ITEM 3.1_attachmentReview No. 1 (revised)
��l
son
I AnIgHde son
ENGINEERING REVIEW
Residential Subdivision
for the City of Otsego
by
Hakanson Anderson
Submitted to: Honorable Mayor and City Council
cc: Lori Johnson, City Administrator
Tami Loff, City Clerk
Dan Licht, City Planner
Andy MacArthur, City Attorney
Bill Christian, CBR Development, LLC
Scott Dahlke, Civil Engineering Site Design
Reviewed by: Ronald J. Wagner, P.E.
Brent M. Larson, P.E.
Date: February 12, 2015
Proposed
Development: Wilson Preserve
Street Location A portion of the SW 1/4 of the NE 1/4 of S21, T121, R23.
of Property: North of 85th Street and East of Odean Avenue.
Applicant: Bill Christian
Developer: CBR Development, LLC
21301 Co. Rd. 81
Rogers, MN 55374
Owners of Record: Christine M. Wilson and CBR Development, LLC
Purpose: Wilson Preserve is a proposed 10 lot single-family residential
development on 35± acres in the City of Otsego, Wright County,
Minnesota. The proposed development will NOT be served with
municipal water and sanitary sewer but will have municipal storm
sewer and public streets typical of an urban setting.
Jurisdictional Agencies: City of Otsego, Wright County, Minnesota Department of
(but not limited to) Health, Minnesota Department of Natural Resources, Minnesota
Pollution Control Agency, Wright Soil and Water Conservation
District.
Permits Required: NPDES, Minnesota Department of Natural Resources, BWSR, and
(but not limited to) Minnesota Pollution Control Agency (independent sewer systems)
TABLE OF CONTENTS
INFORMATION AVAILABLE
PRELIMINARY PLAT
EXISTING CONDITIONS
SUBDIVISION CONFIGURATION, LOT SIZE, DENSITY
STREET/TRAFFIC/ACCESS
PEDESTRIAN TRAIL
FINAL PLAT
CONSTRUCTION AND GRADING PLANS
SANITARY SEWER SYSTEM
WATER SYSTEM
SURFACE WATER MANAGEMENT/STORM SEWER SYSTEM
WETLANDS
NLIt 767,2ITlA2110
11/115 _G_t—wff-_\It • ' 1 uv I uv I a Q I UAI
PAGE 2
S:\Municipal\Aotsego23xa\2327\ot2327RVW1(revised).doc
INFORMATION AVAILABLE
Preliminary Plat for Wilson Preserve, 2/3/15, by Meyer-Rohlin Land Services
Final Plat for Wilson Preserve, 2/3/15, by Meyer-Rohlin Land Services
Construction and Grading Plans for Wilson Preserve, 2/3/15, by Civil Engineering Site Design
As -built Construction Plans for Odean Avenue Project, 8/15/00, by Hakanson Anderson
Associates
Additional Information
Minnesota Rules, Chapter 4410 — EAW Requirement
City of Otsego Engineering Manual
City of Otsego Zoning and Subdivision Ordinances
National Wetland Inventory Map
PAGE 3
S:\MunicipalWotsego23xx\2327\ot2327RVW1(revised).doc
PRELIMINARY PLAT
EXISTING CONDITIONS
The normal water and 100 -yr high water elevations are needed for all ponds/wetlands
within 150' of the boundaries (21-6-2.B.9).
SUBDIVISION CONFIGURATION, LOT SIZE, DENSITY
The existing and proposed zoning is P.U.D. Excluding Lot 1, Block 2 the development is
approximately 50% open space.
STREET/TRAFFIC/ACCESS
1. A single entrance to the development is being provided off of Odean Avenue.
2. The 874h Court (as well as O'Dell Court) are essentially 1,150 ft long cul-de-sacs. Cul-
de-sac streets permanently designed as such, shall not exceed five hundred (500) feet in
length. (21-7-6.A) In blocks longer than nine hundred (900) feet, ten (10') foot wide
pedestrian rights-of-way and/or easements through the block may be required in locations
deemed necessary for the public health, convenience and necessity. Suitable surfacing
shall be provided in pedestrian ways. (21-7-3.B)
PEDESTRIAN TRAIL
A 10' wide mowed trail is being proposed from 85th Street in the SE corner of the site
north, toward Hall's pond and then "meanders" along the rear yards of the lots along
Hall's pond.
There are a few concerns placing a trail along the wetland, especially a mowed
trail along. An unsurfaced trail near the wetland is likely to be muddy and at times
unpassable. A bituminous trail in this area would have issues with a wet/soft subgrade
that may cause it to breakup prematurely and would not be allowed by the DNR.
We recommend that the connection point of the trail at 85th Street be moved to
connect to Odean Avenue (at the new intersection of 87th Court). The trail shall be 10'
wide and paved for approx. 600'-650' until it is past Odell Avenue. The paved trail can
be used in an emergency as a 2nd pave access due to the lengths of cul-de-sacs.
