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HomeMy WebLinkAboutResponsetoDRCComments_01-22-2021 1091 Stoneridge Drive • Bozeman, Montana • Phone (406) 587-1115 • Fax (406) 587-9768 www.chengineers.com • E-Mail: info@chengineers.com Civil/Structural Engineering and Surveying January 22, 2021 Jacob Miller City of Bozeman Planning Department 20 E. Olive Street Bozeman, MT 59715 RE: Response to DRC Comments – Swiss Plaza Master Site Plan Application (#20371) Dear Mr. Miller: This letter is to provide a narrative response to the DRC comments received on the Swiss Plaza Master Site Plan Application. Answers to the city comments are provided in bold. It should be noted that an entirely new lighting photometric plan is provided with this resubmittal to replace the original. The owners wanted to modify the location and style of the parking lot light fixture in the center of the site, necessitating an update to the photometric plan. The original company that did the photometric plan was not able to make the update so Northern Rockies Agency was consulted to do the work. Also, a departure from residential open space requirement (BMC 38.520.060.b) is being requested with this application. The departure narrative is included in the response to comment #1 under the “Required Code Corrections” section of the following response narrative. Planning Division, Jacob Miller, jamiller@bozeman.net, (406) 582-2261 Conditions of approval 1. The applicant is advised that unmet code provisions, or code provisions that are not specifically listed as conditions of approval, does not, in any way, create a waiver or other relaxation of the lawful requirements of the Bozeman Municipal Code or state law. BMC 38.230.040 – DRB review thresholds. This project meets criteria for DRB review. • This is understood. The language regarding DRB was a typo and is not applicable to this project. Required Code Corrections 1. BMC 38.520.060.b – On-site residential open space. Ground level private outdoor space. Because the residential use is required to be on the second floor, the ground level private outdoor space requirement cannot be achieved. Because of that Community Development supports applying for a departure to this standard and counting the terrace spaces as 100% of the open space Civil/Structural Engineering and Surveying requirements. A departure narrative and exhibits, along with the departure fee of $241 will be required. • Thank you for allowing a departure from the residential open space requirement. Given the layout of the site, it was not possible to meet all of the ground level open space requirements. It was discussed with City planning to count the provided terrace open space at 100% instead of 50% of the required open space. All calculations for ground level open space have been removed from the landscape drawings. 100% of the terrace space is counted toward meeting the open space requirement. See updated landscape plan sheet L300. The departure fee of $241 will be paid by the owner. A summary table of open space requirements and areas provided is shown in the table below. Required open space per 2-bedroom dwelling unit Provided terrace area per dwelling unit – buildings 1-6 Provided terrace area per dwelling unit – building 7 150 sq. ft. 558 sq. ft. 740 sq. ft 2. BMC 38.510.030. – Landscaped block frontage standards. Unit 1A must be redesigned so that the entrance presents to the street. Currently the entrance is 90 degrees to the street which is not visible from all of the sidewalk/street and does not meet this standard. This design will require a new elevation for the unit. • See updated architectural plans that show Unit 1A’s revised façade to appear more like the front of a building. See Building 1 architectural drawings A3.1 and A3.3. 3. BMC 38.520.040. – Non-motorized circulation and design. The crosswalks must be concrete, stamped asphalt, or thermoplastic. • Updated drawings contain the following note at the crosswalks. “Crosswalk to be contrasting material per C.O.B Muni Code Sec. 38.520.040.C.3” Engineering Division, Karl Johnson, kajohnson@bozeman.net, (406) 528-2281 Easements 1. BMC 38.410.060 (C) (1) Easements – (Water and Sewer). The applicant must provide a thirty (30) foot public utility easement to accommodate both water and sewer mains prior to Master Site Plan Approval. The applicant may contact the Engineering Department to receive a copy of a utility easement template. • This is understood. Water and Sewer easement document will be filed prior to Master Site Plan approval. 2. BMC 38.410.060 (B) (4) Easements - No building shall be constructed that encroaches on a private utility easement unless written approval from all utility companies is provided to the community development department. a. The proposed storm sewer for roof drains of Phase 3 duplexes is located in existing 20’ utility easement Civil/Structural Engineering and Surveying • The roof drain for Phase 3 buildings has been moved to the west side of Buildings 4, 5 & 6 and is no longer in the existing utility easement. See updated civil sheet C3.0. 