4. CMSCWD Permit 20-005 ER_20200402Emmons & Olivier Resources, Inc. - 1 - 4/2/2020
Carnelian-Marine-St. Croix Watershed District Permit Application Number 20-005
Applicant: Pat Reicherts
Big Marine Lake Store
19261 Manning Trail N
Marine on St. Croix, MN 55047
614-557-4475
twincitie@yahoo.com
Consultants: Todd Shoemaker
Wenck Associates
1802 Wooddale Drive
Woodbury, WI 55125
651-294-4580
tshoemaker@wenck.com
Purpose: Land Disturbance Plan for additions to existing building, expanded parking,
and stormwater improvements for Big Marine Lake Store in Marine on St.
Croix, MN.
Location: 19261 Manning Trail N, Marine on St. Croix.
District Rule: 2 & 3
Recommendation: Conditional Approval pending receipt of the following items related
to:
Stormwater Management
1. Soil boring at the proposed infiltration basin location with a
minimum depth of 5-feet below the basin final grade and
grainsize (and hydrometer analysis if SM or tighter soils are
encountered) for each soil layer. The previously provided soil
boring is located south of the existing dry pond, not in the
infiltration basin.
2. Revised HydroCAD model, and stormwater management plan
as necessary, per the following:
a. Revised existing and proposed conditions models with
accurate drainage boundaries. Specifically, the “1S West”
drainage area is significantly smaller with the eastern
boundary much farther west, at least to the entrance island
curb line. Changes made to existing and proposed
drainage areas do not address the area north of the
existing rain garden. As constructed runoff is blocked from
entering the rain garden from the north by existing curb
and will be instead routed to drainage area 2.
b. For proposed conditions, pervious area within Drainage
Area 2 is overestimated and should be reduced to roughly
3,510 SF.
Permit Application No. 20-005 Big Marine Lake Store Improvements
Emmons & Olivier Resources, Inc. - 2 - 4/2/2020
3. Revised plans addressing existing stormwater management
BMP deficiencies identified by District Engineer via field
inspection of 5/25/18, including:
West Raingarden
a. Removal of accumulated debris and sediment from basin
and outlet manhole sump. Removals are required, not “at
owner’s direction”. Language needs to be revised.
b. Reconstruct the Highway 95 curb cut to eliminate shoulder
ponding, provide pretreatment (via Rain Guardian Turret,
or similar), and stabilize pond slope. Curb cut not
addressed, proposed riprap will provide minimal
pretreatment.
c. Reconstruct south curb cut to provide pretreatment before
discharge to the raingarden. Reconstruction of this curb cut
is required, given original plans (dated 12/3/2003)
designed this curb cut as an inlet to the basin, receiving
drainage from adjacent pavement.
d. Landscaping/revegetation plan with deep rooted
vegetation to enhance volume reduction. Revegetation is
required, given that original plans (dated 12/3/2003)
included seeding and mulch for this basin.
e. Consider if the intended EOF (horizontal manhole grate)
should be reset as it is currently higher than the south curb
cut. Although the curb cut currently acts as the EOF, it
does not provide a stabilized pathway to the ditch.
Overflow from the basin will pool along the curb before
being directed back towards the parking lot or onto
Highway 95.
East Dry Pond
a. Removal of accumulated sediment and vegetation from
basin. Removals are required, not “at owner’s direction”.
Language needs to be revised.
b. Cleanout of skimmer structure. This is likely clogged as
basin is holding water. Removals are required, not “at
owner’s direction”. Language needs to be revised.
c. Repair of downstream Level Spreader washouts and
assessment of downgradient conveyance capacity and
conditions are adequate to handle proposed increased peak
flow or flow volume from the site. Water and/or
burrowing animals have cut into the east bank of the
existing Level Spreader allowing runoff to move offsite at
concentrated discharges. Stabilization of eroded gully, as
noted on plans, is not sufficient. The Level Spreader is
Permit Application No. 20-005 Big Marine Lake Store Improvements
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intended to provide dispersed flow, rather than
concentrated flow. Stabilization of existing washouts are
not clearly shown on the provided plans.
Erosion & Sediment Control
4. Revised Erosion Control Plan updated to include changes to
stormwater management.
5. Revised landscaping plan addressing seeding of all areas likely
to be disturbed (including the area around the existing dry pond).
Administrative
6. Platting or easement documents showing conveyance to Scandia
of drainage and ponding/flowage easements over all stormwater
management facilities, stormwater conveyances, and on-site
floodplain up to the 100-year event. Said easements must
provide for adequate access to maintain stormwater
management facilities and stormwater conveyances.
