Final PlatMEMORANDUM
TO: Todd Gerhardt, City Manager
FROM: Sharmeen Al-Jaff, Senior Planner
DATE: April 10, 2006
SUBJ: Gateway North Final Plat Approval,
Chanhassen Gateway Place, LLC
Planning Case #06-05
PROPOSAL SUMMARY
The developer is requesting final plat approval to subdivide a 6.26 acre parcel into three lots and two outlots for Gateway North.
ACTION REQUIRED
City Council approval requires a majority of City Council present.
BACKGROUND
On February 27, 2006, the City Council adopted the following motions:
PRELIMINARY PLAT
"The Chanhassen City Council approves the preliminary plat for Planning Case 06-05 for Gateway North as shown on the plans received January 6, 2006, subject to the following conditions:
Submit storm sewer design calculations with full-size drainage map for a 10-year, 24-hour storm event.
Finding: This condition has been met.
Work with staff to revise the pond design calculations for the 10- and 100-year storm event.
Finding: This condition has been amended to read: “Work with staff to revise the storm sewer and pond design calculations for the 10- and 100-year storm event”.
Realign Lot 1, Block 2 full access perpendicular at Highway 101 and Lake Susan Drive intersection.
Finding: This condition has been met.
The applicant is required to coordinate with MnDOT on the full access at Lake Susan Drive and the storm pond outlet control sewer construction.
Finding: This condition still applies.
The applicant is responsible for obtaining and complying with all regularity agency permits: Watershed District, MPCA, NPDES, MnDOT, Health Department, etc.
Finding: This condition still applies.
On the grading plan:
Show an emergency over flow.
Finding: This condition has been met.
Show stormwater pond easement.
Finding: This condition has been met.
Show silt fence Type II around the proposed pond.
Finding: This condition has been met.
Extend Type I silt fence to the north along the west side.
Finding: This condition has been met.
Show minimum 75-feet construction rock entrance.
Finding: This condition has still applies.
Add a bench mark.
Finding: This condition has been met.
7. On the utility plan:
Show the watermain within the street Right-of-Way as a public utility.
Finding: This condition has been met.
Revise the existing sanitary sewer flow direction.
Finding: This condition has been met.
Add a note that any connection to any existing structure must be core drilled.
Finding: This condition has been met.
Show all utility sewer pipe type, class, and size.
Finding: This condition has been amended to read: “Show storm sewer pipe type, class, and size.”
Show all utility manholes rim and invert elevations.
Finding: This condition has been amended to read: “Show all storm water manholes rim and invert elevations.”
Add a gate valve to Lot 1, Block 1.
Finding: This condition has been met.
Plan and profile views are required for the entire public utility.
Finding: This condition has been met.
To guarantee the installation of the public improvements, the applicant must supply the City with a financial security in the form of a letter of credit or cash escrow and enter into
a development contract.
Finding: This condition still applies
On the plans, show the pedestrian ramps and a sidewalk connection between the south and north sides of proposed Lake Susan Drive and add a sidewalk along the north portion of Lot 1,
Block 2.
Finding: This condition has been amended to read: “ The sidewalk along the north portion of Lot 1, Block 2, must connect with the Highway 101 sidewalk and be approved by Minnesota
Department of Transportation. The developer is responsible for the construction of the sidewalk from existing Highway 101 to the new Highway 101 extension. If a site plan for Lot
2, Block 2, is approved by the City Council before a Certificate of Occupancy issued for the building on Lot 1, Block 2, the developer of Lot 2, Block 2, will be responsible for constructing
the sidewalk west of the entrance to the apartment building on Lot 1, Block 2.”
Temporary easements are required for any off-site grading.
Finding: This condition still applies.
The applicant must provide a proposed haul route for review and approval.
Finding: This condition still applies.
If fill is coming from and/or going to another site in Chanhassen, a separate grading permit will be required for the other property.
Finding: This condition still applies.
All disturbed areas as a result of construction are required to be reseeded and mulched within two weeks of site grading.
Finding: This condition still applies.
