HomeMy WebLinkAbout5G PLSLWD Rules Revision - Comment Letter 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: OCTOBER 21, 2019
AGENDA #: 5G
PREPARED BY: PETE YOUNG, WATER RESOURCES ENGINEER
PRESENTED BY: PETE YOUNG
AGENDA ITEM:
AUTHORIZE THE MAYOR AND CITY MANAGER TO SIGN A COMMENT
LETTER REGARDING THE PROPOSED PRIOR LAKE-SPRING LAKE
WATERSHED DISTRICT RULES REVISION
GOAL AREA AND
OBJECTIVE:
High-Value City Services
5. Grow collaborations to provide efficient and cost-effective services to the
community.
DISCUSSION: Introduction
The Prior Lake-Spring Lake Watershed District (PLSLWD) is proposing to revise
its rules. The PLSLWD notified the City and other agencies of their proposal on
September 11, 2019. Per State Statute, there is a 45-day comment period for the
proposal. Comments are due on October 28, 2019.
The Prior Lake-Spring Lake Watershed District (PLSLWD) rules apply to a majority
(approximately 74%) of the area within the City of Prior Lake. The remaining area
is within the jurisdiction of the Scott Watershed Management Organization (WMO).
The PLSLWD is nearing the completion of a rules revision process. The
PLSLWD’s rules revision process focused on Stormwater Management (PLSLWD
Rule D), Erosion and Sediment Control (Rule E), Floodplain Alteration (Rule F),
Wetland Alteration (Rule G), Bridge and Culvert Crossings (Rule H), Drainage
Alterations (Rule I), and Buffer Strips (Rule J). The rules revision process included
a series of Technical Advisory Committee (TAC) meetings with representatives
invited from Scott County, Scott WMO, Scott SWCD, MnDOT, MnDNR, MPCA, the
Met Council, the State Board of Water and Soil Resources (BWSR), the SMSC,
and the Cities of Savage and Shakopee. The proposed PLSLWD rules are
included as Attachment 1.
In accordance with Minnesota Statutes 2019, Section 103B.235, the City of Prior
Lake must adopt official controls as necessary to bring local water management
into conformance with watershed plans. The City has previously adopted local
controls that maintain compliance with this State statute.
History
The PLSLWD implemented their own development review and permitting process
from 1999 to 2007. During this period, property developers were required to
submit their proposed projects to both the City and PLSLWD for review and
approval. In addition, the City was required to submit road reconstruction and
other City-led projects to the PLSLWD for review and approval. This process
resulted in duplicate project reviews, conflicting requirements, and confusion
among developers.
The City and PLSLWD worked together to draft an equivalency agreement in 2007
whereby development projects in the City of Prior Lake would no longer require a
parallel review processes. The City then adopted revisions to its Public Works
Design Manual (PWDM) outlining its rules which were approved as equivalent to
PLSLWD’s rules. Under the 2007 equivalency agreement, the City agreed to
complete all development reviews in accordance with the updated PWDM. The
PLSLWD retained the right to permit City-sponsored projects. Neither organization
has substantially revised their rules since 2007 and the equivalency agreement
has remained effective since that time.
The Scott WMO has never had a separate permitting or plan review process within
the City or Prior Lake, with the City maintaining rules equivalency since 2003 when
the City first became responsible for implementing State-mandated stormwater
controls through the Municipal Separate Storm Sewer System (MS4) program.
The Scott WMO references State stormwater controls for their rules; the City
already must comply with these controls under our State MS4 permit.
Current Circumstances
The City currently conforms with both Scott WMO and PLSLWD Rules; with this
proposed rules revision, the City would no longer have official controls that
conform with PLSLWD’s watershed plan and therefore the City would be required
to amend our official controls by updating the City PWDM.
ISSUES: City staff worked closely with PLSLWD staff and consultants during the rules
revision process. City staff and other members of the TAC identified several
potential issues during the process, many of which were addressed during the
TAC process through updated drafts of the rules. Attachment 2 includes a
summary of all comments sent to PLSLWD during the rules update process.
The proposed rules revision includes some items that were not addressed by the
PLSLWD after City staff comments were submitted during the TAC review
process. These items are detailed in the attached comment letter (Attachment 3).
FINANCIAL
IMPACT:
The current PLSLWD rules require the City to incorporate Best Management
Practices (BMPs) such as stormwater ponds and filtration basins as part of linear
projects (street reconstruction projects). Based on these current rules, the City’s
2020-2029 Stormwater CIP (Water Quality Fund) includes approximately $3.3
million in water quality improvement costs associated with Transportation Plan
projects. This cost represents 29% of the Water Quality Fund over that timeframe.
While the new proposed PLSLWD rules relax the current requirements for BMPs,
the proposed rules continue to require stormwater treatment in excess of baseline
State stormwater requirements. Using the 2018 City of Prior Lake road
reconstruction project as an example, the proposed PLSLWD rules would reduce
the cost to comply by approximately 2/3 from current PLSLWD rules. However, the
updated PLSLWD rules represent an increase in cost over complying with the
baseline State requirements that apply in other portions of the City outside the
PLSLWD. For the 2018 Prior Lake road reconstruction project, because the City
reduced the total amount of impervious surface by narrowing the roadway, there
would have been no stormwater BMP requirements for the project under State
rules.
The total amount of increased cost under the CIP is currently unknown because of
design exemptions allowed under the State MS4 permit that would not be
available under the proposed PLSLWD rules – feasibility studies that include ROW
analyses will be required to determine ballpark costs for compliance with the new
proposed PLSLWD rules. The overall cost to taxpayers to reconstruct roads will be
higher in the PLSLWD than it is in the Scott WMO.
ALTERNATIVES: 1. Motion and second as part of the consent agenda to authorize the Mayor and
City Manager to sign a comment letter regarding the proposed Prior Lake-Spring
Lake Watershed District rules revision.
2. Motion and second to remove this agenda item from the consent agenda for
additional discussion.
RECOMMENDED
MOTION:
Alternative #1
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POLICY STATEMENT
The Prior Lake-Spring Lake Watershed District (the District) is a political subdivision of the state
under the Minnesota Watershed Act, and a watershed management organization as defined in the
Metropolitan Surface Water Management Act. These Acts provide the District with power to
accomplish its statutory purpose - the conservation, protection and management of water resources
within the boundaries of the District through sound scientific principles.
The District has adopted a water resources management plan pursuant to the Acts. These Rules
implement the plan’s principles and objectives.
Land alteration and utilization can affect the rate and volume and degrade the quality of surface
water runoff within the District. Sedimentation from ongoing erosion and construction activities
will reduce hydraulic capacity of waterbodies and degrade water quality. Water quality problems
already exist in many waterbodies in the District.
Activities that increase the rate or volume of stormwater runoff will aggravate existing flooding
problems and contribute to new ones. Activities that degrade runoff quality will cause quality
problems in receiving water. Activities that fill floodplain or wetland areas will reduce flood
storage and hydraulic capacity of waterbodies, and will degrade water quality by eliminating the
filtering capacity of such areas.
These Rules protect the public health, welfare and natural resources of the District by regulating
the improvement or alteration of land and waters within the District to reduce the severity and
frequency of high water, to preserve floodplain and wetland storage capacity, to improve the
chemical and physical quality of surface waters, to reduce sedimentation, to preserve the hydraulic
and navigational capacities of waterbodies, to promote and preserve natural infiltration areas, and
to preserve natural shoreline features. In addition to protecting natural resources, these Rules are
intended to minimize future public expenditures on problems caused by the improvement or
alteration of land and waters.
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RELATIONSHIP WITH MUNICIPALITIES AND COUNTY
The District recognizes that the control and determination of appropriate land use is the responsibility
of the municipalities and the county. The District will review permit applications involving land
subdivision before preliminary approval is received from the municipality or county so that District
requirements will be considered in the review process.
The District intends to be active in the regulatory process to ensure that water resources are managed
in accordance with its goals and policies. The District will require permits for developments and
improvements in the watershed that meet the thresholds specified in the Rules. Municipalities will
have the option of assuming a more active role within the permitting process after adoption of local
water management plans approved by the District and implementation of local ordinances consistent
with the approved plan. The District welcomes the execution of Memorandums of Agreement with
all its municipalities to define the purpose and roles of each organization for local water planning and
regulation. With execution of an MOA, the District will continue to review and permit projects
sponsored or undertaken by municipalities and other governmental units, and will require
permits of the contractor in accordance with these Rules for governmental projects which have
an impact on water resources of the District. These projects include but are not limited to, land
development, road, trail and utility construction. In addition, the District will review and offer
comments to the municipality for projects undertaken by the private sector. In the interim,
however, the District will direct the permitting process.
The District desires to provide technical advice to the municipalities and the county in the
preparation of local stormwater management plans and the review of projects that may affect water
resources prior to investment of significant public or private funds.
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RULE A - DEFINITIONS
For the purposes of these Rules, unless the context otherwise requires, the following words and
t erms shall have the meanings set forth below.
References in these Rules to specific sections of the Minnesota Statutes or Rules include
amendments, revisio ns or recodifications of such sections.
The words “shall” and “must” are mandatory; the word “may” is permissive.
Agricultu ral Activity - t he use of land for the production of agronomic, horticultural or
silvicultural crops, including nurser y stock, sod, fruits, vegetables, flowers, cover crops, grains,
Chr ist mas t rees, and grazing.
Alteration or Alter - when used in connect ion with public waters or wetlands, any act ivit y that
will change or diminish the course, current or cross-sect ion of public waters or wetlands.
Applicant - any person or polit ical subdivisio n that submits an applicat ion to the District for a
per mit under these Rules.
Atlas 14 - the Precipitation Frequency Estimates released by the National Weather Service
Hydrometeorlogical Studies Design Center. Volume 8, released in 2013, provides precipitation
frequency estimates for many Midwestern states including Minnesota.
Best Management Practices or BMPs - techniques proven to be effect ive in controlling runoff,
erosion and sedimentation including those documented in the Minnesota Construction Site
Erosion and Sediment Control Planning Handbook (BWSR, 1988); Protecting Water Qualit y in
Urban Areas (MPCA, 2000); Minnesota Urban Small Sites BMP Manual (Metropolitan Council
2001); and Minnesota Stormwater Manual (MPCA, 2014): as such documents may be amended,
revised o r supplemented.
Basic Management Class Wetland – any wetland not classified as a Natural Areas, Hydrology
or Restoration/Enhancement Class Wetland.
Buffer Strip - an area of natural, unmaintained, vegetated ground cover abutting or surrounding
a watercourse or wetland.
Compensatory Storage - excavated volume of material below the floodplain elevat ion required
to offset floodplain fill.
Compliance Agreement - an agreement required pursuant to Paragraph 7 of Rule B to assure
compliance wit h t hese Rules.
Critical duration flood event - means the 100-year precipitation or snow melt event with a
duration resulting in the maximum 100-year return period water surface elevation. For purposes
of these rules, the critical duration flood event is either the 100-year, 24 hour rainfall event as
found in NOAA Atlas 14 or the ten-day snow melt event assumed to be 7.2 inches of runoff
occurring on frozen ground (CN=100); note however that other durations (e.g., 6-hour) may
result in higher water surface elevations.
County - Scott Count y, Minnesota.
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Dead Storage - t he permanent pool vo lume o f a water basin, or the vo lume below the runout
elevat ion of a water basin.
Detention Basin - any nat ural or manmade depression for the temporar y storage of runoff.
Development - t he const ruction of any structure on or the subdivisio n of land.
District - the Prior Lake-Spring Lake Watershed District.
Directly Connected Impervious Surface – an impervious surface that is hydraulically
connected to a conveyance system (i.e. streets, curb and gutter, catch basins, storm drains, etc.)
without flowing over pervious areas.
Drain or Drainage - any method for removing or diverting water fro m waterbodies, including
excavat ion of an open ditch, installat ion of subsurface drainage tile, filling, diking or pumping.
Erosion - t he wear ing away o f the ground surface as a result of wind, flowing water, ice
mo vement or land dist urbing act ivities.