Once past Odell Avenue the trail may change to a mowed trail and run along the
south side the storm pond then turn north towards Hall's pond. Once at Hall's pond the
trail should be cleared and grubbed 8' wide x 10' tall and follow the high side of the 870
contour to the north property line. See Attached sketch.
A short stretch at the very north end will need to be below the 870 contour so that
the trail can continue on the City property and connect to 88th Street. The section lower
than 870 will require approval by Roger Stradal with the DNR. The developer will also
be responsible for clearing and grubbing the trail along the City property along Hall's
pond until it reaches 88th Street.
PAGE 4
S:\Municipal\Aotsego23)cA232Tot2327RVW1(revised).doc
FINAL PLAT
The ROW and Outlot A shall be dedicated to the City?
CONSTRUCTION AND GRADING PLAN
TITLE SHEET
Provide a Approval signature line for Ronald J. Wagner, P.E. City Engineer.
SITE LAYOUT (Sheet CI)
Label the datum of the benchmark (all sheets). This should be NGVD 1929 adj. datum.
All as -built information provided for the Odean Ave and 85th Street project is on the 1929
datum.
2. The acreage showing is 39.54 acres. This differs from the preliminary plat shows 35.13
acres and.
See preliminary plat comments above regarding the pedestrian trail.
GRADING AND DRAINAGE PLAN (Sheet C2-C3)
The soil boring locations shall be shown on the plan. (21-6-2.13.8.)
2. Label the delineated wetland edges.
3. Show and label the 20' wetland buffer.
4. All garage floor elevations shall be a minimum of 18" above the adjacent curb (Lots 1, &
3, Block 1 do not meet this requirement).
The excavation in the middle of the pond will not work to meet the NDPES requirement
for infiltration. The area is under the normal water level and below the ground water
elevation shown in the Lot 4 septic test pit so no infiltration will be able to occur. Per the
NPDES the bottom of all infiltration practices shall be a minimum of 3' above the
seasonally saturated soils.
6. The entire runoff between Lots 8 & 9, Block 1 is being directed to discharge offsite onto
the existing lots to the east with no clear drainage path from there. This runoff can be
contained onsite if the swale is graded to direct the flow towards the pond near the rear of
Lot 9.
7. Label the emergency over flow (EOF) elevations near the curb at approx. station 3+00 on
Odell Court. These EOF's can be as high as 880.5 and still maintain the minimum 1.5' of
freeboard required for the lowest openings.
PAGE 5
S:\Municipal\Aotsego23xx\2327\ot2327RVW1(revised).doc
STREET PROFILE AND STORM SEWER PLAN (Sheets C4-05)
We suggest a trail be placed on the south side of 87th Court. The storm sewer on the
south side of the intersection at Odean Avenue will need to be extended.
2. Many vertical curves do not meet the lengths of K values for a design speed of 30 mph. A
curves shall have a minimum curve length of 90 feet or minimum K values of 37 for sag
curves and 19 for crest.
3. Storm sewer manholes shall receive Neenah R-1733 castings with vented lids (R-1642
are being called out)
SWPPP (Sheet C6)
See comment #5 from Grading and Drainage Plan comments.
DETAILS (Sheet C7)
The street section shall be based on a geotechnical engineers "R -value" recommendation.
2. Standard Plate 408 is duplicated.
SURFACE WATER MANAGEMENT/STORM SEWER SYSTEM
1. Provide calculations for the infiltration basin as well as storm sewer design calculations.
The storm sewer shall be designs for a 10 -yr storm. ATLAS 14 precipitation data shall be
used with a minimum 10 minute time of concentration. Include drainage area maps for
the calculations as well.
2. Once we receive the storm design information we will verify that the existing storm
sewer pipes are adequately sized to handle the additional flow.
WETLANDS
The wetland in Outlot A is a DNR wetland. They will not allow a paved path along the
wetland edge but will allow a mowed path or a boardwalk. A boardwalk would even be
allowed within the delineated wetland. The developer has been working with our
wetland specialist, Becky Wozney to obtain permits and resolve all wetland issues.
ENVIRONMENTAL
Statement certifying the environmental condition of the site including the presence of any
hazardous substance as defined in Minnesota Statutes 11513.02, Subd 8.
MISCELLANEOUS
PAGE 6
S:\Municipal\Aotsego23xx\2327\ot2327RVW1(revised).doc
All new developments will require postmaster approved locking cluster mailboxes to be
installed. The location of these mailboxes shall be shown in the fmal construction plans
for review by the City and Postmaster.
2. A development plan shall be provided as well as a separate tabulation listing the lot and
block numbers with associated garage floor, lowest opening, and lowest level elevations.
SUMMARY AND/OR RECOMMENDATION
We recommend approval contingent upon the above comment being addressed.
PAGE 7
S:\MunicipaMotsego23xx\2327\ot2327RVW1(revised).doc