HomeMy WebLinkAbout5E Surface Water Management Comprehensive Plan Report
Phone 952.447.9800 / Fax 952.447.4245 / www.cityofpriorlake.com
4646 Dakota Street SE
Prior Lake, MN 55372
CITY COUNCIL AGENDA REPORT
MEETING DATE: MARCH 4, 2019
AGENDA #: 5E
PREPARED BY: PETE YOUNG, WATER RESOURCES ENGINEER
PRESENTED BY: PETE YOUNG
AGENDA ITEM:
CONSIDER APPROVAL OF A RESOLUTION APPROVING THE SURFACE
WATER MANAGEMENT PLAN CHAPTER OF THE CITY’S 2040
COMPREHENSIVE PLAN UPDATE
GOAL AREA AND
OBJECTIVE:
Environmental Stewardship & Recreation
2. Protect and enhance the quality of Prior Lake’s surface waters.
DISCUSSION: Introduction
The City is in the process of updating the 2040 Comprehensive Plan. The
Comprehensive Plan is a compilation of policy statements, goals, standards and
maps for guiding the physical, social and economic development, both private and
public, of the City of Prior Lake. Included in the Comprehensive Plan is a Surface
Water Management Plan Chapter.
History
The City is required to update the Surface Water Management Plan as part of its
2040 Comprehensive Plan update. The Surface Water Management Plan must
meet the requirements of Minnesota Statute 103B.235 and Minnesota Rule
8410.0160. The Plan guides the City’s overall approach to surface water
management activities. The plan summarizes the existing surface water regulatory
framework under which the City reviews, installs, and maintains stormwater
infrastructure. The plan also references technical standards, identifies problem
areas and issues, and includes an implementation plan that allows the City to meet
all regulatory obligations while maintaining and improving surface water quality.
Current Circumstances
The City currently meets its regulatory obligations under the State Municipal
Separate Storm Sewer System (MS4) permit. Cities are required to meet certain
MS4 requirements and provide an annual MS4 report to the Minnesota Pollution
Control Agency (MPCA). The updated Surface Water Management Plan includes
references and other information that meets or exceeds MS4 standards. The MS4-
related information in the updated Plan is more concise and contains more
references to outside standards than the previous version.
The City implements the Minnesota Wetland Conservation Act (WCA), which was
enacted in 1991 to ensure no net loss of wetland area and function statewide. In
accordance with City Resolution 94-01 (passed January 18, 1994), the City is
obligated to act as the Local Government Unit (LGU) responsible for administering
the WCA. The Surface Water Management Plan update includes a wetland
management plan outlining the City’s WCA program. The updated Surface Water
Management Plan does not propose any substantive changes to the City’s WCA
program.
The City must continue to work cooperatively with many partners to ensure the
successful implementation of the Surface Water Management Plan. These
cooperative relationships are outlined in the Agency Cooperation section of the
Plan. This section contains critical references to all existing surface-water-related
regulatory requirements that affect the City, residents, and businesses. The Plan
was updated to include new website links, revised agency standards, and current
surface water regulatory agreements.
The Surface Water Management Plan includes the City’s goals and policies related
to surface water quantity/quality, recreation, fish and wildlife habitat, groundwater,
wetlands, erosion and sediment control, the City’s MS4 permit, and financial
management. In addition to protecting water quality, another goal of the Surface
Water Management Plan is to aid with planning for the orderly management of
stormwater as development occurs. The City’s goals and policies continue to evolve
in reaction to increased outside regulatory standards, new information and studies,
and public input through the City’s 2040 Vision and Strategic Plan process.
The Implementation Plan section of the Surface Water Management Plan describes
a range of activities and programs that support maintenance and improvement of
the City’s surface water management program. Capital outlay for the surface water
system (pipes, channels, and ponds) shown on the system maps will be large. For
this reason, a City financing mechanism, called an area charge, is reviewed in this
section. Based on the Capital Improvement Plan and the developable acreage, the
City’s current area charge is reviewed, and application of this charge is discussed.
There are also several City planning and budgeting documents that outline surface
water management activities undertaken by the City; those documents are identified
in a table and are incorporated by reference into the Plan.
Using the updated Surface Water Management Plan as a guide, the City of Prior
Lake will continue to manage our surface water resources to meet regulatory
obligations, maintain and improve surface water quality, and make efficient and
cost-effective decisions with taxpayer dollars.
Subsection 1108.804 of Prior Lake City Code states, the Planning Commission shall
review all requests for an amendment to the Comprehensive Plan or the
Comprehensive Plan Land Use Map at a public hearing and shall report its findings
and recommendations to the City Council.
The Prior Lake Planning Commission held a public hearing on the Surface Water
Management Plan on February 25, 2019 and on a vote of 5-0 recommended the
City Council approve a resolution approving the surface water management plan
chapter of the City’s 2040 Comprehensive Plan update.
ISSUES: Per Minnesota Statute 103B.235, Subd. 3, both local water management
organizations with jurisdiction within the City of Prior Lake and the Metropolitan
Council must approve the Surface Water Management Plan update before final
adoption by the City Council. The Scott Water Management Organization (Scott
WMO) comments were received on October 11, 2018 and Prior Lake-Spring Lake
Watershed District (PLSLWD) comments were received on October 25, 2018. The
Metropolitan Council submitted a letter stating that they have no comments on
October 5, 2018. All Scott WMO and PLSLWD comments were subsequently
addressed with revisions to the Plan. Scott County approved the revised final
version of the Plan at their board meeting on December 12, 2018. PLSLWD
approved the same version at their board meeting on February 12, 2019.
Federal, state, and local regulations continue to evolve with respect to surface water
management. This Plan has been updated to reference outside standards and
technical information for increased flexibility; this allows for outside changes without
the Plan becoming outdated. Future Plan updates may be required to accommodate
significant changes such as updated Scott WMO standards or PLSLWD rules.
Issue 5.4.2 states that the City has limited funding sources available to complete
projects related to water resources, including many of those outlined in the Plan.
Stormwater Utility funds and special assessments are not adequate to implement
the studies, programs, and capital improvements outlined in this Plan, necessitating
grant applications and other potential outside funding sources. The City must
consider increasing the current stormwater utility rate to fund future implementation
items under the Plan.
The appendix for the Surface Water Management Plan is quite large (over 400
pages) so it has not been included in the City Council packet; however, the appendix
is available upon request.
ALTERNATIVES: 1. Motion and a second, as part of the Consent Agenda, to approve a resolution
approving the Surface Water Management Plan.
2. Remove this item from the Consent Agenda for additional discussion.
RECOMMENDED
MOTION:
ATTACHMENTS:
Alternative #1
1. Surface Water Management Plan update
4646 Dakota Street SE
Prior Lake, MN 55372
RESOLUTION 19-___
A RESOLUTION APPROVING THE SURFACE WATER MANAGEMENT PLAN CHAPTER
OF THE CITY’S 2040 COMPREHENSIVE PLAN UPDATE
Motion By: Second By:
WHEREAS, Minnesota Statutes section 473.864 requires each local governmental unit to review
and, if necessary, amend its entire comprehensive plan and its fiscal devices and
official controls at least once every ten years to ensure its comprehensive plan
conforms to metropolitan system plans and ensure its fiscal devices and official
controls do not conflict with the comprehensive plan or permit activities that conflict
with metropolitan system plans; and
WHEREAS, the City Council of the City of Prior Lake authorized the review and update of its
Comprehensive Plan; and
WHEREAS, the City of Prior Lake 2040 Comprehensive Plan Update is a planning tool intended
to guide the future growth and development of the City of Prior Lake in a manner that
conforms with metropolitan system plans and complies with the Metropolitan Land
Planning Act and other applicable planning statutes; and
WHEREAS,
WHEREAS,
WHEREAS,
WHEREAS,
WHEREAS,
WHEREAS,
per Minnesota Statute 103B.235, Subd. 3, both local water management
organizations with jurisdiction within the City of Prior Lake and the Metropolitan
Council must approve the Surface Water Management Plan update before final
adoption by the City Council; and
the Scott Water Management Organization (Scott WMO) comments were received
on October 11, 2018, the Prior Lake-Spring Lake Watershed District (PLSLWD)
comments were received on October 25, 2018 and the Metropolitan Council
submitted a letter stating that they have no comments on October 5, 2018; and
all Scott WMO and PLSLWD comments were subsequently addressed with revisions
to the Plan; and
Scott County approved the revised final version of the Plan at their board meeting
on December 12, 2018 and PLSLWD approved the revised final version at their
board meeting on February 12, 2019; and
the Prior Lake Planning Commission held a public hearing to review the Surface
Water Management Plan on February 25, 2019 and on a vote of 5-0 recommended
the City Council approve a resolution approving the surface water management plan
chapter of the City’s 2040 Comprehensive Plan update; and
the City Council finds using the updated Surface Water Management Plan as a
guide, the City of Prior Lake will continue to manage its surface water resources to
meet regulatory obligations, maintain and improve surface water quality, and make
efficient and cost-effective decisions with taxpayer dollars.
2
NOW THEREFORE, BE IT HEREBY RESOLVED BY THE CITY COUNCIL OF PRIOR LAKE,
MINNESOTA as follows:
1. The recitals set forth above are incorporated herein.
2. The City Manager is hereby authorized to submit the Surface Water Management Plan
Chapter of the City’s 2040 Comprehensive Plan Update to the Metropolitan Council.
Passed and adopted by the Prior Lake City Council this 4th day of March 2019.
VOTE Briggs Thompson Burkart Braid Erickson
Aye ☐ ☐ ☐ ☐ ☐
Nay ☐ ☐ ☐ ☐ ☐
Abstain ☐ ☐ ☐ ☐ ☐
Absent ☐ ☐ ☐ ☐ ☐
______________________________
Michael Plante, City Manager
Local Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
LOCAL SURFACE WATER MANAGEMENT PLAN
FOR THE
CITY OF PRIOR LAKE, MINNESOTA
Final Draft
November 2018
Prepared By:
WSB & Associates, Inc.
701 Xenia Avenue South, Suite 300
Minneapolis, MN 55416
763-541-4800
763-541-1700 (Fax)
TABLE OF CONTENTS
Local Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000 Table of Contents
Title Page
Certification
Table of Contents
SECTION 1: EXECUTIVE SUMMARY
SECTION 2: LAND AND WATER RESOURCE INVENTORY
SECTION 3: WETLAND MANAGEMENT PLAN
SECTION 4: AGENCY COOPERATION
SECTION 5: ASSESSMENT OF ISSUES
SECTION 6: GOALS AND POLICIES
SECTION 7: IMPLEMENTATION PROGRAM
SECTION 8: ADMINISTRATION
LIST OF APPENDICES
Appendix A – Figures
Figure 1: Location Map
Figure 2: Topography
Figure 3: Drainage System
Figure 4: Soils Map
Figure 5: Hydric Soils
Figure 6: Existing Land Use
Figure 7: Future Land Use
Figure 8: Public Waters and Wetlands
Figure 9: Water Quality Monitoring
Figure 10: Impaired Waters
Figure 11: Watershed Districts and Management Organizations
Figure 12: Groundwater
Figure 13: FEMA
Figure 14: MLCCS
Figure 15: Natural Resources
Figure 16: Problem Areas
Figure 17: Surface Water Groundwater Interaction
Appendix B – MS4 Documents
Appendix C – Relevant Ordinances
Appendix D – Prior Lake- Spring Lake Watershed Rules
Appendix E – Scott WMO Standards
Appendix F – Public Works Design Manual
Appendix G – Wellhead Protection Plan
Appendix H – Street Sweeping and Winter Maintenance Policies
Appendix I – Water Resources Related Agreements
Appendix J – Wetland Bank Study
Appendix K – Stormwater Trunk Acreage Charge Review
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Local Surface Water Management Plan
City of Prior Lake Section 1
WSB Project No. 010393-000 Page-1
1. EXECUTIVE SUMMARY
1.1.Local Surface Water Management Plan Purposes
This report provides the City of Prior Lake with a Local Surface Water Management Plan
(LSWMP) that will serve as a policy basis for the management of the surface water system
throughout the City. The LSWMP is incorporated as part of the City’s 2040 Comprehensive Plan.
The LSWMP will carry the City through the end of 2027. Amendments to the Plan will occur in
the intervening 10 years so that the Plan remains current to watershed plan updates and rule
revisions and current to the “state of the art” in surface water management.
The Prior Lake LSWMP will serve as a comprehensive planning document. Through
implementation of the LSWMP, the City will demonstrate its commitment to conserving,
protecting, and managing its surface water resources. The LSWMP meets requirements as
established in Minnesota Rules 8410 and Minnesota Statute 103B.235. In addition, the
participation of other organizations, particularly Scott WMO (SWMO) and Prior Lake-Spring
Lake Watershed District (PLSLWD), ensures the City’s compliance with local and regional
expectations.
1.2. Executive Summary
The Prior Lake LSWMP is organized as follows:
Section 1.0 Executive Summary provides background information and summarizes the
plan contents.
Section 2.0 Land and Water Resource Inventory describes the physical environment
including watersheds and drainage patterns, dominant land uses, and significant water
bodies within the City.
Section 3.0 Wetland Management Plan provides an overview of regulating
requirements, procedures, and wetland protection/enhancement goals.
Section 4.0 Agency Cooperation outlines other governmental controls and programs
that affect stormwater management.
Section 5.0 Assessment of Problems and Issues presents the City's water
management related problems and issues.
Section 6.0 Goals and Policies outlines the City's goals and policies pertaining to water
management.
Section 7.0 Implementation Program presents the implementation program for the
City of Prior Lake, which includes defining responsibilities, prioritizing, and listing
the program elements.
Section 8.0 Administration outlines the continued administration of this plan with
respect to plan updates and amendments.
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Local Surface Water Management Plan
City of Prior Lake Section 1
WSB Project No. 010393-000 Page-2
Appendices are included in the back of the plan. These documents are included
because they provide supporting information to the main body of the plan, are useful
information, and/or are required to be included in this plan update. Direct website
links to relevant reports or documents are provided throughout the report as
appropriate.
o Appendix A – Figures
o Appendix B – MS4 Documents
o Appendix C – Relevant City Ordinances
o Appendix D – Prior Lake-Spring Lake Watershed Rules
o Appendix E – Scott WMO Standards
o Appendix F – Public Works Design Manual (PWDM)
o Appendix G – Wellhead Protection Plan
o Appendix H – Street Sweeping and Winter Maintenance Policies
o Appendix I – Water Resources Related Agreements
o Appendix J – Wetland Bank Study
1.3. Summary of Recommendations
The following recommendations are presented for the City Council's consideration based
upon the data compiled in this report:
1. The City of Prior Lake should adopt the Local Surface Water Management Plan as
presented.
2. Establish standard review procedures to ensure all new development or redevelopment
within the City is in compliance with the grading and stormwater management controls
determined by this Plan.
3. Require detailed hydrologic analyses for all development and redevelopment activities.
4. Establish final high water levels governing building elevations adjacent to ponding areas
and floodplains as development occurs or when drainage facilities are constructed.
5. Establish and maintain overflow routes to provide relief during extreme storm conditions,
which exceed design conditions.
6. Perform stormwater system maintenance to ensure the successful operation of the system.
7. Enforce the erosion and sediment control criteria for new developments.
8. Implement an education program for City residents, staff, and development community.
9. Adopt and implement amendments to the plan as warranted by future standards or
regulations.
10. Amend the plan as required throughout the 10-year implementation period.
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Local Surface Water Management Plan
City of Prior Lake Section 1
WSB Project No. 010393-000 Page-3
11. Promote the use of regional/consolidated BMPs to help achieve water quality and volume
control goals.
12. Pursue partnerships with watershed districts and other organizations to incorporate BMPs
into redevelopment projects, including City projects.
13. Revise ordinances to be consistent with rules detailed in the Public Works Design Manual
(PWDM) regarding stormwater management.
14. Require compliance with state wetland rules through local implementation of the Wetland
Conservation Act (WCA).
SECTION 2
Surface Water Management Plan
City of Prior Lake Section 2
WSB Project No. 010393-000 Page-1
2. LAND AND WATER RESOURCE INVENTORY
2.1.Location and History
The City of Prior Lake is located in north central Scott County at the nexus of major
transportation corridors including Trunk Highway 13, Scott County Road 21 and Scott County
Road 42. Figure 1 shows the City’s location within the Twin Cities metro.
The City’s population has increased from just 848 in 1960 to over 25,000 today, with the greatest
growth occurring in the last 20 years. Table 2.1 provides City populations and population
projections from 1960 through 2040. As the City continues to grow, the importance of adequate
surface water management controls also grows. The LSWMP details these controls and makes
the connection between these controls and the overall city goal of preserving and enhancing its
natural resources and protecting its residents from flooding.
Table 2.1 Population and Households
Year Population Number of Households
1960 848 -
1970 4,127 -
1980 7,284 -
1990 11.482 -
2000 15,917 5,645
2010 22,796 8,447
2016 25,520 9,291
2020 27,500 10,500
2030 32,500 12,600
2040 37,600 14,700
Source: Metropolitan Council Annual Estimates and Population Forecasts
Lakes define the City since the core of the community developed between Upper and Lower
Prior Lake. The City’s uniqueness is tied to the lakes. Consequently, effective surface water
management cuts to the core of the City’s vision for the future.
2.2. Physical Setting
2.2.1.Topography and Geology
The topography and geology of Prior Lake was influenced by several ice sheets that advanced and
retreated across southern Minnesota during the glacier age. The most recent glacier deposited light
yellowish-brown or light olive-brown, calcareous, moderately fine textured material. The glacial
action of the area resulted in the current irregular topography, called an ice-stagnation and
disintegration moraine. Some areas contain deep unconsolidated surficial material, up to several
hundred feet deep.
The City of Prior Lake is located on the upland area of the south side of the Minnesota River, in
Scott County. The area has considerable relief, with steep slopes and potholes common throughout
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City of Prior Lake Section 2
WSB Project No. 010393-000 Page-2
the region. Many of the potholes are low wetland areas. Figure 2 shows the changing topography
within the City.
2.2.2.Drainage Systems
The City of Prior Lake and the Prior Lake hydrologic system are part of the larger Minnesota
River watershed. The City of Prior Lake is approximately 4 miles south of the Minnesota River
and drainage within the Prior Lake system is to the north and northeast. The City’s Prior Lake
system connects directly to the River through the operation of the Prior Lake outlet, which is
owned and maintained by the PLSLWD. A portion of the City, northwest of Spring Lake and
within the Scott WMO jurisdiction, drains northeast into Shakopee. Figure 3 shows the drainage
areas of the City.
