HomeMy WebLinkAbout6 19440 NW Crossing MaSP Eng Com 3.0 w responses 2020-10-13
MEMORANDUM
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TO: Danielle Garber, Associate Planner
FROM: Griffin Nielsen, Engineer II
RE: Northwest Crossing Master Site Plan Review No. 19440
DATE: September 11, 2020 MMI narrative in Blue below
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Engineering Adequacy Comments: The following comments must be addressed prior to
adequacy.
1. BMC 38.410.080. and BMC 38.410.130. Grading and Drainage and Watercourse Setback
- Based on aerial imagery, there appears to be a drainage swells that may convey water
from south to north on the eastern portion of the development, one of which is noted as
a waterway within the wetland report. The application is unclear as to the classification
and current status of these drainage swells. The applicant must receive a determination
from the Gallatin Valley Conservation District and the City's Engineering Department
(Brian Heaston) on whether these drainage swells are natural watercourses and/or
irrigation facilities. In addition, a determination must be made if these drainage swells are
conveying water from adjacent properties. The applicant is advised that offsite drainage
must be accounted in the drainage design.
As presented, insufficient information has been provided in order for the City to
determine if the drainage swells are natural watercourses. Please provide an
exhibit showing the approximant location of the tile drain system along with a
summary of how the tile drain system is currently functioning. In addition, the City
requires an approved wetland delineation report prior to further review. –
Pending acceptance for the wetland report by the City.
This is comment #4 from the May 3rd, 2020 COB review. The latest wetland
comments have been addressed – see the wetland narrative under separate
cover.
The applicant is advised that the City defines a watercourse per 38.700.210. The
applicant needs to demonstrate that the drainage swells are not a watercourse,
otherwise, the watercourse setbacks outlined within the UDC apply.
Lastly, the applicant is advised that the existing tile drain system was installed and
utilized to lower the surrounding groundwater elevations to farm. Therefore,
regardless of the determination of the drainage swells, the applicant must
demonstrate that future development in or around the existing tile drain system
does not change the functionality of existing system, adversely affect the
groundwater elevations, or negatively impact adjacent properties.
2. BMC 38.410.070. Municipal Water, Sanitary Sewer and Storm Sewer Systems. – The use
of an onsite private lift station is not in accordance with the City’s wastewater master plan
(WWMP). The Aajker Creek Division (15 inch) must be in place to serve the property. For
areas where existing topography does not allow service to be provided with the division
those areas must be served by the downstream infrastructure identified within the
WWMP. All references to the private lift station must be removed from the application
material.
We are currently working with the COB (Shawn K, Bob M. and Griffin N.) on creating a
gravity sewer solution for Northwest Crossing. This will require some changes to the
Norton Outfall sewer plans to accommodate a gravity sewer option for NWX. The COB
have issued a change order to COP Construction for this work. See the attached signed
Infrastructure Reimbursement Agreement (CITY OF BOZEMAN and NWX LLC 9 30
20.pdf)
3. BMC 38.410.040. Blocks - Wellsprings Drive must be extend between blocks 3 and 4 (Lots
C and D shown on Sheet MSP 1.03) to meet the City’s block length standard and ensure
the convenient movement of traffic, effective provision of emergency services and
efficient provision of utilities. The topography between the blocks does not inhibit the
connection nor are there critical lands, conflicts with access, or adjacent existing parks or
open space which inhibit the connection.
Wellspring Drive has been extended to Rosa Way with a 60’ Public Street and Utility
Easement. See the updated Master Site Plan for details.
Engineering Code Requirements: The following code requirements must be included with a
master site plan approval.
4. BMC 38.270.070. and BMC 38.400.010. The development is responsible for the local
share of Baxter Lane, Cottonwood Road, Laurel Parkway, and Baxter Lane. The local share
must be provided prior to final plat.
a. With the proposed first phase Cottonwood Road must be completed where
adjacent to the development from the intersection to the phase boundary. The
section must be completed and accepted by the City prior to final plat approval.
b. With the proposed first phase Oak Street must be completed where adjacent to
the development from the intersection to the phase boundary. The section must
be completed and accepted by the City and the properties prior to final plat
approval.
Acknowledged.
5. BMC 38.410.070. Municipal Water, Sanitary Sewer and Storm Sewer Systems. - The
proposed development falls within the wastewater drainage basin for the Norton East
Ranch Outfall and Davis Lane Lift station. The outfall and lift station, listed as Capital
Improvement Project (CIP) no. WWIF38 and WWIF31, are currently in progress. The
proposed projects must be completed and accepted by the City prior to final plat
approval, the City does not guarantee the timing of these projects.
Acknowledged.
6. BMC 38.410.100. Watercourse Setback – Water course setbacks apply to the Baxter Ditch
including the defined bed and back along the Baxter Lane. Any alterations to the
watercourse will be reviewed with future subdivision applications. If alterations are
proposed with a future subdivision written documentation must be provided from all
agencies holding jurisdiction of the water course that changes alterations area acceptable
prior to plat adequacy.
Reducing the water course setbacks by filling within the 100-year flood hazard area
extending beyond the 50 foot setback will be reviewed future subdivision applications.
Acknowledged.
Recommended Conditions of Approval:
1. The traffic impact study does not provide a detailed analysis for phased development as
such must be updated with each phase of the development. The updates must include
verifying traffic counts and incorporating changes to the surrounding transportation
system. The updated study will be required prior to preliminary plat adequacy for each
phase.
2. The all streets and transportation pathways must meet the City’s design standards. The
street layout provided in this application is considered conceptual and will be reviewed
for full compliance with the future subdivision applications.
3. Prior to the development of the intersection of Baxter Lane and Laurel Parkway a detailed
analysis must be performed to determine the intersection design. As present the traffic
impact study notes the need for either a roundabout or signal.
