Schutrop Addition_Riley Perg packet
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protect. manage. restore.
18681 Lake Drive East Chanhassen, MN 55317 952-607-6512 www.rpbcwd.org
Riley Purgatory Bluff Creek Watershed District Permit Application Review
Permit No: 2022-070
Considered at Board of Managers Meeting: December 7, 2022 (RPBCWD extended the permit review
timeline on October 26, 2022 by 60 days pursuant to Minnesota Statutes section 15.99)
Received complete: September 23, 2022
Applicant: Marty Schutrop
Consultant: Civil Methods , Inc., Kent Brander
Project: Schutrop Addition: Proposed redevelopment of an existing single-family home parcel into
two single-family residential lots with homes. The existing home will remain, with
construction of a new home on the second lot. Proposed stormwater feature includes one
rain garden.
Location: 1441 Lake Lucy Road, Chanhassen, MN 55317
Reviewer: Scott Sobiech, P.E., Barr Engineering
Proposed Board Action
Manager ______________ moved and Manager ____________ seconded adoption of the
following resolutions based on the permit report that follows and the presentation of the
matter at the December 7, 2022 meeting of the managers:
Resolved that the application for Permit 2022-070 is approved, subject to the conditions and
stipulations set forth in the Recommendations section of the attached report;
Resolved that on determination by the RPBCWD administrator that the conditions of approval
have been affirmatively resolved, the RPBCWD president or administrator is authorized and
directed to sign and deliver Permit 2022-070 to the applicant on behalf of RPBCWD.
Upon vote, the resolutions were adopted, ______ [VOTE TALLY].
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Applicable Rule Conformance Summary
Rule Issue Conforms to
RBPCWD
Rules?
Comments
C Erosion Control Plan Yes
J Stormwater
Management
Rate Yes.
Volume Yes
Water Quality Yes.
Low Floor Elev. Yes
Maintenance See
comment.
See rule-specific permit condition J1
related to recordation of stormwater
facility maintenance declaration.
Chloride Management Yes.
Wetland Protection Yes.
L Permit Fee Yes. $3,000 received February 8, 2022.
The applicant must replenish the
permit fee deposit to the original
amount due before the permit will be
issued. As of November 8, 2022 the
amount due is $1,962.
M Financial Assurance See
comment.
The financial assurance is calculated
at $7,535
Background
The applicant is proposing a lot split subdividing an existing single residential lot into two lots. The
existing home will remain, with construction of a new home on the second lot. A rain garden is proposed
to provide stormwater quantity, volume and quality control. There is a wetland in the northeast corner
of the site which is not downgradient from and will not be disturbed by the land-disturbing activities. In
addition, surface runoff from the land disturbing activities drains via overland flow to an off-site,
downgradient wetland that is more than 80 feet from the parcel line, such that even the maximum
buffer would not reach the applicant’s parcel. As such Rule D does not impose any buffer requirements
for this project. However, the treated runoff leaving the site from the stormwater management system
is conveyed via a channel to the off-site wetland, thus requiring conformance with the wetland
protection criteria in Rule J, subsection 3.10.
The project site information is summarized below:
Project Site Information Area (acres)
Total Site Area 1.18
Existing Site Impervious 0.15
Disturbed Site Impervious Area 0.07 (48.9%)
Disturbed Impervious Area Restored with
Pervious Surface
0.03
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Project Site Information Area (acres)
Proposed Site Impervious Area 0.19
Change in Site Impervious Area 0.04 (23.7% increase)
Regulated Impervious Surface 0.1
Total Disturbed Area 0.59
The following materials were reviewed in support of the permit request:
1. Application received September 7, 2022 (Incomplete notice was sent on September 12, 2022;
materials submitted to complete application on September 23, 2022)
2. Grading & Drainage plan by Civil Methods, Inc. dated August 29, 2022
3. Schutrop Addition plan set (5 sheets) by Civil Methods, Inc. dated September 23, 2022
4. Subsurface Soil Investigation memo by Interstate Geotechnical Engineering, Inc. dated
August 17, 2022
5. Stormwater Management Report by Civil Methods, Inc. dated August 30, 2022
6. Electronic HydroCAD models received on September 23, 2022
7. Electronic HydroCAD models received on October 21, 2022
8. Infiltration testing results received on October 25, 2022
9. Minnesota Wetland Conservation Act Notice of Decision dated August 8, 2022
10. Engineers’ opinion of probable cost dated September 29, 2022.
11. Response to RPBCWD review comments received September 23, 2022
Rule C: Erosion and Sediment Control
Because the project will involve 0.59 acres of land-disturbing activity, the project must conform to the
requirements in the RPBCWD Erosion and Sediment Control rule (Rule C, Subsection 2.1). The erosion
control plan prepared by Civil Methods, Inc. includes installation of perimeter control (silt fence or
sediment control logs), a stabilized rock construction entrance, inlet protection, daily inspection,
placement of a minimum of 6 inches of topsoil (at 5% organic matter), decompaction of areas
compacted during construction, and retention of native topsoil onsite to the greatest extent possible. To
conform to RPBCWD Rule C requirements, the following revisions are needed:
C1. The Applicant must provide the name, address and phone number of the individual who will
remain liable to the District for performance under this rule and maintenance of erosion and
sediment-control measures from the time the permitted activities commence until vegetative
cover is established.