Prior to 1983, Prior Lake was a land-locked lake which had a natural outlet approximately 18 feet
above what was considered normal water level. In 1981 plans were prepared for constructing a
36” RCP outlet pipe from Prior Lake with an outlet on the west side of County Road 21 into what
is known as “Jeffers Pond.” This project also included upgrading the existing ditch and culvert
system to drain the water all the way to the Minnesota River. The water level to which Prior Lake
is allowed to be drained is 902.5, 18” below the Ordinary High Water Level (OHWL) of 903.9 as
established by the Department of Natural Resources (DNR). According to DNR lake level
records dating back to 1940, the lake level has varied from 893.48 to 906.17, with a long-term
average of 902.02.
Most of the City’s drainage – both current and within the 2040 growth area – ends up in either
Prior Lake or in the Prior Lake outlet channel. Because of this, most of the land area within the
City falls within the jurisdiction of the PLSLWD. A portion of the City and City 2040 growth
area falls within the Scott WMO; this area lies northwest of Spring Lake and generally drains
toward Louisville Swamp, which lies approximately 2 miles west of the 2040 growth area
boundary.
The PLSLWD encompasses approximately 42 square miles of land in the jurisdictions of six
local units of government: Prior Lake, Savage, Shakopee, Sand Creek Township, Spring Lake
Township, and the Shakopee Mdewakanton Sioux Community (SMSC). Primary water resources
within both the PLSLWD and the City, which are discussed in detail below, include Spring Lake,
Upper and Lower Prior Lakes, Rice Lake, and Crystal Lake. Jeffers Pond and Pike Lake are
notable water resources that form a portion of the Prior Lake outlet channel.
Historically, three other watershed management organizations operated near the City of Prior
Lake. These were the Sand Creek, Credit River, and Shakopee Basin WMOs. All three WMOs
were determined to be “non-implementing” and were subsequently disbanded by the state Board
of Water and Soil Resources. Scott County then assumed the powers of these organizations
through creation of the Scott WMO. The Scott WMO includes all of Scott County not currently
managed by the PLSLWD, the Lower Minnesota River Watershed District, the Vermillion WMO
or the Black Dog WMO.
The primary Scott WMO hydrologic features within Prior Lake's existing or 2040 boundary
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WSB Project No. 010393-000 Page-3
include Mystic, Campbell, Markley, and Howard Lakes.
2.2.3.Soils
Soils of the Prior Lake area are classified into three associations:
1. Lester, Webster, Glencoe Association
2. Hayden and Lester soils and Peat bogs Association, and
3. Burnsville, Hayden, Kingsley, Scandia Association.
Information about each of the soil series listed above is available from the Scott County Soil
Survey. Table 2.2 shows the drainage characteristic of each soil series from the above
associations.
Table 2.2 Soil Drainage Characteristics
Soil Series Draining Characteristic Soil Type
Burnsville, Hayden, Kingsley and
Scandia
well drained to excessively drained B
Glencoe very poorly drained D
Hayden well drained B
Lester well drained B
Peat Bogs poorly drained D
Webster poorly drained D
Note: Because the Burnsville, Hayden, Kingsley and Scandia series has formed from a mixing of two
different kinds of glacial drift, it is impractical to separate each into a separate series.
The drainage nature of the soil is important for determining the surface water runoff from a given
area. If the soil is well-drained, a significant portion of the precipitation will be infiltrated into the
ground, whereas if a soil is very poorly drained, most of the precipitation will flow from the site
of impact.
The hydrologic soil group (HSG) defines a soils propensity to generate runoff for a given rainfall
event. Four HSG groups area identified: A, B, C, D. HSG A soils have the lowest potential to
generate runoff and are typically sandy or gravelly soils. HSG D soils have the highest potential
to generate runoff and typically consist of muck, peaty muck, and tight clay soils. The
associations found within the Prior Lake LSWMP study area fall into HSG B to D, indicating a
moderate to high potential to generate runoff. Soil types are showing in Figure 4.
Hydric soils are those characteristic soils found in wetland areas. A wetland must possess three
technical criteria in order for it to be identified as a wetland. These three are: 1) hydrophytic
vegetation, 2) hydric soils, and 3) wetland hydrology. The definition of a hydric soil is: “a soil
that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic
conditions in the upper part”. A map of hydric soils found in Scott County is shown in Figure 5.
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2.2.4.Climate and Precipitation
The climate within the Twin Cities Metropolitan Area is typical of a humid continental climate
with moderate precipitation and wide daily temperature variations. Without the buffering
influence of large bodies of water, cold winters and hot summers predominate. It is generally
understood that global climate change has an effect on the Metropolitan Area’s local climate.
One area where climate change manifests itself is in rainfall intensities and rainfall depths. The
Metropolitan Area has seen more intense rainfalls the last two decades and even the average
rainfalls seem more intense. Because of this change in precipitation, flood control facilities, if
designed for the 100-year rainfall, may get larger as the statistical 100-year rainfall gets larger.
Also, facilities designed for smaller events, such as infiltration areas and small storm sewer may
also get larger as rainfall depths increase for the 1-year to 5-year rainfall events.
The total average annual precipitation in the Metropolitan Area is approximately 30.6 inches. The
total average annual snowfall is approximately 54.4 inches. Additional climatological
information for the area can be obtained from the Minnesota State Climatology Office at
http://www.dnr.state.mn.us/climate/twin_cities/index.html.
Rainfall frequency estimates are used as design tools in water resource projects. Rainfall
frequencies are summarized in Technical Paper No. 40, Rainfall Frequency Atlas of the United
States, published by the U.S. Weather Bureau in 1961. This document was updated in 2013.
Atlas 14 is the current document used as reference for rainfall frequencies. It has been adopted by
the PLSLWD and the City in their respective stormwater management rules. Table 2.3 lists Atlas
14 rainfall frequencies for Prior Lake.
Table 2.3 Atlas 14 Rainfall Depths and Frequency
Recurrence Interval
(yrs)
24-hr Rainfall Depth (in)
1 2.49
2 2.84
5 3.54
10 4.22
50 6.30
100 7.39
Additional precipitation information for the area can be obtained from the National Oceanic and
Atmospheric Administration (NOAA) website at http://hdsc.nws.noaa.gov/.
2.2.5.Land Use
Figure 6 provides the existing land use for the City of Prior Lake. Figure 7 provides a guide to
the timeframe over which annexation will occur and the proposed 2040 land use. City growth
will be concentrated in the areas around Spring Lake and to the west of Spring Lake. Obviously,
growth requires planning for other utilities and transportation in addition to surface water
planning. These utilities are being studied under the auspices of the Comprehensive Plan 2040.
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It should be noted that the land use plan identifies future land use for areas within the 2040
growth boundary. Service areas for the sewer and water system can be effectively defined by this
boundary. In contrast, the surface water system is defined by topography and the drainage that
currently moves through the newly developing areas must continue to be accommodated in the
post development condition. For this reason, the modeling and management strategies
incorporated in the LSWMP must deal substantively with the large rural and agricultural areas
that will continue to drain through the City even after build out of the 2040 Plan. For instance,
drainage to Prior Lake extends as far south as the PLSLWD boundary. This drainage extends
almost to Cynthia Lake, three miles south of the growth boundary and incorporates the discharge
from Fish Lake, which is over 2.5 miles south of the growth boundary. So, while the 2040 Land
Use Plan forms the basis of the urban system outlined in this report, this urban system is also
affected by large rural drainage areas discharging to Prior Lake.
The comprehensive plan provides a significant amount of narrative and statistical detail on
existing and proposed land use and the reader is referred to that document for more information
on land use planning. The hydrologic modeling that supports the LSWMP used the land use plan
to determine hydrologic characteristics of the future landscape. Otherwise, existing land use was
used.
Changes from undeveloped land uses, like agricultural and natural, to more heavily developed
land uses like low, medium and high density residential, and commercial have a pronounced
effect on hydrology. The increased impervious surface associated with the urban land uses leads
to higher runoff peak flows and increased runoff volume. Table 2.4 shows how volume and peak
increase for two typical rainfall events.
Table 2.4 Land Use Based Peak and Volume Comparisons
2-year (2.84”) MSE 3 Atlas 14
24-hour Rainfall
100-year (7.39”) MSE 3 Atlas 14
24-hour Rainfall
Runoff Peak Runoff Volume Runoff Peak Runoff VolumeLand Use
cfs/ac inches cfs/ac Inches
Natural 0.2 0.24 3.8 2.5
Agricultural
(row crop in
May and June)
0.9 0.7 5.7 3.8
Low Density
Residential
(35%
impervious)
1.3 0.9 6.5 4.3
Commer
cial (85%
impervious)
3.1 2.1 8.7 6.3
The intent of the stormwater management system described in this plan is to reduce the post
development peak to a rate more in line with natural conditions. This protects the City’s lakes,
wetlands, and channels from erosion and flooding. The use of volume control is aimed at
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reducing the post development runoff depth. By reducing the post development runoff depth
through infiltration and other methods – to something more akin to the depths seen off the natural
landscape – lake, wetland and channel protection is augmented. Volume control also provides
water quality benefits.
2.3. Water Resources Data
2.3.1.Wetlands
Section 3 of this LSWMP provides an in-depth discussion on City’s wetlands and associated
regulations.
2.3.2.Lakes
There are 14 named lakes located at least partially within the boundaries of the City of Prior
Lake, along with numerous other small, unnamed bodies of water. In addition, some areas of the
City flow to Cleary Lake, located in Credit River Township. Lake information, including
watershed area, depth, and surface area, is provided by PLSLWD. Lakes and wetlands within the
City are shown in Figure 8.
Lake Name DNR ID Shoreland Management
Classification
Prior Lake (Upper)70007200 General Development
Prior Lake (Lower)70002600 General Development
Spring Lake 70005400 General Development
Pike Lake 70007600 Natural Environment
Campbell Lake 70005600 Natural Environment
Howard Lake 70007300 Natural Environment
Markley Lake 70002100 Recreational Environment
Arctic Lake 70008500 Natural Environment
Jeffers Pond 70007700 Recreational Environment
Haas Lake 70007800 Natural Environment
Blind Lake 70005300 Recreational Environment
Rice Lake 70006000 Natural Environment
Crystal Lake 70006100 Natural Environment
Mystic Lake 70007900 Natural Environment
Upper and Lower Prior Lake
Upper Prior Lake lies between Lower Prior Lake and Spring Lake and is connected to Lower
Prior Lake through a channel under County Road 21. Both these lakes have high watershed to
lake area ratios and this, particularly is why they have problems due to nutrient loading. Upper
Prior Lake has a surface area of approximately 416 acres and a total watershed area of 16,038
acres – a ratio of 39 to one. This ratio is extremely high for any water body. Lower Prior Lake
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has a surface area of 940 acres and a total watershed area (including that tributary to Upper Prior
Lake) of 18,904 acres – a ratio of 20 to one. Both lakes are relatively deep with a maximum
depth of 56 feet in the Lower and 43 feet in the Upper, although much of upper Prior Lake is
shallow, and the lake has an average depth of 10 feet. The Prior Lake outlet channel leaves
Lower Prior Lake at its far western shore near County Road 21. Both Upper and Lower Prior
Lake have a public water access together are one of the top 10 most popular recreational lakes in
the state, according to the Minnesota DNR. The land around both lakes is primarily developed.
Spring Lake
Spring Lake flows to Upper Prior Lake through a natural outlet channel. Its 12,430-acre
watershed compares to a lake surface area of 587 acres – a ratio of 21 to one. Spring Lake has a
maximum depth of 34 feet and an average depth of 18 feet. Upper and Lower Prior Lakes and
Spring Lake all have a substantial amount of residential development around them. Spring Lake
has a public water access.
Pike Lake
Pike Lake is a shallow lake through which the Prior Lake outlet channel passes. Pike Lake has a
surface area of 50 acres and a watershed area of 21,770 acres – a ratio of 435 to 1. Although Pike
Lake has a large tributary area due to the outlet channel, Lower Prior Lake has much better water
quality than Pike Lake. An analysis completed for the Prior Lake Outlet Channel EAW showed
that Pike Lake tends to have better water quality when the outlet is open compared to when it is
closed, presumably because the water from Lower Prior Lake dilutes the high-nutrient levels in
Pike Lake.
Campbell Lake
Campbell Lake lies northeast of Spring Lake within the jurisdiction of the Scott WMO. Aerial
photography and USGS mapping indicate that Campbell Lake discharges to the northwest
through a ditch. It is not known at what elevation this would occur. The lake’s OHW is 925.5’.
Campbell Lake is also characterized by a well-developed wetland fringe and is relatively shallow
for a lake though the actual maximum depth is not known. While much of this lakes drainage
area is agricultural, some of it is woodland classified as an isolated Natural Area Corridor by
Scott County. This lake constitutes the headwaters of Picha Creek. Campbell lake does not have a
public access.
Howard Lake
This lake’s OHW is 957.2 feet. Like Campbell it has large, shallow wetland areas around its
perimeter and it is not a deep lake though the actual maximum depth is not known.
Based on USGS mapping the lake apparently discharges west into Shakopee though it is not
known at what elevation, or how frequently, this occurs.
Markley Lake
Markley Lake straddles the City’s eastern boundary. The lake is landlocked and has historically
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exhibited a wide fluctuation in water levels. Total lake area is approximately 22 acres and
maximum depth is 22 feet. The contributing watershed is approximately 434 acres. Since it is
landlocked the lake must be carefully managed. The City of Prior Lake Trunk Storm Sewer Fee
Determination Study (February 2001) considered a pumping station and forcemain from Markley
Lake into the Credit River. The City completed the Markley Lake Study in 2010. The study
found that the level of flood protection for Markley Lake could be minimized to 1991 levels by
creating approximately 20 ac-ft of compensatory flood storage. Through a combination of
projects, the City has provided 15.9 ac-ft of compensatory flood storage within the City limits
since 2012. The remaining 4.1 ac-ft is targeted for areas outside City limits and should be
provided in these areas as properties develop.
Arctic Lake
Arctic Lake flows into Upper Prior Lake through a natural outlet channel. Total lake area is
approximately 33 acres with a maximum depth of 30 feet (average of 9.5 feet). Arctic Lake’s 507
acre subwatershed is comprised of woodlands and low to medium-density residential uses. Arctic
Lake contributes phosphorus loading to Upper Prior Lake. A subwatershed analysis report was
completed for the lake in 2013 that identified opportunities to reduce this loading. In 2017, the
City, SMSC, PLSLWD, Scott County, and Three Rivers Park District completed a large
collaborative project to connect regional trails and improve water quality in Arctic Lake. The
water quality improvements were based on the 2013 subwatershed analysis.
Jeffers Pond
Jeffers Pond is a deep pond located north of Jeffers Pond Elementary School and of Eagle
Creek Ave NE. The Prior Lake Outlet Channel flows through Jeffers Pond north to Pike Lake.
The surface area is approximately 39 acres with a maximum depth of 70 feet in the westernmost
pond. There is a system of public trails and a fishing dock on Jeffers Pond that is only accessible
by trail.
Haas Lake
Haas Lake is located northeast of Mystic Lake just south of 140th St NW. This is considered a
shallow lake with a maximum depth of less than 8 feet. The total surface area is around 27 acres.
The discharge from the lake flows out of the northwest corner through a culvert under County Rd
42 and into a creek that empties into the Minnesota River. PLSLWD completed an aquatic survey
for the lake in 2017. General findings identified native shorelines offered good wildlife habitat,
low species diversity within the lake, and no non-native plant species within the lake.
Blind Lake
Blind Lake is located between County Road 21 and State Highway 13 in southern Prior Lake,
within the Scott WMO. The total surface area is about 11 acres. The lake flows to Markley Lake
through a series of wetlands and ponds. There is no public access. Little is known about the
characteristics of this lake.
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Rice Lake
Rice Lake is located on the southern border of Prior Lake, within the PLSLWD. The lake has a
watershed area of 665 acres and a surface area of 30 acres. The entire shoreline of the lake is
wetland fringe. There is not much available information on water depth or quality, although the
lake is classified as a shallow lake by PLSLWD. It flows north into Crystal Lake through a
private culvert under 174th Street East in Spring Lake Township.
Crystal Lake
Crystal Lake is located north of Rice Lake in southern Prior Lake, within the PLSLWD. The lake
has a watershed area of 1,340 acres and a surface area of 30 acres. Much of the shoreline around
the lake remains in a natural condition and is part of Crystal Lake Park. The City maintains a
popular fishing dock on the lake that is part of the Minnesota DNR’s Fishing in the
Neighborhood (FiN) program.
Mystic Lake
Mystic Lake is located east of County Road 83 in the northwestern portion of Prior Lake.
According to the SMSC, Mystic Lake is a 65-acre basin that receives runoff from the Mystic
Lake Casino parking lots after it is treated in over 10 acres of stormwater ponds. The SMSC has
tracked water quality in the lake since the late 1990s.
2.3.3.Water Courses
Prior Lake Outlet Channel
The Prior Lake Outlet Channel (PLOC) resulted from a citizen petition for an outlet to carry
stormwater from the landlocked Prior and Spring Lakes to ultimately discharge into the
Minnesota River. In 1979, the Minnesota Department of Natural Resources (DNR) issued a
permit to the PLSLWD for construction of the Prior Lake Outlet Channel. The district entered
into a joint powers agreement with Prior Lake and Shakopee in 1981 regarding the channel and
the outlet system was first used in 1983. The original outlet structure consisted of a 36-inch RCP
pipe surrounded by a concrete structure with adjustable gates. The outlet structure was rebuilt in
2010 and consists of an accordion-shaped fixed crest weir (set at an elevation of 902.5) and a
low-flow gate allowing discharge between an elevation of 902.5 and 902.0, in accordance with
the PLSLWD’s operation plan. The maximum discharge capacity is determined to be 65 cfs,
although this discharge rate is only achieved at very high lake levels above 906.0. The PLSLWD
website (www.plslwd.org) contains more detailed information about the outlet structure and the
PLOC.