4. Prior to the development of the intersection of Oak Street and Laurel Parkway a detailed
analysis must be performed to determine the intersection design.
5. A "1 foot No Access" strip must be placed along the Cottonwood Road frontage of any lot
for which the City’s access separation requirement cannot be fully met. This will be listed
as a condition of approval for future subdivision.
6. A "1 foot No Access" strip must be placed along the Oak Street frontage for any lot which
the City’s access separation requirement cannot be fully met. This will be listed as a
condition of approval for future subdivision.
7. A "1 foot No Access" strip must be placed along the Baxter Lane frontage for any lot which
the City’s access separation requirement cannot be fully met. This will be listed as a
condition of approval for future subdivision.
8. A "1 foot No Access" strip must be placed along the Laurel Parkway frontage for any lot
which the City’s access separation requirement cannot be fully met. This will be listed as
a condition of approval for future subdivision.
9. The wastewater report must be updated with each phase of the development. The
updated report is required prior to preliminary plat adequacy for each phase.
10. The water design report doesn’t provide a detailed analysis for phased development as
such the water report must be updated with each phase of the development. The updated
report is required prior to preliminary plat adequacy for each phase.
11. The proposed street cross-sections for the internal streets is conceptual. Lane widths and
striping patterns will be shown as “preliminary, not approved by the engineering
department” and approved with the future subdivision applications.
12. Due to the high groundwater and increased rate of corrosion with in the clay soils all water
mains must have additional cathodic protection. A minimum of V-bio polyrap or approved
equal is required by the City.
13. The stormwater plan provided with the application is conceptual. 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. The comprehensive drainage plan must be provided with the future
subdivision.
a. Low Impact Design (LID) to mitigate stormwater must be used within the REMU
zoning district and is encouraged across the entirety of the development.
Applicant Acknowledges conditions 1 – 13 above.
14. A pedestrian signal warrant analysis must be provided with the first phase of
development in order to determine if additional infrastructure is required to support bike
and pedestrian connectivity/crossing.
A pedestrian signal warrant analysis was part of the TIS for the Phase 1 Subdivision
application submitted to the City of Bozeman on 4/23/20.
15. Public transit route options and stop locations must be consider when each phase of
development. HRDC or the current transit authorities must be contacted allowed to
comment with each phase. If a transit stop is identify with or adjacent to the development
must be completed prior to final plat approval or with subsequent site plan approval.
An email from Taylor Lonsdale dated 2/20/20 dealing with Public Transit
stop locations was provided in the 3-11-20 resubmittal.
16. The sanitary sewer within Rosa Way must be extended to the south side of the section of
Oak Street required to be constructed.
Acknowledged.
17. The sanitary sewer must be designed and extended to accept flow from the Laurel Glen
lift station. The sewer must be south side of the section of Oak Street required to be
constructed.
Acknowledged. The City of Bozeman will have to provide the sewer flow volume that
needs to be accommodated by the NWX sewer collection system in this location. It is
assumed the City of Bozeman will be responsible for the cost to oversize the NWX lines
to accommodate the Laurel Glen flow.
18. Access must be provided to all sanitary sewer lines and manholes. For mains not located
in a street or alley a 12-foot all-weather surface must be provided and maintained by the
property owner's association. In addition, all sewer mains must be located a minimum of
ten feet from all structures and major landscaping features including trees. All points
where mains are proposed within parks must be approved by both the Public Works and
Parks Department.
Acknowledged.
19. The applicant proposes a transfer to City ownership of existing water rights associated
with the subject property. The City hereby elects to accept these existing water rights for
transfer to City ownership pursuant to Sec. 38.410.130.A.2 BMC. The transfer of
ownership of these existing water rights must be in a form and manner suitable for
municipal purposes. The applicant and City shall, prior to final plat approval, enter into
an agreement containing mutually acceptable terms and provisions for the water rights
ownership transfer. 38.410.130 BMC must be satisfied prior to final plat approval.
Acknowledged.
20. Easements must be provided for the tile drain system or any alternative dewatering
system to ensure long-term access and maintenance. The easements must include
language restricting the construction of structures over the tile drain or alternative
system. Where the system crosses public right-of-way a utility occupancy permit must be
obtained from the City.
Acknowledged.
Advisory Comments:
21. The commercial development partially presenting in the master site plan application has
not been reviewed. Due to the significance of the a above comments and the require
changes to the master site plan and the subsequence required subdivision and site plan
review required for the development the engineering department cannot provide a
complete review.
22. The applicant must submit plans and specifications for water and sewer main extensions,
streets, and storm water improvements, prepared and signed by a professional engineer
(PE) registered in the State of Montana, which must be provided to and approved by the
City Engineer. Water and sewer plans must also be approved by the Montana Department
of Environmental Quality. The applicant must also provide professional engineering
services for construction inspection, post-construction certification, and preparation of
mylar record drawings. Construction shall not be initiated on the public infrastructure
improvements until the plans and specifications have been approved and a
preconstruction conference has been conducted. Building permits will not be issued
prior to City acceptance of the site infrastructure improvements unless all provisions
set forth in Section 38.270.030.C of the Bozeman Municipal Code are met to allow for
concurrent construction.
23. The Montana Department of Fish, Wildlife & Parks, SCS, Montana Department of
Environmental Quality and Army Corps of Engineer's shall be contacted regarding the
proposed project and any required permits (i.e., 310, 404, Turbidity exemption, etc.) shall
be obtained prior to future plat approval.
21-23 Acknowledged.
N:\5659\004 NW Crossing Master Site Plan\04 Design\Agency Submittal\COB\3rd COB Comment Respons\19440 NW Crossing MaSP Eng
Com 3.0 - 9-11-20 MMI Narative.docx