3. BMC 38.410.060 (B) Easements - The applicant must provide a ten foot utility easement (power, gas, communication, etc.) for proposed utility lines prior to Site Plan approval. The applicant may contact the Engineering Department to receive a copy of a utility easement template. • This is understood. A ten-foot utility easement document will be filed prior to Master Site Plan approval. Stormwater 1. Buildings 4 and 5 will drain into retention system #2 via roof drains and the storm sewer network. Revise the calculations to include the aforementioned areas within the drainage area map. • The drainage map and associated calculations have been updated in the revised stormwater report. See updated Sheet C4.0 for updated retention system sizes called out. 2. Montana Post-Construction Storm Water BMP Design Guidance Manual - Seasonal High Groundwater - The proposed project is located in an area that is known to have seasonally high groundwater. Engineering recommends that the applicant confirm that groundwater will not impact the function or maintenance of the proposed facilities by providing ground water monitoring. Industry guidance recommends a three-foot minimum separation from the bottom of the proposed facility to the underlying groundwater table. a. The assumed high ground water elevations is located above the bottom elevation of native clayey soils within the proposed development site (starting 8 to 9 feet below grade). Details provided for proposed underground retention require excavation to native gravels to justify the proposed stormwater system. The applicant should certify the retention system will function as designed under the proposed assumptions. • Groundwater monitoring was performed in the spring of 2020 on two monitoring wells that were installed in winter 2019/2020. Because those wells showed dry conditions during peak runoff season (April 2020) our original stormwater report used the old 2016 test pits because that was conservative. We have included the dry monitoring well logs with the updated stormwater report included in this re-submittal for completeness. Yes, the detail calls for removal of all soil between the bottom of the R Tank system and the underlying native gravel layer to ensure the systems drain properly. The bottom of the systems are set above the estimated high groundwater table. Also, it should be noted that the owners plan to do infiltration testing of the native gravel layer in the spring of 2021 once they have commenced with wet utility installation. Once that data is received, C&H will revise the sizing of the R Tank systems and submit a MOD application for engineering to re- review. This will undoubtedly shrink the proposed systems and pull them even further from the underlying high groundwater table. 3. DSSP Section II Drainage Policy (3) – Storm sewer facilities shall be designed to convey the 25 year storm event as specified within the DSSP. Provide calculations for sizing the proposed storm sewer. Civil/Structural Engineering and Surveying • Pipe sizing calculations are included in Appendix C of the updated stormwater design report. 4. DSSP Section II.B. Storm Drainage Plan - The applicant must include a drainage system maintenance plan with the Site Plan application. The City's requirements are contained in the Design Standards and Specifications Policy and the City modifications to Montana Public Works Standard Specifications. • The stormwater maintenance plan is submitted with the design report in Appendix F. Wastewater 1. DSSP Section (V) (B) Sanitary Sewer System Design Criteria - The applicant must provide an estimate of the peak-hour sanitary sewer demand for the different phases certified by a professional engineer for the proposed project prior master site plan approval. This information is used to verify downstream sewer capacity as well as keep the City’s wastewater hydraulic model updated. • An estimate of the peak-hour sanitary sewer demand (by phase) is provided with infrastructure submittal for the water and sewer main extensions which was submitted to the engineering department on January 15, 2021. A summary table is provided below. PHASE COMMERCIAL POPULATION TOTAL POPULATION CUMULATIVE POPULATION CUMULATIVE WASTEWATER FLOW (GPD) 1 2 11 11 3,208 2 3 12 23 6,204 3 2 15 38 10,095 Total 7 38 - 10,095 Building Division, Bob Risk, brisk@bozeman.net, 406-582-2377 1. The max square footage for a live work unit is 3000 sq ft. Most of the units comply, but the manager/owners duplex does not. It is over 3000 feet so it will have to modified to lose the additional footage so that it does not exceed 3000 feet OR provide fire sprinklers and alarms. • Fire sprinklers and alarms are being provided for both the residential and non- residential portions of each unit. Northwestern Energy, Erika Chaney, erika.chaney@northwestern.com 1. The applicant or applicant’s representative will need to work closely with the NWE project engineer to establish the location of transformers and gas main and electric primary extensions through the phasing process. Phase 2 transformer(s) will need the installation of the utility backbone and phase 3 transformer installed during the phase 2 installation. In phase 1 the proposed location of the transformer will require a 10-ft easement along the west side of the property. Utility Civil/Structural Engineering and Surveying Site Plan shows service to Unit 2A & 2B crossing through an existing parking lot. An easement will need to be created to install any utilities on the adjacent property. There is concern with the gas and electric utility services to Unit 2A & 2B crossing the 8” storm sewer pipe. NWE project engineer will need to know the bottom of pipe elevation to assure a 1-ft separation at the crossing for gas and electric services. If an easement cannot be secured, to cross the existing parking lot, installation of the gas and electric service would not be allowed adjacent to the 8” storm sewer main. • Easements for utilities will be provided on-site prior to Master Site Plan approval. There is no longer a conflict with the storm drain as it has been moved to the south side of Buildings 1 and 2. See updated civil sheet C3.0. 