Add City Detail Plates Nos. 1002, 1004, 1005, 1006, 2001, 2101, 2109, 2110, 2201, 2202, 3101, 3102, 3107, 3108, 3109, 5200, 5203, 5206, 5214, 5215, 5217, 5300, and 5301.
Finding: This condition still applies but has been revised to read: “Use the 2006 City Detail Plates Nos. 1002, 1004, 1005, 1006, 2001, 2101, 2109, 2110, 2201, 2202, 3101, 3102, 3104,
3107, 3108, 3109, 5200, 5203, 5206, 5214, 5215, 5217, 5300, 5301, 5302A, and 5313.
On the site plan, show the dimensions of the parking stalls and driveway widths.
Finding: This condition still applies but has been amended to read: “On the sidewalk and paving plan, show the dimensions of the parking stalls and driveway widths. Also, add a stop
sign at the curb cut on Lake Susan Drive.”
FINAL PLAT
The applicant is proposing to subdivide 6.2 acres into three lots and two outlots. Lot 1, Block 1 has an area of 1.1 acres and is proposed to remain vacant at the present time. The
Concept Plan showed a townhouse development on this lot.
Lot 1, Block 2 has an area of 2.19 acres and is proposed to house an apartment building.
Lot 2, Block 2 has an area of 2.28 acres and is proposed to remain vacant at the present time. The Concept Plan showed a townhouse development on this lot.
Outlot A has an area of 0.38 acres and will house a storm pond.
Outlot B is currently a portion of Highway 101. The west one-half right-of-way for Highway 101 was acquired via the Chanhassen Hills plats and MnDOT’s purchase of “Parcel 267” from
James A. Curry as shown on MnDOT Right-of-Way Map Number 10-18. Highway 101 is being realigned to the east; therefore the portion of the existing Highway 101 adjacent to this plat
will be removed and the right-of-way vacated. Since “Parcel 267” was not platted right-of-way, this vacated right-of-way has been turned back to the underlying property, in this case,
the parent property of the Gateway project.
The property is zoned Planned Unit Development-Mixed Use. Access to the site is gained via Lake Susan Drive.
Staff notes that the proposal is consistent with the Comprehensive Plan and generally consistent with the Zoning Ordinance.
WATER RESOURCES
Storm Water Management
Details on the storm sewer connections to proposed Lake Susan Drive and proposed TH 212 should be provided. An emergency overflow for the proposed pond should be illustrated. The applicant
should submit a routing plan for any pond overflows from the site to a public water body. The storm water pond should be platted in an outlot.
Easements
Drainage and utility easements (minimum 20 feet in width) should be provided over all storm water infrastructure, including any emergency overflow structures.
Erosion and Sediment Control
All exposed soil areas should have temporary erosion protection or permanent cover year round, according to the following table of slopes and time frames:
Type of Slope Time (Maximum time an area can
Steeper than 3:1 7 days remain open when the area
10:1 to 3:1 14 days is not actively being worked.)
Flatter than 10:1 21 days
These areas include constructed storm water management pond side slopes, and any exposed soil areas with a positive slope to a storm water conveyance system, such as a curb and gutter
system, storm sewer inlet, temporary or permanent drainage ditch or other natural or man made systems that discharge to a surface water.
The plans should be revised to show rock construction entrance installation per Chanhassen Detail Plate 5301.
Wimco or similar inlet protection should be installed at all inlets that may receive storm water from the site per Chanhassen Detail Plate 5302A. All inlet protection must be inspected
and maintained to comply with NPDES requirements.
Street cleaning of soil tracked onto public streets should include daily street scraping and street sweeping as needed.
Temporary stabilization of the exposed area should include a straw or hay cover at a rate of 2 tons per acre, disc anchored into the soil, including the area around the apartment building.
To minimize tracking and erosion around the apartment building during construction, temporary cover of straw or wood chips should be placed around the building in amounts sufficient
to control rutting.
The plans should be revised to show a concrete washout area, BMPs for containment and potential stockpile locations. Silt fence (Chanhassen Type 1) is needed around the north and east
side of the pond within 24 hours of permanent outlet installation. The plans should be revised to show inlet protection for sediment during construction for the trench drain at the
garage and should include a detail.
