WR Review Memo - 1591 Park Road
Memorandum
To: Rachel Arsenault, Associate Planner
From: Joe Seidl, Water Resources Engineer
CC: Charles Howley, Public Works Director/City Engineer
George Bender, Assistant City Engineer
Charlie Burke, Public Works Operations Manager
Date: 09/06/2024
Re: 1591 Park Road Conditional Use Permit
Project Overview
The property owner seeks a conditional use permit to establish a contracting yard at 1591 Park
Road. Contractor yards typically store construction and landscaping materials and equipment.
These materials may include dirt, sand, construction debris, salt, fuel, and raw building materials
such as lumber and concrete blocks. Equipment might include trucks and construction vehicles
like skid steers, excavators, and bulldozers. Due to the nature of these materials and equipment,
contractor yards have a higher risk of pollutant transport, especially because materials like dirt
and salt can be easily eroded by wind and water. Historically, this property served as a public
works building for the City of Chanhassen and had a similar use.
The applicant has provided supporting documents for the conditional use permit request, which
were reviewed by the Water Resources Department. These documents include:
· Overall Site Plan (Moore Engineering Inc., dated 5/31/24)
· Contractor Yard Site Plan (Moore Engineering Inc., dated 5/31/24)
· Stormwater Memo (Moore Engineering Inc., dated 8/9/24)
· Contractor’s Yard Exhibit (Moore Engineering Inc., dated 8/9/24)
· Drainage Plan Exhibit (Moore Engineering Inc., dated 8/9/24)
Documented Water Resources Issues
In May 2023, City staff visited the site in response to complaints about its condition. The site
exhibited numerous erosion and sediment control issues, including missing best management
practices (BMPs) like perimeter controls, insufficient buffer areas, large areas of disturbed soil,
and uncovered stockpiles. These issues led to sediment and pollutants entering the onsite
wetland/stormwater pond and potentially impacting downstream City infrastructure and local
water resources. The site also showed failing stormwater infrastructure, exacerbating sediment
and erosion problems. The Erosion and Sediment Control Inspection Report of May 5, 2023,
details the site’s past condition and is included as a reference to this memo.
Spring 2023 – Photo of Stockpile and Depressional Area
Spring 2023 – Photo of Contractor’s Yard
Since 2023, the owner has addressed some of the onsite issues by removing stockpiles and
installing silt fence and other Erosion and Sediment Control BMPs. However, disturbed soils and
failing stormwater infrastructure remain onsite.
Wetlands
A small depression in the southwest corner of the property appears to have wetland
characteristics, with wetland vegetation observed during staff inspections conducted in 2023.
This area is classified as a wetland on the City’s GIS inventory. Aerial photographs from 1969
and subsequent observations indicate the presence of standing water in this depression since the
late 1980s/early 1990s.
A review of older site plans from the 1980’s indicates the presence of a depression/channel that
was modified with the development of the site. It is possible that the intent of the modifications
was to create a stormwater management feature, however more detailed review is required to
make an official Wetland Conservation Act decision.
It is recommended that the applicant conduct a wetland delineation to confirm whether this
depression is a jurisdictional wetland. If classified as such, the site should comply with Article
20-6 Wetland Protection of the City Code, which includes establishing buffer areas and
potentially wetland restoration. If the area is classified as a stormwater management feature, then
the applicant could use this area to manage the runoff generated by the site.
Drainage
The site primarily drains to the southwest into the onsite wetland/stormwater pond. From there,
stormwater flows southwest through a railroad ditch system into a City maintained wet pond
before discharging into Bluff Creek. The northern part of the site drains into the City storm
sewer along Park Road, with stormwater eventually reaching Riley Creek. There is limited onsite
stormwater infrastructure including pipes and catch basins which appear to be private as they act
to drain private property, are not contained in easements, and do not benefit the public.
The proposed plans will not significant alter the existing drainage patterns. Some existing
impervious surfaces will be removed and revegetated, and new stormwater infrastructure,
including bituminous curbs and stabilized curb cuts, are proposed to help manage runoff. The
Contractor Site Plan includes temporary BMPs like hay bales and silt fences for interim site
management. A new bituminous drive lane was added in 2023 without permits. No new
permanent BMPs for stormwater management are currently proposed.
Erosion Control
The exact area of disturbance is unclear but appears to exceed 5,000 square feet. If the
disturbance is over one acre, the project will require a General Permit Authorization to Discharge
Stormwater Associated with Construction Activity (NPDES Construction Permit).