The PLOC works to address high lake level issues on Prior Lake and as a trunk stormwater
system for the City of Prior Lake, the City of Shakopee, and the SMSC. The PLSLWD, Cities of
Prior Lake and Shakopee, and the SMSC operate and maintain the PLOC through a
Memorandum of Agreement (MOA).
2.3.4.Monitored Water Quality and Quantity Data
The City will continue to support monitoring of surface waters within its jurisdictional
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boundaries and the PLOC through the MOA. Data will be obtained through cooperation and
coordination with other various agencies, including the Minnesota Pollution Control Agency,
cities and townships adjacent to Prior Lake, the Metropolitan Council, the Minnesota Department
of Natural Resources, the PLSLWD, Scott WMO, and Three Rivers Park District.
Through its own monitoring efforts and those of the Citizen Assisted Monitoring Program
(CAMP) run by Metropolitan Council and Three Rivers Park District, the PLSLWD has been
collecting data on nutrient loading into the impaired waters, and others, identified above.
The PLSLWD water quality data collection and monitoring efforts consist of tributary/outlet
monitoring and in-lake monitoring. Tributary/Outlet monitoring and other sampling occurs at the
following locations:
County Ditch 13 at the second/upstream crossing of Hwy 13 (PLSLWD site CD 1)
Outlet of the Hwy 13 Treatment Wetland (PLSLWD site CD2)
Outlet of the desiltation basin on County Ditch 13 tributary just upstream of Spring
Lake (PLSLWD site CD3)
Outlet from Lower Prior Lake (PLSLWD site PLO)
Outlet from Spring Lake (PLSLWD site SLO)
ST_19 - Tributary to Spring Lake from Scott County Highway Department
Watershed
ST_40 - Tributary to Spring Lake, Outlet of 12/17 Wetland (Spring Lake Wetland)
ST_14 - Tributary to Spring Lake, Outlet of Buck Lake
ST_B3 - Tributary to Fish Lake
ST_T3 - Tile outlet in Tributary to Fish Lake
ST_24 - Tributary to Upper Prior - Cates Creek
ST_S3P and ST_S3PP - Tributary to Lower Prior - Before and After IESF at Fish
Point Park
ST_26A - Tributary to Pike Lake - along outlet channel in Pike Lake Park
DLO - Tributary to MN River, where PLOC crosses Highway 101
A total of eight lakes, totaling 10 sample sites, within the PLSLWD were monitored in 2018 as
part of the Metropolitan Council’s CAMP. These were:
CAMP Lakes
Buck Lake
Haas Lake
Cates Lake
Lower Prior Lake (2 monitoring sites)
Three Rivers Park District Lakes
Lower Prior Lake
Upper Prior Lake
Spring Lake
Pike Lake (2 monitoring sites, East Bay and West Bay)
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City of Prior Lake Section 2
WSB Project No. 010393-000 Page-11
Fish Lake
Figure 9 shows monitoring stations located within the City. Water quality information can be
found from the watershed management organizations having jurisdiction within the City,
Metropolitan Council, and the Minnesota Pollution Control Agency on the following websites:
Metropolitan Council monitoring information, including the Citizen-Assisted Monitoring
Program (CAMP), can be found at: https://metrocouncil.org/Wastewater-
Water/Services/Water-Quality-Management/Lake-Monitoring-Analysis.aspx
Prior Lake – Spring Lake Watershed District’s monitoring program information can be
found at: http://www.plslwd.org/projects-and-programs/monitoring/
Minnesota Pollution Control Agency’s Citizen Lake Monitoring Program (CLMP)
information can be found at: http://www.pca.state.mn.us/water/clmp.html
2.3.5.Impaired Waters
The Minnesota Pollution Control Agency (MPCA) is required to publish a list of impaired
waters; these are lakes and streams in the state that are not meeting federal water quality
standards. For each water body on the list, the MPCA and EPA are required to conduct and
approve a study to determine the allowable Total Maximum Daily Load (TMDL) for each
pollutant that exceeds the standards. Impaired waters in Prior Lake, or those receiving discharge
from Prior Lake, are summarized in Table 2.4 and shown in Figure 10.
Table 2.4 – Impaired Waters
Water Body Year
First
Listed
Affected
Use
Pollutant or
Stressor
TMDL
Completion
Date
Approved
TMDL Study
Spring
(70-0054)
2002 Aquatic
recreation
Excess
nutrients
2011 Spring Lake – Upper
Prior Lake TMDL
Spring
(70-0054)
1998 Aquatic
consumption
Mercury,
FCA
2008 Statewide Mercury
TMDL
Spring (70-
0054)
2018 Aquatic life Fishes
bioassessments
Anticipated
2029
None
Upper Prior
(70-0072)
2002 Aquatic
recreation
Excess
nutrients
2011 Spring Lake – Upper
Prior Lake TMDL
Upper Prior
(70-0072)
2002 Aquatic
consumption
Mercury,
FCA
2008 Statewide Mercury
TMDL
Lower Prior
(70-0026)
2002 Aquatic
consumption
Mercury,
FCA
2008 Statewide Mercury
TMDL
Lower Prior
(70-0026)
2018 Aquatic life Fishes
bioassessments
Anticipated
2029
None
Pike
(70-0076)
2002 Aquatic
recreation
Excess
nutrients
Anticipated
2019
None
Cleary Lake 2008 Aquatic Excess nutrients Anticipated None
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WSB Project No. 010393-000 Page-12
(70-0022)recreation 2019
Cleary Lake
(70-0022)
1998 Aquatic
consumption
Mercury, FCA 2008 Statewide Mercury
TMDL
Minnesota
River
(07020012-
505)
2004 Aquatic
Consumption,
Aquatic
Recreation
Mercury,
PCB’s,
Turbidity,
Dissolved
oxygen (DO)
2006, 2018 Statewide Mercury
TMDL, Lower
Minnesota River DO
TMDL, and Minnesota
River and Greater Blue
Earth River Basin TSS
TMDL
Minnesota
River
(07020012-
506)
1998 and
2016
Aquatic
Consumption,
Aquatic Life
Mercury in Fish
Tissue and
Water Column,
PCBs,
Turbidity,
Nutrient/eutrop
hication
biological
indicators
2008, 2018 Statewide Mercury
TMDL and Minnesota
River and Greater Blue
Earth River Basin TSS
TMDL
Notes:FCA stands for fish consumption advisory and is thus not an independent pollutant or stressor.
Source: MPCA
A Lower Minnesota River Watershed TMDL is currently under development. The City will be
required to update this surface water management plan to incorporate the findings of each
completed TMDL study and will also be required to amend their MS4 permit and Storm Water
Pollution Prevention Plan. This must be done within 18 months of the approved TMDL date.
The Minnesota River, downstream of the Prior Lake Outlet Channel, is also listed as impaired.
This listing will potentially affect management of drainage that directly discharges to the outlet
channel. The river’s affected uses are aquatic consumption, aquatic recreation, and aquatic life
and the pollutants or stressors that have been identified as causing these impairments are the
following:
Fecal coliform
Low oxygen
Mercury
PCB
Turbidity/TSS
The Minnesota River and Greater Blue Earth River Basin Total Suspended Solids TMDL was
completed in 2018 to address the turbidity impairment for the Minnesota River and the Greater
Blue Earth River basin. The City of Prior Lake was included in the categorical wasteload
allocation for those portions of the Lower Minnesota River downstream of the PLOC. The
categorical TSS load reductions for the relevant reaches to the City are as follows:
07020012-505 – 60%
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07020012-506 – 74%
07020012-800 – 73%
The MPCA approved the TCMA Chloride Management Plan in 2016. This plan is intended to
discuss the impacts of chloride on water quality, set performance based goals, and provide
implementation strategies to communities to reduce salt runoff and usage. This plan can be
viewed here: https://stormwater.pca.state.mn.us/index.php/Chloride_Management_Plan
2.3.6.Groundwater
Groundwater resource data for areas within the City is available by reviewing the content of three
reports. A brief description of the content for these documents is provided below along with a
web link.
The Scott County Geologic Atlas completed in 1982 contains information on aquifers,
depth to ground water table, and areas sensitive to ground water pollution.
The Scott WMO Comprehensive Water Resources Management Plan contains
groundwater information, issues and policies for Scott WMO.
City of Prior Lake Wellhead Protection Plan delineates drinking water supply
management areas and wellhead protection areas. Figure 12 shows the Drinking Water
Supply Management Areas (DWSMAs) for the City.
The City’s Wellhead Protection Plan consists of two parts. Part 1 delineates wellhead protection
areas and associated drinking water supply management areas (DWSMAs) and identified two
DWSMAs within the City. Part 2 identified potential contaminant sources within the DWSMAs,
and discusses source management strategies and the goals, objectives, and action plans that
accompany these strategies. Some of these goals include:
Maintaining the current level of water quality so that the municipal water supply will
continue to meet or excess state and federal water quality standards.
Protecting source water aquifers through intercommunity collaboration and data
sharing/collection.
Providing educational material to the public regarding the Wellhead and Source Water
Protection Program.
Specific action items related to these goals can be found in Section 6 of this SWMP. The
Wellhead Protection Plan executive summary can be found in Appendix G. A full version of
Parts 1 and 2 can be requested from the City.
The City will be required to incorporate the requirements of the Wellhead Protection Plan into
their SWPPP for areas located within vulnerable source water protection areas (NPDES MS4
General Permit). Vulnerable Source Water Protection areas are those areas susceptible to water
supply contamination from activities at the land surface and are based on the following three
components: geologic sensitivity, well construction maintenance and use, and water chemistry
and isotopic composition. DWSMA vulnerability is determined using geologic, soils and
groundwater chemistry information. The designation indicates that the aquifer is covered by at
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WSB Project No. 010393-000 Page-14
least 50 feet of clay material.
For areas of vulnerability, the City will incorporate the guidance developed by the Minnesota
Department of Health (MDH) on evaluating proposed stormwater infiltration projects in
vulnerable source water protection areas and the guidance located within the Minnesota
Stormwater Manual when designing infiltration best management practices (BMPs). This will be
of a particular concern in areas where stormwater infiltration is being considered in soils suitable
for rapid infiltration adjacent to municipal and private wells.
Figure 17, Appendix A also shows the surface water/groundwater interaction as analyzed by
regional screening performed by the Metropolitan Council in their report, Evaluation of
Groundwater and Surface-Water Interaction: Guidance for Resource Assessment. The Council
intends on completing this process again in the future as new information becomes available.
Spring Lake and Upper Prior Lake are shown to recharge aquifers.
2.3.7. Flood Insurance Studies
A Flood Insurance Study, dated March 1978, was completed for the City of Prior Lake by the
Federal Insurance and Mitigation Administration, a department of the Federal Emergency
Management Agency (FEMA). This study updated a Flood Hazard Boundary Map that was
prepared by the FEMA in 1975. The 1978 Flood Insurance Study was based on Prior Lake being
a land-locked lake, no outlet was considered in the analysis. The method applied a water mass
balance model to generate historic lake levels. That study established a 100-year flood elevation
of 908.9 with a 1-foot regulatory freeboard elevation of 909.9 for Prior Lake and a 100-year
flood elevation of 914.4 for Spring Lake.
In 1997, an approved Flood Insurance Study was prepared by the US Army Corps of Engineers
for the FEMA to determine if the 100-year flood elevation could be lowered for Prior Lake. The
City and PLSLWD completed a flood mitigation and stormwater management study in 2016 that
included an analysis of Prior Lake and its contributing drainage area. In 2018, FEMA approved a
new 100-year floodplain elevation for Prior Lake at an elevation of 906.9 (regulatory freeboard
elevation of 907.9) based on the results of the 2016 study. FEMA boundaries are shown in
Figure 13. The current FEMA maps can be found on FEMA’s website by searching for the Flood
Map Service Center.
2.4. Natural Resources Data
2.4.1.MLCCS and MCBS
The Minnesota Land Cover Classification System, or MLCCS, categorizes urban and built up
areas in terms of land cover rather than land use. MLCCS serves as a tool for City staff to
integrate natural area preservation into land planning, land use, and zoning decisions. The City is
dominated primarily by developed area with planted or cultivated vegetation areas as the next
majority land classification. The remaining areas are herbaceous areas and wetland throughout
the center of the City. Figure 14 provides MLCCS coverage for Prior Lake.
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According to the DNR, the Minnesota County Biological Survey (MCBS) began in 1987 as a
systematic survey of rare biological features on a county-by-county basis. Prior Lake has several
areas identified as outstanding and high biological significance. These are generally in close
proximity to Prior Lake ’s open space and park land. The DNR has jurisdiction over these areas.
Based on state statute any work within these areas is required to meet DNR permit requirements.
Figure 15 provides the locations of rare and biological features in the City of Prior Lake.
The conservation corridor shown in Figure 15 represents area designated by the DNR to be
protected and to provide restoration of key natural habitats. These corridors are to be used by
local agencies to prioritize areas for conservation.
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WSB Project No. 010393-000 Page-1
3. WETLAND MANAGEMENT PLAN
3.1.Goals
The goal of this Wetland Management Plan is to establish a policy of No Net Loss of wetland area
and function, in accordance with the Wetland Conservation Act (WCA).
The plan is designed to achieve the following goals:
1.Achieve no net loss of wetlands;
2.Protect and preserve wetlands through administration and enforcement of the WCA;
3.Discourage the disturbance of wetlands;
4.Determine the quality of wetlands through the review of wetland assessments prepared for
any project that includes a wetland;
5.Restrict clearing and grading near the wetland boundary and require a protective buffer strip
of natural vegetation to provide protection from stormwater runoff and promote infiltration of
sediment and nutrients;
6.Investigate the establishment of a wetland bank to allow for wetland replacement for City
projects.
7.Identify wetland restoration or enhancement opportunities.
8.Promote wetland stewardship.
3.2. Wetland Conservation Act Administration
The City of Prior Lake will administer the WCA following the duties and procedures set forth in
Minnesota Rule 8420.0200. A wetland assessment will be required for any project parcel that
includes a wetland, as defined by the National Wetland Inventory or other available data.
Wetland-related applications shall be submitted to the Local Government Unit (LGU) contact. The
City may establish fees to offset the costs associated with reviewing these applications. Upon
receipt, the LGU contact or their designee will review the application for completeness within 15
business days. A complete wetland delineation application includes:
Wetland Delineation Report, completed in accordance with the most current versions
of the US Army Corps of Engineers (USACE) Wetland Delineation Manual and
applicable Regional Supplement.
Determination of wetland function through the application of the most current version
of the Minnesota Rapid Assessment Method (MnRAM) for wetlands.
Signed Joint Application Form for Activities Affecting Water Resources in
Minnesota.
Submittal of wetland boundaries via GIS shapefile or CAD file (following approval)
Wetland delineations shall be completed within the growing season, which is generally defined as
between April 15 – October 15 of any given year. Reports for delineations within this time frame
must be submitted to the LGU by November 1. This period may be extended or reduced at the
discretion of the LGU based on local growing season conditions.
The City of Prior Lake discourages wetland disturbances in accordance with the WCA. The City
requires project proponents to first avoid direct or indirect impacts to wetlands. If avoidance is not
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WSB Project No. 010393-000 Page-2
feasible, project proponents must minimize impacts. Finally, wetland impacts must be replaced at a
minimum 2:1 ratio through either project-specific (on-site) replacement or the purchase of
replacement credits from a Board of Water and Soils Resources (BWSR)-approved wetland bank.
A complete application for wetland impacts must include:
Signed Joint Application Form for Activities Affecting Water Resources in Minnesota
Project plans depicting wetland impact area
Mitigation plan (if required)
The Joint Application Form for Activities Affecting Water Resources in Minnesota is available on
the BWSR website at http://www.bwsr.state.mn.us/wetlands/wca/index.html.
All complete applications will be noticed to the Technical Evaluation Panel (TEP) for a minimum
15-day comment period. This comment period may be extended based on the complexity of the
review. During this comment period the LGU may hold a meeting to review the application. In
accordance with MN Rules 8420.0240, the TEP consists of a technical professional employee of
the BWSR, a technical professional employee of the Scott County Soil and Water Conservation
District (SWCD), a technical professional with expertise in water resource management and
Department of Natural Resources (DNR) for projects that involve DNR Public Waters. Although
they cannot officially be part of the TEP, the local watershed district and USACE will be notified
of all complete applications and TEP meetings.
Per Minnesota Statute 15.99, decisions regarding wetland applications must be made within 60
days of receipt of a complete application. This decision deadline may be extended. Decisions
regarding wetland delineations, No Loss, or Exemptions shall be reviewed and approved at the
staff level. Decisions regarding replacement (mitigation) plans and wetland bank establishment
plans shall be approved by the City Council. Other agencies may also regulate wetlands. These
include, but are not limited to the DNR, USACE, Minnesota Pollution Control Agency, and local
watershed district. Approval through the WCA does not obviate the need for approval from other
regulating agencies. It is the responsibility of the applicant to identify and obtain all permits or
approvals needed prior to construction.
3.3. Stormwater Protection
There are many types of wetlands, each determined by its hydrology and vegetative composition.
A wetland’s sensitivity to stormwater input is dependent on the wetland’s community type and the
quality of its plant community. Some wetlands (e.g., sedge meadows with carex species) are
sensitive to disturbance and will show signs of degradation unless water quality, bounce and
duration are maintained at existing conditions after construction. On the other hand, there are other
wetlands (e.g., floodplain forests) which are better adapted to handle the fluctuating water levels
and influx of sediment often associated with stormwater.
Prior Lake’s Public Works Design Manual (PWDM) outlines the allowable uses of wetlands for
stormwater utilization. This document divides wetlands into rankings that include: highly
susceptible, moderately susceptible, least susceptible, and slightly susceptible. The following are
the procedures that were used to determine the wetland susceptibility ranking.
Highly Susceptible: A wetland is considered highly susceptible if:
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Forty percent or more of the wetland complex has a highly susceptible wetland
community (-ities) as shown in Table 3.1 and;
Highly susceptible wetland community (-ities) have medium to exceptional floral
diversity/integrity.
Moderately Susceptible: A wetland is considered moderately susceptible if:
Forty percent or more of the wetland complex has a moderately susceptible wetland
community (-ities) as shown in Table 3.1 and;
Moderately susceptible wetland community (-ities) have medium to exceptional floral
diversity/integrity.
Least Susceptible: Wetlands with low floral diversity, as determined by MnRAM, were least
susceptible wetlands.
Slightly Susceptible: Wetlands that do not fall under the high, moderate, or least susceptible
categories are considered slightly susceptible.