Erosion and Sediment Control Plan - a plan o f BMPs or equivalent measures designed to
cont rol runoff and erosion and to retain or control sediment on land dur ing the period of land
dist urbing act ivit ies in accordance wit h the standards set forth in Rule E.
Excavation - the art ificial remo val o f so il or other earth material.
Fill - the deposit of so il or other earth mater ial by artificial means.
Floodplain - the area adjacent to a waterbody that is inundated during a 100 -year flood.
Hydrology Management Class Wetland – any wetland scoring “high” or “exceptional” for the
MnRAM functions of Downstream Water Quality or Groundwater Interaction.
Impervious Surface - a constructed hard surface that either prevents or retards the entry of
water into the soil and causes water to run off the surface in greater quantities and at an increased
rate of flow than prior to development. Examples include rooftops, sidewalks, driveways,
parking lots, and concrete, asphalt, or gravel roads. Bridges over surface waters are considered
impervious surfaces. Solar panels are considered impervious surface.a surface co mpacted or
covered wit h mat er ial so as to be highly resistant to infiltration by runoff. Impervious surface
shall include roads, driveways and parking areas, whether or not paved, sidewalks greater than 3
feet wide, patios, t ennis and basketball courts, swimming pools, covered decks and other
st ruct ures. Open decks w it h jo ints at least ¼ inch wide, areas beneath overhangs less than 2 feet
wide, and sidewalks 3 feet or less wide shall not constitute impervious surfaces under these
Rules.
Land Disturbance or Land Disturbing Activity - an activity that changes or alters the existing
ground cover (vegetative or non-vegetative) and/or the existing soil topography. Land disturbing
activity includes, but is not limited to, development, redevelopment, public linear projects,
clearing, grading, filling, excavation and borrow pits. The following are among those that do not
constitute land disturbance: mill, reclamation and overlay of impervious surface; routine
vegetation management activity such as the clearing of cattails from ditches; and the use of land
for new or continuing agricultural activity, home gardens, or landscaping adjacent to existing
structures. any change of the land surface to include removing vegetat ive cover, excavat ion, fill,
grading, stockpiling so il, and the construction of any structure that ma y cause or contribute to
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erosion or t he movement of sediment into waterbodies. The use of land for agr icultural act ivit ies
shall not const itute a land dist urbing act ivit y under these Rules.
Landlocked Basin - a basin other than Pr ior Lake that is one acre or more in size and does not
have a natural out let at or below the 100-year flood elevat ion as determined by the 100-year, 10-
day runo ff event .
Low Floor - the finished surface of the lowest floor of a structure.
Mill, reclamation and overlay - the removal of the top layer(s) of an impervious surface (e.g.
roadway, parking lot, sport court) by mechanical means, followed by the placement of a new
layer of impervious surface, without disturbance of the underlying native soil.
Natural Areas Management Class Wetland – any wetland scoring “high” or “exceptional” for
the MnRAM functions of Vegetative Structure/Integrity or Wildlife Habitat Structure.
New development – any development that does not meet the definition of redevelopment.
Managers - the board of managers of the District.
MnDOT - the Minnesota Department of Transportation.
Municipal Separate Storm Sewer System (MS4) - the Prior Lake Outlet Channel, which is
operated by the District and is designed and used to convey water from the outlet for Prior
Lake.
Municipality - any cit y or township who lly or partly wit hin the District.
National Pollutant Discharge Elimination System (NPDES) Stormwater Discharge
Permit – a permit issued by the Minnesota Pollution Control Agency that authorizes the
discharge of pollutants to waters of the State.
NRCS - t he Nat ural Resource Conservat ion Service.
NURP Standard - the design criteria developed pursuant to the Nationwide Urban Runoff
Program (U.S. EPA, 1983) and published by the Minnesota Pollution Control Agency in
Protecting Water Quality in Urban Areas 1991” (sections 4.1 -4 through 4.1 -7), as may be
amendedthe Nat ionwide Urban Runoff Pro gram developed by the Environmental Protection
Agenc y t o st udy stormwat er runoff fro m urban development.
Ordinary High Water Level or OHW - the boundar y of waterbodies and shall be an elevat ion
delineat ing t he highest water level which has been maintained for a sufficient period of time to
leave evidence upon t he landscape, commo nly that point where the natural vegetation changes
fro m predominant ly aquat ic to predominant ly terrestrial. For watercourses, the ordinary high
water level is the elevat ion of the top of the bank of the channel. For reservoirs and flowages, the
ordinar y high wat er level is the operating elevation of the normal summer pool.
Owner - the owner of a parcel of land or the purchaser under a contract for deed.
Parcel - a parcel o f land designated by plat, metes and bounds, registered land survey, auditors
subdivisio n or other accept ed means and separated fro m other parcels or portions by it s
designation.
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Permanent cover - surface types that will prevent soil failure under erosive conditions.
Examples include: gravel, asphalt, concrete, rip rap, roof tops, perennial vegetative cover, or
other landscaped material that will permanently arrest soil erosion. To constitute permanent
cover, perennial vegetative cover must be evenly distributed, without large bare areas and with a
uniform density covering 70% of the area to be vegetated. Permanent cover does not include
temporary erosion control practices.
Permittee - t he person or polit ical subdivisio n in whose name a permit is issued pursuant to these
Rules.
Pre-development condition - the condition at the site prior to the proposed activity that serves
as the baseline against which to measure impacts of the proposed activity for compliance with
stormwater management requirements.
Person - any individual, t rustee, partnership, unincorporated associat ion, limited liabilit y
company or corporat ion.
Political Subdivision - a municipalit y, count y or other polit ical divisio n, agency or subdivisio n
of the st ate.
Prior Lake Outlet Channel - a watercourse improved and maintained by the Distr ict to provide
an out let for Prior Lake.
Public Linear Project - a project in which a public agency is a permittee and that involves a
roadway, sidewalk, trail or linear utility not part of a development pursuant to subdivision.
Public Health and General Welfare - are defined in Minnesota Statutes, section 103D.011,
subdivisio ns 23 and 24.
Public Waters - any wat ers as defined in Minnesota Statutes, section 103G.005, subdivisio n 15.
Public Waters Wetland - any wetland as defined in Minnesota Statutes, section 103G.005,
subdivisio n 15a.
Reconstructed Impervious Surface - area where impervious surface is removed down to the
underlying native soil and the underlying native soil, as distinguished from roadway subgrade
material, is disturbed. The following are among those that do not constitute impervious surface
reconstruction: structure renovation; impervious surface mill, reclamation and overlay; and
minor maintenance activities such as catch basin and pipe repair/replacement with same
hydraulic capacity.
Redevelopment - development on a site that is currently developed below 15% impervious
surface, or was developed beyond 15% impervious surface, but has been razed to below that
measure in anticipation of redevelopmentthe rebuilding, repair or alteration of a structure, land
sur face or facilit y for which over 50 percent of the parcel invo lved is disturbed by a land
dist urbing act ivit y.
Restoration/Enhancement Management Class Wetland – any wetland or basin lacking
wetland hydrology as a result of prior alteration ranked as high priority for restoration per the
District’s Comprehensive Wetland Plan dated April 2012, or as amended.
Runoff - rainfall, snowmelt or irrigat ion water flo wing over the ground surface.
Sediment - soil or other surficial mater ial transported by sur face water as a product of erosion.
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Sedimentation - t he process or action of deposit ing sediment.
Shoreland Protection Zone - land located within a floodplain, within 1,000 feet of the OHW of
a public wat er or public waters wetland, or within 300 feet of the Prior Lake outlet channel.
Standard - a preferred or desired level of quant it y, qualit y or value.
Stormwater Management Plan - a plan for the permanent management and control of runo ff
prepared and implemented in accordance with the standards set forth in Rule D.
Structure - anyt hing manufactured, constructed or erected which is normally attached to or
posit ioned on land, including buildings, portable structures, earthen structures, roads, water and
storage systems, drainage facilit ies and parking lots.
Subdivision or Subdivide - the separation of a parcel of land into 2 or more parcels.
SWCD - t he Scott Soil and Water Conservation District.
Water basin - an enclo sed natural depressio n wit h definable banks capable of containing water
t hat may be partly filled wit h public waters.
Waterbody - all wat er basins, watercourses and wetlands as defined in these Rules.
Watercourse - any nat ural or improved stream, river, creek, ditch (including Scott County Ditch
13), channel, culvert, drain, gully, swale or wash in which waters flow continuously or
int er mittent ly in a definite dir ect ion.Watercourse - any natural or improved stream, river, creek,
ditch (including Scott County Ditch 13), channel or other waterway.
Water Resou rces Management Plan - the watershed management plan for the District adopted
and implemented in accordance wit h Minnesota Statutes, section 103B.231.
Watershed - a region draining to a specific watercourse or water basin.
Wetland - land transit ional between terrestrial and aquatic syst ems as defined in Minnesota
Statutes, section 103G.005, subdivisio n 19.Wetland - any wetland as defined in Minnesota
Statutes, section 103G.005, subdivision 19; and any public waters wetland as defined in
Minnesota Statutes, section 103G.005, subdivision 15a.
Wetland Conservation Act or WCA - the Minnesota Wetland Conservation Act of 1991.
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RULE B - PROCEDURAL REQUIREMENTS
1. APPLICATION REQUIRED. Any person, or political subdivision, undertaking an activity for
which a permit is required by these Rules shall first submit to the District for review a permit
application, design data, plans, specifications and such other information and exhibits as may
be required by these Rules. Permit applications shall be signed by the owner, or the owner’s
authorized agent, except for activities of a political subdivision which may be signed by either
the owner or the general contractor.
2. FORMS. Permit applications shall be submitted on forms provided by the District. Forms are
available at the District office or District website at plslwd.org.
3. ACTION BY MANAGERS. The managers shall approve or deny within 60 days after receipt
of an application containing all required information, exhibits and fees, and complete under
Minnesota Statues, Section 15.99. Failure of the managers to deny an application within 60
days is approval of the application. If the mangers deny an application, they must state in
writing the reasons for the denial at the time they deny the application. If the District receives
an application not containing all required information, exhibits and fees, the 60 day limit starts
over if the District sends notice within 10 business days after receipt of the application telling
the applicant what information is missing. If a state or federal law or court order requires a
process to occur before the managers act on an application, or if an application requires prior
approval of a state or federal agency, the deadline for the managers to approve or deny is
extended to 60 days after completion of the required process or the required prior approval is
granted. The managers may extend the initial 60-day period by providing written notice of the
extension to the applicant. The notice shall state the reasons and anticipated length of the
extension, and may not exceed 60 days unless approved by the applicant. To the extent
inconsistent with these Rules, the provisions of Minnesota Statutes, Section 15.99, shall apply.
4. CONFORMITY WITH SUBDIVISION PLAN. The managers will consider permit
applications for subdivisions before preliminary approval is received from the municipality or
county. The District shall furnish a copy of the approved permit to the municipality or county.
The preliminary and final subdivision approval obtained from the municipality and county
shall be consistent with the conditions of the permit approved by the District. The applicant
shall furnish to the District copies of the resolutions granting preliminary and final subdivision
approval within 30 days after adoption by the municipality or county.
5. SUBMITTAL. A complete permit application with all required information and exhibits shall
be filed with the District at least 14 21 calendar days prior to the scheduled meeting date of the
managers. Late or incomplete submittals will be scheduled to a subsequent meeting date.
6. NOTIFICATION. The District shall mail notice of the permit application to the owners of land
within 500 feet of the described activity, and to the municipality or county with jurisdiction
over the activity, at least 7 days prior to the scheduled meeting date of the managers at which
the application will be considered. The names and addresses of the owners to be notified shall
be obtained by the applicant from a licensed abstractor and furnished to the District with the
permit application. The permit application will not be processed until the list of owners has
been submitted. Neither the failure to give mailed notice to any owner nor any defect in the
notice shall invalidate an action by the managers on a permit application.
