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HomeMy WebLinkAbout180137 Response to DRC Eng. Comments_5-13-2020 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 May 8, 2020 Sarah Rosenberg City of Bozeman Planning Department 20 E. Olive Street Bozeman, MT 59718 RE: Response to DRC Engineering Comments – Palisades Site Plan DRC Comments (#18446) Dear Ms. Rosenberg: This letter is to provide a narrative response to the DRC engineering comments from April 21, 2020: Engineering Division, Griffin Nielsen, gnielsen@bozeman.net, (406) 582-2280 1. Bozeman Unified Development Code (BMC) Section 38.270.020.A.1 states: Construction routes. For all developments, excluding sketch and reuse/further development, a construction route map shall be provided showing how materials and heavy equipment will travel to and from the site. The route shall avoid, where possible, local or minor collector streets or streets where construction traffic would disrupt neighborhood residential character or pose a threat to public health and safety. a. The proposed construction route requires the construction of North 25th Avenue and Breeze Lane, if concurrent construction is requested and approved the construction route must be updated to identify the routing prior to the construction of the local streets. The applicant is advised that the intersection of West Oak Street and North 27th Avenue is planned for construction during the 2019 season. Access at the intersection may be limited and should be accounted for in the construction routing. No formal request for concurrent construction, needs to include Breeze Lane, 25th and the water and sewer could be found in the application. Please provided a formal letter requesting concurrent construction and indicating which items will be covered and how each of the item in section 38.270.030.C will be addressed. • A concurrent construction request is included with this submittal. 2. Bozeman Unified Development Code Section 38.400.050.A.1 states: All streets and roads providing access to, and within, the proposed development shall meet the following standards: 1. Right-of-way width and construction standards contained in this chapter, the most recently adopted long range transportation plan, the City of Bozeman Design Standards and Specifications Policy, and the City of Bozeman Modifications to Montana Public Works Civil/Structural Engineering and Surveying Standard Specifications shall apply. a. North 25th Avenue from the intersection of Tschache Lane to the southern property boundary and Breeze Lane must be competed in order for the site plan to be approved. The applicant may consider advisory comment No. 2. Verify the request for concurrent construction, needs to include Breeze Lane, 25th and the water and sewer? • A concurrent construction request is included with this submittal. 3. BMC 38.400.100.C states: Drive aisles and alleys. At the intersection of each driveway or alley with a street, no fence, wall or planting in excess of 30 inches above the street centerline grade is permitted within a triangular area where corners are defined by two points on the right-of-way line, 15 feet on each side of the centerline of the driveway or alley and a point on centerline ten feet outside the right-of-way. Any driveway or alley wider than 30 feet curb to curb at the right-of-way line must use the vision triangle standard for local streets when intersecting local, collector, or arterial streets. a. The applicant must indicate the street visions triangle for all drive accesses on the architectural sheets. On street parking may not be located within the street vision triangle. In addition on street parking may not be striped, the architectural sheets must be updated to note this. The street vision triangles are shown incorrectly at the intersection of Breeze and 27th and Breeze and 25th. Both the civil and landscaping plans must be updated prior to site plan approval. • The street vision triangles have been updated to meet City code. 4. BMC 38.410.070.A.1 states: The developer must install complete municipal water and sanitary sewer system facilities, or a system allowed by section 38.350.030.D, and may be required by the city to install municipal storm sewer system facilities. These systems must be installed in accordance with the requirements of the state department of environmental quality and the city, and must conform with any applicable facilities plan. The city's requirements are contained in the Design Standards and Specifications Policy and the City of Bozeman Modifications to Montana Public Works Standard Specifications, and by this reference these standards are incorporated into and made a part of these regulations. The developer must submit plans and specifications for the proposed facilities to the city and to the state department of environmental quality and must obtain their approvals prior to commencing construction of any municipal water, sanitary sewer or storm sewer system facilities. a. The provided a peak-hour sanitary sewer flow demand estimate for the proposed project must be provided by a professional engineer (registered in the state of Montana) and include calculations