2. The utility site plan shows an electric service to parking lot light. This service will need to be metered for this light. If not metered the applicant can put in a request for a lighting agreement with NWE. • This light has been moved to the north side of the drive aisle closer to Building 7. It will be metered off the owner’s unit, building 7. See updated civil sheet C3.0. Also, see updated lighting plans. 3. Electric and gas meters will need to be installed on the exterior portion of the building at ground level. The following describes Northwestern Energy’s policy for meter installations. • This is understood. 4. NorthWestern Energy reserves the right to specify the location of NWE meters. All meters are to be located outdoors on the corner or area on the wall of the building closest to the transformer serving the building. On new construction, electric meter locations must be within 10 feet of the gas meter if, NorthWestern Energy will be providing both electric and gas service. Meter locations will need to be approved by NWE. NWE policy is to maintain a minimum, 30-inches wide by 3- foot clear zone between the front of the meter and any landscape screening and allow easy access to the meters for operation and maintenance. This can be determined through the design process after an application is submitted through NWE and the area project engineer will work through allowable shrubs and plants for screening and to determine adequate clearances for access to our meters. a. Buildings with multiple units will need adequate wall space to install electric and gas meters. For gas meters, NWE will only stack gas meters 2 high. The areas for gas and electric meters will need to occupy the same wall space with the needed separation between gas and electric meters. Looking at the elevation plans there seems to be enough wall space to install the gas and electric meters. The NWE project engineer will help in determining the best location and needed wall space to install the electric and gas meters. • This is understood. 5. The following applies to the gas regulator. The gas regulator cannot be placed under a window or Civil/Structural Engineering and Surveying within 3’ of the operable portion of the window or door. It can be placed under a window/deck on the second story, provided the “open/operable” portion has at least 6’ of clearance from the regulator. Ensure that there is 10’ of separation from any mechanical air intake, including air conditioning units. The regulator will need to be 3’ from the closest corner of any portion of the electric meter base. • This is understood. 6. Transformers should be located in areas to reduce the number of transformers to service the duplexes. This can be accomplished by installing single phase transformers where the gas and electric service lines share trenches and terminate on the buildings within close proximity of one another. • This is understood. See updated civil plan sheet C3.0 for transformer locations. Each phase of the Master Site Plan will need to install one transformer. Each transformer location is called out on civil sheet C3.0 with a note indicating which phase of construction it will be installed. 7. Transformer location and clearance requirements to buildings. For oil filled transformers a 2-foot clearance is required to non-combustible walls and surfaces that do not have any openings such as doors, windows, air intake, and fire escapes routes, and meets current NEC or NFPA requirements for non-combustible material. For all transformers, regardless of size, requires a 10-foot unobstructed clearance space in front of the pad where the transformer doors are located. Note, all distances are referenced to the edge of the pad. a. For any combustible surface, not meeting current NEC or NFPA requirements for non- combustible material, a minimum of a 10-foot clearance is required between the building or any combustible surface and the transformer. b. For landscaping, planting of bushes or shrubs a Minimum Working Space for a Pad- Mounted Transformer, is 4-feet on the sides and back portion of the concrete pad and 10- feet of clearance on the front side of the pad where the transformer doors are located. Note, all distances are referenced to the edge of the pad. The NWE project engineer will help to determine the appropriate location for the transformers and allowable landscaping. c. All transformers need to be installed within a utility easement. • This is understood. All transformers shown on the plans have sufficient clearances to landscaping and buildings. Phase 1 transformer is located in a future easement per document to be recorded prior to Master Site Plan approval. Transformers for Phases 2 and 3 are located in an existing utility easement along the east side of the property. 8. For landscaping. No large deep rooted trees or bushes will be allowed within the 10-foot utility easement and it is a recommendation to not plant deep rooted trees or landscaping over any service locations. All other approved landscaping will be placed so as not to damage or prevent or hinder operation and maintenance of NWE utilities. • All trees and deep-rooted shrubs have been removed from all utility easements. Previously, there were trees proposed in the water course setback along the east side of the project due to the city watercourse setback planting requirements. That requirement Civil/Structural Engineering and Surveying has been relaxed. See message from Jacob Miller below. See updated landscape sheet L304. 