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7. CONDITIONS. A permit may be approved subject to reasonable conditions to assure
compliance with these Rules. The conditions may include a requirement that the permittee and
owner, including any mortgagee, enter into an agreement with and in form acceptable to the
District to (a) specify responsibility for the construction and future maintenance of approved
structures, (b) document other continuing obligations of the permittee or owner, (c) grant
reasonable access to the proper authorities for inspection, monitoring and enforcement
purposes, (d) affirm that the District or other political subdivisions can require or perform
necessary repairs or reconstruction of such structures, (e) require indemnification of the District
for claims arising from issuance of the permit or construction and use of the approved
structures, and (f) reimburse the reasonable costs incurred to enforce the agreement. Permits
and agreements may be filed for record to provide notice of the conditions and continuing
obligations.
8. ISSUANCE OF PERMITS. The managers will issue a permit only after the applicant has
satisfied all requirements of these Rules, paid all required fees, and submitted to the District
any required security. Work must be performed under an active permit. If a permit approval
requires conditions to be met before the permit will issue, those conditions must be met
within one hundred twenty (120) days of approval or the Board approval expires and the
applicant must reapply for a permit application with all associated fees. When the District
issues a permit where plans are required, the District shall endorse in writing or stamp the plans
and specifications as “approved.” All activity under the permit shall be done in accordance
with the approved plans and specifications, one set of which shall be kept on the site of the
activity at all times while the authorized work is in progress.
9. VALIDITY. Issuance of a permit based on plans, specifications or other data shall not prevent
the District from thereafter requiring the correction of errors in the approved plans,
specifications and data, or from preventing any activity being carried on thereunder in violation
of these Rules.
10. EXPIRATION. A permit shall expire and become null and void if the approved activity is not
commenced within 180 days after approval by the managers, or if the approved activity is
suspended or abandoned at any time after the activity is commenced for a period of 180 days.
Before the activity can recommenced, the permit must be renewed. An application for renewal
of a permit must be in writing, and state the reasons for the renewal. Any plan changes and
required fees must be included with the application. There must be no unpaid fees or other
outstanding violations of the permit being renewed. The managers shall consider the
application for renewal on the basis of the Rules in effect on the date the application is
considered.
Any permittee may apply for an extension of time to commence the approved activity under an
unexpired permit when the permittee is unable to commence the activity within the time
required by these Rules. An application for an extension of a permit must be in writing, and
state the reasons for the extension. Any plan changes and required fees must be included with
the application. There must be no unpaid fees or other outstanding violations of the permit
being extended. The application must be received by the District at least 30 days prior to the
permit’s expiration. The managers shall consider the application for an extension on the basis
of the Rules in effect on the date the application is considered. The managers may extend the
time for commencing the approved activity for a period not exceeding 180 days upon finding
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that circumstances beyond the control of the permittee have prevented action from being taken.
No permit may be extended more than once.
11. MODIFICATIONS. The permittee shall not modify the approved activity or plans and
specifications on file with the District without the prior approval of the managers.
12. INSPECTION AND MONITORING. After issuance of a permit, the District may perform
such field inspections and monitoring of the approved activity as the District deems necessary
to determine compliance with the conditions of the permit and these Rules. Any portion of the
activity not in compliance shall be promptly corrected no later than 14 days after written notice
of probable violation, sooner if identified in the notice. In applying for a permit, the applicant
consents to entry upon the land for field inspections and monitoring, or for performing any
work necessary to bring the activity into compliance. The cost of the District for field
inspections and monitoring, including services of consultants, shall be payable by the permittee
as provided in Paragraph 4 of Rule K.
13. SUSPENSION OR REVOCATION. The District may suspend or revoke a permit issued under
these Rules wherever the permit is issued in error or on the basis of incorrect information
supplied, or in violation of any provision of these Rules, or if the preliminary and final
subdivision approval received from the municipality or county is not consistent with the
conditions of the permit.
14. CERTIFICATION OF COMPLETION. The District will certify completion of an activity for
which a permit has been issued under these Rules and authorize the release of any required
security upon inspection and submittal of information verifying completion of the activity in
accordance with the approved plans and conditions of the permit. Copies of documents, with
evidence of recording where appropriate, that establish easements or provide for maintenance
of structures required by the permit shall be filed with the District before completion can be
certified and any security released. All temporary erosion and sediment controls practices (such
as silt fence) must be removed following approval of the certificate of completion and before
security release. No activity may be certified as complete if there are any unpaid fees or other
outstanding permit violations. If the District fails to make a determination as to compliance of
an activity with the conditions of the permit within 60 days after submittal of the foregoing
information verifying completion, the activity shall be deemed complete and any surety shall
thereupon be released.
15. PERMIT TRANSFERS. Transfer of a permit without a plan change may be administratively
approved upon receipt of a permit application from the transferee with the applicable fees and
any required surety. Transfer of a permit with plan changes shall be processed as a new permit
application under these Rules. No permit may be transferred if there are any unpaid fees or
other outstanding permit violations. Permit transfer does not release the original permittee from
liability under the permit or extend the permit term.
16. OTHER PERMITS. The applicant shall secure all environmental permits and approvals
required by other governmental entities, and promptly provide the District with copies of such
permits and approvals after issuance.
17. ADMINISTRATION OF RULES. The District Administrator shall administer and enforce
these Rules under the direction and control of, and subject to the powers expressly reserved to,
the managers. At any time within 5 days after a decision or determination by the District
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Administrator interpreting or applying these Rules, the applicant, permittee or any other person
or political subdivision with an interest in the decision or determination, may appeal to the
managers. The managers shall, at a regular or special meeting, consider and affirm, reverse or
remand the decision or determination that is on appeal.
18. REGULAR MEETINGS. Regular meetings of the managers are held on the second Tuesday of
each month at 6:007:30 p.m., unless notice of a different date or time is given.
19. SEVERABILITY. If any provision of these Rules is adjudged unconstitutional or invalid by a
court of competent jurisdiction, the remainder of these Rules shall not be affected thereby.
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RULE C - GENERAL STANDARDS
1. POLICY. It is the policy of the managers to protect the water resources of the District by
requiring that all activities within the District comply with minimum standards for the
protection of water quality and the environment.
2. REGULATION.
(a) All land disturbing activities, whether requiring a permit under these Rules or otherwise,
shall be undertaken in conformance with best management practices and in compliance
with the standards and criteria in these Rules.
(b) No person shall conduct land disturbing activities without protecting adjacent property and
waterbodies from erosion, sedimentation, flooding or other damage.
(c) Land disturbing activities shall be planned and conducted to minimize the extent of
disturbed area, runoff velocities and erosion potential, and to reduce and delay runoff
volumes. Erosion and runoff controls, consistent with best management practices, shall be
properly installed before commencing land disturbing activities, and sufficient to retain
sediment on-site. Erosion and runoff controls shall be regularly inspected and maintained.
Disturbed area within 100 feet of a waterbody, storm sewer inlet or road shall be stabilized
if work within the area ceases or will be suspended for more than 7 days on slopes greater
than 3:1, or 14 days on slopes ranging from 3:1 to 10:1, or 21 days for flatter slopes.
Vegetation shall be installed over the disturbed areas promptly if the land disturbing
activity ceases or is suspended, and upon completion.
(d) When possible, existing natural watercourses and vegetated soil surfaces shall be used to
convey, store, filter and retain runoff before discharge into public waters or a stormwater
conveyance system.
(e) When possible, runoff from roof gutter systems shall discharge onto lawns or other
pervious surfaces to promote infiltration.
(f) Use of fertilizer and pesticides in the shoreland protection zone shall be done so as to
minimize runoff into public waters by the use of earth material, vegetation, or both.
(g) When development density, topographic features, and soil and vegetation conditions are
not sufficient to adequately handle runoff using natural features and vegetation, various
types of constructed facilities such as diversions, settling basins, skimming devices, dikes,
waterways and ponds may be used. Preference shall be given to designs using surface
drainage, vegetation and infiltration rather than buried pipes and man-made materials and
facilities.
(h) Whenever the District determines that any land disturbing activity has become a hazard to
any person, or endangers the property of another, adversely affects water quality or any
waterbody, increases flooding, or otherwise violates these Rules, the owner of the land
upon which the land disturbing activity is located, or other person or agent in control of
such land, upon receipt of written notice from the District, shall within the time period
specified therein repair or eliminate such condition. The owner of the land upon which a
land disturbing activity is located shall be responsible for the cleanup and any damages
from sediment that has eroded from such land. The District may require the owner to obtain
a permit under these Rules before undertaking any repairs or restoration.
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RULE D - STORMWATER MANAGEMENT
1. POLICY. It is the policy o f the managers to:
(a) Preserve natural infiltration, groundwater recharge and subsurface flows that support
groundwater dependent resources including lakes, streams, channels, wetlands, plant
communities and drinking water supplies.
(b) Preserve existing water storage capacity within wetlands and landlocked basins in the
watershed to minimize the frequency and severity of high water.
(c) Minimize the amount of directly connected impervious surface created by the
development and redevelopment, preserve the infiltration capacity of the soil, and
incorporate infiltration practices into the design where feasible.
(d) Limit off-site stormwater runoff volume to prevent down-gradient flooding and impacts
to waters within the District.
(e) Require management of stormwater runoff to limit nutrient and sediment concentrations
conveyed to ground and surface waters and promote water quality.
(c) Require t hat peak runoff rates for new development not exceed exist ing pre-development
condit ions and t he capacit y o f downstream conve yance facilit ies or contribute to flooding.
(f)
(a) Manage subwatershed discharge rates and flood storage volumes to be consistent with the
goals of the water resources management plan.
(g) Cont rol runo ff rat es by the use of regio nal or on-site detention or infiltration facilit ies
where feasible.
(d) .
(e) Review st ormwat er management structures based on the 100 -year cr it ical storm
eventcritical duration flood event for the drainage area.
(h)
(f) Rout e runoff to wat er treatment ponds or other acceptable facilit ies before discharging
int o waterbodies.
(g) Promote t he use of natural waterbodies for storing treated stormwater runoff and
improving water qualit y and other amenit ies.
(h) Promote nat ural infiltration of runo ff.
(i) Minimize the amount of directly connected impervious surface created by t he
development , preserve the infiltrat ion capacit y o f t he soil, and incorporate infiltrat ion
practices int o t he design where feasible.
2. REGULATION. An approved stormwater management permit is required before land
disturbing activity or the development or redevelopment of land that meets any of the
following criteria, unless specifically exempted by Paragraph 8. The District encourages
applicants to consult the District at the concept stage.
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(a) New development or redevelopment that creates more than 3,500 square feet of new or
reconstructed impervious surface and includes more than 10,000 square feet of land
disturbing activity.
(b) A public linear project that creates more than 10,000 square feet of new or reconstructed
impervious surface.
(c) New development or redevelopment of a parcel riparian to public water requiring a
variance from the impervious surface limit for the property.
(a) No person or polit ical subdivisio n shall commence a land disturbing activit y or the
development or redevelopment of land, unless specifically exempted by Paragraph 9
below, wit hout first obtaining a per mit fro m the District that incorporates and approves a
st ormwat er management plan for the act ivit y, development or redevelopment.
(b) Where the District has Memorandum of Agreements with municipalities for Local Water
Planning and Regulation, the municipalities will comply with MS4 Permit requirements
for Post-Construction Stormwater Management.
3. CRITERIA. Stormwater management plans shall comply wit h the fo llowing criteria:
(a) A hydrograph met hod based on sound hydrologic theor y will be used to analyze runo ff
for the design or analysis of flows and water levels.
(b)(a) Peak Runo ff Rrates. Peak runoff rates for the proposed activit ydeveloped condition
shall not exceed exist ing pre-development peak runo ff rates at each point of site
discharges for the 2 - year, 10-year and 100-year cr it ical duration flood eventstorm events.,
Rand runo ff rat es may at a particular point of discharge may increase if there is adequate
conveyance capacity and this increase is offset by a decrease at another point of discharge to
the same waterbody. Runoff rates may also be required to be restricted to less than the
exist ing pre-development rates when necessar y for the public healt h and general welfa re
of the Dist r ict due to the capacity of downgradient stormwater conveyance structures and
features. Runoff rates shall be calculated in accordance with Paragraph 3(g).
(c)(b) Stormwater Volume. Volume must be managed as follows:Where a project creates
one or more acres of new impervious surface, the stormwater runoff volume shall be
retained on site in the amount equivalent to 1.0 inches of runoff over the new impervious
surface. For a project that creates less than one acre of new impervious, the stormwater
runoff volume shall be retained on site in the amount equivalent to 0.5 inches of runoff
over the new impervious.