Table 3.1 Wetland Community Susceptibility to Stormwater Impacts
Highly Susceptible Wetland Communities*Moderately Susceptible
Wetland Communities*
Sedge Meadow Low Prairies Shrub-Carrs
Bogs Coniferous Swamps Alder Thickets
Coniferous Bogs Hardwood Swamps Fresh (wet) Meadows
Open Bogs Seasonally Flooded Basins Shallow Marsh
Calcareous Fens Deep Marsh
* Wetland community (-ities) determined using key provided in MnRAM Version 2.0.
The following sections provide summaries of each protection strategy developed for wetlands
within the City. Refer to the PWDM for complete details regarding stormwater utilization.
3.3.1. Rate Control
Wetlands may be utilized for rate control as long as this use complies with the bounce and
inundation criteria of Section 3.3.2.
3.3.2. Volume Control
In the recent past, surface water management plans have protected wetlands from nutrients but not
water fluctuations or duration. In fact, it was common to use wetlands to reduce flooding potential
through sizing storm sewer pipes to maximize bounce and detention time in wetlands.
This plan addresses stormwater quantity impacts to wetlands by providing protection strategies to
maintain the existing integrity of the wetland through special protection strategies for highly,
moderately, and slightly susceptible rankings and are described in Table 3.2 below.
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Table 3.2 Wetland Quantity Standards
Hydroperiod
Standard
Highly
Susceptible
Moderately
Susceptible
Slightly
Susceptible
Least
Susceptible
Storm Bounce
100-year
Existing Existing
+ 0.5 ft
Existing
+ 1 ft
No limit
Discharge Rate Existing See Rate Control
Standard
See Rate Control
Standard
See Rate Control
Standard
1 & 2 year
NRCS event
Inundation
Existing Existing
+ 1 day
Existing
+ 2 days
Existing
+ 7 days
10 year NRCS
event
Inundation
Existing Existing
+ 7 days
Existing
+ 14 days
Existing
+ 21 days
Outlet control
elevation
Existing Existing 0-2 ft
additional
storage
0-4 ft additional
storage
“Existing” in this chart means the existing hydrologic conditions. If there have been recent
significant changes in conditions, it means the conditions that established the current wetland.
3.3.3.Water Quality
Water quality plays a significant role in the overall quality of a wetland. When the quality of the
incoming water declines, the wetland’s plant community may see a reduction in species diversity
and retain only those species that are tolerant of high nutrient and sediment loads. Once a wetland’s
plant community is changed, the wetland’s character and ecosystem will change, often to a less
valuable system in terms of biodiversity, habitat for wildlife, and aesthetic enjoyment. Stormwater
runoff shall not be discharged into wetlands without pretreatment.
3.3.4. Wetland Buffer and Setback Protection
A wetland buffer is a vegetated area that surrounds a wetland and reduces negative impacts to
wetlands from adjacent development. Catch basins and storm sewers typically collect street and
front yard drainage and direct the drainage to an appropriately-sized pond for pretreatment prior to
discharge to a wetland or waterbody. Backyard drainage typically reaches wetlands or waterbodies
without pretreatment, thereby allowing lawn and garden chemicals, sediments, pet wastes, fertilizer
and other types of contaminants to directly impact the receiving waterbody. Wetland buffers can
help mitigate potential development impacts to wetlands by reducing erosion by stormwater;
filtering suspended solids, nutrients, and harmful substances; and moderating water level
fluctuations during storms. Buffers also provide essential wildlife habitat for feeding, roosting,
breeding, and rearing of young, and cover for safety, movement, and thermal protection for many
species of birds and animals.
For any parcel created or developed in the City, a buffer shall be maintained around the perimeter of
all Major Watercourses (as defined by Scott WMO), watercourses (as defined by PLSLWD), WCA
wetlands, and Public Waters wetlands. The buffer features outlined in Tables 3.4 and 3.5 below are
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required for wetlands and watercourses in the PLSLWD and Scott WMO; buffer requirements will
apply based on the watershed in which the project resides.
Buffer requirements do not apply to any wetland with a surface area equal to or less than the area of
wetland impact allowed without replacement as de minimis under the WCA.
The quality of each wetland can be found using the results of the MnRAM assessment described in
Section 3.2, and defined in Table 3.3:
Table 3.3 MnRAM Wetland Quality Definitions
MnRAM Wetland Classification Wetland Quality Rating
Preserve Exceptional
Manage 1 High
Manage 2 Medium
Manage 3 Low
Table 3.4 Wetland Buffer, Setback, and No-Grade Requirements (areas within PLSLWD)
Wetland QualityBuffer Requirement
Exceptional High Medium Low
Average Width (ft)30 30 30 30
Minimum Width (ft)20 20 20 20
Table 3.5 Wetland Buffer, Setback, and No-Grade Requirements (areas within Scott WMO)
Wetland QualityBuffer Requirement
Exceptional High Medium Low
Average Width (ft)65 50 35 25
Minimum Width (ft)25 25 25 25
Minimum No-Grade
Zone (ft)
25 25 25 25
Foundation setback
from Wetland
35 35 35 35
Refer to the PWDM for complete standards regarding wetland buffer and setback protection.
3.3.5.Buffer Vegetation
Where acceptable natural vegetation exists in wetland buffers, the retention of such vegetation in an
undisturbed state is required unless an applicant receives approval to replace such vegetation. An
existing wetland buffer has acceptable natural vegetation if it:
Has a continuous, dense layer of perennial grasses that has been uncultivated or
unbroken for at least 5 consecutive years; or
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Has an overstory of trees and/or shrubs that has been uncultivated or unbroken for at
least 5 consecutive years; or
Contains a mixture of the plant communities described in the two preceding paragraphs
that has been uncultivated or unbroken for at least 5 consecutive years.
Notwithstanding the performance standards set forth in this section, the City may determine the
existing buffer vegetation unacceptable if:
It is composed of undesirable plant species including but not limited to Prohibited and
Restricted Noxious Weeds listed by the Minnesota Department of Agriculture in the
current Noxious Weed List; or
It has topography that tends to channelize the flow of runoff; or
For some other reason it is unlikely to retain nutrients and sediment.
Where wetland buffers are not vegetated or have been cultivated or otherwise disturbed within 5
years prior to the project application, such areas shall be replanted and maintained. The wetland
buffer plantings must be identified within the application materials. Wetland buffers shall be
established in accordance with the following standards:
Buffers shall be planted with a seed mix included on the current State Seed Mix list.
Seed mixes shall be broadcast in accordance with the State Seed Mix specifications of
the selected mix.
The selected seed mix shall be appropriate for the site soil conditions and free of
invasive species.
Native shrubs may be substituted for native forbs. All substitutions must be approved
by the City. Such shrubs may be bare root seedlings and shall be planted at a minimum
rate of 60 plants per acre. Shrubs shall be distributed to provide a natural appearance
and shall not be planted in rows.
Any groundcover or shrub plantings installed within the buffer are independent of any
landscaping required elsewhere by the City.
Grasses and forbs shall be seeded or planted using a method of application that shall be
approved by the City prior to planting or seeding.
No fertilizer shall be used in establishing new buffer strips, except on highly disturbed
sites when necessary to establish acceptable buffer vegetation and then limited to
amounts indicated by an accredited soil testing laboratory.
All seeded areas shall be mulched immediately with clean straw at a rate of 1.5 tons per
acre or as specified by the agency specifications for the seed mix being used. Mulch
shall be anchored with a disk or tackifier.
Buffers (both natural and created) shall be protected by erosion and sediment control
measures during construction in accordance with the PWDM. The erosion and sediment
control measures shall remain in place until permanent cover, as defined by the current
NPDES Construction Stormwater Permit, is achieved.
A 2-year maintenance period is required as part of the developer’s agreement or other City
agreement. During the first two full growing seasons, any buffer vegetation that does not survive
must be replanted. The owner shall be responsible for reseeding and/or replanting if the buffer
changes at any time through human intervention or activities. At a minimum, the buffer strip must
be maintained as a “no mow” area.
Buffer strips shall be required regardless of whether the wetland is on the same parcel as the
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proposed development or on an adjacent parcel. Wetlands on adjacent parcels need not be
delineated, but an estimation using aerial photos or other desktop resources will be required.
Refer to the PWDM for complete standards regarding wetland buffer vegetation requirements.
3.3.6. Buffer Monuments
Buffers shall be identified within each parcel by permanent monumentation. Monuments shall be
required at each parcel line where it crosses a buffer and shall have a maximum spacing of 200 feet
along the edge of the buffer. Additional monuments shall be placed as necessary to accurately
define the edge of the buffer. Signage requirements and fees are outlined in the City’s PWDM.
3.3.7. Buffer Protection
3.3.7.1. Conservation Easements and Outlots within Scott WMO
Within the Scott WMO, property owners shall submit to the City for its approval a conservation
easement for protection of approved buffers, or include the buffer in an outlot, dedicated to the
City, as part of platting and subdivision approval. Conservation easements shall describe the
boundaries of the wetland or public waters wetland and buffer, identify the monuments and
monument locations, prohibit removal of the buffer monuments, and prohibit any alterations set
forth in section 3.3.8 below. Approved conservation easements must be filed for record and
evidence of filing must be submitted to the City. Outlot descriptions shall provide for an
equivalent level of protection of the buffer and prohibit any alterations set forth in section 3.3.8
below.
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3.3.7.2. Conservation Easements within PLSLWD
Within the PLSLWD, property owners shall submit to the PLSLWD for its approval a
conservation easement for protection of buffers. Conservation easements shall describe the
boundaries of the watercourse or wetland and buffers, identify the monuments and monument
locations, prohibit removal of the buffer monuments, and prohibit any alterations set forth in
section 3.3.8 below. Approved conservation easements must be filed for record and evidence of
filing must be submitted to the PLSLWD.
3.3.8.Buffer Alterations
3.3.8.1. Prohibited Buffer Alterations
Subject to section 3.3.8.2 below, alterations including building, storage, paving, mowing,
plowing, introduction of Prohibited and Restricted Noxious Weeds listed by the Minnesota
Department of Agriculture in the current Noxious Weed List, cutting, dredging, filling,
mining, dumping, grazing livestock, agricultural production, yard waste disposal or
fertilizer application, are prohibited within any buffer. Prohibited and Restricted Noxious
Weeds may be removed. Alterations do not include plantings that enhance the natural
vegetation or selective clearing or pruning of trees or vegetation that are dead, diseased, or
pose similar hazards.
3.3.8.2. Permitted Buffer Alterations
The following activities shall be permitted within any buffer, and shall not constitute
prohibited alterations under section 3.3.8.1 above:
Use and maintenance of an unimproved access strip through the buffer, not
more than 20 feet in width, for recreational access to the watercourse or
wetland and the exercise of riparian rights;
Placement, maintenance, repair or replacement of utility and drainage
systems that exist on creation of the buffer or are required to comply with
any subdivision approval or building permit obtained from the City, so long
as any adverse impacts of utility or drainage systems on the function of the
buffer have been avoided to the extent possible;
Construction, maintenance, repair, reconstruction or replacement of
existing and future public roads crossing the buffer, so long as any adverse
impacts of the road on the function of the buffer strip have been avoided or
minimized to the extent possible;
Clearing, grading, and seeding is allowed if part of an approved Wetland
Replacement Plan.
3.4. Wetland Restoration/Enhancement Opportunities
It is a goal of this plan to identify wetland restoration and enhancement opportunities and achieve
no net loss of wetlands within the City.
The WCA requires replacement for wetland impacts a minimum 2:1 ratio through either site-
specific replacement or through the purchase of credits through a BWSR-approved wetland bank.
Site-specific replacement should be encouraged when a wetland restoration or creation is possible
on-site. When site-specific replacements are not ecologically appropriate, then wetland banks
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located within the City and County should be the next priority. Currently, there are no wetland
banks within the City of Prior Lake. It is a goal of this section and outlined in Policy 7.5 of this plan
to investigate the establishment of a wetland bank for use by the City to mitigate for wetland
impacts within the City.
In January 2017, the City prepared a study that identified potential wetland bank sites. Five sites
were identified, three of which had characteristics that would make wetland mitigation bank
development feasible. Two of these sites are not currently owned by the City. The City does
maintain a conservation easement over the third site. A site visit and initial coordination with the
WCA TEP occurred in Spring 2017. Additional coordination with the TEP and USACE is needed to
further identify mitigation bank potential.
3.5. Wetland Stewardship
There are a number of things that can be done by individuals or groups to enhance wetlands, buffer
strips that surround wetlands, shorelands, or high-quality upland areas. This section describes some
of these practices. It is recommended that individuals and groups contact the City prior to doing any
work within wetlands or buffers.
3.5.1. Enhancement
Native wildflowers, grasses, shrubs and trees can be planted in the wetland or the adjacent buffer
areas to enhance habitat and stormwater filtering. Habitat can be enhanced by creating vertical
layers (planting trees or shrubs where these are absent), and by adding plants that provide food and
cover, such as fruiting shrubs. Increasing the structural and plant species diversity in the landscape
provides additional habitat niches, and can increase the numbers and species of animals using the
area.
Species that are native to the area will probably require the least maintenance, survive harsh
Minnesota weather more easily, and provide the greatest habitat benefits. The DNR has information
available to assist the public with landscaping using native plants:
http://www.dnr.state.mn.us/gardens/nativeplants/index.html.
Structures for nesting and basking can also be added to wetlands and buffer areas to enhance the
habitat availability for wildlife. The Minnesota DNR, Minnesota Waterfowl Association, and other
habitat enhancement organizations can provide information about the types and sources of
structures available. Cost-share may be available from local organizations including the Scott
WMO, PLSLWD, and Scott SWCD.
3.5.2. Control of Invasive Species
Several non-native (invasive) species have become problems in Minnesota wetlands and adjacent
uplands. These plants invade native plant communities and can take over rapidly, eliminating native
plants that provide important food and habitat benefits.
Information related to the identification and control of invasive species is available through the
DNR: http://www.dnr.state.mn.us/invasives/terrestrialplants/index.html.
The State Noxious Weed list is available from the Minnesota Department of Agriculture:
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https://www.mda.state.mn.us/plants/pestmanagement/weedcontrol/noxiouslist.aspx.
3.5.3.Encouraging Pollinators
The City of Prior Lake recognizes the importance of pollinators for assisting in the reproduction of
plants. The City is interested in managing for pollinators and increasing awareness for pollinators
and the benefits they provide.
Managing for pollinators includes a series of steps necessary to create, restore, or enhance a
designated area to provide the necessary habitat to various pollinators (e.g. bees, butterflies, certain
bird species, bats). Strategies include ensuring sufficient foraging habitat, providing structures or
host plants needed for reproduction, providing shelter, and minimizing the use of chemicals to
control invasive species. The City may also provide educational opportunities to area residents to
increase awareness for pollinators and encourage individuals and groups to adopt pollinator-friendly
practices.
3.5.4.Education
The City intends to continue to provide educational opportunities to the public, and currently hosts
periodic workshops and events aimed at educating the public on water quality and water resources.
The City also provides information on stormwater and wetland-related topics in the City’s
newsletter.
Schools and other organizations can adopt wetlands and adjacent areas for use as outdoor
classrooms. Students, parents, and teachers can add native wetlands and upland plants, habitat
structures, and other enhancements to increase learning opportunities and encourage other wetland
owners in the area to make similar enhancements.
3.5.5.Climate Change Resiliency
Studies have indicated that climate change may cause more frequent, extreme, weather events.
Wetlands, some of which serve as areas for flood retention, may be overwhelmed by these weather
events. Additionally, native plant species may not compete well against invasive species under
changing climate conditions, which may adversely affect plant and wildlife habitats.
Developing sustainability goals and preparing for greater climate variability and extreme weather
events can help to facilitate a faster response when these events occur. These efforts may include
identifying potential flooding scenarios, developing a flood reduction target, and assessing the cost
and benefits of infrastructure needs to achieve the target. In addition, efforts to reduce emissions
and energy usage can be used to help the City reach its sustainability goals. Examples of such
efforts include: recycling/composting programs, native plant sales, LED lightbulb promotion,
energy workshops, non-motorized transportation availability, and electric vehicle plug-in parking.
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4. AGENCY COOPERATION
There are a number of local, State, and Federal agencies that have rules and regulations related to local
surface water management. The City recognizes the roles of these other agencies and will cooperate,
coordinate, and when possible partner with these agencies. This section describes the City’s current surface
water management program and practices and identifies the agencies and organizations having roles in the
City’s management of these resources. Table 4.1 summarizes the City’s and other agencies’ respective
regulatory controls related to water resources management and protection.
4.1. City Ordinance, Policy, and Procedures
Prior Lake supports its comprehensive plan with infrastructure plans. These infrastructure plans detail
future sanitary sewer, water, transportation, and surface water systems that must be built to fulfill the
land use plan. This LSWMP serves as the infrastructure plan for surface water systems. Beyond its role
in the comprehensive plan update, the LSWMP has a broader regulatory context that includes meeting
statutory, rule, and watershed requirements.
The Public Works Department is responsible for the planning, administration, design and inspection of
infrastructure improvements. This department coordinates with outside agencies in water resource
management and conservation. They also provide monitoring and maintenance of storm sewers, ponding
areas, water quality devices and other BMPs. The Prior Lake Planning Department manages
comprehensive planning and administers the zoning code within the City, which includes land use,
zoning, transportation, sewer extension and community facility improvements.
Current regulations and policies that govern surface water management within Prior Lake include the
engineering design standards and previous surface water management plans. Table 4.1 summarizes the
City’s regulatory controls regarding surface water.
Table 4.1 – Regulatory Control
Official Control Responsibility Mechanism
Stormwater
Management
City, WD, WMO City Ordinance Section 1004:
Design Standards; Public Works
Design Manual
Erosion and Sediment
Control
City, WD, WMO,
PCA
City Ordinance Section 1004:
Design Standards; Public Works
Design Manual
Shoreland City, WD, WMO,
DNR
City Ordinance Section 1104:
Shoreland Regulations
Floodplain City, WD, WMO,
DNR
City Ordinance Section 1105:
Floodplain Regulations
Wetlands City as LGU, DNR,
USACE & BWSR,
WD
City regulates, WCA
source/delegated. TEP = DNR,
BWSR, SWCD, Corps is
separate process, WD regulates
buffer conservation easements
Illicit Discharge City, WD City Ordinance Section 1004:
Design Standards; Public Works
Design Manual; WD within the
PLOC
Grading and Drainage City, WD, WMO City Ordinance Section 1004:
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Design Standards; Public Works
Design Manual
Public Waters City, DNR, Scott
County
City Ordinance Section 703:
Public Waters
*Acronyms are defined in the sections below
City staff is supported by commissions and committees. These include:
Planning Commission – reviews all applications for development and recommends
approval or denial based on conformance with the comprehensive plan and zoning
regulations.
