does not allow the construction of half streets and will coordinate with the adjacent landowner to have an additional 30 feet of right-of-way dedicated on the “Bus Barn Property” at the time that Honor Lane needs to be improved. The applicant plans to provide 30 feet of right of way along the southern property line of Zone D as part of this master plan. 2. BMC 38.400.010.: North 27th Avenue must be upgraded to a minor arterial standard according to the City’s Transportation Master Plan (TMP). Timing of this improvement must be clearly identified. As proposed, North 27th must be upgraded as part of Phase 1 of the development. We clarified in our meeting on August 31, 2020 that North 27th Avenue is classified as a collector versus a minor arterial. North 27th Avenue is proposed to be widened to a collector street standard along the west side of North 27th from Honor Lane to Street “A” as part of Phase 1. The portion of North 27th between Street “A” and East Valley Center Road is proposed to be widened to a collector street standard on the west side as part of future development in Zone “C” as noted on the Master Site Plan. It is our understanding that the east side of North 27th Avenue will be widened by the property owner to the east. 3. BMC 38.400.010.: Davis Lane must be upgraded to a minor arterial standard according to the City’s TMP. The timing of this improvement will depend on the phasing of the development, however, the ROW required for full buildout adjacent to the subject property must be provided prior to master site plan approval or with the pending annexation agreement, whichever is first. There is no connection proposed to Davis Lane as part of the Phase 1 development. Street “A” is anticipated to connect to Davis Lane as part of future development within Zone “A” or Zone “B” as noted on the Master Site Plan. Davis Lane will be widened to a minor arterial street section along the property frontage at the time Street “A” connects to Davis Lane as noted on the Master Site Plan. It is also our understanding that Davis Lane may also be improved to a minor arterial standard as part of a future City CIP project depending on the timing of future developments in the immediate area. 4. BMC 38.410.040 Blocks: The applicant must construct an appropriate local street grid through the property that meets block length requirements upon future development. A local street between Street A and Westlake road is required. The proposed street between Street “A” and Westlake Road is currently proposed as a private drive but is designed to a local street standard which we understand meets the intent of the code per our August 31, 2020 meeting. 5. BMC 38.400.110. and 38.410.120.: A trail network must be constructed through the property as defined in the City Parks, Recreation, Open Space, and Trails (PROST) Plan and TMP. The design of all trails identified in the TMP must be included on the infrastructure plan submittal for the corresponding phase. In addition, the applicant is encouraged to coordinate with the Bozeman public transit service (Streamline) to incorporate service into the development. Please refer to the “Community Design Framework” plan included with the Master Site Plan which identifies the proposed trail network for the campus which meets or exceeds the PROST and TMP recommendations. Portions of this trail network will be completed as part of Phase 1 of the development and the remaining portions will be completed as part of future phases of the campus as noted in the Master Site Plan. Water and Wastewater 1. BMC 38.410.070.: The development must abide by the agreement title “AGREEMENT REGARDING INFRASTRUCTURE” approved by the City Commission on May 4, 2020. As presented, the sanitary layout shows a future connection to the City’s Norton East Ranch Outfall (CIP No. WWIF138) and the Davis Lane Lift Station (CIP No. WWIF31 and WWIF24) projects, which were identified in the agreement as Option A. At this time, the aforementioned capital improvements are under construction. The applicant is advised that the City cannot guarantee the overall time and completion of these improvements but can provide updates to the applicant as requested throughout the construction process. Acknowledged. 2. BMC 38.410.070.: The sanitary sewer report indicates a peak sewer flow of 602 gpm for the Billings Clinic Campus and adjacent properties. a. The report must show that the provided design estimates are in accordance with City of Bozeman design standards and are sized to accurately accommodate the full build out of the Billings Clinic development. b. Localized Infiltration & Inflow must be included in sewer main sizing. Per the DSSP, an infiltration rate of 150 gallons/acre/day shall be added to all flow calculations when designing new sewers. c. Provide a summary of allocated sewer flows for each future lot (including the offsite lots located to the east) that may be referenced for individual site plan design review. Please see attached updated sanitary sewer report that addresses the above items. 3. BMC 38.410.070. and 38.230.100.A.12.: Each phase of development must connect to the water distribution system at a minimum of two points to allow a redundant feed (per City of Bozeman Engineering DSSP Section V.A. 5). Acknowledged. It is noted that the proposed Phase 1 improvements provides two points of connection and the proposed Master Site Plan provides for additional water main loops and redundancy. 