Surface Water Management Fees
All applicable water quantity and quality fees have been paid.
Other Agencies
The applicant should apply for and obtain permits from the appropriate regulatory agencies (e.g., Riley-Purgatory-Bluff Creek Watershed District, Minnesota Pollution Control Agency (NPDES
Phase II Construction Permit), Minnesota Department of Natural Resources (for dewatering)) and comply with their conditions of approval.
GRADING/DRAINAGE/EROSION CONTROL
The existing site is about 7.73 acres in size and almost 100% of the area will be graded by MnDOT for the extension of the proposed Lake Susan Drive and by the applicant. The proposal
includes three lots and an outlot. The current plans show an apartment building with underground parking. The applicant is proposing to grade the site to prepare the building pad,
parking lot, and stormwater ponding areas. The parking lot and building drainage will be collected by a system of catch basins within the parking lot and conveyed by storm sewers to
the proposed pond in the southwest corner of the site. The plans show a catch basin at the low point in the northwest corner of the proposed building with an emergency overflow discharging
around the building along the east side to the south. Also, the proposed pond outlet control structure discharges to the south to the proposed Highway 212 storm sewer. The plans are
not clear on how the stormwater pond overflow and the south area at a flooding period will be draining. The grading plan does not show the proposed development and Highway 212 contour
elevations. The applicant must coordinate and obtain MnDOT approval for this proposal and show the overall proposed drainage flow direction in relation with Highway 212.
A public drainage and utility easement is required over the proposed pond. This easement shall cover the pond up to the 100-year high water elevation. The applicant has submitted pond
sizing calculations for a 10- and 100-year, 24-hour storm event; minor revisions are necessary. The pond must be built to National Urban Runoff Program (NURP) standards in accordance
with the City's Surface Water Management Plan (SWMP) and must satisfy the requirements of MPCA’s phase 2 design standards. As per Walker model criteria, the proposed pond must have
a mean depth of three feet and be designed for a 2.5-inch rain event. Storm sewer sizing calculations with a full-size map for a 10-year, 24-hour storm event are required.
Proposed erosion control consists of silt fence along the east and south grading limits of the site. A rock construction entrance is proposed at the access off proposed Lake Susan Drive,
but it must be minimum 75 feet long. All disturbed areas as a result of construction, must be seeded and mulched or sodded immediately after grading to minimize erosion. The applicant
should be aware that any off-site grading will require an easement from the appropriate property owner. If importing or exporting material for development of the site is necessary,
the applicant will be required to supply the City with detailed haul routes.
The applicant must be aware that any retaining wall exceeding four feet in height must be designed by a registered structural engineer, with an approved safety fence. A building permit
from the City's Building Inspections Dept. must be obtained.
UTILITIES
The site has access to public sanitary sewer and watermain from the proposed Lake Susan Drive and existing Highway 101. The developer must show a connection to the existing watermain
within Highway 101, extend it to the east along the south side of the proposed Lake Susan Drive to serve the proposed building and the lots in the future phase. The applicant must
be aware that the watermain within the public street right-of-way will be a public utility and needs to
coordinate with MnDOT on the construction of the watermain. The private watermain that services Lots 1 & 2, Block 2 must be located within a 20-foot wide private utility easement along
the property line. A private sanitary sewer service to the proposed building will be extended from the existing sanitary manhole within the proposed Lake Susan Drive extension at the
northeast corner of Lot 1, Block 2. The installation of the private utilities for the site will require permits and inspections through the City’s Building Department.
The underlying property has been assessed for sewer, water, and street improvements and there is no remaining assessment due payable to the City. The applicant has already paid all
SAC and sanitary and water hook-up fees.
All of the utility improvements are required to be constructed in accordance with the City’s latest edition of Standard Specifications and Detail Plates. Upon completion of the public
utility improvements, the utilities will be turned over to the City for maintenance and ownership. The applicant is also required to enter into a development contract with the City
and supply the necessary financial security in the form of a letter of credit or cash escrow to guarantee installation of the improvements and the conditions of final plat approval.