Citizen Engagement Committee – performs outreach and education within the community
for a wide range of topics including those relating to water resources and surface water
management.
4.2. Support Agencies
This plan is in conformance with, but does not restate all other agency rules that are applicable to water
resource management. The following agencies deal with or regulate water resources throughout the City.
● Scott County https://www.scottcountymn.gov/
● Prior Lake- Spring Lake Watershed District https://www.plslwd.org/
● Scott Watershed Management Organization
https://www.scottcountymn.gov/746/Watershed-Management-Organization
● Scott County Soil and Water Conservation District https://www.scottswcd.org/
● Minnesota Department of Health www.health.state.mn.us
● Minnesota Pollution Control Agency www.pca.state.mn.us
● Board of Water and Soil Resources www.bwsr.state.mn.us and the Wetland
Conservation Act www.bwsr.state.mn.us/wetlands/wca/index.html
● Minnesota Department of Natural Resources (DNR) www.dnr.state.mn.us
● US Army Corps of Engineers www.mvp.usace.army.mi
● Minnesota Department of Agriculture www.mda.state.mn.us
● US Fish and Wildlife Service www.fws.gov
● Minnesota Environmental Quality Board www.eqb.state.mn.us
● Metropolitan Council www.metrocouncil.org
● Minnesota Department of Transportation (MnDOT) www.dot.state.mn.us/
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● U.S. Environmental Protection Agency (EPA) https://www.epa.gov/
● Federal Emergency Management Agency (FEMA) https://msc.fema.gov/portal
● Natural Resources Conservation Service (NRCS) https://www.nrcs.usda.gov/
● U.S. Geological Survey (USGS) https://www.usgs.gov/
While these other agencies’ rules, policies, and guidelines are not all restated in this Plan, they are
applicable to projects, programs, and planning within the City. The MPCA Minnesota Stormwater
Manual, which is a document intended to be frequently updated, is also incorporated by reference into
this Plan and can be found at www.pca.state.mn.us/water/stormwater/stormwater-manual.html.
4.3. NPDES Permitting Process
The MPCA has designated the City of Prior Lake as an NPDES Phase II MS4 community (MN Rules
Chapter 7090). Prior Lake’s application for permit coverage was extended in 2014. The permit outlines
Prior Lake ’s Stormwater Pollution Prevention Plan (SWPPP) to address six minimum control measures:
Public education
Construction site runoff control
Public involvement
Post-construction runoff control
Illicit discharge detection and elimination
Pollution prevention in municipal operations
The City’s SWPPP contains several best management practices within each of the listed control
measures. These were identified using a self-evaluation and input process with City staff. The most
recent 5-year permit cycle required cities to reapply for coverage in the Fall of 2018. Permit coverage
was extended to Prior Lake in 2014 for the current 5-year permit cycle.
Many of the goals and policies discussed in this local surface water management plan are directly related
to requirements listed as part of the MS4 program. As a result, the implementation section of this plan
repeatedly references items listed in the City’s MS4 SWPPP.
Along with the City’s MS4 permit requirements, the MPCA also issues permits to construction site
owners and operators to prevent stormwater pollution during and after construction. The National
Pollutant Discharge Elimination System (NPDES) Construction Stormwater General Permit regulates
any stormwater runoff from construction sites. An NPDES permit is needed if the following activities are
triggered:
Disturbing one acre or more of soil.
Disturbing less than one acre of soil if that activity is part of a "larger common plan of
development or sale" that is greater than one acre.
Disturbing less than one acre of soil, but the MPCA determines that the activity poses a risk to
water resources.
The NPDES Construction Stormwater General Permit was reissued on August 1, 2018.
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4.4. Comparison of Regulatory Standards
Developing property within Prior Lake is subject to review and approval from the two watersheds
covering the City (Figure 11). Each watershed has established rules or standards governing
stormwater management and protection of natural resources. Currently these rules vary in content
between agencies, and may be more restrictive than City standards.
4.4.1.Prior Lake- Spring Lake Watershed District (PLSLWD)
The Prior Lake – Spring Lake Watershed District (PLSLWD) defers permitting authority for most
projects to the LGUs and requires local municipalities to adopt standards equivalent to the
PLSLWD standards. A copy of the most recent rules is located in Appendix D.
The District’s Water Resources Management Plan was adopted in 2010 and revised in 2013. This
Plan details the goals and policies of the District and provides the foundation for its activities and
projects. It identifies problems and short-term strategies and goals. A link to the most recent plan is
located above.
4.4.2. Scott Watershed Management Organization (WMO)
The Scott Watershed Management Organization (WMO) defers permitting authority to the LGUs
and requires local municipalities to adopt standards equivalent to the Scott WMO standards. A copy
of the most recent standards is located in Appendix E.
The Scott WMO has completed the process of updating their Comprehensive Water Resources
Management Plan and will adopt it in late 2018. Plan implementation will begin starting January
2019.
4.5.Water Resource Related Agreements
This section summarizes those water resources related agreements the City of Prior Lake has
established with other entities.
4.5.1. Prior Lake Outlet Channel MOA
The City of Prior Lake is party to a 2006 Memorandum of Agreement (MOA) with the City of
Shakopee, PLSLWD, and the Shakopee Mdewakanton Sioux Community (SMSC) regarding the
operation and management of the outlet channel for Prior Lake. A copy of the MOA is attached as
Appendix I.
4.5.2.PLSLWD Equivalency Rules
To be updated with new equivalency agreement. Assessment of equivalency will be conducted upon
completion of the PLSLWD rule revisions and any necessary revisions to the City’s ordinances and
PWDM.
4.5.3. Scott WMO Equivalency Rules
To be updated with new equivalency agreement if needed.
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5. ASSESSMENT OF ISSUES
5.1. Stormwater Management System Assessment
Previous sections of this Local Surface Water Management Plan (LSWMP) provide background on
the physical and regulatory forces shaping surface water management in Prior Lake. This section
describes problems and challenges of specific waters, neighborhoods or programs identified by the
City, watershed districts and others. Minnesota Statutes and Rules and Metropolitan Council guidance
documents require "issues and corrective actions" or "problems and corrective actions" as elements of
Local Surface Water Management Plans. The assessment includes stormwater management issues,
current and future, identified by the City, the two watersheds with jurisdiction within the City, and
other state and federal agencies. Prior Lake emphasizes the surface water management challenges
ahead and that these challenges will test the City’s financial and technical resources. Figure 16
provides locations for specific issues throughout the City.
5.2. Water Quality
5.2.1. Issue: Spring Lake, Upper Prior Lake, Lower Prior Lake and Cleary Lake were placed
on the MPCA’s impaired waters list for high mercury concentrations in fish.
Corrective Action: The EPA has approved the statewide TMDL mercury study. The
MPCA has since prepared a plan to reduce mercury releases by 2025. This plan describes
specific strategies that the State will employ to achieve the goals of the TMDL. No
additional action by the City is needed.
5.2.2. Issue: Spring Lake, Upper Prior Lake, Pike Lake and Cleary Lake are on the MPCA’s
impaired waters list for excess nutrients.
Corrective Action: Prior Lake-Spring Lake Watershed District completed the TMDL
report and TMDL Implementation Plan for Spring Lake and Upper Prior Lake in 2011.
Site-specific eutrophication criteria were also approved for Spring Lake in 2016. The
site-specific water quality standards set a different goal condition for Spring Lake than
the ecoregional water quality standards; the new goal reflects pre-European natural
conditions.
Clearly Lake and Pike Lake are included in the Lower Minnesota WRAPS that has been
completed in 2018. The final plan is expected to be officially approved in 2019.
The City will continue to collaborate with Scott WMO and PLSLWD to implement the
recommended strategies outlined in the Lower Minnesota WRAPS and the Spring Lake
and Upper Prior Lake TMDL Implementation Plan. Specific projects identified at this
time are listed in Table 7.3 of this Plan.
5.2.3. Issue: Spring Lake and Lower Prior Lake were placed on the MPCA’s impaired waters
list for fish bioassessments in 2018.
Corrective Action: The City will update this plan to include new information provided
by the MPCA or DNR as it becomes available. No additional action by the City is
needed.
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5.2.4. Issue: It is anticipated that there may be additional, future impaired waters listed that will
affect the City.
Corrective Action: The City will work with PLSLWD, Scott WMO, MPCA and others
to develop and implement future TMDLs or other similar water quality-related planning
efforts that affect the City.
5.2.5. Issue: The possibility of contamination exists when there are connections between
groundwater and surface water.
Corrective Action: The City has developed a Wellhead Protection Plan which identifies
DWSMAs and their vulnerability. The City will continue to follow the requirements of
its Wellhead Protection Plan to protect groundwater. Guidance from the MPCA and
MDH will be followed to determine the applicability of infiltration in the DWSMAs.
The City will also cooperate with Scott County and Scott WMO on the completion of an
assessment of the Prior Lake Drinking Water Supply Management Area (DWSMA). This
assessment would provide a methodology for identifying probable locations of
abandoned/unsealed wells and would be used to target contacts for the well sealing cost
share practice implementation. Additional information can be found in the Scott WMO
Watershed Plan.
5.2.6. Issue: The Minnesota River has been identified by the MPCA as an impaired water.
Impairments include mercury, PCBs, dissolved oxygen (DO), and turbidity.
Corrective Action: The EPA has approved the statewide TMDL mercury study and no
additional action by the City is needed. The Minnesota River and Greater Blue Earth
River Basin TSS TMDL was completed in 2018, which delegated a categorical
wasteload allocation to Prior Lake to reduce TSS prior to discharging to the Lower
Minnesota River. A WRAPS study is currently underway, which would outline
implementation measures to be completed to meet the TMDL requirements. The City
will look to implement projects from this report once it has been approved.
5.2.7. Issue: In 2016, the EPA approved the Twin Cities Metropolitan Area (TCMA) Chloride
TMDL Study. The study established an allowable chloride concentration and a
categorical wasteload allocation has been established for the permitted MS4s within each
impaired watershed.
Corrective Action: The City will continue to follow their Winter Maintenance Policy for
deicing practices and chloride management. New and more efficient deicing practices
will be researched to reduce the amount of chloride used for roads and walkways.
5.2.8. Issue: Poor water quality has been monitored in Arctic Lake.
Corrective Action: The City will partner with PLSLWD and SMSC to implement BMPs
listed in the Arctic Lake Subwatershed Assessment and BMP Retrofit Analysis. Specific
projects are listed in Table 7.3.
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5.3. Flooding and Stormwater Management
5.3.1. Issue: The culvert under Jeffers Pass leading into Jeffers Pond has been observed to
become clogged with debris placed by beavers, reducing the hydraulic capacity of the
pipe. Additionally, the homes on the upstream side of the culvert lie below the road EOF,
therefore are in danger of flooding when the culvert does not function as designed.
Corrective Action: Install a grate or barrier to prevent the build-up of debris placed by
beavers. This may include an outlet improvement on the downstream side of the culvert
as well. These actions will be consistent with the MOA between PLSLWD and the City.
5.3.2. Issue: The culvert north of Island View and under the trail by Arctic Lake near the
intersection of Fremont Ave and 82nd St frequently becomes blocked with debris and
carp.
Corrective Action: The City will upgrade the structure and coordinate with the
PLSLWD and DNR as needed. This will be a City funded project.
5.3.3. Issue: Culvert under Glynwater Trail NW may be undersized. Additionally, when the
culvert is blocked with debris, the EOF is over the roadway. Homes on the upstream side
of the culvert are in danger of flooding.
Corrective Action: An outlet improvement project will be completed to provide an
overflow structure with an improved skimmer. The outlet will also include preventative
measures to prevent beavers from blocking the outlet. The City will also complete an
analysis to replace the undersized culvert.
5.3.4. Issue: The outlet at Wildwood Pond near Woods at the Wilds Park has the potential to
become plugged and the resulting high water levels could impact nearby homes.
Corrective Action: An outlet improvement project will be completed to provide an
overflow structure with an improved skimmer. The outlet will also include preventative
measures to prevent beavers from blocking the outlet.
5.3.5. Issue: The channel that flows to the Priorwood Street pond is subject to ice buildup in
the winter/spring and regularly floods.
Corrective Action: The City will complete a feasibility study to determine if a
realignment of the channel is possible.
5.3.6. Issue: The south wetland near Fountain Hills Drive continues to wash out and
overwhelm structures through the ravine.
Corrective Action: This issue will be addressed as development occurs. The City will
continue to provide ongoing maintenance until such time of development.
5.3.7. Issue: The outlet of the wetland west of Northwood Road near Linden Circle is not
functioning properly and has issues with the structure that maintains water levels.
PLSLWD has observed carp using the wetland as a possible spawning area. The
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Minnesota DNR formerly used the wetland as a northern pike rearing pond and was
responsible for the existing gate installation.
Corrective Action: An outlet improvement project will be completed to provide an
overflow structure with an improved skimmer that will better maintain the water level.
The outlet will also include preventative measures to prevent beavers from blocking the
outlet. This work may also include a carp grate installed in cooperation with the
PLSLWD.
5.3.8. Issue: The ravine along Shady Beach Trail currently drains through a city easement and
experiences drainage issues.
Corrective Action: The City will complete a feasibility study to determine the best
options for drainage mitigation.
5.3.9. Issue: The pond located near County Road 21 and Adelmann Street currently has an
outlet that is not functioning properly. Backups can occur that cause flooding near the
adjacent structures. Both ponds also have a significant population of cattails which could
indicate that the ponds need to be cleaned out.
Corrective Action: The City will complete a survey of the pond and perform a pond
cleanout project as necessary.
5.3.10. Issue: The lakes within the City, including primarily Spring Lake and Prior Lake,
experience periodic flooding.
Corrective Action: The City will adhere to its Flood Response Policy, adopted in 2017,
when responding to lake flooding events. The City will evaluate and update the Flood
Response Policy on a regular basis. Additionally, the City will work with local
government agencies, including the PLSLWD and Spring Lake Township, to implement
the recommended corrective actions per the Prior Lake Stormwater Management and
Flood Mitigation Study (2016).
5.3.11. Issue: City streets experience temporary flooding due to intense rainfall events. Portions
of the storm sewer system may be undersized or in need of repair. This type of flooding
can lead to public safety hazards, property damage, and sediment discharges to receiving
waters.
Corrective Action: The City will create a stormwater system model to identify problem
areas and needed system repairs/upgrades.
5.3.12. Issue: The outlet of Crystal Lake, located near the intersection of Village Lake Drive and
Panama Avenue (County Road 23), can become clogged with debris, potentially leading
to high water in the entire Crystal Lake drainage area. High water on Crystal Lake due to
a clogged outlet has the potential to flood Panama Avenue.
Corrective Action: An outlet improvement project will be completed to provide an
overflow structure with an improved skimmer that will better maintain the water level.
The outlet will also include measures to prevent beavers from blocking the outlet.
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5.3.13. Issue: A series of ponds located near Priorwood Lane and Kestrel Lane frequently
experience blockage issues that flood the trail and brings high water levels near existing
structures.
Corrective Action: A feasibility study will be completed to analyze improvements to
drainage paths and options to reduce pond flooding.
5.3.14. Issue: A small pond near Deerfield Lane occasionally floods due to lack of capacity due
to sediment deposits.
Corrective Action: The City will complete a survey of the pond and evaluate the need
for a pond cleanout project to remove any deposited sediment. The City will also
consider other options to add capacity such as removing the outlet between the adjacent
pond to allow for more storage.
5.4. Adequacy of Existing Regulations and Programs to Address Adverse Impacts on Local
Water Resources
5.4.1. Issue: The City has adopted ordinances related to floodplain regulation, illicit discharge,
surface water management, native vegetation planting, wetland management and erosion
and sediment control. These ordinances need to be kept up to date as requirements
change. A copy of the ordinances can be found in Appendix C.
Corrective Action: The City will continually evaluate these ordinances and will update
them as needed. The City will continue to enforce all ordinances as necessary.
5.4.2. Issue: The City currently has limited funding sources available to complete projects
related to water resources.
Corrective Action: Stormwater funds and special assessment funding are not adequate
to implement the studies, programs, and capital improvements outlined in this plan. The
City must apply for grants to fund the implementation of capital improvements identified
in this management plan. The City will consider increasing the current stormwater utility
rate to fund future implementation items.
5.5. Erosion and Sediment Control
5.5.1. Issue: Cates Creek, originating on the north side of TH 13 east of Creekside Cir SE and
discharging to Upper Prior Lake near the intersection of Green Heights Trail and Dutch
Avenue SE, should be monitored for erosion.
Corrective Action: The City will continue to monitor Cates Creek.
5.5.2. Issue: There are significant erosion issues on a City-owned parcel on the south side of
Markley Lake (PID 255280020).
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Corrective Action: The City will provide short term stabilization measures as needed.
The long-term goal for this area will be to stabilize an eroding ravine and provide
additional flood storage as well.
5.5.3. Issue: The culvert at the north end of Haas Lake under County Road 42 requires frequent
maintenance due to an excess of sediment causing blockage in the pipe.
Corrective Action: The City provides frequent maintenance to clean out the contributing
drainage channel and will continue to coordinate with the County on this issue. The
County infrastructure may require repairs or modifications to ensure long-term function.
5.6. Impact of Land Use Practices and Development
5.6.1. Issue: Lack of space for stormwater management BMPs on individual redevelopment or
road reconstruction projects.
Corrective Action: The City will work with PLSLWD and Scott WMO to ensure local
stormwater management requirements are met for each project. Alternatives to on-site
BMPs may be proposed on a site-by-site basis. The City must also ensure that all State
stormwater management requirements are met for each site.
5.6.2. Issue: Subsurface sewage treatment systems (SSTSs) have the potential to contaminate
surface and groundwater.
Corrective Action: The City will ensure SSTS are properly abandoned within 1 year of
the extension of new services. Procedures will follow the City’s ordinances.
