HomeMy WebLinkAbout2.13_Engineering Comment Response 12-18-2020
December 15, 2020
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
September 24, 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. A concurrent construction letter outlining and acknowledging BMC 38.270.030
(Completion of Improvements) requirements (Prior to site plan approval)
The concurrent construction letter has been provided in the resubmittal.
ii. Documented easements for the proposed upgrades (i.e. street sections, water, sewer,
etc.)(Prior to site plan approval).
An easement package has been submitted with a draft of all the easements for
the proposed upgrades.
iii. Plan and Specification approval from the City and State (Prior to issuance of building
permit).
Understood. The applicant is using Montana Public Works Standard
Specifications for the site specifications.
iv. Submittal of an executed original conditional irrevocable offer of dedication, please
contact the Engineering Department (Lance Lehigh) to receive a copy of this
document if needed. (Prior to site plan approval).
The submittal of an executed original conditional irrevocable offer of dedication
is provided in this resubmittal.
v. Written approval from the fire department for concurrent construction (Prior to site
plan approval).
Understood, correspondence with Scott Mueller attached – he requested this be
a part of the site plan application resubmittal before he reviews and approves.
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
2. 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.
An additional sheet Ex-8 has been added to illustrate the infrastructure to be constructed in
Phase 1.
a. Sheet Ex-6 (Master Site Plan) states that the water and sewer will be constructed in Phase 1.
However, Sheet C300 (Wet Utility Plan) states that water main will be constructed in two
separate phases. The phasing plan needs to be consistent across the entire plan set.
C300 has been modified to reflect the intent of the phasing plan that the water main will
be constructed in Phase 1.
Legal
1. 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).
Existing site features and topography sheet C100 has been updated with this information and
a new exhibit with all the proposed easements is included with this resubmittal.
2. 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.
A package with all the existing and proposed easements have been included in this
resubmittal.
The following easements have been identified in the application:
a. Public Street and Utility easement for North 15th Avenue
b. Temporary Construction and Access easement for North 15th and Patrick Street.
c. Public Utility easement along the street frontage per 38.410.060.B.2.a. This includes Tschache
Lane as well as North 15th Avenue.
d. Public Access easement for the mid-block crossing that runs from Tschache Lane through the
center of the development and connects to North 15th.
e. Sewer and Water pipeline access easement for the mains intended to service the development.
f. A public drainage easement for the drainage from Tschache Lane.
g. A trail corridor easement for the proposed crushed fines trail as identified in the City’s PROST
plan.
Acknowledged.
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.
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.
Acknowledged – a draft of the release and reconveyance has been included in this
resubmittal. The property owner based on the original easement agreement has the
right to relocate the drainage system and easement but must deliver written notice of
intent to Bridger Peaks, LLC. The lawyers from both parties are currently reviewing
the noticing and easement documents. It is understood that this must be done prior to
site plan approval.
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 North 15th Ave and Tschache Lane.
Understood – this has been included in the plans.
4. BMC 38.400.110 - The applicant is advised that proposed crushed fines trail shared use path must
be constructed as defined in the City Parks, Recreation, Open Space, and Trails (PROST) plan
upon future development. The applicant must coordinate with the City’s parks department and
provide a trail corridor easement with the master site plan application.
Understood – a trail corridor easement has been included with the master site plan
application.
5. BMC 38.410.080.E - A pubic drainage easement must be provided for the stormwater facilitates
supporting drainage from public roadways, which include Tschache Lane. The property owner(s)
are responsible for the maintenance of these facilities.
Understood – a public drainage easement has been provided for stormwater facilities from
public roadways.
6. 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 applicant needs to verify that the above easement condition is satisfied given the complexity
of the development.
Understood, trees and landscaping features have been removed so that this condition has
been satisfied.
