1b1 Knob Hill 2nd Addition Fina CITYOF
7700 Market Boulevard
PO Box 147
Chanhassen. MN 55317
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Web Site
',',,':,','.ci.chanhassen.mn.us
TO:
Todd Gerhardt, City Manager
FROM:
DATE:
Bob Generous, Senior Planner
July 22, 2002
SUB J:
Knob Hill 2nd Addition Final Plat, Subdivision #2002-2
PROPOSAL SUMMARY
The developer is requesting final plat approval to subdivide 7.59acres to create
nine lots, two outlots and fight-of-way for Knob Hill Lane.
BACKGROUND
On April 8, 2002, the Chanhassen City Council denied a variance for the use of a
private street based on the findings in the staff report and approved the
preliminary plat for Knob Hill 2nd Addition, plans prepared by RLK Kuusisto,
Ltd., dated January 17, 2002, revised February 6, 2002, creating nine lots, two
outlots and fight-of-way for Knob Hill Lane
FINAL PLAT REVIEW
GRADING, DRAINAGE & EROSION CONTROL
The plans propose to grade about 50% of the site for the new house pads, a
proposed street ending with a cul-de-sac and a storm water pond. The proposed
lots located in the southwesterly portion of the site will be custom graded. As
such, detailed grading, drainage, tree removal, and erosion control plans will be
required for each of the custom graded lots at the time of building permit
application. The proposed grading will prepare the site for lookout-type
dwellings on Lots 7, 8 and 9, Block 1. Drainage swales have been proposed along
the sides of the houses to maintain the neighborhood drainage pattern through the
property. There is an existing tennis court, bituminous private driveway, and an
existing pond to be removed. Also, the plans propose an approximately 85-foot
long 3.5-foot high retaining wall adjacent to the east side of the cul-de-sac. A
permit is required for the retaining wall and can be obtained through the Building
Department.
The existing site drainage is encompassed within four different drainage areas.
The northeasterly quarter of the site drains off site to the north. The east central
The Cily of ChanMssen · A gro;vin~ community with clean !akes. quality schoois, a charming downtown, thrivino~ businessesl windind~ trails., and beautilul parks. A ~,~o~'a~'. place to ,,,~,,, work, and play.
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 2
part of the site drains off site toward the east to an existing storm sewer inlet in the rear yards of
1368 and 1376 Ithilien. The extreme northwesterly comer of the site drains to the north through
an existing 15" culvert in the Knob Hill development. The remaining portion of the site, along
the south and west property lines, drains to Clasen Lake and its tributary outlet.
Under developed conditions, the applicant is proposing to capture all of the drainage from Lots
7-9, all of the street drainage, and all of the front yard drainage from Lots 1-6. This storm water
will be conveyed via storm sewer to a proposed NURP pond in the northeasterly comer of the
site. The amount of area that will still drain off site to the east has been dramatically reduced
from approximately 1.6 acres to 0.3 acre.
The applicant is required to meet the existing site runoff rates for the 10-year and 100-year, 24-
hour storm events. The storm sewer system must be designed for a 10-year, 24-hour storm
event. Drainage and utility easements shall 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.
The minimum easement width shall be 20 feet wide. In addition, the pond must be moved to
avoid holding water over the existing watermain on the northwest side of the property.
The applicant should be aware that any off-site grading will require an easement from the
appropriate property owner.
UTILITIES
Municipal sewer and water service is available to the site from Knob Hill Lane. The existing
home on the property is already connected to municipal sewer and water from Knob Hill Lane.
Watermain is also bordering the parcel on the northwest side. The applicant is proposing to
extend sewer and water lines along Knob Hill Lane to service the proposed lots.
According to the City's Finance Department records, the parcel was previously assessed for one
sanitary sewer and water hookup. Since the developer will be responsible for extending lateral
sewer and water service to the lots, the sanitary sewer and water connection charges will be
waived. However, the sanitary sewer and water hookup charges will still be applicable for each
of the new lots. The 2002 trunk hookup charge is $1,383 for sanitary sewer and $1,802 for
watermain. Sanitary sewer and watermain hookup fees may be specially assessed against the
parcel at the time of building permit issuance.
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 utility
improvements, the utilities will be turned over to the City for maintenance and ownership. The
applicant shall finance all of the proposed improvements. 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, Department of Health, MCES, and
Watershed District.
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 3
STREETS
Concerns were raised at the February 19, 2002 Planning Commission meeting regarding the
close proximity of the road to the rear yards of adjacent homes on Ithilien and the lack of
adequate buffeting. Staff believes the revised plan does a good job of addressing each of these
issues. The proposed road has now been moved approximately 20 feet farther away from the
rear yard lot line and a row of over a dozen evergreen trees are proposed to be planted between
the road and the lot line. In addition, the applicant is planning to transplant existing site trees in
this area to further buffer the residents.