for the estimate so the City Engineering Division can verify downstream sewer capacity. The City is currently monitoring the downstream sewer flows as part of the process to verify capacity. Until monitor is completed capacity cannot be fully verified. The applicant should contact the engineering department (Griffin Nielsen) for an update on the status of monitoring. The estimate must include Civil/Structural Engineering and Surveying the calculations used to determine the peak hour demand including the peaking factor used, per the City of Bozeman Design Standards and Specifications Policy Manual V.B. The estimate provided has not been updated to reflect the change in intensity, nor does it provided a total demand for the project. The estimate must certified by a professional engineering registered in the state of Montana. b. The proposed sewer in the center median of North 27th Ave will be in conflict with the existing overhead utility line and will not be allowed. Addressed c. The applicant is responsible for the construction the water main from the intersection of Tschache Lane to the southern property line and the looped connection in Breeze Lane to North 27th Avenue. Please provided a formal letter requesting concurrent construction and indicating which items will be covered and how each of the item in section 38.270.030.C will be addressed. d. Utility lines must maintain 10 feet of clear between all structures and major landscaping feature including trees, the proposed routing for services does not provide adequate clearance. There appears to be less than 10ft of separation from the proposed street tree and the sanitary sewer service to row houses. e. NEW: Please profile view of the fire, water and sanitary services to demonstrate that minimum bury depths can be achieved for all service lines specifically beneath the stormwater pond. Fire and Water require 6.5 feet of cover and 5 feet for sanitary service. • The sanitary sewer demand has been updated with this submittal. • This comment has been addressed. • A concurrent construction request is included with this submittal. • The street tree has been moved to be 10’ away from the sanitary sewer service. • Profile views of the water/fire and sanitary sewer services are included with this submittal. The sanitary sewer main running within Breeze Lane is very deep so the service will not require any insulation to maintain 5’ of cover. The water and fire services will require foam insulation for the length of the pond. This has been called out on sheet C2.0 and will be reflected on the fire line construction plans. 5. BMC Section 38.410.060.A states: Where determined to be necessary, public and/or private easements shall be provided for private and public utilities, drainage, vehicular or pedestrian access, etc. a. The “New Common Open Space Boundary (Subdivision Exemption)” must be complete prior to site plan approval. Prior to approval of the subdivision exemption, the applicant must provide sufficient stormwater pond volume to replace the existing volume and to accommodate the proposed new project. The applicant is advised that the active stormwater pond volume must be located above the seasonal high groundwater level. The applicant must measure the seasonal high groundwater level to confirm the placement of the stormwater pond volume above the groundwater level. Addressed a subdivision exemption is no longer required. b. The proposed utility easements along the property frontages must be provided prior to site plan approval. The applicant should contact the City Engineering Department (Griffin Nielsen) to obtain a copy of the standard public utility easement. Please Civil/Structural Engineering and Surveying provide the recorded document number with dedicates the utility easements. • A subdivision exemption is no longer required. • Utility easements along the property frontages were finalized with the Correction Plat of the Amended Plat of Lot 5, Annie Subdivision, Phase 2 (Plat J-204-A). 6. BMC Section 38.410.080.A. states: The developer must install complete drainage facilities in accordance with the requirements of the state department of environmental quality and the city, and must conform to any applicable facilities plan and the terms of any approved site specific stormwater control plan. The city's requirements are contained in the Design Standards and Specifications Policy and the City of Bozeman Modifications to Montana Public Works Standard Specifications, and by this reference these standards are incorporated into and made a part of these regulations. The developer must submit plans and specifications to the city and to the state department of environmental quality (if applicable), and must obtain their approvals prior to commencing construction of any drainage system facilities. a. The underground structure will only be allowed if the applicant installs a system to manage groundwater pumped from the underground structure on-site. The applicant must demonstrate that the storage provided with the proposed dry wells is adequate for discharge from the sump-pump during the season high groundwater. In order to do this the applicant