1a. Plans & Specs Lake Susan Hills West 4th Addition / a....
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CITY OF -
1 CHANHASSEN
F 690 COULTER DRIVE •• P.O. BOX 147 •• CHANHASSEN, MINNESOTA 55317
' (612) 937-1900 • FAX (612) 937-5739
Amex By City A3nrtrfstttt.
I MEMORANDUM `�-r/VV
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_
TO: Gary Warren, City Engineer 8 ;" "---p: -,
FROM: Charles Folch, Assistant City Engineer _
De-I DATE: September 5 , 1990 ;� ^ V
SUBJ: Approve Plans and Specifications for
I Lake Susan Hills West 4th Addition
Project No. 90-14 (pvt)
IA review has been conducted of the final plans and specifications
submittal for Lake Susan Hills West 4th Addition. The public
improvements will encompass the construction of sanitary sewer,
I
watermain and related services, storm sewer and street
construction for the following areas: Lake Susan Hills Drive
beginning at the existing southerly limits and extending south to
I the proposed connection with Powers Boulevard (County Road 17) ,
the adjacent cul-de-sacs off of Lake Susan Hills Drive (Tern
Court and Merganser Court) , Flamingo Drive extending from its
I present southerly limits south to Pintail Court, and a small
portion of Flamingo Drive off of Lake Susan Hills Drive extending
west into Kingfisher Court.
•
ISANITARY SEWER
I Sanitary sewer is proposed to be connected to the existing
system on Lake Susan Hills Drive extending south approximately
900 feet along the new Lake Susan Hills Drive extension. It
I should be noted that at this time, due to elevation limitations,
gravity sewer will not be able to serve a small area at the south
end of the Lake Susan Hills Drive, thus, these areas are platted
as outlots . These outlots will likely be served by gravity sewer
' in the future from the subdivision on the east side of County
Road 17. A small segment of gravity sewer is also proposed to be
extended south from the existing Flamingo Drive and west into
1 Pintail Court. Based on the type of pipe, sizes, grades proposed
and submitted calculated verification, the system appears to be
adequately sized for capacity and minimum scour velocities .
I
I
Gary Warren
September 5, 1990
Page 2
' WATERMAIN
A 10-inch DIP watermain is proposed to be connected to the
existing line at the southerly limits of Lake Susan Hills Drive
and extended south approximately 900 feet to the last serviceable
' lot, at the present time, with gravity sewer . This 4th Addition
watermain system is proposed to be looped with future additions
via interconnects through Kingfisher Court and Pintail Court to
' provide additional flow sources in times of emergencies and
breakage. The Fire Marshall has reviewed these plans for hydrant
location requirements and other safety issues and is satisfied
with the current submittal .
STORM SEWER
Storm sewer is proposed throughout the 4th Adddition. The
majority of the storm sewer system has been designed to carry the
rainfall runoff to a proposed ponding basin and sedimentation
basin configuration in the park area. A small area on the
southerly portion of Lake Susan Hills Drive will drain down to
the County Road 17 ditch. Outlet velocities have been designed
' to yield discharge rates of less than three feet per second
during design storms as recommended by staff. It should also be
noted that a County utility permit will be required for the
installation of the storm sewer within the County right-of-way
along County Road 17 .
The outlet for the detention pond has been designed to maintain
the predeveloped runoff rate for the 100-year 24-hour storm.
This has been verified with submitted calculations and mass
diagrams . The proposed ponding outlet will discharge across a
pipeline easement of Williams Brothers . It is the City' s desire
to see this outlet extended approximately another 100 feet
crossing the pipeline easement and outletting into a natural
' draw. I have previously met with the applicant' s engineer, Peter
Molinaro, and have requested that information be obtained from
Williams Brothers pipeline as to location and depth of the
pipeline to determine whether extending the outlet through the
' pipeline easement is feasible. To date, this information has not
been obtained. However, when it becomes available, the applicant
has agreed to work with the City on implementing the best outlet
' location.
1
Gary Warren
September 5 , 1990
Page 3
STREETS '
A 35-foot back-of-curb to back-of-curb street width is proposed
for Lake Susan Hills Drive consistent with the previous
construction. This street section will extend down approximately
1 , 000 feet where it will transition into a 28-foot temporary road
section. The justification for the temporary road section
results from the inability to serve the abutting properties along
this segment of street via gravity sewer at the present time.
When the sanitary sewer and watermain is provided for the
abutting property in this area, the City will require that the
street be reconstructed to the approved width of 35 foot
back-of-curb to back-of-curb.
A 5-foot concrete sidewalk is also proposed to be extended along
the west boulevard area of Lake Susan Hills Drive and along the
southerly portion of Flamingo Drive. The sidewalk is proposed to
discontinue at the limit of serviceable lots. However, the City
recommends constructing the walk out to C.R. 17 at this time.
It is recommended that temporary construction barricades will be
installed at the current limit of Lake Susan Hills Drive in order
to eliminate any potential construction vehicles from accessing
the site .from the residential area. Barricades will also be
installed on Flamingo Drive just south of Pintail Court and south
of Kingfisher Court as a temporary safety measure until these
road segments are extended in the future.
The parkland area is also proposed to be constructed at this
time. Improvements will involve grading of the park area,
installation of storm sewer and outlets and construction of the
detention ponds . The 8-foot wide bituminous trails proposed for
the park accesses will be constructed from the public streets
through the easement areas to the back property lines of the
residential lots under this contract. The trails will then be
extended under a separate park improvement contract at a future
date. '
RECOMMENDED CONDITIONS
1. Applicant shall work with and abide by staff recommendation
in determining the most appropriate location for the
detention pond outlet in relation to the William' s Brothers
pipeline.
2 . Sidewalk on Lake Susan Hills Drive shall be extended to County
Road 17.
1
' Gary Warren
September 5 , 1990
Page 4
3 . The name Pintail Court shall be changed as it has been
previously assigned in the City.
' 4 . Upon final inspection and approval of the sanitary sewer, the
applicant shall furnish the City with a television report and
' a copy of the VHS video.
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' Attachment: Plans
pF�1�1R�ENGINEERING COPY
Received
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APpr0V2d by G iY Er:�
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