Letter from C. Moehrl 12-6-05
December 6, 2004
Robert Generous
Senior Planner
City of Chanhassen
7700 Market Bvld.
P.O.Box 147
Chanhassen, MN 55317
Re: Pinehurst
Ref: 20041064
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Dear Robert:
Following is a copy of the conditions in the staff report with our responses in bold to each item. I thought this
would be a good list to get to you and Matt before we meet on Monday to give you a chance to review the items.
Please don't hesitate to call if you have any questions or concerns before then.
RECOMMENDA TION
Staff recommends that the Planning Commission adopt the following two motions:
A. "The Chanhassen Planning Commission recommends approval of the Rezoning of the 27.62 acres located within
the Pinehurst subdivision from Rural Residential (RR) to Single-Family Residential (RSF) based on consistency with
the City of Chanhassen Comprehensive Plan and compatibility with surrounding development."
B. "The Chanhassen Planning Commission recommends approval of the preliminary plat for Pinehurst Addition with
a variance for the use of private streets, plans prepared by Westwood Professional Services, Inc., dated 9/17/04,
revised 9/22/04 and 11105/04, based on the findings of fact attached to this report and subject to the following
conditions:
1. Setbacks shall be a minimum of 20 feet from the back of the private street.
Agreed; setbacks are shown 20' from the back of curb of the private streets.
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2. Outlots A and B shall be dediçated to the city,
Plowshares would like to dedicate Ou]ot B & donate Outlot A. We can discuss on Monday.
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3. Water Resources Coordinator Conditions:
a. Wetland buffer widths of 16.5 feet to 20.0 feet shall be maintained around all wetlands on-site.
Noted and shown·
b. All structures shall maintain a 40-foot setback from wetland buffer edges.
Noted and shown
c. The building pad on Lot 9, Block 1 shall be revised to reflect the wetland setback requirements.
Already shown on plan. Easiest to see on the preliminary plat sheet. The pad line is trimmed to
match the setback.
d. Wetland buffer areas shall be preserved, surveyed and staked in accordance with the City's
wetland ordinance. The applicant shall install wetland buffer edge signs, under the direction of City staff,
before construction begins and shall pay the City $20 per sign.
Noted
e. 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
Mr. Robert Generous
December 5, 2004
Page 2
following table of slopes and time frames:
Time
Type of Slope (maximum time an area can remain unvegetated
when area is not actively being worked)
Steeper than 3: 1 7 Days
10:1 to 3:1 14 Days
Flatter than 10:1 21 Days
These areas include constructed storm water management pond side slopes, 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 man made systems that discharge to a surface water.
Noted
f. Daily scraping and sweeping of public streets shall be completed any time construction site soil,
mud, silt or rock is tracked or washed onto paved surface or street that would allow tracked materials or
residuals of that material to enter the storm water conveyance system.
Noted
g. Construction site access points shall be minimized to controlled access points with rock entrance
and exit pads installed and maintained throughout construction.
Noted
h. Based on the proposed developed area of23.36 acres, the estimated total SWMP fee, due payable
to the City at the time of final plat recording is $83,465.
Noted. Would there be a credit for the future development water being accounted for from the
north?
\. The applicant shall 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.
Noted
4. Natural Resources Coordinator Conditions:
a.
A minimum of two overs tory trees shall be required in the front yard of each lot.
Noted
The developer shall be responsible for installing all landscape materials prop,osed, in rear an~ side
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We would like to modify this to read "developer and/or builder". ¡\JO.." '. . >' I)
Tree preservation fence shall be installed at the edge of the grading limits prior to any
construction.
Noted. We also assume that orange silt fence can double as tree protection fence where appropriate. l¡
Tree preservation on site shall be according to tree preservatio.n plans dated 09/17/04. Any trees
removed in excess of proposed tree preservation plans wìll be replaced at a ratio of 2: 1 diameter inches.
We would like this to reference final tree preservation plans as some additional trees may be
removed due to the need for a right turn lane.