4. BMC 38.410.130.: Water rights and/or payment of cash-in-lieu of water right is required prior to development for the demand on the City’s potable water system. The development’s annual water demand profile must be provided with the Preliminary PUD or Master Site Plan application. The analysis should include an analysis of meter records from the owners existing facilities. The applicant is advised to contact Brian Heaston in the City’s Engineering Department to discuss the required water rights analysis. a. The applicant is advised that provision of water rights or cash in lieu thereof is required with the phased site plans. Given the large landscaping area of the campus a significant landscape irrigation water demand is anticipated. The City encourages the applicant to maximize the utilization of exempt groundwater wells to provide irrigation water supply. The applicant is encouraged to coordinate with Kerri Strasheim at the MT DNRC Bozeman Area Office now, in order to understand the exempt groundwater well limitations applicable to the development. Acknowledged. The current proposed Phase 1 site plan proposes to utilize groundwater well(s) for irrigation purposes and we have been in contact with Kerri Strasheim regarding this item. b. Given the institutional use of the site, and the particular water uses of hospital facilities, the City will request the applicant provide an estimate of the anticipated annual domestic water use with each site plan for City review. The anticipated domestic use estimate should be based on actual metered water use of existing comparable facilities in the Billings Clinic network (building size, use, HVAC system type, etc.). Acknowledged. The applicant can provide the water use data from similar facilities as requested. c. If a geothermal heating/cooling plant is proposed for any building(s) on the site, the applicant is notified that a geothermal water right must be secured from the MT DNRC prior to occupancy of any building(s) utilizing the geothermal system. Applicant proceeds at its own risk in securing the geothermal water right. Acknowledged. The current Phase 1 plan does propose to use geothermal heating/cooling at this time, but the systems are designed so that they can be converted in the future if needed. Stormwater 1. BMC 40.04.700.: A comprehensive drainage plan is required for all development larger than five acres. "Comprehensive drainage plan" means a stormwater management plan that covers all current and anticipated development on a site greater than five acres and sites planned for phased development, including the impact on existing off-site infrastructure. a. The drainage design appears to utilize retention to satisfy the City’s drainage requirements, however, the drainage standard does not allow for a reduction in retention volume based on infiltration during the 10-year 2-hour storm. As proposed, the retention facilities appear to be under sized. The applicant is advised that if the drainage design is switched to a detention system and accounts for infiltration, the applicant must demonstrate that the infiltration rate can be maintained for the lifespan of the facility. To maintain infiltration, the design must include pretreatment, which removes silts and sediment from entering the infiltration area. The retention areas have been redesigned to exclude infiltration from the calculations in the revised Comprehensive Drainage Plan. b. The stormwater report for the master site plan should include calculations demonstrating that adequate space has been dedicated to meet the City storage requirement during seasonal high groundwater. Detailed calculations for these facilities are not required with the master site plan. As noted in the geotechnical reports, seasonal high groundwater levels may not have been collected. The applicant is advised to verify local groundwater elevations and incorporate these levels into the drainage design report. This is addressed in the revised “Comprehensive Drainage Plan” c. Based on aerial imagery, the subject property appears to be bisected by a swale running from south to north. The swale is a conveyance pathway for offsite drainage. The drainage design must account for the offsite drainage. This is addressed in the revised “Comprehensive Drainage Plan” and will be addressed through the stormwater design upon future development in Zones “C” and “D” as noted on the Master Site Plan. It is anticipated that an overland relief route or other means of conveyance will be provided to address offsite drainage upon future development in this area. d. As presented, the preliminary plans in the Masterplan_070220 (Sheets C2.0, C3.1, and C3.2) appear to indicate that portions of the storm drainage system from Street A and Westlake Road will directly discharge into Cattail Creek Direct discharge into Cattail creek violates the City’s MS4 permit. The applicant will need to demonstrate that runoff from the subject property historically flowed into Cattail or treat all of the generated runoff onsite. If it is determined that flows did historically flow into Cattail Creek, runoff will need to be treated and reduced to predevelopment rates. The site will need to meet DSSP Manual Section II.A.4. Acknowledged. This will be addressed if and when future connection(s) are proposed to outfall to Cattail Creek. Based on existing topography a significant portion of the west and northwest side of the parcel has historically drained to Cattail Creek. e. The drainage report must include an exhibit with that defines the overall drainage area, respective subwatersheds, and required storage volumes. The overall stormwater design must consider the proposed phasing of the development and ensure that both water quality and quantity standards are satisfied. This is addressed in the updated “Comprehensive Drainage Plan” 2. BMC 38.600.090.B.4.a.: Requires the flood hazard evaluation be certified by a Professional Engineer registered in the state of Montana. The