9. Utility easements. Any extension of gas main or electric primary will need to be installed within an 10-ft utility easement. For this development the applicant needs to review the plat and assure the easements along the east, west and north property line specify 10-ft underground utility easements for gas and electric. To establish the needed utility easement locations the NWE project engineer and Northwestern Energy’s real estate representative will help to establish these locations as well as the needed documentation. • The plat was reviewed with Dylan Swanson at Northwestern Energy and it was determined that the existing easement on the east side of the lot can be used for future utility installation. See message from Mr. Swanson below. Civil/Structural Engineering and Surveying 10. With the proposed installation of utilities along the east side property line landscape and any fencing will need to be install so as to allow at least a 10-ft access to inspect and maintain the gas and electric utilities. It is recommended no fencing or large landscaping be installed along this route. • No fencing or large landscaping is proposed along the eastern portion of the site within the existing utility easement. 11. Recommendation. Submit an application online as soon as possible to have the NWE project engineer work with the applicant through NWE engineering design process. Go to www.northwesternenergy.com/construction to apply online Montana Construction Application, and access Montana New Service Guide to provide information on electric and gas service requirements. • An application for service was submitted to Northwestern Energy on December 16, 2020. We are actively working with Erika Chaney on facilitation and coordination of the power and gas infrastructure design. Fire Department, Scott Mueller, smueller@bozeman.net, 406-582-2382 2012/2018 International Fire Code: APPENDIX D FIRE APPARATUS ACCESS ROADS See PDF attachment for graphic. 1. D103.6 Signs. Where required by the fire code official, fire apparatus access roads shall be marked with permanent NO PARKING—FIRE LANE signs complying with Figure D103.6. Signs shall have a minimum dimension of 12 inches (305 mm) wide by 18 inches (457 mm) high and have red Civil/Structural Engineering and Surveying letters on a white reflective background. Signs shall be posted on one or both sides of the fire apparatus road as required by Section D103.6.1 or D103.6.2. • Based on communication with Mr. Mueller on December 10, 2020, a few fire sign locations were removed due to conflicts with the snow storage areas. See red lined site map below from Mr. Mueller. Areas that require signage are shown on the updated civil site drawings sheet C2.0 1. D103.6.1 Roads 20 to 26 feet in width. Fire lane signs as specified in Section D103.6 shall be posted on both sides of fire apparatus access roads that are 20 to 26 feet wide (6096 to 7925 mm). • See updated civil plan sheet C2.0 Civil/Structural Engineering and Surveying 2. D103.6.2 Roads more than 26 feet in width. Fire lane signs as specified in Section D103.6 shall be posted on one side of fire apparatus access roads more than 26 feet wide (7925 mm) and less than 32 feet wide (9754 mm). • See updated civil plan sheet C2.0 Parks Department, Addi Jadin, ajadin@bozeman.net, 406-582-2908 1. Staff recommends CILP to the meet the parkland requirements as proposed. All CILP proposals are reviewed by the Subdivision Review Committee. Parks staff will schedule this item for review at their December 17th meeting at 3:30 pm. • It is understood that this meeting was moved to January 28, 2021. 2. Each new unit will require CILP for 0.03 acres of parkland. Appraisal readjustment in early December will be between $1.70-$1.75 sf. The applicants may pay CILP for the entire development with Phase I at current CILP appraisal value or pay for units as they receive approval based on appraisal value at the time of Site Plan completion. Please indicate payment/# of units paid for on Site Plan and contact the Parks Division for new appraisal value. • The owners would like to pay the CIL fee on a phase-by-phase basis. The updated CIL parklands figure is $1.72 as provided by Addi Jadin in January 2021. Sheet C1.0 has been updated to include a table showing the required CIL of parkland broken out by phase. The owners are aware that Phase 1 CIL of parkland must be paid prior to master site plan approval in the amount of $8,990.78. Forestry Division; Alex Nordquest, anordquest@bozeman.net, 406-582-3205 1. River Birch species proposed for watercourse setback (east end) may conflict with overhead electric. Recommend only appropriate species for planting under power lines, as per City of Bozeman Street Tree Guide. Appropriate species are marked with a “U” in the guide. Street Tree Guide: https://www.bozeman.net/home/showdocument?id=10024 • All trees have been removed from under the power lines on the east side of the site due to utility conflicts. This area will be seeded with native grass species and watercourse shrubs instead of trees due to it’s location within the utility easement. See updated landscape sheet L304. If you require any further information, please give me a call at (406) 587-1115. Sincerely, Tim Staub, P.E.