5.6.3. Issue: Wetland degradation caused by agriculture or urbanization.
Corrective Action: The City will implement WCA requirements for any development or
agricultural practice that has the potential to cause wetland degradation.
5.6.4. Issue: Increase in runoff volume as development occurs
Corrective Action: To assess the impact development might have on water levels in Prior
Lake, the PLSLWD created a calibrated model of the watershed. The most effective
mitigation strategies, other than removing the homes, are retention storage in the
watershed and volume control measures.
5.6.5. Issue: Development near Campbell Lake has the potential to impact the sensitive
resources for Picha Creek downstream.
Corrective Action: The City will partner with Scott WMO to complete a study that
would assess potential issues with development, and identify potential opportunities for
regional stormwater management.
5.7. Education Program
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5.7.1. Issue: The City recognizes the need for local water education programs to increase
public awareness of local water management and improve the quality of stormwater
runoff. An education program is one of the requirements of the City’s MS4 Stormwater
Pollution Prevention Program (SWPPP).
Corrective Action: The City will continue to provide educational content and
opportunities to residents, businesses, developers, and others. These efforts may include
regular notices in the City's monthly newsletter, articles in the local paper, postings on
the City website, and flyers in the utility bill. The City will coordinate with PLSLWD
and the Scott WMO (including the Scott Clean Water Education Program) to improve the
efficiency of educational efforts and reduce duplication. Educational topics may include,
but are not limited to:
• Stormwater pond function and maintenance
• Wetland buffers
• Yard/pet waste management
• Illicit discharge to stormwater
• Utility easements related to location, purpose,
encroachments/obstruction
• Controlling invasive species
• Erosion and sediment control on small scale landscaping projects
adjacent to impaired waters
• FEMA floodplain issues
• Water Surface Use Management (WSUM) and water-based recreation
• Salt usage
• Benefits and care of native vegetation
• Groundwater issues
5.8. Identification of Potential Problems to Occur in the Next 20 Years
5.8.1. Issue: Inspecting and maintaining existing stormwater infrastructure throughout the City.
Corrective Action: The City of Prior Lake is responsible for maintenance of its
stormwater system in conformance with the MPCA’s MS4 Program. This includes
maintenance of pipes, inlets, outlets, constructed ponds, ditches, swales, and other City
stormwater infrastructure. Proper maintenance will ensure that the stormwater system
continues to provide the necessary flood control and water quality treatment. The City
will continue to refine its comprehensive stormwater infrastructure inspection program
which is the primary means to identify issues and prioritize needed stormwater
infrastructure repairs. Refer to Appendix B for a copy of the City’s MS4 SWPPP.
5.8.2. Issue: Presence of polycyclic aromatic hydrocarbons (PAHs) in stormwater ponds from
runoff of roadways and other surfaces.
Corrective Action: As stormwater ponds are inspected and maintained, the City will
identify any ponds that are contaminated with PAHs and follow MPCA protocol for
disposal of dredged material. The State of Minnesota banned the use and sale of coal tar-
based sealants for paved surfaces in 2014 but PAHs deposited in stormwater ponds
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before that time are expected to persist until they are manually removed during
stormwater pond maintenance activities. There is an increased cost associated with
removing PAHs from stormwater ponds as contaminated sediment is considered a
hazardous material and must be landfilled.
5.8.3. Issue: Accumulation of debris and material on City streets.
Corrective Action: The City will continue to sweep debris and salt from streets in
accordance with the City’s Street Sweeping Policy. Enhanced street sweeping, including
targeting the watersheds of impaired lakes and other undertreated areas within the City,
is part of the Policy. More information regarding street sweeping activities can be found
in Appendix H.
5.8.4. Issue: Elevated levels of chloride concentrations have been found in stormwater ponds,
surface water bodies, and groundwater throughout the Twin Cities Metro Area. At levels
exceeding the water quality standards, chloride can be toxic to aquatic life and can make
drinking water sources not economically feasible to treat.
Corrective Action: The City will continue to implement chloride best management
practices such as reducing salt use on roadways, education to private business owners
about correct salt application, and improve policies designating salt usage. The City will
continue to track and implement ways to reduce road salt usage based on its MPCA
Level 1 and 2 Smart Salt Certifications.
5.8.5. Issue: Prioritizing inspection and maintenance of stormwater ponds as well as
determining the performance of existing stormwater ponds throughout the City.
Corrective Action: The City of Prior Lake will prioritize pond maintenance activities
and BMP inspections. This program will need to be updated regularly to result in an
updated prioritization of pond inspection and maintenance activities. In addition, the
program will estimate the current treatment provided by each pond to determine if the
desired amount of treatment is being achieved. This program will help meet the MS4
permit requirements related to the management of stormwater ponds.
5.9. Availability and Adequacy of Existing Technical Information to Manage Local Water
Resources
5.9.1. Issue: Atlas 14 (updated precipitation probability information) was recently released by
NOAA.
Corrective Action: The City will continue to implement Atlas 14 in the review and
approval of new or redevelopment projects. The City will coordinate with the
watersheds, FEMA and the DNR on implementing Atlas 14 into its floodplain
management and other applicable regulations.
5.9.2. Issue: The City has mapped the majority of its storm sewer system. As new and
redevelopment projects are completed, the storm sewer GIS database needs to
continually be updated.
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Corrective Action: The City will annually update its storm sewer GIS database to
incorporate recent projects, BMPs, and associated storm sewer improvements.
5.9.3. Issue: The PLSLWD maintains Hydrologic and Hydraulic models for waterbodies
within the City.
Corrective Action: The City will annually provide routine updates to PLSLWD per new
development, redevelopment, and any substantive stormwater management
improvements implemented.
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6. GOALS AND POLICIES
6.1.Purpose
Prior Lake’s Local Surface Water Management Plan (LSWMP) aids with planning for the orderly
management of stormwater as development occurs in the city. The plan provides clear guidance on
how Prior Lake intends to manage surface water in terms of both quantity and quality.
Much has changed since the city prepared its first LSWMP in 1973. Since that time, the city has seen
a marked increase in residential and commercial development. Not accounting for population growth
due to annexation, city population has increased from almost 16,000 in 2000 to 25,049 in 2015; a
growth of approximately 57%. Population growth combined with increased regulation of stormwater
at both the state and federal level necessitate that the city’s stormwater management goals evolve.
6.2. 2040 Vision and Strategic Plan
The original 2020 vision effort began in 2002 and since that time has included input from
numerous stakeholders in the community. The 2040 Vision and Strategic Plan focuses on
preserving surface water and other natural resources, economic vitality, and an overall safe and
healthy community. The Prior Lake LSWMP is a piece of a larger effort, conducted in
partnership with the City’s two watershed organizations, toward addressing the 2040 vision of
natural resources preservation.
The key issues facing the City constitute its vision statements. The elements of that vision
become the City’s implementation goals out into the future. The 2040 vision includes goals in a
variety of areas. Of specific importance in the context of the LSWMP are the following:
a.Community Assets
Continue City commitment to on-going infrastructure maintenance and replacement.
b.Natural Resources
Update the Surface Water Management Ordinance in accordance with the City’s MS4
permit.
Work with stakeholders to prepare and implement a plan which will address flooding
issues and surface water matters.
Work with local agencies to implement items listed in TMDL implementation plans
6.3. Comprehensive Plan 2040 Goals and Policies
The Prior Lake 2040 Comprehensive Plan is currently being updated and will be adopted in
2018. The primary purpose of this effort is determination of the land use plan (included in the
LSWMP as Figure 2) which becomes the basis of the hydrologic calculations summarized in the
LSMWP. These Comprehensive Plans are mandated by the Metropolitan Land Planning Act.
The goals of the Prior Lake 2040 Comprehensive Plan are:
Housing Quality and Diversity
Environmental and Natural Resource Protection
Economic Vitality
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Security
Access
Information and Technology
Human Development
This Prior Lake LSWMP expands upon the goals and objectives provided in the 2040 vision and
the 2040 Comprehensive Plan related to water resources management and protection.
6.4. City of Prior Lake LSWMP Goals and Policies
This section of the LSWMP outlines goals and policies specific to surface water management in
Prior Lake. The policies that follow individual goals are specific requirements that promote
attainment of the goal.
6.4.1.Water Quantity
Goal 1:
To identify, plan and implement means to control runoff rate and volume.
Policy 1.1:
Stormwater volume management, when required, shall meet the standards of the Public Works
Design Manual (PWDM).
Policy 1.2:
Preserve and optimize where feasible the retention capacities of the existing drainage systems by
utilizing lakes, ponds, and wetlands for storing stormwater runoff.
Policy 1.3:
Establish 100-year flood levels based on critical storm events using Atlas 14 rainfall data.
Policy 1.4:
All minor storm sewer system design and analyses shall be based on the 10-year Atlas 14 rainfall
event consistent with the standards of this plan and the City’s PWDM.
Policy 1.5:
Stormwater best management practices (BMPs) shall be designed for the 100-year Atlas 14
rainfall event, consistent with the standards of this plan and the City’s PWDM.
Policy 1.6:
Landlocked basins shall be analyzed and managed consistent with the standards of the PWDM.
Policy 1.7:
All hydrologic studies and drainage design shall be based on ultimate development of the 2040
land use plan. In some cases, near term conditions should also be analyzed to determine whether
unrestricted drainage from rural areas may lead to construction of interim facilities, or
management based upon interim high water levels or discharge rates.
Policy 1.8:
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In order to mitigate future development flows from increasing erosion potential to the PLOC, the
proposed discharge rates will be held to rates agreed to in the MOA. A copy of the current PLOC
MOA can be found in Appendix I of this Plan.
Policy 1.9:
All developments shall, to an extent determined by the City, provide land, funding, or a
combination of both for developing regional detention sites to achieve the runoff rates as
indicated in this plan.
Policy 1.10:
Implement volume control and encourage low impact development techniques in developing and
redeveloping areas to minimize runoff volumes that tend to increase with an increase in
impervious area.
Policy 1.11
Regional detention basins are used to manage peak flow rates and provide flood storage and
flood retention. On-site detention basins are utilized when regional basins are not in place or are
not feasible. The city encourages the use of regional versus on-site basins for rate control and
flood protection.
Policy 1.12
Promote the use of overland versus pipe conveyance so that the benefits of natural channels can
be realized. These benefits include filtration, flow attenuation, infiltration, and other water
quality and quantity benefits. The city encourages the use of natural vegetation within overland
conveyance systems.
Policy 1.13:
Support the implementation of the prioritized policies per the Prior Lake Stormwater
Management and Flood Mitigation Study (2016). These polices are listed below:
a.Protection of public safety and maintain emergency access at all times;
b.Protection of health and safety by protecting public utility infrastructure;
c.Maintain traffic flow through the County Road 21 corridor; and
d.Maintain access to private properties
Policy 1.14:
Implement the short and long term feasible options to address flooding identified in the Flood
Mitigation Study.
6.4.2.Water Quality
Goal 2:
To identify, plan, and implement means to effectively protect and improve water quality.
Policy 2.1:
The City will work with partner agencies to implement TMDLs for impaired water bodies in the
City and that receive drainage from the City.
Policy 2.2
Require water quality treatment for new construction, reconstruction, and other projects based on
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the PWDM standards.
Policy 2.3:
Construct, where practicably feasible, best management practices (BMPs) to serve not only new
development, but also existing development where opportunities arise to treat those areas that
were established prior to stormwater management criteria summarized in the PWDM.
Policy 2.4:
Implement a stormwater pollution prevention program (SWPPP) that meets or exceeds the
requirements of the City’s MS4 permit.
Policy 2.5:
Continue to partner with the WD and WMO to implement stormwater management
improvements, even when not required by local or state regulations.
Policy 2.6:
Continue to be proactive on salt usage by implementing the Winter Maintenance Policy,
incorporating chloride BMPs listed in the TCMA Chloride Management Plan, and providing staff
training on salt usage and its impacts on water quality.
Policy 2.7
Assess existing stormwater management facilities for potential water quality enhancements when
planning MS4 maintenance
Policy 2.8
Identify partnership opportunities to implement water quality improvement practices that exceed
minimum local or state requirements.
6.4.3.Water Resources Recreation
Goal 3
To protect and enhance water recreational facilities.
Policy 3.1
The City of Prior Lake will work with and support to the maximum extent practical the efforts of
Minnesota Department of Natural Resources, the Corps of Engineers, the United States
Environmental Protection Agency, and other appropriate agencies in promoting public enjoyment
and recreational resource values.
Policy 3.2
Activities related to recreation, parks, open space, and trails systems shall be consistent with the
City’s 2040 Comprehensive Plan and City Ordinances.
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6.4.4.Fish and Wildlife Habitat
Goal 4:
To protect and enhance fish and wildlife habitat.
Policy 4.1:
To the greatest possible extent, natural areas shall be preserved, especially when adjacent to
wetland areas.
Policy 4.2:
Buffer zones of natural vegetation shall be maintained around lakes, ponds and wetlands as much
as possible.
Policy 4.3:
Coordinate with the Department of Natural Resources (DNR) and the U.S. Fish and Wildlife
Service to protect rare and endangered species.
Policy 4.4:
Explore with the DNR, Prior Lake-Spring Lake Watershed District, and Scott WMO new
methods of eradicating or controlling aquatic and terrestrial invasive species.
Policy 4.5:
The City will work to create wildlife corridors throughout the City, where feasible.
Policy 4.6:
The City will coordinate with local and state agencies to protect threatened and endangered plant
and animal species.
6.4.5.Groundwater
Goal 5:
To promote groundwater protection and recharge.
Policy 5.1:
Implement the City’s approved Wellhead Protection Plan (Appendix G). Specific policies
include:
1. Promote proper management and sealing of wells.
2. Continue to identify potential contaminant sources.
3. Educate the public with the Annual Water Quality Report and other information
through the City website.
4. Collect data and promote data sharing among agencies.
Policy 5.2:
Collaborate as necessary with various agencies to perform special studies related to groundwater
protection and recharge. The City will also work with the agencies to fill gaps in assessments of
groundwater data.
Policy 5.3:
Provide a permanent ponding volume below the outlet or overflow in ponds and wetlands to
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promote groundwater recharge.
Policy 5.4:
Maximize infiltration with the use of BMPs whenever possible, in open areas within all proposed
developments following MS4 requirements and the Minnesota Stormwater Manual guidelines.
Policy 5.5:
Cooperate with state and regional agencies on groundwater monitoring, inventorying or
permitting programs. These agencies could include the MPCA, MDH, DNR, Scott WMO and
PLSLWD. The City’s groundwater protection policies are intended to preserve groundwater
levels and flow and protection of drinking water supplies.
Policy 5.6:
Cooperate with the Department of Health and Scott WMO to ensure that all unsealed or
improperly abandoned wells within the City are properly sealed. Technical requirements for the
abandonment of these wells will be in conformance with the local and State regulations.
6.4.6.Wetlands
Goal 6:
To protect and preserve wetlands through administration of the Wetland Conservation Act.
Policy 6.1
Act as the local government unit responsible for enforcing the Wetland Conservation Act of
1991.
Policy 6.2
Discourage wetland disturbance. Wetlands must not be drained or filled, wholly or partially,
unless replaced by restoring or creating wetland areas of at equal public value, as permitted by
the Wetland Conservation Act.
Policy 6.3
Restrict clearing and grading within close proximity of the wetland boundary to provide for a
protective buffer strip of natural vegetation to promote infiltration of sediment and nutrients. In
the event that grading occurs close to the wetland boundary native plant materials shall be
reestablished as a buffer strip per PWDM requirements.
Policy 6.4
Establish for City use a wetland bank account to allow for wetland debits and credits for city
projects.
Policy 6.5
Require that a wetland delineation be prepared for any project that potentially includes a wetland.
6.4.7.Erosion and Sediment Control
Goal 7:
To prevent soil erosion and sediment discharge into surface water systems through enforcement
of the City’s MS4 SWPPP and NPDES Construction permit.
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Policy 7.1:
Erosion and sediment control plans shall be required per the PWDM.
Policy 7.2:
The City may prohibit work in areas having steep slopes and high erosion potential. The
provisions of the shoreland ordinance should be followed to prevent impact to these erosion
sensitive areas.
Policy 7.3:
The City shall maintain a street sweeping program to minimize sediment entering the MS4.
Streets will be swept according to the City’s street sweeping policy. The City’s Street Sweeping
Policy can be found in Appendix H of this Plan.
Policy 7.4
The City will periodically review ordinances related to erosion and sediment control and drainage
to maintain conformance with the NPDES construction permit, the City's MS4 permit, guidance
from Metropolitan Council, and the requirements of the regulating watersheds.
6.4.8.Prior Lake’s MS4 Permit
Goal 8:
To operate and manage the City’s surface water system consistent with best current practices and
the City’s MS4 SWPPP.
Policy 8.1:
Projects to correct existing deficiencies, to the extent they are identified, will be prioritized as
follows:
1.Projects intended to reduce or eliminate flooding of structures in known problem areas
2.Projects intended to improve water quality in the City’s lakes
3.Projects intended to reduce maintenance costs
4.Projects intended to restore wetlands and habitat
Policy 8.2:
The City will actively inspect, and properly operate, maintain and repair its public stormwater
facilities per MS4 permit requirements. The City will follow a regular inspection, cleaning, and
repair schedule. Frequency of maintenance will be event-based and informed by experience and
inspection history.
Policy 8.3:
The City will follow best management practices on its own lands and for its own projects
including street reconstruction projects – in accordance with the City’s MS4 SWPPP.
Policy 8.4
Assess all existing stormwater management facilities for retrofit opportunities to enhance water
quality treatment during scheduled MS4 maintenance.
Policy 8.5
The City will implement a program that identifies and prioritizes pond maintenance activities and
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BMP inspections. This program will need to be updated regularly to result in an updated
prioritization of pond inspection and maintenance activities.
Policy 8.6:
Operation and maintenance agreements shall be developed as part of all private BMPs. This
agreement must include inspection schedules, procedures for maintenance and must meet any
requirements outlined in the PWDM and the Minnesota Stormwater Manual.
6.4.9.Financial Management
Goal 9:
To ensure that the costs of the surface water system are equitably distributed and to utilize
available funding mechanisms to construct and maintain a sustainable stormwater management
system.
Policy 9.1:
The City will continue to update and apply area based charges so that the surface water related
costs of development can be fairly borne by the development.