Engineer's Conditions:
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a. The applicant will be required to meet the existing site runoff rates for lO-year and 100-year, 24-
hour storm events. The proposed ponds must be designed to National Urban Runoff Program (NURP)
standards. In addition, the proposed ponding must be sized to accommodate the drainage generated from
the property to the north, as shown in the City's Surface Water Management Plan (SWMP).
Noted and provided on the plans and drainage report. Is there a ponding credit for treatment of the
future development to the north?
b. The storm sewer must be designed for a lO-year, 24-hour storm event. Submit storm sewer sizing
cales and drainage map prior to final plat for staff review and approval.
Noted. Will provide with construction plans.
Mr. Robert Generous
December 5,2004
Page 3
c. Drainage and utility easements must be dedicated on the final plat over the public storm drainage
system including ponds, drainage swales, and wetlands up to the 100-year flood level.
Noted.
d. Staff recommends that Type II silt fence, which is a heavy duty fence, be used adjacent to the
existing wetland, existing creek area, and around the proposed pond. In addition, tree preservation fencing
must be installed at the limits of tree removal. Erosion control blankets are recommended for all of the
steep 3: 1 slopes with an elevation change of eight feet or more.
Noted
e. All plans must be signed by a registered Civil Engineer in the State of Minnesota.
Noted
f.
On the utility plan:
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1. Show all existing and proposed utility and pond easements.
Noted
2. Maintain lO-foot horizontal separation between all sanitary/water/storm sewer mains.
Provided on plans
3. Increase the watermain pipe size in Street D to 8-inches in diameter.
Noted. Note that the connection is proposed as open trench construction. The tree impact can !
,H be minimized through the use of t!'~l!Çhb,ºxes.
\ 4) Add a storm sewer line between Lots 7 and 8, Block 1 with a catch basin at the north property line for
future connection by the property to the north.
Noted. An additional line will be added. Note that the drainage report incorporates this future
. '~\ developed condition to the north. Will there be an oversize credit on storm sewer for additional
\lsize needed due to designing for a future condition?
5. Extend sanitary manhole #12 to the north property line with an invert elevation of 1049.0.
Noted. Will the property owner to the north grant an easement for construction of the manhole
on the property line? If not, can the manhole be held south of the property line an appropriate
distance to keep construction south of the line? Will there be an 9.ver depth credJt?
g. On the grading plan: - -- .
1. Show all existing and proposed easements..
Shown on the plan.
2. Show the benchmark used for the site survey.
Noted. Will add to construction plans.
3. Maximum allowable side slope is 3:1; revise in the rearyard of Lots 14 and 15, Block 1 and the rear
yard of Lot 3, Block 2.
Noted
4. Show the location and elevation of all emergency overflows; the elevation must be 1.5' lower than any
adjacent house pad elevations.
Noted. Will add to construction plans.
5. Show the retaining wall top and bottom elevations.
Noted. Will add to construction plans.
6. Use storm sewer class 5 in roadway; revise note under general grading and drainage notes
accordingly.
Noted for pipe 18" and smaller. Larger pipe can be classed based upon the appropriate
structural charts based on depth of pipe. These charts can be submitted to staff for review if
needed for the construction plans.
Any retaining wall over four feet in height must be designed by a registered civil engineer and a
permit from the city building department must be obtained. In addition, encroachment agreements will be
required for any retaining wall within a public easement.
Noted
I. The sanitary sewer and water hookup charges along with the Lake Ann Interceptor charge will be
applicable for each of the new lots. The 2004 trunk hookup charge is $1,458.00 per unit for sanitary sewer
and $2,814.00 per unit for watermain. The total 2004 Lake Ann Interceptor charge is $2,102 per unit and
the SAC fee is $1,425.00 per unit. All of these charges are based on the number of SAC units assigned by
the Metropolitan Council. Sanitary sewer and water-main hookup fees may be specially assessed against
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Mr. Robert Generous
December 5, 2004
Page 4
the parcel at the time of building permit issuance.
Noted
j. All disturbed areas, as a result of construction, must be seeded and mulched or sodded
immediately after grading to minimize erosion.