Permits from the appropriate regulatory agencies will have to be obtained, including but not limited to the MPCA, NPDES, MN Department of Health, Watershed District, Carver County,
MnDOT, etc.
STREETS
The plans propose three full accesses off the proposed Lake Susan Drive, two to serve Lots 1 and 2, Block 2 and one to serve Lot 1, Block 1. No public streets are proposed in conjunction
with this project. MnDOT proposes to extend Lake Susan Drive from existing Highway 101 to the proposed Highway 101 realignment. The timing of the Lake Susan Drive extension is unknown;
therefore, the applicant must coordinate the proposed construction access with MnDOT. A temporary access of existing Highway 101 may be required. The applicant must be aware that
the MnDOT right-of-way turnback issue will not be resolved before this is platted. Also, the applicant must extend the sidewalk further east to the proposed Highway 101 intersection.
INTERNAL SITE CIRCULATION
The approved site plan identified a 24 foot wide shared driveway between Lots 1 and 2. The westerly 12 feet of this shared driveway was shown on Lot 2.
The current proposal identifies a shared access to Lake Susan Drive. Since the site plan for Lot 2 is unknown at this time, the developer proposes to construct the eastern 12 feet of
the shared driveway within Lot 1. Given the current configuration, staff recommends that a “Do Not Enter, One Way” sign be installed within the northern parking lot island and that
the 12 foot driveway be striped for one-way traffic for north-bound vehicles.
If a site plan for Lot 2 is submitted and does not require the shared access from Lake Susan Drive, staff recommends that the developer of Lot 1 examine an alternative parking lot layout
in this vicinity to reduce the amount of hard surface coverage. This would be a minor change that can be approved administratively.
LANDSCAPING
Landscaping requirements for the proposed development is shown in the following table:
Landscaping Item
Required
Proposed
Parking lot
1,533 ft2 landscape area
6 overstory trees
3 islands/peninsulas
1,890 ft2 landscape area
7 overstory trees
6 understory trees
East/South property line - Bufferyard B, 570’
6 overstory trees
12 understory trees
12 shrubs
18 overstory trees
20 understory trees
48 shrubs
berm provided
North property line - Bufferyard B, 300’
3 overstory trees
6 understory trees
12 shrubs
3 overstory trees
14 understory trees
52 shrubs
berm provided
West property line - Bufferyard A, 160’
2 overstory trees
4 understory trees
6 shrubs
2 overstory trees
4 understory
16 shrubs
Boulevard Trees –
Lake Susan Drive
1 per 30 feet –
13 overstory trees
13 overstory trees
The applicant meets all landscaping requirements.
Staff recommends that the applicant replace the Colorado blue spruce specified on the landscape plan with an alternate species of spruce or evergreen such as white spruce, Black Hills
spruce, or white fir. Colorado blue spruce tends to become unsightly with age due to disease problems.
TRAILS AND SIDEWALKS
Maintaining and creating new pedestrian/bicycle routes to the subject site is very important. The construction of new Highway 101 will include the installation of a 10-foot trail along
the east side of the highway. In conjunction with the construction of Highway 212, trails will be installed from Great Plains Boulevard to Lyman Boulevard, and along the north side
of Lyman Boulevard. Appropriate and adequate internal sidewalk connections are planned to allow convenient and safe non-vehicular traffic throughout the site. Park dedication is not
being required as part of the approval. Park dedication fees were prepaid with the application.
RECOMMENDATION
Staff recommends that the City Council adopt the following motion:
“The City Council grants final plat approval of Planning Case #06-05 for Chanhassen Gateway North for three lots and two outlots, as shown on the plans stamped ‘Received March 3, 2006’,
subject to the following conditions:
Details on the storm sewer connection to proposed Lake Susan Drive and proposed TH 212 should be provided.
Erosion control blanket shall be installed on all slopes greater than or equal to 3:1. All exposed soil areas shall have temporary erosion protection or permanent cover year round,
according to the following table of slopes and time frames:
Type of Slope Time (Maximum time an area can remain open
Steeper than 3:1 7 days when the area is not actively being worked.)