Rule J: Stormwater Management
Because the redevelopment project will disturb 0.59 acres of land-surface area, the project must meet
the criteria of RPBCWD’s Stormwater Management rule (Rule J, Subsection 2.1). The criteria listed in
Subsection 3.1 will apply only to the disturbed portion of the project site and additional impervious area
because the project will disturb only 48.9 percent of the existing impervious surface and will increase
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the imperviousness of the entire site by only 23.7 percent (i.e., less than 50 percent; Rule J, Subsection
2.3).
The developer is proposing construction of one rain garden to provide rate control, volume abstraction
and water quality management on the site.
Rate Control
In order to meet the rate control criteria listed in Subsection 3.1.a, the 2-, 10-, and 100-year post
development peak runoff rates must be equal to or less than the existing discharge rates at all locations
where stormwater leaves the site. The applicant used a HydroCAD hydrologic model to simulate runoff
rates for pre- and post-development conditions for the 2-, 10-, and 100-year frequency storm events
using a nested rainfall distribution, and a 100-year frequency, 10-day snowmelt event. The existing and
proposed 2-, 10-, and 100-year frequency discharges from the disturbed site area are summarized in the
table below. The proposed project is in conformance with RPBCWD Rule J, Subsection 3.1.a.
Modeled Discharge
Location
2-Year Discharge
(cfs)
10-Year Discharge
(cfs)
100-Year Discharge
(cfs)
10-Day Snowmelt
(cfs)
Ex Prop Ex Prop Ex Prop Ex Prop
West 1.3 1.3 2.6 2.6 5.7 5.7 0.1 0.1
Volume Abstraction
Subsection 3.1.b of Rule J requires the abstraction onsite of 1.1 inches of runoff from all new or
disturbed impervious surface of the parcel. An abstraction volume of 414 cubic feet is required from the
0.1 acres (4,518 square feet) of regulated impervious area on the site for abstraction. The Applicant
proposes one rain garden to provide volume abstraction. Pretreatment is provided by a grass filter strips
between the impervious surfaces and the rain garden (Rule J, Subsection 3.1.b.1).
Three soil borings performed by Interstate Geotechnical Engineering, Inc. during August 2022 show that
soils in the project area are primarily clay loam with granular soils (loamy sand) at intermediate depths.
Groundwater was observed in the soil boring located at the rain garden (boring #2 at elevation 980.5
feet and redoximorphic soils where noted on the boring log at elevation 985.5 feet. The following table
demonstrates that the proposed design provided adequate separation between the bottom of the
stormwater facilities and the groundwater (Rule J, Subsection 3.1.b.2.a).
Groundwater Separation Analysis
Proposed
BMP
Nearest Subsurface
Investigation
Boring is within
footprint?
Groundwater
Elevation/Redoximorphic
Soils
(feet)
BMP Bottom
Elevation (feet)
Separation
(feet)
Rain Garden SB-02 Yes 985.5 988.6 3.1’
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Double ring infiltrometer testing results show an average infiltration rate of 0.52 inches per hour (in/hr)
beneath the proposed stormwater management feature. The engineer concurs with the applicant’s
design infiltration rates of 0.3 inches per hour. The proposed stormwater facility provides adequate
surface area to drawdown the abstraction volumes within the required 48-hour period, thus conforming
with Rule J, Subsection 3.1.b.3. The table below summarizes the volume abstraction required and the
volume abstraction achieved by the proposed stormwater management facilities on site. The engineer
concurs with the submitted information and finds that the proposed project will conform with Rule J,
Subsection 3.1.b.
Volume Abstraction Summary
Required
Abstraction Depth
(inches)
Required Abstraction
Volume
(cubic feet)
Provided Abstraction
Depth
(inches)
Provided Abstraction
Volume
(cubic feet)
1.1 414 1.2 451
Water Quality Management
Subsection 3.1.c of Rule J requires the Applicant provide volume abstraction in accordance with 3.1b or
least 60 percent annual removal efficiency for total phosphorus (TP), and at least 90 percent annual
removal efficiency for total suspended solids (TSS) from site runoff, and no net increase in TSS or TP
loading leaving the site from existing conditions. Because the BMP proposed by the applicant provides
more volume abstraction than is require by 3.1b, the engineer finds that the proposed project is in
conformance with Rule J, Subsection 3.1.c.