Water and Sewer
1. Bozeman Design Standards and Specifications Policy (DSSP) V.D.1 – The alignment of all
water, sanitary sewer, and storm sewer mains and services shall be arranged so that there is a
minimum of ten (10) feet of horizontal separation between these lines and with any gas lines,
power lines, communication lines, utility poles or other above-grade utility structures, and street
lights.
a. There are a lot of proposed wet and dry utilities as show on sheets C300 and C301. The
proposed gravity sewer main running down the center corridor of the development is
approximately 4-feet away horizontally from a gas main. The applicant must provide
adequate separation. In general, private utilities should be removed from public utility
easements or have adequate separation. The applicant is advised to work with the water and
sewer department to determine what is acceptable for future maintenance. As presented, the
applicant must revise the proposed utility plans to satisfy DSSP conditions prior to master site
plan approval.
The utilities have been relocated to meet this condition.
2. DSSP. V.D.2.c – 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. The applicant must verify all utility crossings. The proposed storm sewer as well as buried
power crosses public sewer and water at a number of locations at different angles. This can
become problematic for future maintenance. As presented, the applicant must revise the
proposed utility plans to satisfy DSSP conditions prior to master site plan approval.
Understood.
b. The applicant is advised to minimize utility crossings, cross perpendicular, and keep private
utilities, including storm drainage out of public easements, whenever possible.
Understood
c. The applicant is advised that the City must have the ability to access buried utilities for
maintenance activities.
Understood
d. Horizontal alignment between manholes shall be straight.
Understood
3. BMC 38.540.020 (F) Surfacing - Areas must be paved with concrete or asphaltic concrete or
approved pavers; an alternative surfacing method such as pervious pavement may be used,
subject to review and approval by the review authority. Surfacing methods which minimize
stormwater runoff and provide for functional parking and circulation are encouraged.
a. As presented, the center pedestrian corridor shows a publicly maintained gravity sewer main.
It is unclear the type of material and landscaping associated with the development. The
applicant must coordinate with the City’s water and sewer department to determine if the
proposed surfaces are acceptable for both future access and maintenance. Verification from
the water and sewer department must be obtained prior to master site plan approval.
Understood – John Alston has been contacted with regards to the center pedestrian
corridor. The concrete surface has been widened over the sewer line as to prevent paver
replacement during maintenance.
b. Engineering is not opposed to an alternative surface, however, if we have to gain access to
our utilities we recommend asphalt, in which we have the means to maintain.
Understood – We are currently proposing a concrete surface
c. Alternative surfaces outside of the public utility easement would be acceptable.
Understood
4. DSSP Section (V) (A) (B) – The water and sewer design reports must be prepared by and
stamped by a professional engineer for the proposed project prior to master site plan
approval.
Water and Sewer design reports stamped by a professional engineer have been
included in this resubmittal.
5. Water Riser Room - The applicant is advised to appropriately size the mechanical room to
fit the water service line lay length. See the attached pdf showing the recommended
mechanical room sizes based on pipe size lay lengths. Please contact John Alston
(jalston@bozeman.net) the City’s water and sewer superintendent if additional questions
arise. It is unclear if the mechanical rooms have been size correctly.
The mechanical rooms have been revised to meet the water service lay length
standard. The mechanical rooms are shown and dimensioned in the wet utility plan.
Transportation
1. BMC 38.400.050 & BMC 38.400.060 – The applicant is advised that the segment of North 15th
Avenue between Patrick Street and Tschache Lane must be constructed prior to site plan
approval unless the requirements outlined concurrent construction section have been satisfied.
North 15th Avenue must be constructed to a collector standard according to the City’s
Transportation Master Plan (TMP).
Understood. Per conversations with Shawn Kohtz, the city is working with Bennett
Properties to construct the segment of North 15th Avenue between Patrick Street and
Tschache Lane.
2. BMC 38.400.050 & BMC 38.400.060 – The applicant is advised that the segment of Tschache
Lane from the property’s eastern boundary to intersection of North 15th Avenue must be
constructed prior to site plan approval unless the requirements outlined concurrent construction
section have been satisfied. Tschache Lane must be constructed to a local standard.
Understood
3. The applicant must coordinate pedestrian crossings between the subject property and the
Arrowleaf Park and Perennial Park multi-family housing development located directly north of
the subject property prior to master site plan approval.
a. The pedestrian crossing at the intersection of Sacco Drive and Tschache Lane must line up
with the Arrowleaf crossing.