The applicant is proposing a 60-foot wide street tight-of-way with a 60-foot cul-de-sac radius.
The pavement width is proposed to be 31 feet as per City standard.
LANDSCAPING/TREE PRESERVATION
Staff has worked with the applicant to develop a satisfactory landscaping plan.
PARKS AND RECREATION
The Parks and Recreation Commission met February 26, 2002, to review the proposed
development. The Parks and Recreation Commission voted to recommend that a trail easement be
required along the eastern property line of Lot 6, Block 1, which will eventually connect with an
existing trail in the Curry Farms development.
The proposed development will create eight new lots that will place additional demand on city
park facilities. Full park and trail fees will be required for development of each of the new lots.
Pursuant to city ordinance, one-third will be paid at the time of final plat recording and two-
thirds will be paid with the building permit.
COMPLIANCE TABLE
Description Area (sq. ft.) Frontage (ft.) Depth (ft.) Notes
RSF District 15,000 90 125 Setbacks (ft.):
front - 30', rear-
30', side 10'
Lot 1, Block 1 66,853 346 204 30, 30, 10, 60 rear
conservation
Lot 2, Block 1 28,979 95 266 30, 30, 10
60 rear
conservation
Lot 3, Block 1 21,238 106 235 30, 30, 10
60' rear
conservation
Lot 4, Block 1 19,790 165 175 30, 30, 10, 55'
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 4
rear conservation
Lot 5, Block 1 26,472 75@ 141 30, 30, 10, 60'
rear conservation
Lot6, Block l 30,187 315 234 30, 30, 10, 60'
rear conservation
Lot 7, Block 1 25,204 313 173 30, 30, 10
Lot 8, Block 1 15,019 90 171 30, 30, 10
Lot 9, Block 1' 18,824 90 139 30, 30, 10
Outlot A 24,666 Storm water pond
Outlot B 4,218
Knob Hill Lane 53,155
Average Lot Size 27,638
Total 330,785
@ 90 feet at building setback line
REVIEW CONDITIONS OF APPROVAL
1. Lots 1-6, Block 1, shall contain tree preservation easements in the rear yards as follows:
Lot 1, Block 1
Lot 2, Block 1
Lot 3, Block 1
Lot 4, Block 1
Lot 5, Block 1
Lot 6, Block 1
Rear 60'
Rear 60'
Rear 60'
Rear 55'
Southerly 60' and the westerly 60'
Rear 60'
*This condition still applies.
2. Tree protection fencing shall be installed prior to site grading.
.
*This condition still applies.
Demolition pe~Tnits must be obtained from the Inspections Division before demolishing any
structures on the property. The shed on Lot 2, Block 1 must either be moved to Lot 1, Block
1, or demolished.
*This condition still applies.
A final grading plan and soils report must be submitted to the Inspections Division before
building permits will be issued.
>:"This condition still applies.
5. Separate sewer and water services must be provided for each lot.
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 5
6. An exemption or wetland replacement plan shall be approved prior to any alterations to the
wetland on-site.
*This condition has been met.
7. Storm water calculations shall be submitted to ensure the proposed storm water pond is sized
adequately for the proposed development.
* This condition has been met.
8. CBMH 2 shall be a catch basin with a sump to remove grit from the storm water prior to
discharge into the proposed pond.
* This condition has been met.
9. The proposed pond shall outlet into a public drainage system capable of handling the
discharge.
* This condition has been met.
10. Silt fence shall be provided immediately down slope of all proposed custom graded areas.
Silt fence shall be removed upon completion of site grading and reestablishment of
vegetation.
*This condition still applies.
11. Erosion control blanket shall be installed on all slopes greater than or equal to 3:1.
*This condition still applies.
12. All upland areas disturbed as a result of construction activities shall be immediately restored
with seed and disc-mulched, covered with a wood-fiber blanket or sodded within two weeks of
completion of each activity in accordance with the City's Best Management Practice Handbook.
*This condition still applies.
13. Based on the proposed developed area of approximately 7.05 acres, the water quality fees
associated with this project are $5,640; the water quantity fees are approximately $13,959.
The applicant will be credited for water quality where NURP basins are provided to treat
runoff from the site. This will be determined upon review of the ponding and storm sewer
calculations. At this time, the estimated total SWMP fee, due payable to the City at the time of
final plat recording, is $19,599.
*This condition shall be modified as follows: Based on the proposed developed area of
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 6
approximately 7.05 acres, the water quality fees associated with this project are $5,640; the
water quantity fees are approximately $13,959. The applicant will receive $6,908.00 credit
for water quality where NURP basins are provided to treat runoff from the site. The total
SXVMP fee, due payable to the City at the time of final plat recording, is $12,691.