(i) New Development: The volume equal to 1.0 inches of runoff from impervious
surfaces must be captured and treatedDevelopment that creates impervious surfaces
must explicit ly address the use of best management practices to limit the loss of
pervious area, and meet the volume reduction standards to the extent feasible
considering site-specific condit ions. This volume is calculated as follows:
Required Treatment Volume (ft3) = Entire Site Impervious Surface (ft2)
x 1.0 (in) ÷ Volume Conversion Factor ÷12 (in/ft)
(i)
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1) Volume reduction techniques considered shall include infiltration, reuse and
rainwater harvesting, canopy interception and evapotranspiration, and/or
additional techniques included in the Minnesota Stormwater Manual, as
amended. High priority shall be given to BMPs that include volume reduction.
Secondary preference is to employ filtration techniques, followed by water
quality ponding BMPs.
2) The District may approve alternative BMPs instead of infiltration, provided
that the proposed BMPs meet the requirements of the NPDES General
Construction Permit, as amended.
(ii) Redevelopment: The volume equal to 1.0 inches of runoff from new and
reconstructed impervious surface must be captured and treated. This volume is
calculated as followsBMPs shall be designed and installed in accordance with
generally accepted design practices and guidance contained in the Minnesota
Pollution Control Agency’s Minnesota Stormwater Manual, as amended:.
1. If the project will disturb more than 50 percent of the site or reconstruct more
than 50 percent of existing impervious surface:
Required Treatment Volume (ft3) = Entire Site Impervious Surface (ft2)
x 1.0 (in) ÷ Volume Conversion Factor ÷12 (in/ft)
2. If the project will disturb 50 percent or less of the site and reconstruct 50
percent or less of the existing impervious surface:
Required Treatment Volume (ft3) = Area of New and Reconstructed
Impervious Surface (ft2) x 1.0 (in) ÷ Volume Conversion Factor ÷12
(in/ft)
(iii) Public Linear: The volume equal to either 0.5 inches of runoff from all new and
reconstructed impervious surfaces, or 1.0 inches of runoff from the net increase in
impervious area, whichever greater, must be captured and treated. This volume is
calculated as follows:
Required Treatment Volume (ft3) = Area of New and Reconstructed
Impervious Surface (ft2) x 0.5 (in) ÷ Volume Conversion Factor ÷12
(in/ft), or
(ii) Required Treatment Volume (ft3) = Net increase in Impervious
Surface (ft2) x 1.0 (in) ÷ Volume Conversion Factor ÷12 (in/ft)
(c) Infiltration Feasibility. The volume control criteria must be met, to the extent feasible, by
one or more volume reduction practices including infiltration, rainwater reuse and
harvesting, canopy interception and evapotranspiration, and other practices included in
the MIDS calculator and the Minnesota Stormwater Manual. In assessing feasibility, the
applicant must consider site design that allows the siting of effective volume reduction
practices. If volume reduction is claimed infeasible, the applicant must document the
basis for infeasibility.
(d) Alternative Compliance for Volume Control. If the stormwater volume control criteria is
not fully met by a volume reduction practice, alternative management practices must be
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considered onsite to comply or partially comply with the criteria. The volume conversion
factors for alternative management practices are as follows:
Table D.3.1 Volume Conversion Factors for Properly Designed Practices
BMP BMP Design Variation Volume Conversion
Factor*
Infiltration ** Infiltration Feature 1.00
Water Reuse ** Irrigation 1.00
Enhanced Filtration Iron or other additive 0.70
Biofiltration Underdrain 0.65
Stormwater Wetlands Pond/Wetland 0.55
Stormwater Ponds *** Multiple Pond 0.60
Wet Pond 0.50
Source: Adapted from Table 7.4 from the Minnesota Stormwater Manual, MPCA.
* Refer to MPCA Stormwater Manual for additional information on practice
performance. Volume conversion factors shown reflect comparative average annual
total phosphorus percentage removal efficiencies to compare water quality treatment
among various practices.
** These BMPs reduce runoff volume.
*** Stormwater ponds must also provide 2.5” of dead storage.
For alternative management practices not found in Table D.3.1, or to deviate from a
volume conversion factor found in Table D.3.1, the applicant may submit a volume
conversion factor, expressed as annual percentage removal efficiency, with supporting
technical data, for District approval.
(e) Water Quality. The following additional water quality standards apply:
(i) For New Development only, one or more stormwater management practices listed
in Table D.3.1 shall be sized (without the conversion factor) to treat the volume of
stormwater runoff that the developed site will generate for the 2-year, 24-hour
precipitation event. Alternatively, water quality modeling may be provided
demonstrating that the proposed stormwater management practices result in a
reduction of at least 60% of total Phosphorus and 90% of total suspended solids.
Note the volume managed under 3(b)(i) counts towards this standard.
(ii) For any impervious surface subject to regulation under Paragraph 3(b), total
suspended solids in runoff that is not captured by a practice under Paragraph 3(d)
must be reduced to the maximum extent practicable. Compliance with this criteria
may be achieved, for example, by incorporation of practices such as a SAFL
Baffle®, sump manholes, or filter strips and vegetated swale along rural section
roadways.
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(f) Wetland Bounce and Inundation Period. A project must remain within the limits stated
below for bounce in water level and duration of inundation, for a 24-hour precipitation
event for each specified return period and for the downgradient wetland. The analysis
must use NOAA Atlas 14 precipitation depths.
Wetland
Susceptibility
Class
Permitted Bounce
for 2-Year and 10-
Year Events
Inundation Period
for 2-Year event
Inundation Period
for 10- & 100-Year
Events
Highly Pre-development Existing Existing
Moderately Pre-development +
0.5 feet Existing plus 1 day Existing plus 2 days
Slightly Pre-development +
1.0 feet Existing plus 2 days Existing plus 14
days
Least No limit Existing plus 7 days Existing plus 21
days
Source: State of Minnesota Stormwater Advisory Group, “Stormwater and Wetlands Planning and
Evaluation Guidelines for Addressing Potential Impacts of Urban Stormwater and Snowmelt
Runoff on Wetlands” (June 1997).
(g) Calculating Off-Site Stormwater Flow. This paragraph governs calculation of site
discharge under Paragraphs 3(a), 3(e) and 3(f). To calculate discharge, Soil Conservation
Service TR-20 method shall be used. For New Development, the following curve
numbers will be used for the pre-development condition:
Hydrologic Soil Group Curve Number
A 30
B 55
C 71
D 77
For Redevelopment and Public Linear projects, curve numbers from NRCS Technical
Release #55 (TR-55) representative of existing conditions, including impervious surfaces,
may be used for the pre-development condition.
For all projects, a distributed curve number approach must be used to calculate flows; i.e.,
runoff from directly connected impervious surfaces must be modeled separately from
pervious areas. For solar farm projects, the solar panel surface area may be composited
with pervious areas.
To determine curve numbers for the post-development condition, the Hydrologic Soil
Group (HSG) of areas within the construction limits must be lowered one classification
for HSG B (to HSG C) and one-half classification for HSG A (to midway between HSG
A and HSG B) to account for the impacts of grading on soil structure, unless the project
specifications incorporate soil amendment or other method approved by the District to
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restore soil structure. This requirement only applies to that part of a site that has not been
disturbed, tilled or compacted prior to the proposed project.
(h) Wetland and Landlocked Basin Storage. Fill within wetland and landlocked basin
floodplain is prohibited unless compensatory floodplain storage volume is provided
within the floodplain of the same water body, and within the permit term. If offsetting
storage volume will be provided off-site, it shall be created before any floodplain filling
by the applicant will be allowed. This criteria does not apply to the floodplain of Prior
Lake.
(d)(i) Infiltration Feature Design Considerations.features shall include the followingDesign
of infiltration features shall: design considerations:
(i) Include a minimum of one soil boring at the location of any proposed infiltration
facility is required. Multiple borings may be needed dependent on the size of the
infiltration practice and the variability of the geologic materials on the site. Soil
borings shall include detailed information on depth to water table, if applicable, and
extend at least 5 feet below the bottom of the proposed infiltration facility. Grain
size analysis, either alone or in conjunction with a hydrometer analysis shall be
used to verify the ASTM classification of the soil material controlling the rate of
infiltration (the least permeable within 5 feet of the bottom of the proposed practice)
at each proposed practice. The following table summarizes the soil lab analysis
required for borings related to infiltration practices.
Lab Test Description When Required
Grain Size
Analysis
Provides a distribution of particle
size greater than 75μm (sand size
which correlates to the No. 200
sieve)
Always
Hydrometer
Analysis
Provides a distribution of particle
size less than 75μm (silt and clay
sized particles)
Sample has greater than
10% fines as identified in
the field or by lab test AND
all soils classified as silty
sand or SM.
(ii) Select soil infiltration rates based on the appropriate HSG classification and
associated infiltration rates of Appendix D.1. Notwithstanding, permeameter
testing, via a method approved in advance by the District, may be used to determine
the design infiltration rate.
(i)(iii) The infiltration area shall bBe capable of infiltrating the required volume within
48 hours for surface and subsurface BMPs.
(ii) Infilt rat ion areas will be limited to the horizontal areas subject to prolonged wetting.
(iii) Areas of permanent pools tend to lose infiltration capacity over time and will not be
accepted as an infiltration practice.
(iv) Include Stormwater runoff must be pretreatedment of stormwater runoff to remove
solids before dischargeing to infiltration areas to maintain the long term viability of
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the infiltration areas. A pretreatment device such as a vegetated filter strip, small
sedimentation basin, or water quality inlet (e.g., grit chamber) must be included in
the design and sized according to MPCA Stormwater Manual guidance.
(e) Regional det ent ion basins shall be utilized to manage peak flow rates and runo ff vo lumes,
and meet wat er qualit y object ives when feasible. On-site detention basins, infiltrat ion
facilit ies, and permanent sedimentation and water qualit y ponds will be utilized for land
dist urbing act ivit ies exceeding one acre when regional basins are not in place or feasible.
A waiver may be granted for special circumstances descr ibed in Paragraphs 4(a) and 4(b)
below.
(f) The applicant will provide water quality BMPs sized to infiltrate and/or retain the runoff
volume generated on the site by the 2 year, 24-hour event under the developed condition
for all points where discharges leave a site. For that portion of the 2 year, 24-hour event
runoff volume that is not required to be infiltrated under paragraph (c), water quality
BMPs or additional infiltration will be incorporated. The order of preference for water
quality BMPs is biofiltration, filtration, wetland treatment system, extended detention,
and wet detention in accordance with NURP standards.
(g) Anal ys is of flood levels, storage volumes and flow rates for waterbodies and detention
basins shall be based on the range of rainfall and snow melt durations producing the
crit ical flood levels and discharges.
(h)(j) Landlocked Basin Outlets. Landlocked water basins may be provided wit h outlets
t hat :
(i) Retain a hydrologic regime co mplying with Rules F and G;
(ii) Provide sufficient dead storage to retain back-to-back 100-year, 24-hour rainfalls
and runoff above the highest ant icipated groundwater elevation and prevent damage
to propert y adjacent to the basin; and
(iii) Do not create adverse downstream flooding or water qualit y condit io ns, or
materially affect stabilit y o f downstream water courses.
(i) Retention Pond Design Criteria. Detention basins shall be des igned to provide:
(i) An out let st ructure to control the 2-year, 10-year and 100-year crit ical storm events
to predevelopment runoff rates;
(ii) An identified over flow spillway sufficient ly stabilized to convey a 100 -year crit ical
storm event ;
(iii) A normal wat er elevation above the OHW of adjacent waterbodies; and
(iv) Access for fut ure maintenance.
(j)(k) Per manent sedimentation and water qualit y ponds shall be designed to the Wet
Pond Design Standards set forth on Appendix A to these Rules and provide:
(i) Water qualit y featuresBe cons istent with NURP criteria and best management
pract ices;
(ii) HaveA permanent wet pool with dead storage of at least the runoff fro m a 2.5 -inch
storm event ;
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(iii) A Have a no rmal water elevation above the OHW of adjacent waterbodies;
(iv) An Have an outlet skimmer to prevent migrat ion of floatables and o ils for at least
the one year storm event; and
(iv)(v) Have an identified overflow spillway sufficient ly stabilized to convey a 100 -year
crit ical storm event.and
(v) Access for future maintenance.
