HomeMy WebLinkAbout2014-03-12 City Engineer 03-07-2014 Plan Review Comments Stantec Consulting Services Inc.
2335 Highway 36 West
St. Paul MN 55113
Tel: (651) 636-4600
Stantec Fax: (651) 636-1311
March 12,2014
File: 193800151
Attention: Eric Johnson
City of Oak Park Heights
14168 Oak Park Blvd. N
P.O. BOX 2007
Oak Park Heights,MN 55082
Reference: Gateway Building-Plan Review
Dear Eric,
We have reviewed the site Development plans for Oak Park Heights Gateway as submitted by
Erickson Civil Site on March 7, 2014. Following are our initial comments and/or recommendations.
Sheet C1.1 -Existing Conditions & Demo Plan
1. Clearly identify existing sewer and water service locations from the mains to the building.
2. Clearly dimension and identify all existing or future easements and public right-of-ways
within and adjacent to the site.
Sheet C2.1 -Layout Plan
1. Concrete commercial driveway apron shall be provided at the proposed entrance
location, and shall be installed per attached City standard detail Plate No.STR-8
2. Clearly dimension and identify all existing, proposed or future easements and public right-
of-ways within and adjacent to the site.
3. A sidewalk connection needs to be shown between the future trail and the site.
4. Coordinate with MnDOT the proposed driveway entrance connection to the future
Oakgreen Avenue N. alignment.
Sheet C3.1 -Grading Plan
1. The future Oakgreen Avenue N. roadway and trail alignment adjacent to the property
may impact the proposed contours and cutoff the drainage swale on the north end of the
property as currently shown. Coordinate with MnDot and revise the proposed contours to
accommodate the future grading of Oakgreen Avenue N.
Design with community in mind
March 12,2014
Mr. Eric Johnson
Page 2 of 3
Sheet C4.1 - Utility Plan
1. Details on how the infiltration system will be cleaned and maintained need to be provided. A
maintenance agreement is required by the City with this storm water feature.
2. Utilize City standard castings and adjustment rings for utilities within the right of way.
3. The sanitary service needs to include an inline cleanout if the length of service is greater than
100 feet from the main to the building. Cleanout shall follow attached City standard detail
Plate No.SER-3.
4. Coordinate all water main connections with MnDOT.
5. Please clarify the pipe material conflict from MH 4 to the FES 3. The line style indicates CMP but
the attached note specifies HDPE.
6. Rip rap size and placement shall be per attached City standard detail Plate No.STO-13
Sheet C5.1 -Details
1. Add the following City Standard Details:
a. SER-3-PVC SERVICE LINE CLEANOUTS
b. STO-13- RIPRAP AT OUTLETS
c. STR-8-COMMERCIAL DRIVEWAY APRON
Sheet D1 -Drainage Map
Runoff Rate:
1. The peak runoff rate for proposed development shall not exceed the existing rate for the 2, 10,
and 100-year rainfall events. To adequately review the proposed development, the applicant
shall supply the requested materials and modify the submittal based on the comments below.
2. All hydrologic computations completed to design the proposed storm water management
facilities shall be provided. This includes all model inputs (curve number, tc, etc), and all
resulting model outputs.
3. The proposed drainage map shall be modified or expanded to demonstrate that each
drainage area (specifically P2) drains to a single point. Does the entirety of the drainage west
of the proposed building eventually travel north to Oasis Pond?
4. The proposed peak runoff rate of 2.25 cfs for the 2-year rainfall event shall be reexamined to
ensure that the existing peak runoff rate of 2.22 cfs is not exceeded.
Runoff Volume:
5. Per the City's LSWMP,infiltration standards for proposed projects are based on the Middle St.
Croix Watershed Management Organization's Watershed Management Plan. The applicant
shall work through the review process with the MSCWMO to ensure all standards are being
met.
Design with community in mind
March 12, 2014
Mr. Eric Johnson
Page 3 of 3
6. Based on the proposed impervious surface area, an infiltration volume (1/2" over impervious)
of 857 cubic feet is required. The 60" perforated HDPE underground storage trench provides
for an infiltration volume of 1288 cubic feet. The applicant shall provide soil information (soil
borings, if available) and any other relevant information to ensure that infiltration is a feasible
option.
If you have any questions or require further information please call me at (651)604-4722.
Regards,
STANTEC CONSULTING SERVICES INC.
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Brad A. Reifsteck, P.E.
c. Andy Kegley-Oak Park Heights
Scott Richards-The Planning Company LLC
Chris Long, City Engineer-Stantec.
Design with community in mind