must identify the season high groundwater elevations. Water from sump pumps may not be pumped or overflow into the existing drainage system or into the public right-of-way. Addressed, this comment is no longer relevant. b. The applicant must provide a maintenance manual for the proposed stormwater retention system for review and approval prior to site plan approval. The applicant must also demonstrate that maintenance manual has been included in the homeowner’s association covenants and restrictions prior to site plan approval. An exhibit should be provided identifying the stormwater infrastructure which must be maintained as a number of the facilities are located offsite. The maintenance manual must include in the owner’s association covenants and restrictions. c. The applicant proposed to place stormwater retention for N. 25th Avenue and Breeze Land in Rose Park. The applicant must obtain approval for the proposed stormwater system on Rose Park from the City Parks and Recreation Department, and the master park plan for Rose Park must be amended and approved by City Commission prior to site plan approval. Alternatively, the stormwater detention/retention for N. 25th Avenue and Breeze Lane may be located on the Palisade site. The Maintenance responsibility for the stormwater infrastructure must be clearly define within the stormwater maintenance plan. This comment has not been addressed, please provided the document define maintenance responsibility for the stormwater infrastructure included in the design of 25th and Breeze. d. The drainage report must include capacity calculations demonstrating that the conveyance infrastructure can pass the 25-year event. Calculations must be provided for the sidewalk chases. The flow rate for the 25-year event is not identified, the calculations end at the time of concentration, nor are there capacity calculations for the onsite storm chase and western swale, please provide these. e. The stormwater pond must be located outside for the public utility easement along the Civil/Structural Engineering and Surveying property frontage or receive approval from the dry utility companies that the encroachment is acceptable. f. Please update the drainage exhibit to clearly define the basin, the line type and lack of color makes it difficult to distinguish the boundaries. Addressed g. The volume of the drywells noted in the stormwater report narrative verses the supporting calculations differ, please correct. In addition, Detail 6 Sheet C1.3 show inconsistent dimensions of the dry well height. h. New: Please provided the relevant sections of the drainage report for the 25th and Breeze which demonstrate that the downstream infrastructure was designed to accommodate from the project. i. New: The stormwater design report includes a reduction in required retention volume for the dry well in Drainage Area #2 based on infiltration. The City’s design standard do long allow for this reduction. The calculations must be revised and the system increased as necessary prior to site plan approval. • This comment has been addressed. • Two sheets from the construction set for the 25th and Breeze project have been included in Appendix E of the Stormwater Design Report showing the layout of the retention pond within Rose Park. • The City Parks department approved the location of the proposed stormwater retention pond within Rose Park during the construction review of the 25th and Breeze project. Documentation of the maintenance responsibility is included with this submittal. • The stormwater design has been revised slightly. The curb cut and chase have been eliminated and storm inlets and piping have been added. Calculations for the 25-year event for each inlet and pipe have been included in the Stormwater Design Report. • This comment has been addressed. • The drywell volume has been updated to match on both the plan sheets and the stormwater design report. • The relevant sections from the 25th and Breeze Stormwater Design Report have been included at the end of the Stormwater Design Report for this development. The section discussing the retention pond has been highlighted. • Infiltration calculations have been eliminated from the drywell sizing. 7. BMC Section 38.410.130.A states: Prior to a final approval of all development reviewed as a site plan, conditional use permit, planned unit development, or subdivision and prior to an annexation of any land, one of the following must occur: Payment must be made to the city of a payment-in-lieu of water rights, calculated based on the annual demand for volume of water Civil/Structural Engineering and Surveying the development will require multiplied by the most current annual unit price; a. The applicant must pay cash-in-lieu of water rights due prior to site plan approval. Not addressed, payment has not been made. • The applicant has provided an updated calculation for the CILWR based on the new layout with the 7-plex and 18-plex building. Please review the estimate and the applicant will make the payment prior to site plan approval. 