7. Completion of a draft Declaration for Maintenance of
Stormwater Facilities for access to and maintenance of existing
and proposed stormwater features (see attached District
template).
Stipulations: 1. Contact information for the responsible erosion
control contractor/site manager must be provided
to the District Administrator prior to initiating
work.
2. Notify District Administrator after erosion
control is installed but prior to start of
construction.
3. All work shall be in accordance with the
approved design, plans, computations and
specifications on file with the Carnelian-Marine-
St. Croix Watershed District and any stipulations
identified in this permit. Any proposed revision
to grading drainage, landscaping and erosion
control plans shall be submitted to the District for
prior approval.
4. Applicant is responsible for obtaining all other
required permits and approvals for construction
of proposed project.
Permit Application No. 20-005 Big Marine Lake Store Improvements
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5. Install and maintain silt fence down-gradient
from all proposed disturbed soil prior to start of
any construction.
6. Upon approval by the District of the draft
maintenance agreement, the document shall be
executed and recorded at the County on the
deed. Submit certified copy to District within 60
days of notice of District approval of draft
agreement.
7. Stabilization must be initiated immediately to
limit soil erosion on any portion of the site when
construction activity has permanently ceased or
will not resume for a period exceeding fourteen
(14) calendar days. Stabilization must be
completed no later than fourteen (14) calendar
days after the construction activity in that portion
of the site has ceased. Stabilization must be
completed no later than twenty-four (24) hours
after the construction activity has ceased in that
portion of the site within two hundred (200)
lineal feet of and draining to a wetland,
waterbody, a discernable surface drainage
feature or a stormwater system inlet.
8. Notify District Administrator after completion of
work for final inspection and return of surety.
9. The permittee shall supply an as-built survey
within 35 days of project completion. The
District shall review this survey as a part of the
certificate of completion for the project.
Exhibits: 1. Permit Application received 3/27/2020.
2. Permit Application fee ($2,000) and surety ($3,920) received
3/27/2020.
3. Draft Plan Set (7 sheets) prepared by Wenck Associates, last revised
3/10/2020, received 3/10/2020.
4. Watershed response memo prepared by Wenck Associates, dated
3/9/2020, received 3/10/2020.
Permit Application No. 20-005 Big Marine Lake Store Improvements
Emmons & Olivier Resources, Inc. - 5 - 4/2/2020
5. Drainage Area Maps (2 sheets) and HydroCAD Modeling Results,
dated 3/9/2020, received 3/10/2020.
6. Soil Profile prepared by Wenck Associates, dated 5/10/2018, received
3/10/2020.
7. CMSCWD Permit Files 18-007 and 03-044.
Findings: 1. Description – The proposed project entails constructing additions to
the existing building, expanding the parking lot, and additional
stormwater improvements. The site is 2.13 acres in size, with 0.91
acres of existing impervious. The proposed project would result in
0.32 acres of additional impervious surface and disturbance of 0.57
acres.
2. Stormwater Management – Less than 50 percent of the existing
impervious is disturbed such that the redevelopment criteria is not
triggered and the stormwater management criteria apply only to the
new and reconstructed impervious surfaces.
Stormwater management will be provided through an existing
raingarden receiving runoff from the west portion of the site; and an
infiltration basin, which will be graded in the northeast corner of the
site and overflows into an existing dry pond, receiving runoff from the
remainder of the site. A 3-foot buffer strip around the edge of the
proposed parking lot provides pretreatment for the new lot.
It appears the stormwater management plan is consistent with District
stormwater management standards; however, modeling revisions
noted in the pending items are required for review and verification,
along with repairs to existing stormwater facilities.
3. Erosion & Sediment Control – An erosion control plan has not been
provided. A satisfactory erosion and sediment control plan was
previously submitted with the application for CMSCWD Permit 18-
007, but has not been updated to include changes to project design.
4. Floodplain – The EOF of the proposed infiltration basin and existing
dry basin is approximately 976, well below the low entry elevation of
the store thereby satisfying District freeboard requirements.
5. Wetlands – Based on the District’s CWPMP wetland inventory, there
are no known wetlands on site; District Rule 8.0 does not apply.
However, it should be noted that the site drains to a Category 1
wetland (82-211W) east of the site. This wetland is a groundwater-
dependent natural resource.
Permit Application No. 20-005 Big Marine Lake Store Improvements
Emmons & Olivier Resources, Inc. - 6 - 4/2/2020
Board Action: The CMSCWD Board will consider this application at their April 8th,
2020 Board Meeting,