(l) Flood Elevation Freeboard. All new residential, commercial, industrial and other
habitable or non-habitable structures, and all stormwater basins, must be constructed so
that the lowest floor and lowest entry elevations of structures comply with the following:
Regional
Elevations*
Local Detention
Basins & Wetlands Infiltration Basins Rain
gardens
Elevation 100-yr EOF 100-yr EOF Bottom 100-yr EOF EOF
Low Floor
Freeboard 2-ft 1-ft 0-ft NA 0-ft NA NA NA
Low Entry
Freeboard NA NA 2-ft 1-ft NA 2-ft 1-ft 0.5-ft
Within a landlocked basin, lowest floor elevations must be at least one foot above the
surveyed basin overflow elevation. Where a structure is proposed below the runout
elevation of a land-locked basin, the low-floor elevation will be a minimum of three feet
above the high water level as determined from an estimate of high water levels
determined from the highest of either the 100-year, ten-day runoff event or back-to-back
100-year, 24-hour rainfalls. Aerial photos, vegetation, soils, and topography will be used
to derive a "normal" water elevation for the basin for the purpose of computing the 100-
year elevation.
* Regional elevations are as established by FEMA or District SWMM model results in
absence of a FEMA FIS elevation.
(m) Off-Site Stormwater Management. One or more of the applicable criteria of Paragraph 3
may be met by use of an off-site stormwater management practice upgradient of
downstream receiving waters, provided there are no local rate, volume, water elevation or
water quality impacts. An applicant must document permission to use capacity of the
practice and that it is in maintained condition, and the practice must be subject to a
maintenance obligation under Paragraph 5. The practice must provide volume reduction
to the same extent as would be feasible on the site.
(n) Local Stormwater Management Plan. A unit of government may prepare a plan by which
regional stormwater management facilities may be constructed in anticipation of, or
concurrent with, land disturbing activity within the jurisdiction of that unit of
government. On finding that the criteria of this Rule D are met, the District will approve
or approve with conditions. Thereafter, the plan will apply to subsequent applications for
permits according to its terms.
(o) Volume Control Credits. Volume control provided in excess of the volume control
criteria may be banked for use on another project. Excess banked volume control
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amounts shall not exceed the volume of two inches over the impervious surfaces of the
drainage area to the BMP or the volume provided within the BMP, whichever is less.
To the extent an applicant has not met the volume control criteria by application of
paragraphs 3(b), 3(c), 3(d), 3(n) and 3(m) the applicant may utilize District approved
volume credits. If approved volume credits are not available, and if the applicant is a
Public Road Authority, the District will establish debits that the applicant must meet by
implementing future volume control measures, as approved by the District. Measures
must be located within the same drainage area or subwatershed and cannot serve to meet
an independent District-imposed regulatory requirement. The application must describe
how debits will be met within a reasonable time specified by the District and the
applicant must report to the District annually on the status of outstanding debits. The
obligation will be formalized in a writing signed by the applicant. Regardless, total
suspended solids in runoff from regulated impervious surface must be reduced onsite to
the maximum extent practicable.
Transfer of banked volume credits between applicants is allowed. Applicants shall submit
a letter to the District outlining the conditions of the transfer and confirming the volume
of the transfer. The District must review and approve all credit transfers.
(p) Linear Project Cost Cap. For linear projects, costs specific to satisfying the volume
control criteria shall not exceed a cost cap which will be set by the Board annually. The
cap shall apply to costs directly associated with the design, testing, land acquisition, and
construction of the volume reduction BMPs only. Unit costs for project components shall
be developed by the applicant and approved by the District Engineer to determine the
cost of the volume reduction BMPs. The District may contribute the amount above the
cap in order to meet the volume reduction criteria or it may allow the applicant to
partially comply with the standards when the cap is met.
(q) Stormwater Impact Fund. If it is demonstrated that volume control is not feasible onsite
and credits are not available, the applicant shall pay into the District’s Stormwater Impact
Fund to cover the cost of implementing equivalent volume reduction elsewhere in the
watershed. The required amount to contribute to the Stormwater Impact Fund will be set
by the Board annually.
(i) Funds contributed from a local government unit shall be spent within that local
government unit’s jurisdiction to the extent possible.
(ii) Funds shall be allocated to volume reduction projects by the District according to the
Stormwater Impact Fund Implementation Plan as approved by the District Board.
(r) Obligation to Ensure Performance. To find that the criteria of this rule have been met, the
District shall require as-built drawings for all stormwater management practices within
35 days of substantial completion of construction. The District may also impose
additional requirements as a specific condition of approval. The District may require
monitoring or performance evaluation as a condition of approving a stormwater
management practice that has not been adequately demonstrated in the proposed
application.
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(k) Unless a municipalit y or the count y has adopted an ordinance prescr ibing a minimum low
floor elevation, which ordinance shall govern, any new resident ial, co mmercial, industrial and
ot her habitable struct ures shall be constructed with the fo llowing low floor elevat ion:
(l) In t he case of a land-locked basin, the low floor elevat ion shall be at least 3 feet above the
sur veyed basin over flow or three feet above the high water level of the basin as determined from
an est imate of high water levels using the higher of either the 100-year, 10-day runoff event and
back-to-back 100-year, 24-hour rainfalls under full build-out condit ions. Aerial photographs,
veget ation, soils and topography shall be used to derive a “nor mal” water elevat ion for the basin
to comput e the 100-year elevat ion.
(m) In all other cases, the low floor elevation shall be at least 2 feet above the critical event 100-year
high water elevation and three feet above the overflow elevation of nearby waterbodies and stormwater
basins.
4. WAIVERS.
(a) The managers may waive the on-site runoff rate and water qualit y control design criteria
in Paragraphs 3(a), 3(b), 3(d), 3(e), 3(f), 3(h), and 3(i) above, if a municipalit y has an
approved local water management plan which provides for off-site stormwater facilit ies
capable of cont rolling and treating runo ff.
(b) The design criteria in Paragraphs 3(b), 3(c), 3(d), 3(e), and 3(i) above may be waived for
sit es wit h total new impervious sur face of less than one acre, or for sites with land
dist urbing act ivit ies less than one acre; if volume control, runoff rate control, and water
qualit y BMPs have been incorporated to the maximum extent possible.
5.4.EXHIBITS. The following are to be prepared and certified by a professional engineer
registered in the State of Minnesota, registered land surveyor, or other appropriate
professional, and submitted to the District with the application for stormwater management
permit. All submittals shall be in both electronic format and hard copy. Exhibits for flowage
and drainage easements and covenants shall be submitted as shapefiles.The following
exhibits shall acco mpany the permit application (one set full size, and two sets reduced to a
maximum size of 11" x 17"):
(a) Propert y lines and delineation o f lands under ownership of the applicant.
(b) Delineat ion of the subwatershed contributing runoff fro m off-site, proposed and existing
subwat ersheds on-site, emergency over flo ws and watercourses.
(c) Proposed and exist ing stormwater facilit ies location, alignment and elevation.
(d) Delineat ion of exist ing on-site wetland, marsh, shoreland, drain tiling and floodplain
areas.
(e) For applicat ions proposing infiltration as a stormwater management practice,
ident ificat ion, descr ipt ion, permeabilit y and approximate delineat ion of site so ils in both
exist ing and proposed as-developed condit io n. Soil boring and lab analysis is required in
accordance with Paragraph 3(i).
(f) Exist ing and proposed ordinar y high and 100-year water elevat ions on-site.
(g) Exist ing and proposed site contour elevat ions at 2 foot intervals, referenced to NGVD,
1929 datum.
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(h) Const ruct ion plans and specificat ions of all proposed stormwater management facilit ies,
including design details for outlet controls.
(h)(i) A maintenance schedule for all proposed facilities that will not be maintained by
an MS4.
(i)(j) Runo ff vo lume and rate analysis for the 2-year, 10-year and 100-year crit ical
st orm events, exist ing and proposed.
(j)(k) All hydro logic, water qualit y and hydraulic co mputations made in designing the
proposed stormwater management facilit ies.
(k)(l) Narrat ive addressing incorporation of infiltration BMPs.
(m) Delineat ion of any ponding, flowage or drainage easements, or other prop ert y interests, to
be dedicated for stormwater management purposes.
(l)(n) Documentation as to the status of a National Pollutant Discharge Elimination
System stormwater permit for the project from the Minnesota Pollution Control Agency,
with the Storm Water Pollution Prevention Plan (SWPPP) being provided when it
becomes available.
6.5.MAINTENANCE. The applicant, and all successors in title, is responsible to maintain in
perpetuity all stormwater management facilities used to meet the criteria of Section 3.
Unless the Board specifies otherwise, as a condition of permit issuance, the permittee must
submit a maintenance instrument specifying the methods, schedule and responsible parties
for maintenance for District review and, after District approval, provide for the instrument to
be recorded or registered on the property title. In place of a recorded instrument, a public
permittee may execute with the District a maintenance agreement that achieves the same
purposes as an instrument on the title and provides that such an instrument will be recorded
or registered if the public land is conveyed into private ownership. The District will make
standard maintenance instruments and agreements available for permittee use.All stormwater
management structures and facilit ies shall be maintained in perpetuit y to assure that the
st ruct ures and facilit ies funct ion as originally designed. The responsibilit y for maintenance
shall be assumed either by the municipalit y or count y wit h jurisdict ion over the structures and
facilit ies, or by t he applicant entering into a compliance agreement with the District.
7.6.EASEMENTS. The applicant shall establish in form acceptable to the District temporar y and
perpetual easements for ponding, flowage and drainage purposes over hydro logic features
such as waterbodies and stormwater basins. The easements shall include the right of
reasonable access for inspect ion, monitoring, maintenance and enforcement purposes.
8.7.COVENANTS. The District may requir e that the land be subjected to restrict ive covenants or
a conservat ion easement, in form acceptable to the District, to prevent the future expansio n of
imper vious surface and the loss of infiltrat ion capacit y.
9.8.EXCEPTIONS. No permit or stormwater management plan shall be required under this Rule
for the fo llowing land disturbing activit ies:
(a) Minor land dist urbing activit ies such as home gardens, repairs and maintenance work.
(b) Const ruct ion, inst allation and maintenance of individual sewage t reatment systems.
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(c) Const ruct ion, installation and maintenance of public utilit y lines or individual service
connections unless the activit y disturbs more than one acre, in which event Paragrap h 9(e)
below shall apply.
(d) Linear trails no more than 10 feet wide, bordered downgradient by vegetated soil or filter
strip at least 5 feet wide, is not considered impervious surface under Rule D.
(c)(e) The reconstructed impervious surface of a road that will remain rural -section that
is bordered downgradient by vegetated open space or a vegetated filter strip with a
minimum width of 5 feet with a slope less than 2 percent is exempt from the requirements
of Paragraph 3(b)(iii).
(f) Const ruct ion of any st ructure on an individual parcel in a subdivisio n wit h a stormwater
management plan approved by the Distr ict, so long as any the land disturbing activit y
complies with t he approved plan.
(d)(g) Land zoned as RR-1 Rural Residential Reserve District developed in conformance
with County requirements.
(e) Development or redevelopme nt of, or construction of a structure on, an individual parcel
wit h a land dist urbing act ivit y that does not cause off-site erosion, sedimentation,
flooding or other damage, and disturbs:
(i) Less than 10,000 square feet in the shoreland protection zone; provided that, if a
municipality or county with jurisdiction has adopted an ordinance requiring
stormwater management consistent with this Rule D that also regulates the activity,
such ordinance shall govern the activity. Where the municipality or county with
jurisdiction regulates the activity, the exemption shall increase from 10,000 square
feet to one acre, at which point this Rule shall apply in addition to the municipal or
county regulation for land disturbing activities greater than one acre; or
(ii) Less than one acre outside of the shoreland protection zone.