Noted
k. The applicant should be aware that any off-site grading wìll require an easement from the
appropriate property owner.
Noted
I. 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.
Noted. This can be provided once the contract is awarded.
m. Due to the depth of the proposed sanitary sewer from MH-20 to MH-17, the required easement
width wìll be increased to 50 feet.
A 50' easement is provided on the plan.
n. All of the utility improvements are required to be constructed in accordance with the City's latest
edition of Standard Specifications and Detail Plates. 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.
Noted
o. A temporary cul-de-sac turnaround for emergency vehicles will be required at the north end of
Street B along with a sign stating that the road wìll be extended in the future.
Noted
p.
Eliminate Lot 27 and shift the proposed pond to the north to eliminate some of the retaining wall.
We have reviewed the retaining wall and ponding in detail and have the following comments:
F\ 1. The retaining wall is designed primarily for the benefit of tree preservation
~;;\ to the south and was not proposed to facilitate Lot 27. Eliminating Lot 27
\':J does not have a significant impact on ponding and thereby does not
significantly reduce the amount of retaining wall. We can show a rough
sketch on Monday to explain.
2. Swales are proposed on both the rear and the side of the lot to facilitate
drainage away from the house pad. If there is a drainage concern, we can
show more detail with spot elevations in the swales to demonstrate that
good drainage is proposed around the house.
3. A 20 foot flat area is proposed at the walkout elevation which is typically a
desired minimum for builders.
4. The lot fully conforms to City codes and standards without the need for a
variance. Lot size = 18,323 sq. ft.
5. Removal of this lot would have a negligible reduction in retaining wall size.
6. From a market perspective the lot is highly desirable. It provides for a
side-load garage and a walkout pad, which abuts an attractive water
feature.
Delete the western sanitary sewer line; all sanitary sewer must drain to Manchester Drive.
Eliminating this connection will force the sanitary sewer to depths around 45'. The specific location
of the sanitary line through the City outlot is somewhat flexible. Based on the steep slopes, it would
appear that any future pump house would need to be located on the far west end of the Outlot. Let's
discuss at the Monday meeting.
Revise Street C to be a standard cul-de-sac.
The proposed Street C is a feature that adds character and an open space green amenity to the
development. The total width from ROW line to ROW line is 130'. A standard cul·de-sac has a
ROW diameter of 120'. If maintenance is a concern for the City, the green island maintenance
responsibility could be assigned to the association and written into the homeowner's association
documents. The island could also be platted as an outlot. Fee title could rest with the association.
Let's discuss further on Monday.
Lower the western end of the site in the area of the two private drives.
There are some problems that are created by lowering the west end of the site. In order to lower
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Mr. Robert Generous
December 5, 2004
Page 5
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Private Drive D, Street A would also have to be lowered which would cause the removal of the trees
in the rear yards of Lots 1-6, Block 1 and Lots 18 and 19, Block 1. Lowering the west end of the site
would also drive the sanitary sewer deeper and potentially make it difficult if not impossible to
convey storm sewer to the pond. The lots along Private Drive E tie in nicely to the existing grades as
shown. Lowering the road would change this condition. The wall behind the lots along Private
Drive D are not completely necessary. They were added to the plan primarily to save trees. All walls
will be designed and constructed in full conformance with the City building department
requirements. We can review further at the Monday meeting.
This development is required to provide enough additional platted right-of-way which results in 50
feet of right-of-way on the western side of the Galpin Boulevard centerline.
Provided on the plans. Note that the section line is not the centerline of the road. Our survey
department has computed the centerline of the road and has provided ROW 50' from that line. We
can provide more information if needed.
A right-turn lane into the site off of Galpin Boulevard will be required to be constructed. The
turn-lane must meet Carver County design requirements.
Noted. Jay Molnau at the County has requested verbally a 200' turn lane with a 180' taper.
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Please contact me if you have any questions.
Sincerely,
WESTWOOD PROFESSIONAL SERVICES, INC.
Chris Moehrl, PE, LSIT
Project Manager