14. The applicant shall apply for and obtain permits from the appropriate regulatory agencies (e.g.
Minnehaha Creek Watershed District, Minnesota Pollution Control Agency, Minnesota
Department of Natural Resources, Army Corps of Engineers) and comply with their conditions
of approval.
*This condition can be deleted since it is duplicated in condition 23.
15. Detailed grading, drainage, tree removal, and erosion control plans will be required for each
of the custom graded lots at the time of building permit application.
*This condition still applies.
t6. Phor to final plat approval, a professional civil engineer registered in the State of Minnesota
must sign all plans.
This condition still applies.
17. Revise the cul-de-sac right-of-way to a 60-foot radius and the street pavement width to 31
feet.
*This condition has been met.
18. The applicant will be required to meet the existing site runoff rates for the 10-year and 100-
year, 24-hour storm events. The proposed pond must be designed to National Urban Runoff
Program (NURP) standards. The high water level (I-~VL) of the proposed pond, shown on
the grading plan as 1003.9, must be lowered to a maximum elevation of 1002. This new
ITWL will provide the required 3-foot vertical separation between the walkout elevations
(1005) of the existing homes at 1368 and 1376 Ithilien and the pond's ITWL in accordance
with the City's SWMP. The storm sewer must be designed for a 10-year, 24-hour storm
event. Drainage and utility easements shall be dedicated on the final plat over the public
sto~xn drainage system including ponds, drainage swales, and wetlands up to the 100-year
flood level. The minimum easement width shall be 20 feet wide.
*This condition shall be modified as follows: The applicant will be required to meet the
existing site runoff rates for the 10-year and 100-year, 24-hour storm events. The proposed
pond must be designed to National Urban Runoff Program (NURP) standards. The storm
sewer must be designed for a 10-year, 24-hour storm event. Drainage and utility easements
shall 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. The minimum easement width
Knob Hill 2n~l Addition Final Plat
July 22, 2002
Page 7
shall be 20 feet wide.
19. Staff recommends that Type III silt fence be used along the western property line of the site
adjacent to Clasen Lake. In addition, tree preservation fencing must be installed at the limits
of tree removal. A 75-foot minimum rock construction entrance should be added to the
entrance that will be accessed during construction. The applicant should be aware that any
off-site grading will require an easement from the appropriate property owner.
*This condition still applies.
20. The pad elevation of Lot 1, Block 2 shall be raised to 1012 to better facilitate drainage on the
west side of the lot.
*This condition has been met.
21. Installation of the private utilities for the site will require permits and inspections through
the City's Building Department.
*This condition still applies.
22. Each newly created lot will be subject to City sanitary sewer and water hookup charges at
the time of building permit issuance. The 2002 trunk utility hookup charges are $1,383 per
unit for sanitary sewer and $1,802 per unit for water.
*This condition still applies.
23.
Public utility improvements will be required to be constructed in accordance with the City's
latest editions of Standard Specifications and Detail Plates. Detailed construction plans and
specifications will be required at the time of final platting. The applicant will also be
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 must be obtained, including but not limited to the MPCA, Department of
Health, Watershed District, Carver County, etc.
*This condition shall be modified as follows: Public utility improvements will be required to
be constructed in accordance with the City's latest editions of Standard Specifications and
Detail Plates. Detailed construction plans and specifications will be required at the time of
final platting. The applicant shall finance all of the proposed improvements. Permits from
the appropriate regulatory agencies must be obtained, including but not limited to the MPCA,
Department of Health, Watershed District, Carver County, etc.
24.
Addthe following City of Chanhassen Detail Plates Numbers: 1002,1003,1005,1006,
2001,2109,2110,2201,2202,2203,2004,2205,3104,3106,3107,5301,5302,5232, and
5234.
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 8
*This condition has been met.
25. Lower MH-3 be lowered by approximately 3 feet in order to serve the basement of Lot 5,
Block 1.
*This condition has been met.
26. On the utility plan:
a. Show all the existing and proposed utility easements.
b. Add a legend.
c. Show the proposed storm sewer length, slope, and type.
d. Show sanitary sewer pipe class, length and slope.
'.":This condition has been met.
27.
On
a.
the grading plan:
Show all existing and proposed utility and pond easements.
Show the benchmark used for the site survey.
Add a note for removing existing bituminous driveway and restore with vegetation.
Show the storm sewer pipe, slope, and length.
Show a minimum of 75-foot rock construction entrance.
Add a legend which describes the existing and proposed contours, Type II silt fence,
property lines, etc.
Show typical house pad with definitions.
*This condition has been met.
28. On the preliminary plat'
a. Side and rear lot line easements should be shown as 5 feet wide.
b. Show all existing and proposed drainage and utility easements.
*This condition has been met.
29. A minimum 20-foot wide public easement is required for the pond outlet, which extends
outside the site property lines.