(f)(h) Inst allat ion of any fence, sign, telephone or electric poles, or other kinds of posts
or poles.
(g) Emergenc y activit y necessar y to protect life or prevent substantial har m to persons or
propert y.
(i) All land disturbing activit ies not required by this Rule to obtain a permit or have an
approved stormwat er management plan shall nevertheless be conducted in full
compliance wit h Rule C.
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APPENDIX D.1
Design Infiltration Rates
Hydrologic
Soil Group Soil Textures* Corresponding Unified Soil Classification**
Infiltration
Rate
[inches/hour]
A
Gravel, Sandy
Gravel, Silty
Gravel
GW - Well-graded gravel or well-graded gravel
with sand
GP – Poorly graded gravel or poorly graded
gravel with sand
GM - Silty gravel or silty gravel with sand
SW - Well-graded sand or well-graded sand
with gravel
1.6
Sand, Loamy
Sand, Sandy
Loam
SP – Poorly graded sand or poorly graded sand
with gravel 0.8
B Loam, Silt
Loam
SM - Silty sand or silty sand with gravel See table below
for SM soils
MH – Elastic silt or elastic silt with sand or
gravel 0.3
C Sandy Clay
Loam
ML – Silts, very fine sands, silty or clayey fine
sands 0.2
D
Clay Loam
Silty Clay
Loam
Sandy Clay
Silty Clay
Clay
GC – Clayey gravel or clayey gravel with sand
SC – Clayey sand or clayey sand with gravel
CL – Lean clay or lean clay with sand or gravel
or gravelly lean clay
OL – Organic silt or organic silt with sand or
gravel or gravelly organic silt
CH – Fat clay or fat clay with sand or gravel or
gravelly fat clay
OH – Organic clay or organic clay with sand or
gravel or gravelly organic clay
0.06
Source: Adapted from the Minnesota Stormwater Manual, MPCA, (January 2014).
*U.S. Department of Agriculture, NRCS, 2005. National Soil Survey Handbook, title 430-VI.
**ASTM Standard D2487-00 Standard Practice for Classification of Soils for Engineering Purposes.
Hydrometer Analysis and Design Infiltration Rates for SM soils
% Fines Fines Identified as Silt
or Clay ASTM Classification Design Infiltration Rate
[in/hr]2
5 -12 Silt SP-SM 0.7
12 - 25 Silt SM 0.6
>25 Silt with <5% Clay SM 0.3
5-12 Clay SP-SC 0.2
>12 Clay SC 0.06
>12 Silty Clay1 SC-SM 0.06
1 Per ASTM Classification
2 If more than 50% of the sample passes the No. 200 sieve (sand sized), then the sample will be classified as fine
grained and a design infiltration rate of <0.2 in/hr shall be used.
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(h)
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RULE E - EROSION AND SEDIMENT CONTROL
1. POLICY. It is the policy o f the managers to require the preparation and implementation of
erosion and sediment control plans to control runo ff and erosion and to retain or control
sediment on land during land disturbing activit ies.
2. REGULATION. No person or polit ical subdivision shall commence a land disturbing activit y
of more than 10,000 square feetor the development or redevelopment of land, unless specifically
exempted by Paragraph 7 10 below, without first obtaining a permit fro m the District that
incorporates and approves an erosion and sediment control plan for the activit y, development
or redevelopment.
3. CRITERIA. Erosion and sediment control plans shall co mply wit h the following criteria:
(a) The plan must be prepared by a qualified individual showing proposed methods of
retaining waterborne sediments on site during the period of construction and showing
how the site will be restored, covered, or revegetated after construction, including a
timetable for completion.
(a)(b) Natural sit e topo graphy and so il condit io ns shall be used to control runo ff and
reduce erosion and sedimentation during construction and after completion o f the land
dist urbing act ivit y.
(b)(c) Erosion and sediment control measures shall be consistent with the standards of the
General Permit Authorization to Discharge Stormwater Associated With Construction
Activity Under the National Pollutant Discharge Elimination System/State Disposal System
Permit Program, Permit MN R100001 (NPDES General Construction Permit), issued by the
Minnesota Pollution Control Agency, except where more specific requirements apply,
including:
(i) Phasing to minimize disturbed areas subject to erosion at any one time.
(ii) Implementation of BMPs to minimize the discharge of sediment and other
pollutants. Redundant BMPs are required adjacent to all waterbodies, spaced a
minimum of 5 feet apart except where conditions are limiting.
(iii) All turbid or sediment-laden waters related to dewatering must be discharged to a
temporary sediment basin on the project site unless infeasible. Permittees must
provide appropriate Best Management Practices (BMPs) to water discharged to a
surface water such that the discharge does not adversely affect the receiving water
or downstream properties. Permittees must continuously monitor discharge to any
surface water to ensure adequate treatment has been achieved. Discharge points
must be adequately protected from erosion and scour through accepted energy
dissipation methods.
(iv) Use of temporary sediment basins are required where 10 or more acres of disturbed
soil drain to a common location, or where 5 or more acres of disturbed soil are
located within one mile of and discharge to a special or impaired water. Basin
design and construction must comply with NPDES General Permit requirements.
(ii)
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(iii) Treatment of dewatering discharge to limit total suspended solids. Dewatering
activities shall be discharged in a manner that does not cause nuisance conditions.
(iv)(v) Proper storage and disposal of all construction site projects, materials or wastes.
(v)(vi) Site inspections and records of rainfall events.
(vi)(vii) Proper maintenance of all BMPs.
(vii)(viii) Management of solid and hazardous wastes on each project site.
(viii)(ix) Final stabilization upon completion of the construction activity.
(x) Provisions for the use of temporary sediment basins to control runoff and provide
treatment during construction, when applicable.
(xi) Identification of wetland types and locations as identified in wetland delineation, as
applicable.
(ix)(xii) Include contact information for the District’s permit staff.
(d) The plan will specify measures for indefinite stabilization of exposed soil and stockpiled
earth and erodible materials in the event that site work is suspended. These measures will
be implemented within 7 days of a request by the District, unless, on the basis of
permittee’s written response and official inspection, the District finds that the site is
active and actively managed under the erosion and sediment control plan. The District
may set a later deadline for implementation if site conditions warrant.
(e) Requirement of site stabilization no later than November 15th of any given calendar year
for exposed soil areas where construction activities have ceased and are not expected to
continue until after frozen ground conditions.
(f) All erosion and sediment controls shall be installed before commencing the land
dist urbing act ivit y, and shall not be removed without District approval or until the District
has issued a certificate of complet ion pursuant to Paragraph 14 of Rule B.
(c)(g) Use of erosion control blanket shall be limited to ‘bio-netting’ or ‘natural netting’
types, and specifically not products containing plastic mesh netting or other plastic
components.
4. EXHIBITS. The following are to be prepared and certified by a professional engineer
registered in the State of Minnesota, registered land surveyor, or other appropriate
professional, and submitted to the District with the application for stormwater management
permit. All submittals shall be in both electronic format. and hard copy.The following
exhibits shall acco mpany the permit applicat ion (one set full size, and two sets reduced to a
maximum size of 11" x 17"):
(a) An exist ing and proposed topographic map showing contours on and adjacent to the land,
propert y lines, all hydrologic features, the proposed land disturbing act ivit ies, and the
locat ions of all runo ff, erosion and sediment controls and so il stabilizat ion measures.
(b) P lans and specificat ions for all proposed runoff, erosion and sediment controls,
dewatering methods, and temporary and permanent soil stabilization measures.
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(c) Detailed schedules for impleme ntation of the land disturbing activit y, the erosion and
sediment cont rols, and soil stabilization measures.
(d) Detailed descript ion of the methods to be emplo yed for monitoring, maintaining and
removing the erosion and sediment controls, and soil stabilizat ion measures.
(d)(e) Contact information for the person(s) responsible for erosion and sediment control
inspection and maintenance.
(e)(f) Soil borings if requested by the Distr ict.
(f)(g) For projects over one acre of disturbed area, documentation that the permittee has
applied for the NPDES General Construction Permit from the Minnesota Pollution Control
Agency (MPCA) shall be submitted, in addition to the Stormwater Pollution Prevention
Plan (SWPPP) prepared for the NPDES Permit.
(g)(h) Other project site-specific submittal requirements as may be required by the
District.
5. CONSTRUCTION ACTIVITY REQUIREMENTS. Any activity subject to a permit under
this Rule must conform to the standards of the NPDES General Construction Permit, as
amended, regarding construction site erosion and sediment control.
6. INSPECTION. The permittee shall be responsible for inspection of all erosion and sediment
control measures until final soil stabilization is achieved.
7. MAINTENANCE. The per mittee shall be responsible for proper operation and maintenance
of all erosion and sediment controls, and so il stabilizat ion measures, in conformance with
Best Management Practices, the Minnesota Stormwater Manual and the requirements of the
NPDES General Construction Permit, as amended. The permittee shall, at a minimum,
inspect and maintain all erosion and sediment controls and soil stabilizat ion measures daily
dur ing construction, weekly thereafter unt il vegetative cover is established, and after ever y
rainfall event exceeding 0.5 inches. Inspection and maintenance schedule should follow time
requirements outlined in Appendix ______.
7.8.VEGETATION ESTABLISHMENT . The per mittee shall prepare soils, sod, seed and/or
otherwise stabilize the permit project areas according to the approved plans submitted with the
permit application unless other written approval has been received by the District for an alternate
vegetation establishment plan. If after initial vegetative establishment efforts, the site has not
reached 70% uniform cover within a year, the area must be prepped and reseeded, and covered
with blanket, mulch or straw as recommended by the District. Erosion control blanket is
required on all seeded areas with a slope greater than or equal to 3:1, unless otherwise
approved by the District in writing.
8.9.SECURITY. Any bond or other securit y required in accordance wit h Rule L shall be
maintained unt il final soil stabilizat ion and removal o f erosion and sediment controls, and the
paym ent of all fees and other amounts due the Distr ict.
9.10. EXCEPTIONS. No permit or erosion control plan shall be required under this Rule for the
fo llowing land disturbing activit ies:
(a) Minor land dist urbing activit ies such as home gardens, repairs and maintenance work.
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(b)(a) Const ruct ion, installation and maintenance of individual sewage t reatment
syst ems.
(c)(b) Const ruct ion, installation and maintenance of public utilit y lines or individual
ser vice connect ions unless the activit y disturbs more than one acre, in which event
Paragraph 7(e) below shall apply10,000 square feet .
(d) Const ruct ion of any st ructure on an individual parcel in a subdivisio n wit h an erosion and
sediment control plan approved by the District, so long as any land disturbing activit y
complies with t he approved plan.
(e) Development and redevelopment of, or construction of a structure on, an individual parcel
wit h a land dist urbing act ivit y that does not cause off-site erosion, sedimentation, flooding
or other damage, and disturbs:
(i) In the shoreland protection zone, an area less than 10,000 square feet; provided that,
if a municipalit y or count y with jur isdict ion has adopted an ordinance requiring stormwater
management consist ent with this Rule E that also regulates the activit y, such ordinance shall
govern the act ivit y, and t he exempt area shall increase fro m 10,000 square feet to one acre (at
which point this Rule shall apply in additio n to the municipal or count y regulat ion); or
(ii)(c) Out side of t he shoreland protection zone, an area of less tha n one acre.
(f)(d) Inst allat ion of any fence, sign, telephone or electr ic poles, or other kinds of posts
or poles.
(g)(e) Emergenc y activit y necessar y to protect life or prevent substantial harm to persons
or propert y.
(h) All land disturbing activit ies not required by this Rule to obtain a permit or have an
approved erosion and sediment control plan shall nevertheless be conducted in full
compliance wit h Rule C. All drainage alterat ions not required by this Rule to obtain a
per mit shall nevert heless be conducted in full compliance wit h Rule C.
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RULE F - FLOODPLAIN ALTERATION
1. POLICY. It is the policy of the managers to:
(a) Preserve existing water storage capacity below the 100-year critical flood elevation on all
waterbodies in the District to minimize the frequency and severity of high water.
(b) Minimize development in the floodplain which will unduly restrict flood flows or
aggravate known high water problems. Require compensatory storage for unavoidable
floodplain fill.