Low floor Elevation
All new buildings must be constructed such that the lowest floor is at least two feet above the 100-year
high water elevation or one foot above the emergency overflow of a stormwater-management facility
according to Rule J, Subsection 3.6a. In addition, a stormwater-management facility must be constructed
at an elevation that ensures that no adjacent habitable building will be brought into noncompliance with
this requirement, according to Rule J, Subsection 3.6b. The low floor elevation of the proposed home
and the adjacent stormwater management feature is summarized below and shows the proposed
project is in conformance with Rule J, Subsection 3.6a.
Lot Riparian to
Stormwater
Facility
Low Floor
Elevation of
Building (feet)
Adjacent
Stormwater Facility
100-year Event Flood
Elevation of Adjacent
Stormwater Facility (feet)
Freeboard to
100-year Event
(feet)
Proposed House 994.8 Rain Garden 990.67 4.13
Proposed House 994.8 Existing conveyance
channel
992.8 2.0
Existing House 995.5 Rain Garden 990.67 4.83
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Maintenance
Subsection 3.7 of Rule J requires the submission of a maintenance plan. All stormwater management
structures and facilities must be designed for maintenance access and properly maintained in perpetuity
to assure that they continue to function as designed. The Applicant provided a draft maintenance and
inspection declaration for review that provides the maintenance and inspection required by Rule J,
Subsection 3.7.
J1. Permit applicant must provide a proof of recordation of the maintenance and inspection
declaration as a condition of issuance of the permit. A draft of the declaration must be provided
for District review and approval prior to recordation as a condition of issuance of the permit.
Chloride Management
Subsection 3.8 of Rule J requires the submission of chloride management plan that designates the
individual authorized to implement the chloride management plan and the MPCA-certified salt
applicator engaged in implementing the plan. The RPBCWD chloride-management plan requirement
applies to the streets and common areas of the project site, but not the individual single-family homes.
Because there are no street or common areas, Rule J, subsection 3.8 does not impose requirements on
this project.
Wetland Protection
Because runoff from this site is directly tributary to a downstream, off-site medium value wetland, the
project must comply with the wetland protection criteria in Rule J, Subsection 3.10
In accordance with Rule J, subsection 3.10a, there is no proposed activity subject to Rule J that will alter
the site in a manner that increases the bounce in water level, duration of inundation, or change the
runout elevation in the subwatershed for the wetland receiving runoff from the land disturbing
activities. Because the applicant’s HydroCAD model results demonstrate, and the engineer concurs, that
the proposed flow rate and volumes flowing towards the off-site wetland are less than the under
existing conditions, the bounce and inundation will not increase, thus the project meets the Bounce and
Inundation criterion.
Rule J, Subsection 3.10b requires that treatment of runoff to medium value wetland meet the water
quality treatment criteria in Rule J, subsection 3.1c. Because the proposed the rain garden provides the
water quality treatment required in accordance with 3.1c.i, the engineer finds that the proposed project
is in conformance with Rule J, Subsection 3.10b.
Rule L: Permit Fee Deposit:
The RPBCWD permit fee schedule adopted in February 2020 requires permit applicants to deposit
$3,000 to be held in escrow and applied to cover the $10 permit-processing fee and reimburse RPBCWD
for permit review and inspection-related costs and when a permit application is approved, the deposit
must be replenished to the applicable deposit amount by the applicant before the permit will be issued
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to cover actual costs incurred to monitor compliance with permit conditions and the RPBCWD Rules. A
permit fee deposit of $3,000 was received on September 7, 2022. The applicant must replenish the
permit fee deposit to the original amount due before the permit will be issued. Subsequently, if the
costs of review, administration, inspections and closeout-related or other regulatory activities exceed
the fee deposit amount, the applicant will be required to replenish the deposit to the original amount or
such lesser amount as the RPBCWD administrator deems sufficient within 30 days of receiving notice
that such deposit is due. The administrator will close out the relevant application or permit and revoke
prior approvals, if any, if the permit-fee deposit is not timely replenished.
L1. The applicant must replenish the permit fee deposit to the original amount due before the
permit will be issued. The amount needed to replenish the permit fee deposit is $1,962 as of
November 8, 2022.