A pedestrian crossing has been coordinated with the Arrowleaf Project and shown in
the drawings. A pedestrian ramp has been added on the site to align with the
pedestrian crossing.
b. A mid-block crossing on Tschache Lane is required to allow safe pedestrian crossing
between the two proposed trail networks as well as connectivity to a proposed streamline
bus stop location (located on the Arrowleaf project). The approximate mid-block crossing
on the Arrowleaf is shown below. Again, the applicant must coordinate the crossing
Arrowleaf project. The applicant is advised that the crossing will require a street light as
outlined in the DSSP lighting standards section.
A proposed street light at the mid-block crossing has been added to the site and
electrical plans. This light has been located with the coordination with the Arrowleaf
project.
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. The applicant is advised to
contact Brian Heaston in the City’s Engineering Department to discuss the required water rights
analysis.
Brian Heaston has been contacted and sent the draft calculation of the cash in lieu of
water rights, correspondence has been attached. Commercial use for each building is not
known yet but once the uses are confirmed, Brian 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. As noted in the geotechnical reports, seasonal high
groundwater levels have been collected (Well TP3). Standing groundwater was observed at
the facility on 9/22/2020.
The applicant is advised to verify local groundwater elevations and incorporate these levels
into the drainage design report. This includes the detention facilities as well as the storm
drain piping.
The high ground water has been addressed in a separate section of the drainage
report. Standing groundwater was most likely observed because of improper pond
maintenance. With the construction of the final phase and the full use of the detention
facility, the pond will be properly maintained with debris cleaned from the outlet
regularly. A stormwater maintenance plan has been included with this resubmittal.
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. It appears that Pond 2 in the original drainage design
will no longer be needed. Again, the comprehensive drainage plan must address these
changes, phasing, etc.
Pond 2 in the NE corner in the original drainage design of the development will be
expanded as a part of the final phase of Bridger Peaks development. Stormwater
phasing has been elaborated in the drainage report. The expansion of Pond 2 will
occur in the first phase to ensure that the pond will be able to detain the entirety of
the existing and proposed development.
c. Section 7 of the existing drainage easement states the following “In addition, if Saccoccia
relocates any portion of the drainage system. The parties will execute and record an
amendment to the easement or replacement easement agreement which reflects the
revisions to the drainage system.” The applicant must satisfy the conditions outlined within
the existing easement document prior to master site plan approval.
The existing drainage easement will be released and reconveyed with a new one to be
dedicated.
d. Deep basin’s designed for stormwater shall be placed in remote areas and be fenced.
Although the basin was designed prior to the basin criteria sizing for maximum water
depth, the applicant is proposing to expand the existing facility to accommodate future
runoff from Lot 5. The maximum water depth of the facility is 3.6 ft, which exceeds the 2.5
ft maximum depth requirement. The applicant must work with the planning department to
ensure the facility is fenced, safe to the general public, and aesthetically matches the
development and surrounding area.
Additional detail has been added to the landscape plan to illustrate the specific fencing
that will be used around the pond. The fencing will provide a safe barrier while
aesthetically matching the development and surrounding area.
e. The proposed C value from the development was determined to be 0.70. However, almost
the entire development is either pavement, concrete, or rooftops, which warrant a C value
of 0.9. Provide the composite C factor calculation with associated subwatersheds identified
within the report.
The justification for this C value is calculated and addressed in the revised storm
report.
f. The proposed pond 2 outlet structure needs to be included in the detail sheets within the civil
package.
The pond 2 outlet structure detailed is included in C040 detail sheet
2. DSSP II.B – A storm drainage facilities maintenance plan is required. The applicant must be able
to access the site for routine maintenance to ensure the site is safe and the system operationally
effective. This includes subsurface facilities, such as the storm drain pipe.
A storm drain maintenance plan has been included in this resubmittal.
3. BMC 38.600.090.B.4.a - Requires the flood hazard evaluation be certified by a Professional
Engineer registered in the state of Montana.
A signed flood hazard evaluation has been included in this resubmittal.
RECOMMENDED CONDITIONS OF
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
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