8. BMC Section 38.520.050 states: The standards herein supplement the provisions of divisions 38.400 and 540. Where there is a conflict, these provisions apply. A. Intent: 1. to create a safe, convenient, and efficient network for vehicle circulation and parking. 2. To enhance the visual character of interior access roads. 3. To minimize conflicts with pedestrian circulation and activity. a. The drive accesses require inconsistent vehicle circular at the corners of the internal drive aisles which will present vehicle conflicts and will not be supported. Addressed b. The drive accesses at the southern portion or each lot require vehicles to back over the internal and public site walk and into the public right-of-way, also see UDC Section 38.540.020.D.. This is not permitted and must be changed prior to site plan approval. Addressed • Both of these comments have been addressed. 9. BMC Section 38.520.070.B.1 states Service areas (loading docks, trash dumpsters, compactors, recycling areas, electrical panels, and mechanical equipment areas) must be located for convenient service access while avoiding negative visual, auditory, olfactory, or physical impacts on the streetscape environment and adjacent residentially zoned properties. Service areas must be sited for alley access if available. a. The applicant must receive approval for the arrangement of all trash encloses prior to site plan approval. Pending approval from the solid waste division. • The solid waste division requested that the doors open 180 degrees for the garbage enclosure. The proposed enclosure has doors that meet this requirement. 10. BMC Section 38.540.020.C: Circulation between bays. Except in the case of one to four- household dwellings and individual townhouse/rowhouse units, parking areas must be designed so that circulation between parking bays occurs within the designated parking lot and does not depend upon a public street or alley. Turning radii between bays and additional back-up length for dead end aisles must conform to requirements of the International Fire Code. a. The applicant must demonstrate that the layout of the internal drive aisle provide reasonable access for emergency services. The applicant must provide vehicle turning diagrams for the City’s fire truck for each internal corner. – Addressed Civil/Structural Engineering and Surveying • This comment has been addressed. 11. BMC Section 38.540.020.M states: Snow removal storage areas.Snow removal storage areas must be provided sufficient to store snow accumulation on site. Such areas may not cause unsafe ingress/egress to the parking areas, may not cause snow to be deposited on public rights- of-way, may not include areas provided for required parking access and spaces, and may not be placed in such a manner as to damage landscaping. All snow removal storage areas must be located and designed such that the resultant stormwater runoff is directed into landscaped retention/detention and water quality improvement facilities as required by the engineering department, or in compliance with the storm drainage provisions of chapter 40 article 4, and/or best practices manual. a. The snow storage location provided is unreasonable as the location requires the onsite parking to be empty for the placement of snow. As the development is providing minimum parking its unreasonable for assume vacancy of these spots. Adequate snow storage must be provided prior to site plan approval. Addressed. • This comment has been addressed. Conditions of Approval: 1. If not already filed, 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 West Oak Street including paving, curb/gutter, sidewalk, and storm drainage b. Street improvements to North 27th Avenue including paving, curb/gutter, sidewalk, and storm drainage c. Street improvements to North 25th Avenue including paving, curb/gutter, sidewalk, and storm drainage d. Street improvements to Tschache Lane including paving, curb/gutter, sidewalk, and storm drainage e. Intersection improvements for Tschache Lane and North 27th Avenue f. Intersection improvements for West Oak Street and Tschache Lane g. Intersection improvements for West Oak Street and North 27th Avenue The document filed must specify that in the event an SID is not utilized for the completion of these improvements, the developer 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 filed SID waiver prior to final plat approval. • The waiver of right to protest SIDs will be finalized and recorded prior to final plat. A draft copy is included in this submittal. 2. The project falls in the “Far West Sewer Payback” area. The applicant must pay the sewer payback ($467.18/acre) prior to site plan approval. Civil/Structural Engineering and Surveying • The applicant is prepared to make a payment of $718.85 (1.5387 AC*$467.18). Due to the current pandemic, please reach out directly to the applicant and have them pay via credit card or mail in a check. Note: During preparation of the staff report for future applications, additional conditions of approval may be recommended based on comments and recommendations provided by other applicable review agencies involved with the review of the project. If you require any further information, please give me a call at (406) 587-1115. Sincerely, Luke Stein, E.I.