Rule M: Financial Assurance: Unit Unit Cost # of Units Total
Rules C: Silt fence: LF $2.50 520 $1,300
Inlet protection EA $100 2 $200
Rock Entrance EA $250 1 $250
Restoration Ac $2,500 0.59 $1,475
Rules J: Stormwater Management
Rain Garden: 125% of engineer’s opinion of cost ($2900)
EA 125% OPC 1 $3,625
Contingency (10%) 10% $685
Total Financial Assurance $7,535
Applicable General Requirements:
1. The RPBCWD Administrator and Engineer shall be notified at least three days prior to
commencement of work.
2. Construction must be consistent with the plans, specifications, and models that were submitted
by the applicant that were the basis of permit approval. The date(s) of the approved plans,
specifications, and modeling are listed above and on the permit.
3. The grant of the permit does not relieve the permittee of any responsibility to obtain approval
of any other regulatory body with authority.
4. The issuance of this permit does not convey any rights to either real or personal property, or any
exclusive privileges, nor does it authorize any injury to private property or any invasion of
personal rights, nor any infringement of federal, state, or local laws or regulations.
5. In all cases where the doing by the permittee of anything authorized by this permit involves the
taking, using or damaging of any property, rights or interests of any other person or persons, or
of any publicly owned lands or improvements or interests, the permittee, before proceeding
therewith, must acquire all necessary property rights and interest.
6. RPBCWD’s determination to issue this permit was made in reliance on the information provided
by the applicant. Any substantive change in the work affecting the nature and extent of
applicability of RPBCWD regulatory requirements or substantive changes in the methods or
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means of compliance with RPBCWD regulatory requirements must be the subject of an
application for a permit modification to the RPBCWD.
7. If the conditions herein are met and the permit is issued by RPBCWD, the applicant, by accepting
the permit, grants access to the site of the work at all reasonable times during and after
construction to authorized representatives of the RPBCWD for inspection of the work.
Findings
1. The proposed project includes the information necessary, plan sheets and erosion control plan
for review.
2. The proposed project will conform to Rules C and J if the Rule Specific Permit Conditions listed
above are met.
Recommendation:
Approval of the permit issuance contingent upon:
1. Financial Assurance in the amount of $7,535.
2. Receipt of the name, address and phone number of the individual who will remain liable to the
District for performance under this rule and maintenance of erosion and sediment-control
measures from the time the permitted activities commence until vegetative cover is established.
3. Receipt showing recordation of the maintenance declaration for the stormwater management
facilities. Drafts of any and all documents to be recorded must be reviewed and approved by the
District prior to recordation. Permit applicant must provide a proof of recordation as a condition
of issuance of the permit.
4. The applicant must replenish the permit fee deposit to the original amount due before the
permit will be issued. The amount needed to replenish the permit fee deposit is $1,962 as of
November 8, 2022.
By accepting the permit, when issued, the applicant agrees to the following stipulations:
1. Continued compliance with General Requirements.
2. Per Rule J Subsection 4.5, upon completion of the site work, the permittee must submit as-built
drawings demonstrating that at the time of final stabilization, the stormwater management
facility conform to design specifications and function as intended and approved by the District.
As-built/record drawings must be signed by a professional engineer licensed in Minnesota and
include, but not limited to:
a) the surveyed bottom elevations, water levels, and general topography of all facilities;
b) the size, type, and surveyed invert elevations of all stormwater facility inlets and outlets;
c) the surveyed elevations of all emergency overflows including stormwater facility, street,
and other;
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d) other important features to show that the project was constructed as approved by the
Managers and protects the public health, welfare, and safety.
e) photographic evidence of buffer marker locations indicated by permanent, free-
standing markers in accordance with Rule D, Subsection 3.4 criteria.
3. Providing the following additional close-out materials:
a) Documentation that constructed infiltration facility performs as designed. This may
include infiltration testing, flood testing, or other with prior approval from RPBCWD
b) Documentation that disturbed pervious areas remaining pervious have been
decompacted per Rule C.2c criteria
4. The work under the terms of permit 2022-070, if issued, must have an impervious surface area
and configuration materially consistent with the approved plans. Design that differs materially
from the approved plans (e.g., in terms of total impervious area) will need to be the subject of a
request for a permit modification or new permit, which will be subject to review for compliance
with all applicable regulatory requirements.
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Barr Footer: ArcGIS 10.8.1, 2022-11-22 16:37 File: I:\Client\RPBC_WD\Work_Orders\Monthly_General_Services\Permitting\Maps\2022\2022-070 Schutrop Addition.mxd User: mbs2
Permit Location Map
SCHUTROP ADDITIONPermit 2022-070Riley Purgatory Bluff CreekWatershed District
!;N
0 1,000
Feet
SITE