Policy 9.2:
The City will periodically update its storm water utility rate structure to accomplish the
following:
1.Meet the requirements of its MS4 SWPPP.
2.Provide for the maintenance and repair of stormwater infrastructure.
3.Support its system planning efforts.
4.Implement water quality improvement projects identified in the CIP.
Policy 9.3:
The City will utilize various funding sources including, but not limited to, PLSLWD, Scott
WMO, cost sharing and grants, area charges, stormwater utility, and other grants to accomplish
improvements listed in this plan and other surface water documents.
6.5. Impacts of the Prior Lake LSWMP on Other Units of Government
Other units of government with surface water-related jurisdiction within the City of Prior Lake
include the Minnesota Pollution Control Agency (MPCA), Minnesota Department of Natural
Resources (DNR), United States Army Corps of Engineers (USACOE), the Shakopee Mdewakanton
Sioux Community (SMSC), the Prior Lake-Spring Lake Watershed District (PLSLWD), and the
Scott Water Management Organization (Scott WMO).
The MPCA has jurisdiction over stormwater discharges to waters of the state of Minnesota. The City
will meet MPCA’s Municipal Separate Storm Sewer (MS4) permit and Construction Stormwater
General Permit (MNR100001) requirements as outlined within in this Plan.
The DNR has jurisdiction over public waters and public waters wetlands as defined in Minnesota
Statute 103G. The City will follow all DNR requirements with respect to public waters and public
waters wetlands when sponsoring or permitting projects that could impact these resources.
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The USACOE is the federal agency that regulates discharges of dredged or fill material into waters of
the United States (wetlands, tributaries, lakes, etc.) under Section 404 of the Clean Water Act (CWA)
and regulates work in navigable waters under Section 10 of the Rivers and Harbors Act. The City will
ensure that USACOE regulations are followed when sponsoring or permitting projects that fall under
USACOE jurisdiction.
The Shakopee Mdewakanton Sioux Community (SMSC) is a federally recognized sovereign nation
located partially within the boundaries of the City of Prior Lake. The SMSC has jurisdiction over
water resources on lands placed in trust for the SMSC by the Department of the Interior. Areas of the
SMSC that do not have trust status are subject to City jurisdiction. The City works closely with the
SMSC to manage our water resources within our common boundaries.
Two watershed management organizations have jurisdiction within the City: The Scott WMO and the
PLSLWD. Both watersheds must review and approve the LSWMP. The City envisions its two
watersheds as partners in implementing this Plan. Because the City must meet water quality
regulations and standards through the state-mandated MS4 and Construction Stormwater General
permits, much of the City’s available stormwater budget will be used meeting these regulations and
standards and maintaining existing MS4 infrastructure. Therefore, the City envisions the watersheds
taking the lead on water quality monitoring, voluntary water quality projects, enhancing the water
quality improvement aspects of City-led maintenance projects, and other water quality initiatives in
accordance with their Watershed Management Plans.
The City will work closely with the PLSLWD to implement projects and initiatives called out in the
Prior Lake Stormwater Management and Flood Mitigation Study (2016). Although most flood
retention storage will likely be located outside the existing City boundary, the City will provide
support for these projects as warranted by each specific project.
The City and PLSLWD entered into a Memorandum of Agreement (MOA) for local water planning
and regulation in 2007. The MOA specified the responsibilities of the PLSLWD and the City for
issuing permits affecting water resources within the City. The City assumed all permitting powers
within its jurisdiction after the MOA was signed by both organizations, with the exception of its own
projects. The MOA terminated automatically when the PLSLWD adopted a revised Water Resources
Management Plan (WRMP) in 2010 and the MOA was not extended by written agreement of both
parties (Section 4.4, 2007 MOA). The MOA stated that the City’s implementation plan for local
water management was in conformance with PLSLWD’s WRMP. Although the MOA technically
expired, the City and PLSLWD rules have not been substantively changed since 2007 and should still
be considered equivalent. The City intends to enter into a new permitting MOA with the PLSLWD.
The new MOA should be based on existing rules and updated after completion of the PLSLWD’s
next WRMP and/or rules updates. This may require an additional process to evaluate rules
equivalency and possibly an amendment to the City’s LSWMP.
The City and Scott WMO have substantially equivalent rules. The City maintains permitting
authority within the Scott WMO, with Scott WMO retaining the right to audit project reviews that
occur within its jurisdiction. The Scott WMO portion of the City’s current and 2040 boundary drains
toward the City of Shakopee and the Credit River. The flows and routes that discharge from Prior
Lake into Shakopee were developed in consultation with the City of Shakopee and in conjunction
with their surface water planning efforts. Further coordination will be needed to address the concerns
of the WMO when areas within the upper reaches of the WMO are proposed for development.
SECTION 6
Surface Water Management Plan
City of Prior Lake Section 6
WSB Project No. 013093-000 Page-10
6.6. Watershed Goals and Strategies that Affect the City of Prior Lake
6.6.1 PLSLWD
The City of Prior Lake, PLSLWD, and Spring Lake Township jointly developed goals related to
volume management that will have a profound effect on the City as it implements its surface water
system. Specifically, the Prior Lake Stormwater Management and Flood Mitigation Study (2016)
calls for retention storage to mitigate the impact of future development on Prior Lake and its outlet
channel. The City will work closely with the PLSLWD to implement practices outlined in the Flood
Study’s Implementation Plan. PLSLWD will assume the lead role for all practices located outside the
City; the City will provide support for those practices.
The City will work with PLSLWD Spring Lake Township to periodically review the Flood Study
Implementation Plan, evaluate progress, and update as needed.
6.6.2 Scott WMO
The City’s 2040 boundary includes areas in the Scott WMO that may merit additional protections
based on past water quality improvement projects and downstream impairments. These include the
Picha Creek watershed and areas draining to Campbell Lake, and ultimately to Sand Creek and the
Minnesota River. The City will work with Scott WMO to determine the adequacy of on-site and/or
regional stormwater management facilities in these areas.
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-1
7. IMPLEMENTATION PROGRAM
7.1.Overview
The Implementation Plan section of the Prior Lake LSWMP describes a range of activities and
programs that support improvement of the City’s surface water management program. Capital outlay
for the surface water system (pipes, channels, and ponds) shown on the system maps will be large.
For this reason, a City financing mechanism, called an area charge, is reviewed in this section.
Based on the Capital Improvement Plan and the developable acreage, the City’s current area charge
is reviewed and application of this charge is discussed.
The concept of an area charge to finance expansion of the trunk stormwater management system is
not a new concept for the City. Since its report titled Trunk Storm Sewer Fee Determination Study
(February 2001) the City has quantified future trunk and ponding needs and developed an area
charge based on actual costs of these needs spread across the potential developable acreage. With
the analysis contained within the LSWMP the City will update the fees for the 2040 growth area.
Much of this section of Prior Lake’s LSWMP focuses on the analysis that supports the development
of the area charge. There are also several City planning and budgeting documents that outline
surface water management activities undertaken by the City.
Those documents are identified in Table 7.1, and are incorporated by reference into this Plan.
Table 7.1 Planning and Budgeting Documents
Plan/Document Revision Frequency/Notes
Capital Improvement Program Annually
City Budget Documents Annually
Stormwater Pollution Prevention Program Every five years (minimum)
7.2.Review of the Existing Trunk Stormwater Acreage Charge
In 2018, the City completed a review of their Trunk Stormwater Acreage Charge. The original fee
has not changed significantly from 2001-2016. The City performed a review of the construction cost
index (CCI) from 2005-2016 and identified there has been a 36% increase in construction costs over
this period. A decision from the City Council directed staff to phase the CCI increase over several
years. The incremental increase recommended was 10% over the years of 2016-2019. A copy of the
complete memo can be found in Appendix K.
7.3.Operation and Maintenance
7.3.1.Activities
A stormwater system is a major investment for the City of Prior Lake – both in terms of initial
capital cost and in terms of ongoing maintenance costs. The capital improvement program
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-2
outlines the costs for new trunk system construction which will be funded by area charges.
System maintenance is funded by the city’s stormwater utility.
The city’s stormwater system maintenance responsibilities include the following:
Stormwater basins
Cleaning of sump manholes and catch basins
Inspection and repair of storm sewer inlet structures
Open channels
Assessing pipe condition (typically by televising)
De-icing practices
Street sweeping
A brief description of each of these practices is listed below.
7.3.2. Stormwater Basins
Stormwater basins represent a sizable investment in the City's drainage system. General
maintenance of these facilities helps ensure proper performance and reduces the need for major
repairs. Periodic inspections are performed to identify possible problems in and around the basin.
Inspection and maintenance cover the following:
Basin outlets/inlets
Side slopes
Illicit dumping and discharges
Sediment buildup
A key issue with stormwater basins is ensuring that the outlets perform at design capacity and
that the outlet is kept clear of debris and vegetation. Inlets are inspected for erosion and excess
sediment deposits. Side slopes are to be kept well-vegetated to prevent erosion and sediment
deposition into the basin and are inspected for noxious weeds. Basins are periodically inspected
for evidence of illicit dumping or discharges. The most common of these is dumping of yard
waste into the basin. Sediment removal is performed where excessive sediment buildup has
occurred. Table 7.2 provides a typical maintenance schedule for wet ponds.
Table 7.2 Stormwater Pond Maintenance Schedule
Activity Schedule
Inspect regional pond outlets for clogging.After significant
rainfalls
Inspect for damage.
Note signs of hydrocarbon build up.
Monitor for sediment accumulation in the facility and forebay.
Examine to ensure that inlet and outlet devices are free of debris
and operational.
Annual inspection
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-3
Repair undercut or eroded areas.As needed
Remove sediment accumulated sediment in the forebay and
permanent pool
2 to 7 years or when 50%
of capacity has been lost
Adapted from the Minnesota Stormwater Manual: Operation and Maintenance of Stormwater Ponds
7.3.3. Sump Manholes and Sump Catch Basins
Sump manholes and sump catch basins are included in storm sewer systems to collect sediments
before they are transported to downstream water bodies. These structures keep sediments from
degrading downstream water bodies. Once sediments are transported to a lake or pond, they
become much more expensive to remove.
Construction activity and erosion are the main contributors of sediment into the stormwater
system. Since these structures are designed to collect these sediments, they are routinely
inspected and cleaned to provide capacity for future sedimentation. Suction vacuum equipment is
typically used.
7.3.4. Storm Sewer Inlet Structures
To fully utilize storm sewer capacity, inlet structures are kept operational in order to transport
stormwater runoff into the system. All efforts are made to keep catch basins and inlet flared ends
free of debris and sediments so as not to restrict inflow and cause flood damage. Leaf and lawn
litter are the most frequent cause of inlet obstructions. On a routine basis, City staff visually
inspects inlet structures to ensure they are operational.
7.3.5.Open Channels
Overland flow routes constitute an important part of the surface water drainage system. Open
channels are typically vegetated and occasionally lined with more substantial materials. The lined
channels typically require little or no maintenance. Vegetated channels are periodically inspected
and maintained, as high flows may create erosion within the channel.
Eroded channels can contribute to water quality problems in downstream water bodies as the soil
is continually swept away. If not maintained, the erosion of open channels would accelerate and
the repair would become increasingly more costly. The use of bioengineering and natural stream
technology, which mimics the characteristics of natural streams to promote channel stability, can
reduce the potential for erosion.
7.3.6. Piping System
The storm sewer piping system constitutes a multimillion-dollar investment for the City. The
City performs a comprehensive maintenance program to maximize the life of the facilities and
optimize capital expenditures. The following periodic inspection and maintenance procedures are
followed:
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-4
Catch basin and manhole castings are inspected and are cleaned and replaced as
necessary.
Catch basin and manhole rings are inspected and are replaced and/or regrouted as
necessary.
Catch basin and manhole structures are inspected and are repaired or replaced as needed.
Pipe inverts, benches, steps (verifying integrity for safety), and walls are checked.
Cracked, deteriorated, and spalled areas are grouted, patched, or replaced.
Storm sewer piping is inspected either manually or by television to assess pipe
condition. Items looked for include root damage, deteriorated joints, leaky joints,
excessive spalling, and sediment buildup. The piping system is programmed for
cleaning, repair, or replacement as needed to ensure the integrity of the system.
7.3.7. De-Icing Practices
Minnesota receives approximately 54 inches of snow during a typical year. This requires a large
amount of de-icing chemicals (primarily salt) to be applied to roads and sidewalks each winter.
Improper storage as well as overuse of salt increases the risk of high chloride concentrations in
runoff and groundwater. High chloride concentrations can be toxic to fish, wildlife, and
vegetation.
The following procedures are used for storing de-icing chemicals in the City.
1.De-icing material is stored in waterproof sheds. Where this is not possible, stockpiles are
covered with polyethylene and placed on impervious surfaces.
2.Road de-icing stockpiles are not located near municipal well areas or in other sensitive
groundwater areas.
3.Runoff from stockpiles is not allowed to flow directly into streams or wetlands where
environmental damage can occur.
Prior Lake has established a detailed Winter Maintenance Policy to address winter maintenance
needs. Street conditions are assessed for each individual event and ice control material
application is adjusted accordingly. Equipment is maintained in good working order to place ice
control material on roadways and is properly calibrated to prevent excessive application.
7.3.8. Street Sweeping
Street sweeping is an integral part of the City’s effective surface water management system. It
greatly reduces the volume of sediments that have to be cleaned out of sump structures and
downstream water bodies. The City has a “street sweeping policy” that includes one sweeping of
the entire city in the spring and additional sweepings around targeted areas throughout the
remainder of the year. Sweeping priorities for targeted areas in order are the following: TMDL
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-5
drainage areas, non-TMDL direct drainage areas for nonimpaired lakes, drainage areas with
existing stormwater treatment systems that drain to surface waters, and landlocked areas. Spring
sweeping begins either late March or early April after the risk of later snowfall has passed and
targets sand left from winter sanding operations.
Prior Lake does not allow residents to rake leaves into the street for pick up, but does provide a
compost site where residents can bring their leaves. This greatly reduces the incidence of inlet
blockages and protects the water quality of downstream water bodies.
The objective of both programs is to minimize impacts from leaf litter, salt and other debris on
the surface waters of the City.
7.4.Education
In order to obtain the necessary political and economic support for successful LSWMP
implementation, it is vital to inform City residents about basic stormwater management and water
quality concepts, policies and recommendations in the LSWMP, and the progress of stormwater
management efforts. Education is also required as part of the MS4 Permit.
This information is presented to the public through the City newsletter, press releases on the City
website or to local papers, through the Mayor’s and City Manager’s columns, and at public meetings
as appropriate. Periodic updates on the progress of LSWMP implementation and information on
specific improvement projects is also provided to the public.
7.5.Financing and Stormwater Utility
The City of Prior Lake implemented a stormwater utility in 1993. The current quarterly residential
charge is $14.34 per residential unit. As the city’s maintenance responsibilities grow, the stormwater
utility funding also needs to grow to keep pace. The NPDES permit and SWPPP commit the city to
certain activities, including capital projects, for the purpose of improving the quality of the city’s
stormwater discharge. Prior Lake’s capital improvement projects and MS4 permit requirements are
listed in Table 7.3.
The City will use funds generated from its stormwater utility as the primary funding mechanism for
its implementation program including; maintenance, repairs, capital projects, studies, etc. If funds
from this utility fee do not cover necessary costs, the City will consider adjusting the stormwater
utility fee to cover the costs associated with the implementation program. The City will continue to
review the stormwater utility fee annually and adjust based on the stormwater related needs of the
City and other available funding mechanisms. The City will also take advantage of grant or loan
programs to offset project costs where appropriate and cost-effective. Below is a list of various
sources of revenue that the City will attempt to utilize:
Grant monies possibly secured from various agencies. This could include PLSLWD,
Scott WMO, Scott County, Mn/DOT, the MPCA, the DNR, Legislative-Citizen
Commission on Minnesota Resources (LCCMR), the Board of Water and Soil Resources
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-6
(BWSR), Metropolitan Council and others.
Special assessments for local improvements performed under authority of Minnesota
Statutes Chapter 429.
Developer funds.
Other sources potentially including tax increment financing, tax abatement, state aid, and
others.
7.6.Design Standards
The City of Prior Lake has produced and regularly updates the Public Works Design Manual. The
latest version of this manual is titled Public Works Design Manual, City of Prior Lake, July 2007.
This manual, as revised, is adopted by reference into City ordinance and into this Surface Water
Management Plan as the applicable design standard for surface water management.
7.7.Watershed Implementation Priorities
The Prior Lake-Spring Lake Watershed District has adopted a Water Resources Management Plan
that includes programs and projects focused on water quality and runoff management, land
management to improve water quality and reduce runoff volumes, and management of the Prior
Lake Outlet System. As part of the PLSLWD Water Resources Management Plan, a detailed list of
implementation priorities have been developed for partnership opportunities between the City and
watershed district.
The Scott WMO will adopt a revised Water Resource Management Plan at the end of 2018. This
Plan focuses on select priorities and major issues identified through input from various agencies and
presents goals and policies to help implement solutions for these issues. The Scott WMO
implementation priorities specifically for the City of Prior Lake include two assessments related to
Campbell Lake and the DRSMA, deicing and street sweeping practices and priorities, and
addressing water-related CIPs in this LSWMP.
7.8.City of Prior Lake Implementation Priorities
Projects listed in Table 7-3 to correct existing deficiencies, to the extent they are identified, will be
prioritized as follows:
1.Projects intended to reduce or eliminate flooding of structures in known problem areas
2.Projects intended to improve water quality in the City’s lakes
3.Projects intended to reduce maintenance costs
4.Projects intended to restore wetlands and habitat
Other implementation priorities for the City as it adopts this Plan and begins the implementation
phase of the Plan include:
1.Implement the City’s MS4 SWPPP.
2.Partner with PLSLWD to implement options listed in the Prior Lake Stormwater
Management & Flood Mitigation Study.
SECTION 7
Surface Water Management Plan
City of Prior Lake Section 7
WSB Project No. 013093-000 Page-7
3.Ensure the Stormwater Utility Funding is adequate to maintain the existing stormwater
system and to meet its current and future obligations toward pond maintenance and MS4
compliance.
4.Application of the revised area charge outlined in this report and update of the area charge
based on increases in land value and construction costs.
5.Implementation of the rate control targets as outlined in the appendices and stormwater
modeling that supports this plan.
