HomeMy WebLinkAbout2003-03-12 MSCWMO Ltr to OPH Re Proposed McKean SquareMIDDLE ST. Ch. jIX RIVER WATERSf
MANAGEMENT ORGANIZATION
P.O. Box 135
Stillwater, MN 55082
A Joint Powers Watershed Mana
Communities that was established under
resources within the watershed.
March 12, 2003
Ms. Jud Holst, Actin Administrator
Cit of Oak Park Hei
14168 Oak Park Boulevard
Oak Park Hei MN 55082-2007
ED
Cc
i � ►a
Or composed of ten St. Croix Valley
State Statue 103B to cooperativel mana water
RE: Proposed McKean S — Boutwells Landin Phase 11 — Cit of Oak Park Hei
Dear Ms. Holst:
Our office has received and reviewed the draina report and construction plans dated Januar 24, 2003 for the
proposed McKean S — Boutwells Landin Phase 11 pro site, located in Section 5, Town 29 North,
Ran 20 West, Cit of Oak Park Hei Previousl the Middle St. Croix Watershed Mana
Or reviewed commented on the northwest portion of the development. This review will be for the
remainder of the site. Based on review of the plans submitted to the Middle St. Croix Watershed Mana
Or we offer the follows comments.
Stormwater Mana
Runoff rates increased for nearl all subwatersheds. Subwatersheds P6, P7, and P 11 ultimatel leave the site
and have overall rate control at the lar Boutwells Landin pondin network. The Cit En should verif
that with the additional of this proposed development overall rate control is maintained. The remainder of the
site subwatersheds Pl-P5, will have the increased runoff treated and maintained on site in Pond I and Pond 8.
Onl durin events lar than the 100- event would water leave Pond I and dischar to the east. We
would re a meetin between Oak Park Hei and Ba Township officials to address the potential
dischar of water to the east. Additionall water q ualit y pondin for stormwater treatment must also be
achieved within the overall pondin network. The draina report indicates this will be achieved in all ponds
except Pond 3. The amount of dead stora (stora available above the NWL re is sli less than the
dead stora provided ( 15,37+ cu. ft. re 14,765 cu. ft. provided). We would ask that minor alterations be
made to the desi of Pond 3 to meet the dead stora re Further, we would ask that the storm
sewer inlet on the east side of the south lobe of Pond 3 be moved to the north lobe of the pond. Maximizin the
distance between the inlet and outlet in treatment ponds increases the effectiveness of treatin stormwater.
Additionall MSCWMO recommends that all structures lowest flow elevations be no less than 2 feet above the
I 00- hi water elevation of the nearest pond.
Middle St. Croix Watershed Mana Organization
MEMBER COMMUNITIES:
Afton Ba Ba Township, Lakeland, Lakeland Shores, Lake St. Croix Beach, Oak Park Heights, St. Mar Point, Stillwater and West Lakeland Township
i� �D
Ms. Judy Holst
March 12, 2003
Page Two
Wetland protection
Although the MSCWMO does not currently have a wetland setback standard, we would recommend that the
setback be 25' with the 16 feet closest to the wetland remaining undisturbed. No filling of wetlands on site is
proposed. The setbacks to the new buildings from the delineated edge of the wetland are at a minimum 25 feet
and a 16 -foot no -grade buffer is maintained. It appears that the preliminary grading plan provides adequate
wetland setbacks and buffers.
Erosion Control
It appears that a large portion site will be disturbed at some time during construction. Perimeter controls such as
silt fence and temporary seeding/mulching are the best methods of sediment control during the construction
phase. All of the stormwater ponds should have a temporary standpipe (riser) to enhance sedimentation during
construction. Stormwater /sedimentation basins and perimeter controls must be in place before major earthwork
is begun. Staging the construction, to minimize the amount of disturbed area is the preferred alternative to mass
grading of the entire parcel. General grading contours are provided in the Engineering Report for Site Drainage.
An erosion control plan should be submitted that is consistent with the MPCA Protecting Water Quality manual.
Specifically, erosion and sediment control measures should be focused around the existing wetlands on site (P 1,
P5, P6 P8) and at the stormwater inlets of all ponds. We would also ask that as many trees as possible be
preserved and protection of the tree as well as the root zone be provided for.
If you have any questions, please feel free to call me at 275-1136 ext. 21.
Sincerely,
Bob Fossum
Water Resource Planner
cc: David Beaudet, Middle St. Croix Watershed Management organization, oak Park Heights
Anders Hansen, Middle St. Croix Watershed Management organization, Baytown Township
Todd Erickson, Folz, Freeman, Erickson, Inc., 5620 Memorial Avenue North, Stillwater, MN 55082
Middle St. Croix Watershed Management Organization
MEMBER COMMUNr TIES:
Afton, Bayport, Baytown Township, Lakeland, Lakeland Shores, Lake St. Croix Beach, oak Park Heights, St. Mary's Point, Stillwater and west Lakeland Township