The project must comply with Section 19-145 of the City Code regarding Erosion and Sediment
Control. Given the disturbance size and sediment transport concerns, the applicant should submit
an Erosion and Sediment Control Plan adhering to City regulations. All erosion control measures
must be installed and inspected by City staff before site grading/construction begins. If
disturbance exceeds one acre, a Stormwater Pollution Prevention Plan (SWPPP) should be
included in the next submittal.
The site is within the Riley Purgatory Bluff Creek Watershed District (RPBCWD). The district
requires an erosion and sediment control permit if the site grades 50 cubic yards or more of earth
or disturbs 5,000 square feet or more of area. The applicant should confirm whether these
thresholds are met and secure all necessary permits, including after-the-fact permits.
Stormwater Management
The City's Code Section 20-232 outlines General Issuance Standards for Conditional Use
Permits. Relevant standards include:
Sec 20-232 General Issuance Standards
The planning commission shall recommend a conditional use permit and the council shall issue
such conditional use permits only if it finds that such use at the proposed location:
a. Will not be detrimental to or endanger the public health, safety, comfort, convenience or
general welfare of the neighborhood or the city.
b. Will be consistent with the objectives of the city's comprehensive plan and this chapter.
e. Will be served adequately by essential public facilities and services, including streets,
police and fire protection, drainage structures, refuse disposal, water and sewer systems
and schools; or will be served adequately by such facilities and services provided by the
persons or agencies responsible for the establishment of the proposed use.
City Code requires that site be in compliance with the objectives of Chanhassen’s
Comprehensive Plan. The Local Stormwater Management Plan (LSWMP) is part of the
city’s Compressive Plan. The first three goals of the LSWMP are:
Goal 1. Promote abstraction through infiltration, reuse and other methods where
practicable to do so to provide flood protection, ground water recharge and improved
water quality.
Goal 2. Achieve water quality standards in lakes, streams, and wetlands consistent with
their designated uses and established classifications.
Goal 3. Protect and rehabilitate wetlands to maintain or improve their function and value.
When not properly managed, a contractor’s yard increases pollution risks to downstream water
resources and can increase maintenance needs on downstream stormwater infrastructure. This
would not align with the goals of the LSWMP and as a result a contractor’s yard requires proper
stormwater management facilities in order to meet the goals of the City’s LSWMP. The onsite
wetland/stormwater pond is in disrepair and there have been documented erosion and sediment
control issues that have very likely impacted local water quality. To comply with City Code and
the LSWMP, it is recommended that the applicant develop a comprehensive stormwater
management plan, including:
· Paved surfaces for maintenance
· Develop and implement an Erosion and Sediment Control Plan
· Permanent private stormwater management facilities meeting water quality standards
· Assessment and repair of existing stormwater infrastructure
· Covered storage facilities
· Schedule of regular maintenance activities as needed to manage the contractor’s yard
(practices to contain sediment, fuel, and other runoff associated with contracting yards)
· Execution of an Operations and Maintenance Agreement to ensure the functionality of
the private stormwater infrastructure onsite.
The project is also subject to RPBCWD rules and regulations. The applicant should confirm any
applicable rules and obtain necessary permits as part of the Conditional Use Permit.
WATER RESOURCES CONDITIONS:
1. It is the developer’s responsibility to ensure that permits are received from all other
agencies with jurisdiction over the project (i.e. Carver County, RPBCWD, Board of
Water and Soil Resources, MnDOT, etc.) prior to the commencement of construction
activities.
2. The applicant shall complete a wetland delineation onsite to confirm if the depressional
area is a jurisdictional wetland. If any area onsite is determined to be a jurisdictional
wetland then the applicant shall revise plans to meet all applicable city code regulations.
The Wetland delineation shall be completed within 3 months after the approval of the
Conditional Use Permit.
3. The applicant and their Engineer shall work with City staff in amending the construction
plans, dated May 31, 2024, and August 9, 2024 prepared by Moore Engineering Inc. to
fully satisfy construction plan comments and concerns within 6 months after the approval
of the Conditional Use Permit.
4. The applicant shall provide updated plans and models to demonstrate that the contractor’s
yard site is meeting water quality standards. A permanent BMP to manage the runoff
generated by the contractor’s yard is anticipated. These models shall be submitted as part
of all future submittals.
5. The applicant shall create a storm water management plan approved by staff to describe
how the site is meeting city requirements including water quality and erosion control.
The stormwater management plan including site improvements shall be executed within
12 months after the approval of the Conditional Use Permit.
6. The developer shall enter into encroachment agreements for all existing and proposed
improvements located in public easements. The encroachment agreements shall be
recorded within 12 months after the approval of the Conditional Use Permit.