2. REGULATION. No person or political subdivision shall alter or fill land below the 100-year
critical flood elevation of any public waters, public waters wetland or other wetland without
first obtaining a permit from the District.
3. CRITERIA.
(a) Floodplain alteration or filling shall not cause a net decrease in flood storage capacity
below the projected 100-year critical flood elevation unless it is shown that the proposed
alteration or filling, together with the alteration or filling of all other land on the affected
reach of the waterbody to the same degree of encroachment as proposed by the applicant,
will not cause high water or aggravate flooding on other land and will not unduly restrict
flood flows.
(b) All new structures shall be constructed with the low floor at a minimum of two feet above
the 100-year critical flood elevation.
(c) A land disturbing activity within a floodplain may require a District permit under Rules D
and E.
(d) An activity that alters or fills a wetland within a floodplain may require a permit under
Rule G.
4. EXHIBITS. The following are to be prepared and certified by a professional engineer
registered in the State of Minnesota, registered land surveyor, or other appropriate
professional, and submitted to the District with the application for stormwater management
permit. All submittals shall be in both electronic format and hard copy.The following
exhibits shall accompany the permit application (one set full size, and two sets reduced to a
maximum size of 11" x 17"):
(a) Site plan showing boundary lines, delineation and existing elevation contours of the work
area, ordinary high water level, and 100-year critical flood elevation. All elevations shall
be referenced to NGVD, 1929 datum.
(b) Grading plan showing any proposed elevation changes.
(c) Preliminary plat of any proposed subdivision.
(d) Determination by a registered professional engineer of the 100-year critical flood
elevation before and after the proposed activity.
(e) Computation of the change in flood storage capacity as a result of the proposed alteration
or fill.
(f) Erosion control and sediment plan which complies with Rule E.
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(g) Soil boring results if available.
5. EXCEPTIONS. If a municipality or county has adopted a floodplain ordinance which
prescribes an allowable degree of floodplain encroachment, the applicable ordinance shall
govern the allowable degree of encroachment and no permit will be required under this Rule
F.
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RULE G - WETLAND ALTERATION
1. POLICY. It is the policy of the managers to:
(a) Achieve no net loss in the quantity, quality and biological diversity of wetlands in the
District.
(b) Increase the quantity, quality and biological diversity of wetlands in the District by
restoring or enhancing diminished or drained wetlands.
(c) Avoid direct or indirect impacts from activities that destroy or diminish the quantity,
quality and biological diversity of District wetlands as determined using the Minnesota
Routine Assessment Method (MnRAM) for Evaluating Wetland Functions Version 2.0.
(d) Replace affected wetlands where avoidance is not feasible and prudent.
2. REGULATION. No person or political subdivision shall drain, fill, excavate or otherwise
alter a wetland without first obtaining the approval of a wetland replacement plan from the
local government unit with jurisdiction over the activity.
3. CRITERIA.
(a) Any drainage, filling, excavation or other alteration of a wetland shall be conducted in
compliance with Minnesota Statutes, section 103G.245, the wetland conservation act, and
regulations adopted thereunder.
(b) A wetland may be used for stormwater storage and treatment only if the use will not
adversely affect the function and public value of the wetland as determined by the local
government unit.
(c) Other activities which would change the character of a wetland shall not diminish the
quantity, quality or biological diversity of the wetland.
(d) A land disturbing activity within a wetland may require a District permit under Rules D
and E.
(e) An activity within a wetland that alters or fills a floodplain may require a District permit
under Rule F.
4. LOCAL GOVERNMENT UNIT. The District intends to serve as the local government unit
for administration of the wetland conservation act, unless a particular municipality in the
District has elected to assume that role in its jurisdictional area.
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RULE H - BRIDGE AND CULVERT CROSSINGS
1. POLICY. It is the policy of the managers to regulate crossings of watercourses for
driveways, roads and utilities to maintain channel profile stability and conveyance capacity.
2. REGULATION. No person or political subdivision shall construct, improve, repair or alter a
driveway, road or utility across the Prior Lake outlet channel or a watercourse with a
tributary area in excess of 100 acres without first obtaining a permit from the District.
3. CRITERIA. Crossings shall:
(a) Retain adequate hydraulic capacity, which for any crossing over the Prior Lake outlet
channel shall be based on the hydraulic model for the outlet channel.
(b) Retain adequate navigational capacity.
(c) Not adversely affect water quality.
(d) Represent the "minimal impact" solution to a specific need with respect to all reasonable
alternatives.
(e) Allow for future erosion, scour, and sedimentation considerations.
(f) Require a permit under Rules D and E if part of a land disturbing activity or subdivision.
4. EXHIBITS. The following are to be prepared and certified by a professional engineer
registered in the State of Minnesota, registered land surveyor, or other appropriate
professional, and submitted to the District with the application for stormwater management
permit. All submittals shall be in both electronic format and hard copy.The following
exhibits shall accompany the permit application (one set full size, and two sets reduced to a
maximum size of 11" x 17"):
(a) Construction plans and specifications.
(b) Analysis prepared by a registered professional engineer showing the effect of the project
on hydraulic capacity and water quality.
(c) An erosion and sediment control plan which complies with Rule E.
5. MAINTENANCE.
(a) The maintenance, reconstruction and stabilization of any public crossing shall be the
responsibility of the political subdivision with jurisdiction over the crossing.
(b) The maintenance, reconstruction and stabilization of any private crossing shall be the
responsibility of the owner of the crossing.
(c) If a crossing over the Prior Lake outlet channel is determined by the District to be causing
significant erosion of the outlet channel cross-section or profile, the District may order
the owner of the crossing to make necessary repairs or modifications to the crossing and
outlet channel. If the owner of the crossing fails to make the necessary repairs or
modifications after notice from the managers, the District may repair, modify or remove
the crossing or repair or modify the outlet channel. The owner shall pay the cost of the
District to repair, modify or remove the crossing and outlet channel within 10 days after
issuance of a statement by the District. The amounts payable to the District under this
Rule H shall be collectable in the same manner as fees under Rule K.
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(d) As a condition to the approval of a permit under this Rule H, the District may require the
applicant and owner to enter into a compliance agreement with the District.
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RULE I - DRAINAGE ALTERATIONS
1. POLICY. It is the policy of the managers that surface water may be drained only in a manner
which does not unreasonably burden upstream or downstream land.
2. REGULATION. No person or political subdivision shall artificially drain surface water, nor
obstruct or redirect the natural flow of runoff, so as to affect a drainage system established
under Minnesota Statutes, chapter 103E, or the public health and general welfare of the
District, without first obtaining a permit from the District.
3. CRITERIA. The applicant for a drainage alteration shall:
(a) Describe the overall environmental impact of the proposed drainage alteration and
demonstrate that:
(i) There is a reasonable necessity for such drainage alteration;
(ii) Reasonable care has been taken to avoid unnecessary injury to upstream and
downstream land;
(iii) The utility or benefit accruing to the land on which the drainage will be altered
reasonably outweighs the gravity of the harm resulting to the land receiving the
burden; and
(iv) The drainage alteration is being accomplished by reasonably improving and aiding
the normal and natural system of drainage according to its reasonable carrying
capacity, or in the absence of a practicable natural drain, a reasonable and feasible
artificial drainage system is being adopted.
(b) Provide a hydraulic design which complies with Rules F and G, and if the alteration
involves a landlocked basin, the alteration must comply with Rule D.3(f) for outlets from
landlocked basins.
(c) Provide a stable channel and outfall.
(d) Obtain a permit under Rules D and E if the drainage alteration is part of a land disturbing
activity or a development or redevelopment of land.
4. EXHIBITS. The following are to be prepared and certified by a professional engineer
registered in the State of Minnesota, registered land surveyor, or other appropriate
professional, and submitted to the District with the application for stormwater management
permit. All submittals shall be in both electronic format and hard copy.The following
exhibits shall accompany the permit application (one set full size, and two sets reduced to a
maximum size of 11" x 17"):
(a) Map showing location of proposed alteration and tributary area.
(b) Existing and proposed cross sections and profile of affected drainage area.
(c) Description of bridges or culverts required.
(d) Narrative and calculations verifying compliance with Paragraph 3(a) and 3(b) above.
5. EXCEPTIONS.
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(a) No permit shall be required under this Rule for the alteration of drainage in connection
with the use of land for agricultural activities.
(b) The managers may waive the requirement of Paragraph 4(d) above if the applicant
submits easements or other documentation in form acceptable to the District evidencing
the consent of the owner of any burdened land to the proposed alteration. Such
easements or other documentation shall be filed for record and evidence thereof
submitted to the District.
(c) All drainage alterations not required by this Rule to obtain a permit shall nevertheless be
conducted in full compliance with Rule C.
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RULE J - BUFFER STRIPS
1. POLICY. Natural vegetation around watercourses and wetlands is integral to maintaining the
water quality and ecological functions these resources provide. Vegetative buffers reduce the
impact of surrounding development and land use on watercourse and wetland functions by
stabilizing soil to prevent erosion, filtering sediment from runoff, and moderating water level
fluctuations during storms. Buffers provide essential habitat for wildlife. Requiring buffers
recognizes that watercourse and wetland quality and function are related to the surrounding
upland.
1.2.REGULATION. For any parcel created or redeveloped after the effective date of this Rule J,
a buffer strip shall be maintained around the perimeter of all watercourses, natural ponds or
wetlands. The buffer strip provisions of this Rule shall not apply to any parcel of record as of
the date of this Rule until such parcel is subdivided or redeveloped. The District does,
however, strongly encourage the use of buffer strips on all parcels in the District.
2. DEFINITIONS: For the purposes of this Rule J, unless the context otherwise requires, the
following words and terms shall have the meanings set forth below. Words and terms not
defined in this Rule shall have the meanings set forth in Rule A.
Buffer Strip - an area of natural, unmaintained, vegetated ground cover abutting or surrounding
a watercourse or wetland.
Watercourse - any natural or improved stream, river, creek, ditch (including Scott County Ditch 13),
channel or other waterway with a tributary area in excess of 50 acres.
Wetland - any wetland as defined in Minnesota Statutes, section 103G.005, subdivision 19; and any
public waters wetland as defined in Minnesota Statutes, section 103G.005, subdivision 15a.
3. GENERAL PROVISIONS.
(a) This Rule shall apply to all lands containing watercourses or wetlands and lands within
the buffer strips required by this Rule. Watercourses and wetlands shall be subject to the
requirements established herein and other applicable federal, state and local ordinances
and regulations.
(b) This Rule does not apply to any wetland with a surface area equal to or less than the area
of wetland impact allowed without replacement as de miminis minimis under the
Wetland Conservation Act.
(c) An applicant shall determine whether any watercourse or wetland exists on land or within
the applicable buffer strip on adjacent land, and shall delineate the boundary for any
wetland on the land. An applicant shall not be required to delineate wetlands on adjacent
property, but must review available information to estimate the wetland boundary.
(d) Documentation identifying the presence of any watercourse or wetland on the applicant’s
land, including wetland delineation and buffer strip vegetation evaluation, must be
provided to the District with a permit application.
(e) Wetland and buffer strip identifications and delineations shall be prepared in accordance
with state and federal regulations.
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4. STANDARDS. The following standards apply to all lands that contain or abut a watercourse
or wetland:
(a) Best management practices shall be followed to avoid erosion and sedimentation during
land disturbing activities.
(b) When a buffer strip is required the applicant shall, as a condition to issuance of a permit:
(i) Submit to the District for its approval a conservation easement for protection of
approved buffer strips. The easement shall describe the boundaries of the
watercourse or wetland and buffer strips, identify the monuments and monument
locations, and prohibit any of the alterations set forth in Paragraph 5(ef) below and
the removal of the buffer strip monuments within the buffer strip or the watercourse
or wetland;
(ii) File the approved conservation easement for record and submit evidence thereof to
the District; and
(iii) Install the wetland monumentation required by Paragraph 7 below.
(c) All open areas within the buffer strip shall be seeded or planted in accordance with
Paragraph 8 below. All seeding or planting shall be completed prior to removal of any
erosion and sediment control measures. If construction is completed after the end of the
growing season, erosion and sediment control measures shall be left in place and all
disturbed areas shall be mulched for protection over the winter season.