*This condition still applies.
30. The developer shall dedicate a 20-foot wide trail easement along the eastern property line of
Lot 6, Block 1. The development shall pay full park and trail fees pursuant to city ordinance for
the eight new lots.
".'"This condition still applies.
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 9
31. The applicant shall work with staff to develop a detailed evergreen buffer plan along the
eastern property line. The plan will include number and height of trees to be moved and
specific location where trees will be transplanted and also the height and location of new
evergreens to be planted.
*This condition has been met.
Upon review of the construction plans and final plat documents, staff is recommending that the
following conditions be added:
1. The pond must be moved to avoid holding water over the existing watermain on the
northwest side of the property.
2. The center point of the cul-de-sac must be on the same line as the center line of the right-of-
way.
RECOMMENDATION
Staff recommends that the City Council approve the following motion:
"The City Council approves the final plat for Knob Hill 2nd Addition, Subdivision #2002-2, subject
to the following conditions:
1. Lots 1-6, Block 1, shall contain tree preservation easements in the rear yards as follows:
Lot 1, Block 1
Lot 2, Block 1
Lot 3, Block 1
Lot 4, Block 1
Lot 5, Block 1
Lot 6, Block 1
Rear 60'
Rear 60'
Rear 60'
Rear 55'
Southerly 60' and the westerly 60'
Rear 60'
2. Tree protection fencing shall be installed prior to site grading.
o
Demolition permits must be obtained from the Inspections Division before demolishing
any structures on the property. The shed on Lot 2, Block 1 must either be moved to Lot
1, Block 1, or demolished.
4. A final grading plan and soils report must be submitted to the Inspections Division before
building permits will be issued.
o
Silt fence shall be provided immediately down slope of all proposed custom graded areas.
Silt fence shall be removed upon completion of site grading and reestablishment of
vegetation.
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 10
6. Erosion control blanket shall be installed on all slopes greater than or equal to 3:1.
,
All upland areas disturbed as a result of construction activities shall be immediately restored
with seed and disc-mulched, covered with a wood-fiber blanket or sodded within two weeks
of completion of each activity in accordance with the City's Best Management Practice
Handbook.
o
Based on the proposed developed area of approximately 7.05 acres, the water quality fees
associated with this project are $5,640; the water quantity fees are approximately
$13,959. The applicant will receive $6,908.00 credit for water quality where NURP
basins are provided to treat runoff from the site. The total SW1MP fee, due payable to the
City at the time of final plat recording, is $12,691.
9. Detailed grading, drainage, tree removal, and erosion control plans will be required for
each of the custom graded lots at the time of building permit application.
10. Prior to final plat approval, a professional civil engineer registered in the State of
Minnesota must sign all plans.
11. The applicant will be required to meet the existing site runoff rates for the 10-year and
100-year, 24-hour StO~Tn events. The proposed pond must be designed to National Urban
Runoff Program (NURP) standards. The sto~xn sewer must be designed for a 10-year, 24-
hour sto~n event. Drainage and utility easements shall 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. The minimum easement width shall be 20 feet wide.
12. Staff recommends that Type III silt fence be used along the western property line of the
site adjacent to Clasen Lake. In addition, tree preservation fencing must be installed at
the limits of tree removal. A 75-foot minimum rock construction entrance should be
added to the entrance that will be accessed during construction. The applicant should be
aware that any off-site grading will require an easement from the appropriate property
owner.
13. Installation of the private utilities for the site will require pro, nits and inspections through
the City's Building Department.
14.
Each newly created lot will be subject to City sanitary sewer and water hookup charges at
the time of building permit issuance. The 2002 trunk utility hookup charges are $1,383
per unit for sanitary sewer and $1,802 per unit for water.
15.
Public utility improvements will be required to be constructed in accordance with the
City's latest editions of Standard Specifications and Detail Plates. Detailed construction
plans and specifications will be required at the time of final platting. The applicant shall
finance all of the proposed improvements. Permits from the appropriate regulatory
Knob Hill 2nd Addition Final Plat
July 22, 2002
Page 11
agencies must be obtained, including but not limited to the MPCA, Department of Health,
Watershed District, Carver County, etc.
16. A minimum 20-foot wide public easement is required for the pond outlet, which extends
outside the site property lines.
17. The developer shall dedicate a 20-foot wide trail easement along the eastern property line of
Lot 6, Block 1. The development shall pay full park and trail fees pursuant to city ordinance
for the eight new lots.
18. The pond must be moved to avoid holding water over the existing watermain on the
northwest side of the property.
19. The center point of the cul-de-sac must be on the same line as the center line of the right-
of-way."
ATTACHMENTS
1. Reduced Copy of Final Plat
2. Location Map
g:\plan\bg\development review\Knob Hill 2nd FP.doc
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