6.Application of the wetland susceptibility criteria in determining how wetlands are used for
flood storage, retention, and rate control.
7.Maintaining equivalency with Scott WMO and PLSLWD rules.
8.Working in partnership with WMO and WD to minimize downstream impacts.
Specific implementation items for the City are listed in Table 7-3.
SECTION VII
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
1
General stormwater improvements - Placeholder for
stormwater projects listed in the City's CIP.
$250,000 City-Wide
Stormwater Fee,
Scott WMO,
PLSLWD,
Grants
$25,000 $25,000 $25,000 $25,000 $25,000 $25,000 $25,000 $25,000 $25,000 $25,000
City's CIP
2
PLSLWD Storage and Infiltration Projects - Continue to
partner with the PLSLWD on projects to reduce runoff,
increase infiltration, and reduce pollutant loading and
transport to Spring and Upper Prior Lakes.
$450,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$50,000 $50,000 $50,000 $50,000 $50,000 $50,000 $50,000 $50,000 $50,000
Spring and Upper Prior Lake
TMDL Implementation Plan
3
Wetland Restoration - Continue to partner with PLSLWD on
projects to restore key wetland to increase storage, improve
habitat, and create a wetland bank to mitigate future wetland
loss from development.
$250,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$50,000 $50,000 $50,000 $50,000 $50,000
Spring and Upper Prior Lake
TMDL Implementation Plan
4
PLSLWD Public Infrastructure Partner Projects - Continue to
partner with PLSLWD to retrofit streets,
highways, and other public infrastructure with volume
management and load reduction BMPs on routine street,
highway, and other reconstruction projects. Upcoming
projects could include Balsam, Sunrise, and Manitou.
$675,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$75,000 $75,000 $75,000 $75,000 $75,000 $75,000 $75,000 $75,000 $75,000
PLSLWD Watershed
Management Plan
Implementation Items
5
Jeffers Pass Outlet Improvement - Install a grate or barrier to
prevent the build-up of debris placed by beavers. $20,000 PLSLWD Stormwater Fee,
Grants $20,000
Issue 5.3.1
6
Island View Culvert Replacement - The City will upgrade the
structure and coordinate with the PLSLWD and DNR as
needed.$20,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$20,000
Issue 5.3.2
7
Glynwater Trail NW Culvert Replacement - An outlet
improvement project will be completed to provide an
improved overflow structure and resizing of the culvert. $30,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$30,000
Issue 5.3.3
8
Wildwood Pond Outlet - An outlet improvement project will be
completed to provide an overflow structure with an improved
skimmer.$30,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$30,000
Issue 5.3.4
Possible
Funding
Sources 2
Proposed Cost By Year1
10 Year Total
Cost Estimate
1,3
Capital Improvement Projects (CIP)
TABLE 7.3
SURFACE WATER MANAGEMENT IMPLEMENTATION PLAN
No.Project Description Watershed
District4 Comments
Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
TABLE 7.3
SECTION VII
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
Possible
Funding
Sources 2
Proposed Cost By Year1
10 Year Total
Cost Estimate
1,3
No.Project Description Watershed
District4 Comments
9
Northwood Road Wetland Outlet - An outlet improvement
project will be completed to provide an overflow structure with
an improved skimmer that will better maintain the water level.
This work may also include a carp grate installed in
cooperation with the PLSLWD.
$40,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$40,000
Issue 5.3.7
10
Adelmann Street Pond - The pond located near County Road
21 and Adelmann Street currently has an outlet that is not
functioning properly. The City will complete a survey of the
pond and perform a pond cleanout project as necessary. $153,000 Scott WMO
Stormwater Fee,
Scott WMO,
Grants
$3,000 $150,000
Issue 5.3.9
11
Crystal Lake Outlet Improvement - An outlet improvement
project will be completed to provide an overflow structure with
an improved skimmer that will better maintain the water level.
The outlet will also include measures to prevent beavers from
blocking the outlet.
$20,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$20,000
Issue 5.3.12
12
Deerfield Lane Pond Improvement - Survey and cleanout the
pond to remove sediment. Identify the need to remove the
outlet to the adjacent pond to provide additional storage. $80,000 Scott WMO
Stormwater Fee,
Scott WMO,
Grants
$80,000
Issue 5.3.14
13
Markley Lake Erosion - There are significant erosion issues
on a City-owned parcel on the south side of Markley Lake.
The City will provide short term stabilization measures as
needed. The long-term goal for this area will be to stabilize an
eroding ravine and provide additional flood storage as well.
$280,000 Scott WMO
Stormwater Fee,
Scott WMO,
Grants
$15,000 $15,000 $250,000
Issue 5.5.2
Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
TABLE 7.3
SECTION VII
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
Possible
Funding
Sources 2
Proposed Cost By Year1
10 Year Total
Cost Estimate
1,3
No.Project Description Watershed
District4 Comments
14
Education Activity - Complete education activity outlined in
the MS4 permit and SWPPP. Continue to partner with Scott
WMO and PLSLWD on education related items including
involvement in the Scott Clean Water Education Program,
demonstration projects, resident education, education
materials, etc.
$15,000 City-Wide Stormwater Fee $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500
Spring and Upper Prior Lake
TMDL Implementation Plan;
MS4 Permit
15
Annual SWPPP Assessment & Annual Reporting City staff
will conduct an annual SWPPP assessment in preparation of
each annual report. Proposed SWPPP modifications are
subject to Part II.G of the MS4 permit.
$10,000 City-Wide Stormwater Fee $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000
City's MS4 Permit And
SWPPP
16
Online Availability of the Stormwater Pollution Prevent Plan
(SWPPP) Program Document - The City will make the
SWPPP and each year's annual report available on the City's
webpage and will update as needed.
$2,000 City-Wide Stormwater Fee $200 $200 $200 $200 $200 $200 $200 $200 $200 $200
City's MS4 Permit And
SWPPP
17
Employee Training - Continue to host a minimum of one staff
training event per year to discuss illicit discharge recognition
and reporting. City staff will continue to develop an annual
training schedule, record the employee names, topics
covered, and date of each event.
$5,000 City-Wide Stormwater Fee $500 $500 $500 $500 $500 $500 $500 $500 $500 $500
City's MS4 Permit And
SWPPP
18
Establishment of Procedures for Site Inspections and
Enforcement - The City will inspect construction sites for
conformance to NPDES construction permit standards and
applicable City standards. This goal will be met by enforcing
the City's erosion control and waste disposal standards.
$50,000 City-Wide Stormwater Fee $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000
City's MS4 Permit And
SWPPP
19
Site Plan Review Program - The City will review and revise (if
necessary, during the plan review process) permanent BMP
designs and criteria for post-construction stormwater
management associated with new development and
redevelopment projects of one acre or more. The City will
also actively look for non-structural opportunities where
prudent and feasible.
$30,000 City-Wide Stormwater Fee $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000
City's MS4 Permit And
SWPPP
20 Storm Sewer Mapping - The City will annually update its
storm sewer system map.$8,000 City-Wide Stormwater Fee $800 $800 $800 $800 $800 $800 $800 $800 $800 $800 City's MS4 Permit And
SWPPP
21
Street Sweeping - Conduct street sweeping operations per
the City's Street Sweeping Policy. $200,000 City-Wide Stormwater Fee $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000
City's MS4 Permit And
SWPPP
22
Structural Stormwater BMP Inspections - Continue to inspect
100% of all structural stormwater BMPs each year as
required per the MS4 permit. $80,000 City-Wide Stormwater Fee $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000
City's MS4 Permit And
SWPPP
23
Inspect MS4 Outfalls and Ponds - Continue to inspect 20% of
all MS4 outfalls each year, until 100% of all MS4 Outfalls and
Ponds have been inspected.$80,000 City-Wide Stormwater Fee $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000 $8,000
City's MS4 Permit And
SWPPP
MS4 Permit Items and Regular Maintenance
Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
TABLE 7.3
SECTION VII
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
Possible
Funding
Sources 2
Proposed Cost By Year1
10 Year Total
Cost Estimate
1,3
No.Project Description Watershed
District4 Comments
24
Review Inspection Reports - Annually, review all pond, outfall,
and SPCD inspection records to determine if maintenance,
repair, or replacement is needed. Include a description of the
findings and any maintenance, repair, or replacement as a
result of the inspection findings. Evaluate each structural
pollution control device (SPCD) inspection frequency and
adjust as needed per MS4 Permit Part III.D.6.e(1.).
$20,000 City-Wide Stormwater Fee $2,000 $2,000 $2,000 $2,000 $2,000 $2,000 $2,000 $2,000 $2,000 $2,000
City's MS4 Permit And
SWPPP
25
Stormwater Systems Maintenance Training Program -
Training focused on parking lot and street cleaning, storm
drain systems cleaning, road salt materials management.$15,000 City-Wide Stormwater Fee $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500 $1,500
City's MS4 Permit And
SWPPP
26
Road Salt Application Review - The City will record the
annual activities of the salt distribution program and adjust
current practices as necessary.$10,000 City-Wide Stormwater Fee $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000 $1,000
City's MS4 Permit And
SWPPP
27
Operation and Maintenance - Continue to perform and track
annual inspections of all public water quality BMPs. Track all
required maintenance and repairs required and completed.
$50,000 City-Wide Stormwater Fee $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000
City's MS4 Permit And
SWPPP
28
Pond Surveys - The City will annually complete pond surveys
to schedule and prioritize the necessary maintenance
projects.
$30,000 City-Wide Stormwater Fee $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000 $3,000
City's MS4 Permit And
SWPPP
29
Pond Maintenance and Retrofit - The City will annually
maintain stormwater ponds and enhance overall system
treatment efficiency. $1,625,000 City-Wide Stormwater Fee $300,000 $25,000 $300,000 $25,000 $300,000 $25,000 $300,000 $25,000 $300,000 $25,000
City's MS4 Permit And
SWPPP
30
Chloride Management - The City will promote and adopt
strategies included in the TCMA Chloride Management Plan. $50,000 City-Wide Stormwater Fee $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000 $5,000
City's MS4 Permit And
SWPPP
31
Stormwater Infrastructure Maintenance - Maintenance,
retrofit, and creation of structural stormwater practices such
as sump manholes, bioretention, infiltration and filtration $520,000 City-Wide Stormwater Fee $60,000 $60,000 $60,000 $60,000 $20,000 $60,000 $60,000 $60,000 $60,000 $20,000
City's MS4 Permit And
SWPPP
32
PLSLWD District-Wide Model Updates - Continue to
cooperate and data share as the District completes regular
updates of their XPSWMM models. $5,000 City-Wide Stormwater Fee $500 $500 $500 $500 $500 $500 $500 $500 $500 $500
City's MS4 Permit And
SWPPP
Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
TABLE 7.3
SECTION VII
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
Possible
Funding
Sources 2
Proposed Cost By Year1
10 Year Total
Cost Estimate
1,3
No.Project Description Watershed
District4 Comments
33
Ordinance Updates - The City will continually review their
ordinances related to stormwater, erosion and sediment
control, wetlands, and floodplains for consistency with state
and watershed requirements.
$5,000 City-Wide Stormwater Fee $500 $500 $500 $500 $500 $500 $500 $500 $500 $500
34
Prioritize Inspections - The City will develop a process to
determine the frequency for inspecting high priority inspection
sites (e.g. near sensitive receiving waters).
$2,000 City-Wide Stormwater Fee $1,000 $1,000
35
Evaluate the Need to Update the Stormwater Utility Fee - The
City will review the implementation of proposed programs and
improvements identified in this plan and will determine the
potential update of the stormwater utility fee.$5,000 City-Wide Stormwater Fee $1,000 $1,000 $1,000 $1,000 $1,000
36
Flood Response Policy - Review and update as needed the
City's Flood Response Policy and evaluate the effectiveness
of action items. $8,000 City-Wide Stormwater Fee $800 $800 $800 $800 $800 $800 $800 $800 $800 $800
37
Winter Maintenance and Street Sweeping Policies - Review
and update as needed the City's Winter Maintenance Policy
and Street Sweeping Policy.
$8,000 City-Wide Stormwater Fee $800 $800 $800 $800 $800 $800 $800 $800 $800 $800
38
Campbell Lake Regional Stormwater Assessment - Additional
development is planned around Campbell Lake, which is the
headwaters for Picha Creek. Partner with Scott WMO to
complete a study that would assess potential issues with
development, and identify potential opportunities for regional
stormwater management.
$30,000 Scott WMO
Stormwater Fee,
Scott WMO,
Grants
$30,000
Scott WMO Watershed
Management Plan; Issue
5.6.5
39
City of Prior Lake DWSMA Abandoned Well Assessment -
Partner with Scott WMO to review the City's Drinking Water
Supply Management Area to develop a methodology for
identifying probable locations of abandoned/unsealed wells.
Results will also be used to target contacts for the well
sealing cost share practice implementation through the TACS
program.
$30,000 Scott WMO
Stormwater Fee,
Scott WMO,
Grants
$30,000
Scott WMO Watershed
Management Plan
40
Innovative Phosphorus Load Reductions Study - Complete
feasibility reports to identify areas suitable for new
management methods and innovative technologies for TP
load reductions. $90,000 City-Wide
Stormwater Fee,
Watershed
Partnerships,
Grants
$30,000 $30,000 $30,000
Spring and Upper Prior Lake
TMDL Implementation Plan
41
BMP Research - Partner with local agencies to investigate or
contribute to research on the functionality of constructed
BMPs and/or innovative BMP options for stormwater
treatment. $200,000 City-Wide
Stormwater Fee,
Watershed
Partnerships,
Grants
$20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000 $20,000
Spring and Upper Prior Lake
TMDL Implementation Plan
Monitor and Study
Official Controls
Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
TABLE 7.3
SECTION VII
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
Possible
Funding
Sources 2
Proposed Cost By Year1
10 Year Total
Cost Estimate
1,3
No.Project Description Watershed
District4 Comments
42
Priorwood Street Pond - The City will complete a feasibility
study to determine a realignment of the channel is to the
pond possible. $40,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$40,000
Issue 5.3.5
43
Shady Beach Trail Ravine - The City will complete a feasibility
study to determine the best options for drainage mitigation. $40,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$40,000
Issue 5.3.8
44
Priorwood Lane Pond Study - The City will complete a
feasibility study to analyze the existing pond system to
mitigate outlet issues and flooding. $30,000 PLSLWD
Stormwater Fee,
PLSLWD,
Grants
$30,000
Issue 5.3.13
45
City-wide Stormwater Model - The City will create a
stormwater system model to identify problem areas and
needed system repairs/upgrades.$85,000 City-Wide
Stormwater Fee,
Watershed
Partnerships,
Grants
$85,000
Issue 5.3.11
TOTAL $5,676,000 $534,100 $373,100 $675,100 $458,100 $652,100 $568,100 $750,100 $413,100 $919,100 $333,100
1 Cost estimates are preliminary and subject to review and revision as engineer's reports are completed and more information becomes available. Table reflects 2018 costs and does not account for inflation. Costs generally include labor, equipment, materials, and all other costs necessary to complete each activity. Some of
the costs outlined above may be included in other operational costs budgeted by the City.
2 Funding for stormwater program activities projected to come from following sources - Surface Water Management Fund, Developers Agreements, Grant Funds, General Operating Fund, or Special Assessments.
3 Staff time is not included in the cost shown.
Surface Water Management Plan
City of Prior Lake
WSB Project No. 010393-000
TABLE 7.3
SECTION 8
Surface Water Management Plan
City of Prior Lake Section 8
WSB Project No. 010393-000 Page-1
8. ADMINISTRATION
8.1.Review and Adoption Process
Review and adoption of this Surface Water Management Plan will follow the procedure
outlined in Minnesota Statutes 103B.235:
‘After consideration but before adoption by the governing body, each local government unit
shall submit its water management plan to the watershed management organization[s] for
review for consistency with the watershed plan. The organization[s] shall have 60 days to
complete its review.’
‘Concurrently with its submission of its local water management plan to the watershed
management organization, each local government unit shall submit its water management
plan to the Metropolitan Council for review and comment. The council shall have 45 days
to review and comment upon the local plan. The council’s 45-day review period shall run
concurrently with the 60-day review period by the watershed management organization.
The Metropolitan Council shall submit its comments to the watershed management
organization and shall send a copy of its comments to the local government unit.’
‘After approval of the local plan by the watershed management organization[s], the local
government unit shall adopt and implement its plan within 120 days, and shall amend its
official controls accordingly within 180 days.’
8.2. Amendment Procedures
The Prior Lake LSWMP is intended to extend through the year 2027. For the plan to remain
dynamic, an avenue must be available to implement new information, ideas, methods,
standards, management practices and any other changes that may affect the intent and/or results
of the LSWMP. The amendment procedure for the LSWMP is presented below.
1)Request for Amendment
Written request for plan amendment is submitted to City staff. The request shall outline the
need for the amendment as well as additional materials that the City will need to consider
before making its decision.
2)Staff review of Amendment
A decision is made as to the validity of the request. Three options exist: 1) reject the
amendment, 2) accept the amendment as a minor issue, with minor issues collectively
added to the plan at a later date, or 3) accept the amendment as a major issue, with major
issues requiring an immediate amendment. In acting on an amendment request, City staff
shall recommend to City Council whether or not a public hearing is warranted.
3)Council Consideration
The amendment and the need for a public hearing shall be considered at a regular or
special Council meeting. Staff recommendations should also be considered before
decisions on appropriate action(s) are made.
SECTION 8
Surface Water Management Plan
City of Prior Lake Section 8
WSB Project No. 010393-000 Page-2
4)Public Hearing and Council
This step allows for public input based on public interest. Council shall determine when the
public hearing should occur in the process. Based on the public hearing, the City Council could
approve the amendment.
5)Council Adoption
Final action on an amendment is City Council adoption. However, prior to the adoption, an
additional public hearing could be held to review the plan changes and notify the appropriate
stakeholders.
6)Coordination with WMO and WD
To the extent and manner required by the PLSLWD and Scott WMO, all major amendments to
the LSWMP (including, but not limited to, substantive new data, updated management
practices, and rule revisions) shall be submitted to the watersheds for review and approval in
accordance with applicable state rules and statutes (Section 103B and Rules). For any minor
updates, the City will coordinate with the WMO and WD as any changes are made. Minor
amendments, such as those completed for TMDLs, CIP updating, Nondegradation Planning, and
Groundwater Protection, do not need to be submitted to the WD and WMO for approval.