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HomeMy WebLinkAbout2.15_Bozeman East Mixed-Use Development Site Plan Review - Engineering Comment Response_03-19-21 February 19, 2021 Brian Krueger, Development Review Manager City of Bozeman Department of Planning and Community Development P.O. Box 1230 Bozeman, MT 59771-1230 Re: Bozeman East Mixed-Use Master Site Plan Review COB#: 19230/19231 MMI#: 3959.022 Dear Brian: This letter is to provide written responses to the comments stated in the engineering review memo dated January 13, 2020. Below are our responses associated with each comment. ENGINEERING COMMENTS: Concurrent Construction 1. BMC 38.270.030 (C) Completion of improvements - The applicant has requested concurrent construction for the public infrastructure associated with the development. a. The applicant must provide all required concurrent construction documents i. Documented easements for the proposed upgrades (i.e. street sections, water, sewer, etc.)(Prior to site plan approval). See below comments for required updates to easement documents. Understood, the easements have been updated per these comments. ii. Written approval from the fire department for concurrent construction (Prior to site plan approval). Understood, Scott Mueller at the Fire department has been contacted and is reviewing concurrently. Email correspondence has been included with this resubmittal. The applicant is advised that no occupancy, either temporary or final, may be issued until all on- site and off-site water, sewer, and street or drive improvements are installed and accepted or approved as applicable by the City. The construction of the development will be phased according to the City approved construction phasing plan. Deviations from the approved construction phasing plan could require a MOD application from the applicant. Unapproved changes could result in the City issuing an immediate stop work order. Understood. Legal 1. BMC 38.410.060 - All public easements must be provided with the master site plan submittal in a clean draft format for review prior to master site plan approval. 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. Please provide a complete easy to follow easement package for review. This includes all existing and proposed easements; this complete package is helpful for tracking purposes. The following easements have been identified in the application: a. Public Street and Utility easement for North 15th Avenue i. The provided easements are acceptable. This easement has been included in the easement package. b. Public Utility easement along the street frontage per 38.410.060.B.2.a. This includes Tschache Lane as well as North 15th Avenue. i. The draft easement is acceptable. ii. Provide finalized document with signatures and surveyor stamp. This easement has been included in the easement package with a signature and surveyor stamp. c. Public Access easement for the mid-block crossing that runs from Tschache Lane through the center of the development and connects to North 15th. i. The public access and utility easement is the improper template for the sidewalk/trail through the site. The applicant must provide the easement using the Public Access Easement for Multiuse Path template. Please contact me at kajohnson@bozeman.net to receive a copy of the template. ii. Provide finalized document with signatures and surveyor / engineer stamp. This easement has been revised to reflect the Multiuse Path template and include the signatures and surveyor stamp. d. Sewer and Water pipeline access easement for the mains intended to service the development. i. The fire hydrants must be included in the water and sewer utility easement. At no time will the utility line in question be less than 9 feet from the edge of the easement. ii. Provide finalized document with signatures and surveyor / engineer stamp. This easement has been revised to include the fire hydrants and has the signatures and surveyor stamp. e. A public drainage easement for the drainage from Tschache Lane. i. The draft easement is acceptable. ii. Provide finalized document with signatures and surveyor stamp. This easement has been revised to include the signatures and survey stamp. f. A trail corridor easement for the proposed crushed fines trail as identified in the City’s PROST plan. i. The draft easement is acceptable. ii. Provide finalized document with signatures and surveyor stamp. This easement has been revised to include the signatures and survey stamp. The following easements have been identified for release and reconveyance in the application: a. Release of platted temporary easement 50-foot temporary cul-de-sac. i. Provide finalized document with signatures and surveyor / engineer stamp. The surveyor does not have the authority to stamp the existing easement to be released. We will get the city to sign off on the release of the 50-foot temporary cul-de-sac and finalize it as a condition of approval. b. Stormwater Drainage Easement (see stormwater comments) - The applicant is proposing to change an existing private stormwater drainage easement. The private easement must be updated to reflect these changes. i. Provide exhibit depicting location of easement. The exhibit has been provided in the easement document. ii. Provide finalized document with signatures and surveyor / engineer stamp. The surveyor does not have the authority to stamp the existing easement to be released. We will get the owner to sign off on the release of the storm easement and finalize it as a condition of approval. 