flood hazard evaluation is stamped and signed by a PE. 3. BMC 38.600.: All recommendations provided in the flood hazard evaluation conclusion section (report pg. 4) must be incorporated into their respective phases of the development. Provide a phasing plan which identifies the respective phase each recommendation will be completed in. Three recommendations are provided: a. Widening of Cattail Creek channel b/w cross sections W and Z; The widening of this portion of Cattail Creek is proposed to be completed as part of future development within Zone “B” as noted on the Master Site Plan. It is noted that the Phase 1 development is not impacted by the 100-year flood boundary from the flood hazard study. b. Maintain the existing drainage pattern within the existing conveyance swale along the east and northwest boundaries of the site; and As noted on the Master Site Plan and revised “Comprehensive Drainage Plan”, this will be addressed upon future development in Zones “C” and “D”. It is anticipated that an overland relief route or other means of conveyance will be provided to address offsite drainage upon future development in this area. c. Construct buildings with a minimum finished floor elevation +2 feet above the calculated base flood elevation (BFE). It is noted on the Master Site Plan that all buildings be constructed a minimum of 2 feet above the base flood elevation identified in the flood hazard study. 4. BMC 38.600.: As presented, Street A is shown crossing Cattail Creek in order to access Davis Lane. The flood analysis must be updated to account for the Street “A” crossing when the associated phase is submitted for site plan approval. Acknowledged. This will be addressed at the time Street “A” connects to Davis Lane and crosses Cattail Creek. Multiple crossing options could be considered including a culvert, arch span or potential small bridge that would clear span the crossing. 5. BMC 38.600.: The infrastructure set provided shows a 30-inch RCP culvert crossing, which appears to be undersized to adequately convey the 100-yr discharge without overtopping the road. The culvert design must conform with the engineering design standards to convey the 25-yr discharge. Road overtopping is allowable when conveying the 100- yr discharge; however, it cannot cause an increase in the existing identified flood hazard. Acknowledged. As noted above, this will be addressed at the time Street “A” connects to Davis Lane and crosses Cattail Creek. Multiple crossing options could be considered including a culvert, arch span or potential small bridge that would clear span the crossing. Recommended Conditions of Approval 1. Upon future development, the applicant must provide and file with the County Clerk and Recorder's office executed Waivers of Right to Protest Creation of Special Improvement Districts (SID’s) for the following: a. Street improvements to East Valley Center Road including lighting signalization paving, curb/gutter, sidewalk, lighting and storm drainage b. Street improvements to North 27th Avenue including lighting signalization paving, curb/gutter, sidewalk, lighting and storm drainage c. Street improvements to Davis Lane including lighting signalization paving, curb/gutter, sidewalk, lighting and storm drainage d. Street improvements to West Lake Road including lighting signalization paving, curb/gutter, sidewalk, lighting and storm drainage e. Intersection improvements to East Valley Center Road and North 27th Avenue f. Intersection improvements to East Valley Center Road and Davis Lane g. Intersection improvements to East Valley Center Road and Catamount Street h. Intersection improvements to Catamount Street and North 27th Avenue i. Intersection improvements to Catamount Street and Davis Lane The applicant may obtain a copy of the template SID waiver from the City Engineering Department (Griffin Nielsen). The document filed must specify that in the event an SID is not utilized for the completion of these improvements, the applicant agrees to participate in an alternate financing method for the completion of said improvements on a fair share, proportionate basis as determined by square footage of property, taxable valuation of the property, traffic contribution from the development, or a combination thereof. The applicant must provide a copy of the SID waiver filed with the County Clerk and Recorder prior to master site plan approval. Acknowledged. 2. The subject property is located in an area with high groundwater with potentially corrosive soils, which can increase the likelihood of water main failure over the lifespan of the asset. The applicant must perform a corrosivity analysis to determine if cathodic protection is required for the proposed distribution mains. Polyethylene encasement will be provided for the ductile iron water mains to address this item. Engineering Advisory Comments 1. The applicant is advised that any street or driveway connection to East Valley Center Road must be approved by the Montana Department of Transportation. Acknowledged. 2. Prior to scheduling an infrastructure pre-construction meeting with the City, the applicant must obtain approval from The Montana Department of Environmental Quality for water and sanitary sewer infrastructure constructed with this project. Acknowledged. 3. In the event that the applicant wishes to dedicate the proposed street and utility easements as public ROW public drainage easements must be provided for all storm conveyance facilities located outside of the easements. All stormwater basins must be located in common open space lots, overlaid with a pubic drainage easement. The property owner(s) will remain responsible for the maintenance of the facilities. Acknowledged.