10:1 to 3:1 14 days
Flatter than 10:1 21 days
These areas include constructed storm water management pond side slopes, and any exposed soil areas with a positive slope to a storm water conveyance system, such as a curb and gutter
system, storm sewer inlet, temporary or permanent drainage ditch or other natural or man made systems that discharge to a surface water.
Rock construction entrance shall be installed as illustrated on Chanhassen Detail Plate 5301.
Wimco or similar inlet protection shall be installed at all inlets that may receive storm water from site per Chanhassen Detail Plate 5302A. All inlet protection shall be inspected and
maintained to comply with NPDES requirements.
Street cleaning of soil tracked onto public streets shall include daily street scraping and street sweeping as needed.
Temporary stabilization of the exposed area shall include a straw or hay cover at a rate of 2 tons per acre, disc anchored into the soil, including the area around the apartment building.
On the grading plan, the following should be revised:
The second note should include language to address maintenance of the rock construction entrance as needed.
The sixth note should be revised to read “All exposed soils not actively worked must be seeded and mulched within…”
The tenth note should include a statement about maintaining compliance with the requirements of the NPDES permit.
Show storm water structures rim and invert elevations.
Show minimum 75-feet construction rock entrance.
Show the contours for proposed Highway 212 and the area south of Highway 212.
The applicant must coordinate and obtain MnDOT approval for the proposed drainage discharge south of the proposed pond.
Work with staff to revise the storm sewer and pond design calculations for the 10- and 100-year storm event.
The applicant is required to coordinate with MnDOT regarding the full access at Lake Susan Drive and the storm pond outlet control sewer construction.
The applicant is responsible for obtaining and complying with all regularity agency permits: Watershed District, MPCA, NPDES, MnDOT, Health Department, etc.
On the utility plan:
Show storm sewer pipe type, class, and size.
Show all storm water manholes rim and invert elevations.
The developer shall coordinate the watermain construction within the Right-of-Way of Lake Susan Drive extension with MnDOT and Zumbro River Construction.
To guarantee the installation of the public improvements, the applicant must supply the City with a financial security in the form of a letter of credit or cash escrow and enter into
a development contract.
The sidewalk along the north portion of Lot 1, Block 2, must connect with the Highway 101 sidewalk and be approved by Minnesota Department of Transportation. The developer is responsible
for the construction of the sidewalk from existing Highway 101 to the new Highway 101 extension. If a site plan for Lot 2, Block 2, is approved by the City Council before a Certificate
of Occupancy issued for the building on Lot 1, Block 2, the developer of Lot 2, Block 2, will be responsible for constructing the sidewalk west of the entrance to the apartment building
on Lot 1, Block 2.
Temporary easements are required for any off-site grading.
The applicant must provide a proposed haul route for review and approval.
If fill is coming from and/or going to another site in Chanhassen, a separate grading permit will be required for the other property.
All disturbed areas as a result of construction are required to be reseeded and mulched within two weeks of site grading.
Use the 2006 City Detail Plates Nos. 1002, 1004, 1005, 1006, 2001, 2101, 2109, 2110, 2201, 2202, 3101, 3102, 3104, 3107, 3108, 3109, 5200, 5203, 5206, 5214, 5215, 5217, 5300, 5301, 5302A,
and 5313.
On the sidewalk and paving plan:
Show the length of the parking stalls.
The access at Lake Susan Drive must be minimum 26 feet wide.
All driveway aisles must be minimum 26 feet wide.
A “Do Not Enter, One Way” sign must be installed within the northern parking lot island and the 12 foot driveway be striped for one-way traffic for north-bound vehicles.
Installation of the private utilities for the site will require permits and inspections through the City’s Building Department.
On the plat and plans, show a 20 foot drainage and utility easement centered on the property line between Lots 1 and 2, Block 2.
A cross access easement over the shared driveway must be obtained and recorded against Lots 1 and 2, Block 2.
ATTACHMENT
Final Plat.
g:\plan\2006 planning cases\06-05 gateway north subdivision-gateway place site plan\final plat.doc