2. DSSP Section (D) (5) Easements - No permanent structures shall be placed within a utility easement unless an encroachment permit has been obtained. Trees or other significant landscaping features shall not be placed within ten (10) feet of any utility main or service lines. a. The light pole near the west entrance off of Tschache is within 10 feet of the sewer main The light pole has been moved so that it is 10’ away from the sewer and water main. Water and Sewer 1. DSSP. V.D – When water mains cross sanitary or storm sewer mains, the water line must have an eighteen (18) inch minimum vertical separation, with all water pipe joints no closer than ten (10) feet horizontal from the sewer pipe centerline, and the crossing will be perpendicular to the sewer line. A minimum of (10) feet horizontal separation shall be maintained between any water main and any sanitary storm sewer main. a. 10 feet of horizontal separation must be maintained between buried power line and water main and sewer manhole west of the north end of building 2/B. The buried power line has been moved to maintain horizontal separation from the water main and sewer manhole. b. 10 feet of horizontal separation must be maintained between the sewer line running out of the grease interceptor for Building 1/A and the water main. The sewer line has been revised to maintain the 10’ horizontal separation c. 10 feet of horizontal separation must be maintained between the sewer services and water services to Building 4/D. Understood these utilities have been revised to maintain the 10’ horizontal separation Water Rights 1. BMC 38.410.130 - Water rights and/or payment of cash-in-lieu of water right is required prior to site plan approval for the demand on the City’s potable water system. Understood. Brian Heaston has been contacted and sent the draft calculation of the cash in lieu of water rights. Commercial use for each building is not known yet but once the uses are confirmed, Briand will work on a draft agreement with the developer. 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 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. i. The seasonal high ground water level in the most recent drainage report (12-18- 2020) assumed groundwater levels are 3.78 feet below grade, which is deeper than all but 1 seasonal high ground water monitoring recordings. Particularly, the two monitoring wells closest to the existing retention pond have a seasonal high groundwater level of 1.06 and 2.39 feet below grade (Based on 6-29-2018 measurements). The applicant needs to provide further rational why a seasonal high ground water level of 3.78 feet below grade is accurate for design. The pond has been enlarged to accommodate the high groundwater level. This has been revised in the plan set and the stormwater design report. b. 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. i. The drainage report does not show the offsite drainage that will contribute to the detention pond. This must be included in resubmittal. The Bridger Peaks subdivision Revised Drainage Report is included in this resubmittal. The relevant sections of the report have been highlighted. The offsite drainage that contributes to the detention pond is located on Figure 1 Phase I/II Developed Drainage Map. The information from these existing developed basins was used to appropriately size the detention pond. c. The Existing Conditions section of the report references the Bridger Peaks subdivision Revised Drainage Report. i. Applicable sections of this report must be included in the appendices of the drainage plan. The Bridger Peaks subdivision Revised Drainage Report is included in this resubmittal. The relevant sections of the report have been highlighted. 2. DSSP II.B – Storm drain plan shall include Details and specifications (including invert and other pertinent elevation information) for all storm drainage improvements, such as storm sewers, manholes, inlets, discharge structures; and retention/detention pond dimensions and volume, side slope, and top, bottom, and maximum water surface elevations. a. The drainage analysis (12-18-2020) did not include the following information for review: retention/detention pond dimensions, side slope, and top, bottom, and maximum water surface elevations. Exhibit 1 in the drainage analysis has been revised to reflect the dimensions, side slopes and water surface elevations of the pond. Lighting 1. DSSP Section XII.F - Pedestrian lighting is defined as luminaires mounted between 12ft and 15ft. Two pedestrian lights shall be installed on opposite sides of the street at all intersections of pathways and local streets located within the proposed development or along existing streets or roads abutting the development. a. Provide pedestrian light for the mid-block trail crossing on the south side of Tschache Lane meeting the height requirements and lighting requirements in Table C. Pedestrian Lighting Guidance. Average Horizontal Illuminance in footcandles and Illuminance Uniformity Ratio must be provided. This information has been revised in the Electrical/Photometric Sheets 2. BMC 38.400.070 - Street Lighting: The required public street light(s) must be included in a Special Improvement Lighting District (SILD), in accordance with the City of Bozeman Lighting and Electrical Specifications, prior to occupancy. Understood 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 Tschache Lane including lighting signalization paving, curb/gutter, sidewalk, lighting and storm drainage b. Street improvements to North 15th Avenue including lighting signalization paving, curb/gutter, sidewalk, lighting and storm drainage c. Intersection improvements to North 19th Ave and Tschache Lane 1. The applicant may obtain a copy of the template SID waiver from the City Engineering Department (Lance Lehigh). 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. Understood. The owner would like to revisit signing the waiver of right to protest with the city once the preliminary master site plan approval has been received. An unsigned copy of the Waiver of Right to protest is included in this submittal. ENGINEERING ADVISORY COMMENTS: 1. The applicant is advised that the proposed project falls within the Bozeman Solvent Site boundary. The property is underlain by an aquifer contaminated with perchloroethylene (PCE). The applicant has acknowledged that irrigation wells will not be dug as part of this project. Additionally, excavations and associated dewatering may be impacted by PCE contaminated groundwater. Understood. If you should have any questions regarding these comments, revisions and corrections for the Bozeman East Mixed-Use Site Plan Application don’t hesitate to contact me, Celine Saucier, PE Project Engineer