5. BUFFER STRIPSCRITERIA.
(a)5. For any parcel created or redeveloped after the effective date of this Rule J, a
buffer strip shall be maintained around the perimeter of all watercourses or wetlands.
The buffer strip provisions of this Rule shall not apply to any parcel of record as of the
date of this Rule until such parcel is subdivided or redeveloped. The District does,
however, strongly encourage the use of buffer strips on all parcels in the District.
(a) Buffer strips on watercourses shall be a minimum of 20 15 feet wide with an average
width of 30 feet, measured from the ordinary high water level of the watercourse or
wetland.
(b) Buffers on wetlands, as measured from the delineated edge of the wetland, shall comply
with the following minimums and averages:
Management Class Minimum Width [ft] Average Width [ft]
Natural Areas Wetland 50 75
Hydrology Wetland 25 50
Restoration/Enhancement &
Basic Wetland 15 30
(b)
(c) Buffer strips shall apply whether or not the watercourse or wetland is on the same parcel
as a proposed development.
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(c)(d) Buffer areas of specific concern, including locations with significant flow
accumulation, must be at least the average buffer width.
(d)(e) Buffer strip vegetation shall be established and maintained in accordance with
Paragraph 8 below. Buffer strips shall be identified within each parcel by permanent
monumentation in accordance with Paragraph 7 below.
(e)(f) Subject to Paragraph 5(gf) below, alterations including building, storage, paving,
mowing, plowing, introduction of noxious vegetation, cutting, dredging, filling, mining,
dumping, grazing livestock, agricultural production, yard waste disposal or fertilizer
application, are prohibited within any buffer strip. Noxious vegetation, such as European
buckthorn, purple loosestrife and reed canary grass, may be removed as long as the buffer
strip is maintained to the standards required by the District. Alterations would 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.
(f)(g) The following activities shall be permitted within any buffer strip, and shall not
constitute prohibited alterations under Paragraph 5(fe) above:
(i) Use and maintenance of an single, unimproved access strip through the buffer, not
more than 20 5 feet in width and maintained only by means of mowing, for
recreational access to the watercourse or wetland and the exercise of riparian
rights;
(ii) Placement, maintenance, repair or replacement of utility and drainage systems that
exist on creation of the buffer strip or are required to comply with any subdivision
approval or building permit obtained from the municipality or county, so long as
any adverse impacts of utility or drainage systems on the function of the buffer
strip have been avoided or minimized to the extent possible; and
(iii) Construction, maintenance, repair, reconstruction or replacement of existing and
future public roads crossing the buffer strip, 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.
6. ALTERNATE BUFFER STRIPS.
(a) Because of unique physical characteristics of a specific parcel, narrower buffer strips may
be necessary to allow a reasonable use of the parcel; and in combination with other best
management practices may provide equivalent water quality treatment performance. The
District may choose to will permit an alternative buffer width if any one or more of the
following conditions is met:
(i) The proposed activity, development or redevelopment of land will not increase
runoff volumes for the 5-year critical storm event, not including the 10-day snow
melt event, that is discharged to the watercourse or wetland; or
(ii) The applicant demonstrates that a combination of best management practices to be
incorporated with the proposed activity, development or redevelopment of land will
provide storm water quality treatment performance equivalent to a 30-footthe
average-width buffer required by Paragraphs 5(a) or (b); or
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(iii) The dominant wetland type, as determined by methods acceptable under the
Minnesota Wetland Conservation Act, is a low quality Type 1 or 2 Wet Meadow,
where low quality is defined as having a highly impacted vegetative community
such that reed canary grass comprises more than 40 percent cover, and/or European
buckthorn, if present, comprises greater than 30 percent cover, and/or vegetation
was frequently (at least three of the past five years) removed by cropping.
(b) The use of alternative buffer strips will be evaluated as part of the review of a stormwater
management plan under Rule D. Where alternative buffer strip standards are approved,
the width of the buffer strips shall be established by the managers based on a minimum
width of 16 15 feet. Alternative buffer strips must be in keeping with the spirit and intent
of this Rule. The District may require maintenance agreements, restrictive covenants or
easements, in form acceptable to the District, to cover best management practices used to
justify the alternative standard, to assure maintenance in perpetuity and that best
management practices continue to function as originally designed.
7. MONUMENTATION. A monument shall be required at each parcel line where it crosses
a buffer strip and at each point where the bearing of the buffer strip boundary line
changes. and Monuments shall have a maximum spacing of 200 feet along the edge of the
buffer strip. Additional monuments shall be placed as necessary to accurately define the
edge of the buffer strip. A monument shall consist of a post and a buffer strip sign. The
signs shall be obtained from the District and include warnings about disturbing or
developing the buffer strip. The signs shall be 5 inch wide x 7 inch vertical, have a
brown field with white lettering, and shall be securely mounted on a 4” x 4” wooden post
to a minimum height of 4 feet above grade.
8. VEGETATION ESTABLISHMENT.
(a) Where acceptable natural vegetation exists in buffer strip areas, the retention of such
vegetation in an undisturbed state is required unless an applicant receives approval to
replace such vegetation. A buffer strip has acceptable natural vegetation if it:
(i) Has a continuous, dense layer of perennial grasses that has been uncultivated or
unbroken for at least 5 consecutive years; or
(ii) Has an overstory of trees and/or shrubs that has been uncultivated or unbroken for
at least 5 consecutive years; or
(iii) Contains a mixture of the plant communities described in Subparagraphs 8(a)(i) and
(ii) above that has been uncultivated or unbroken for at least 5 years.
(b) Notwithstanding the performance standards set forth in Paragraph 8(a), the managers may
determine existing buffer strip vegetation to be unacceptable if:
(i) It is composed of undesirable plant species including but not limited to common
buckthorn, purple loosestrife, leafy spurge or noxious weeds; or
(ii) It has topography that tends to channelize the flow of runoff; or
(iii) For some other reason it is unlikely to retain nutrients and sediment.
(c) Where buffer strips are not vegetated or have been cultivated or otherwise disturbed
within 5 years of the permit application, such areas shall be replanted and maintained.
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The buffer strip plantings must be identified on the permit application. The buffer strip
landscaping shall comply with the following standards:
(i) Buffer strips shall be planted with a seed mix approved by MnDOT, NRCS or
SWCD, with the exception of a one-time planting with an annual nurse or cover
crop such as oats or rye.
(ii) The seed mix shall be broadcast according to MnDOT, NRCS or SWCD
specifications of the selected mix. The annual nurse or cover crop shall be applied
at a minimum rate of 30 pounds per acre. The MnDOT or NRCS seed mix selected
for permanent cover shall be appropriate for soil site conditions and free of invasive
species. MnDOT, NRCS or SWCD approved mixtures appropriate for specific soil
and moisture conditions can be used to meet these requirements.
(iii) Native shrubs may be substituted for native forbs. All substitutions must be
approved by the District. Such shrubs may be bare root seedlings and shall be
planted at a minimum rate of 60 plants per acre. Shrubs shall be distributed so as to
provide a natural appearance and shall not be planted in rows.
(iv) Any groundcover or shrub plantings installed within the buffer strip are independent
of any landscaping required elsewhere by the municipality or county.
(v) Grasses and forbs shall be seeded or planted by a qualified contractor. The method
of application shall be approved by the District prior to planting or seeding.
(vi) No fertilizer shall be used in establishing new buffer strips, except on highly
disturbed sites when necessary to establish acceptable buffer strip vegetation and
then limited to amounts indicated by an accredited soil testing laboratory.
(vii) All seeded areas shall be mulched immediately with clean straw at a rate of 1.5 tons
per acre. Mulch shall be anchored with a disk or tackifier.
(viii) Buffer strips (both natural and created) shall be protected by erosion and sediment
control measures during construction in accordance with Rule E. The erosion and
sediment control measures shall remain in place until the area crop is established.
(d) Buffer strip vegetation shall be established and maintained in accordance with the
requirements found in this Paragraph 8 based on an establishment plan meeting the
following requirements:.
(i) Establishment plans must extend for the period beginning at the time of planting
and extending through the end of the fifth growing season.
(ii) Establishment plans must include an irrigation or watering plan for the period
beginning at the time of planting and extending through the end of the first
complete growing season.
(iii) Establishment plans must include replacement of any buffer strip vegetation that
does not survive dDuring the first two full growing seasons, the owner must
replant any buffer strip vegetation that does not survive.
(iv) The owner shall be responsible for reseeding and/or replanting if the buffer strip
vegetation does not survive at any time through human intervention or activities.
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(v) Establishment plans must include a schedule for weeding throughout the duration
of the plan.
(vi) The owner shall be responsible for reseeding and/or replanting if the buffer strip
changes at any time through human intervention or activities.Establishment plans
must be approved by the District.
(vii) Establishment plans must be accompanied by an escrow account for the term of
the establishment plan. At the end of the term of the establishment plan the balance
of the account shall be returned to the permittee, less the amount required to
complete the establishment of acceptable natural vegetation (if any)At a minimum
the buffer strip must be maintained as a “no mow” area.
9. COMPLETION. The following conditions must be met before the District will issue a
Certificate of Completion and release buffer strip escrow:
(a) Buffer strip vegetation must be successfully established per Paragraph 8.
(b) Monumentation must be installed per Paragraph 7.
(d)(c) The conservation easement described in Paragraph 4(b)(i) must be recorded with
Scott County.
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RULE K - FEES
1. POLICY. The managers find that it is in the public interest to require applicants to pay the
cost of administering and reviewing permit applications, and inspecting approved activities to
assure compliance with these Rules, rather than using the District’s annual administrative
levy for such purposes.
2. APPLICATION. Each application for the issuance, transfer or renewal of a permit under
these Rules shall be accompanied by an application fee of $10.00 to defray the cost of
recording and processing the application.
3. REVIEW. An applicant for the issuance, transfer or renewal of a permit under these Rules
shall pay a review fee equal to the actual cost of the District for the review and analysis of the
proposed activity, including services of engineering, legal and other consultants. The District
may require a deposit based on a good faith estimate of the cost to review an application at
the time of filing. The review fee shall be payable upon issuance of a statement after
consideration of the application by the managers. No permit may be issued until the review
fee has been paid.
4. INSPECTION. A permittee shall pay a field inspection fee equal to the actual cost of the
District for field inspections and subsequent monitoring of the permitted activity, including
services of engineering, legal and other consultants. The District may require a deposit based
on a good faith estimate of the cost to inspect and monitor a proposed activity at the time the
application is filed. Additional field inspection fees shall be payable within 10 days after
issuance of a statement if continued inspection and monitoring of an activity is required. A
permit may be revoked, or a certificate of completion withheld, if the field inspection fee is
not fully paid.
5. FAILURE TO OBTAIN PERMIT. Any person or political subdivision performing any
activity for which a permit is required under these Rules without having first obtained a
permit from the District, shall pay, in addition to such fines, court costs or other amounts as
may be payable by law as a result of such violation, a field inspection fee equal to the actual
cost of the District for field inspections, monitoring and investigation of such activity,
including services of engineering, legal and other consultants. The field inspection fee shall
be payable within 10 days after issuance of a statement by the District. No permit shall be
issued for the activity if there are any unpaid field inspection fees or other outstanding
violations of these Rules.
6. RECOVERY. The fees provided for in these Rules may be recovered by the District in any
legal proceeding authorized by law.
7. AGENCIES EXEMPT. The fees in Paragraphs 2, 3 and 4 above shall not be charged to the
federal government, the state, or a political subdivision.
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RULE L - SECURITY
1. POLICY. It is the policy of the managers to protect and conserve water resources by
requiring a bond or other security to assure compliance with these Rules.
2. REQUIREMENT. The managers may require a deposit of cash, a performance bond, an
irrevocable letter of credit or other security with the District as a condition to the issuance of
a permit under these Rules.
3. AMOUNT. The amount of the security shall be set by the managers as the amount the
managers deem necessary to cover the following potential liabilities to the District:
(a) Post permit field inspection, monitoring and related fees authorized under Minnesota
Statutes, section 103D.345;
(b) The cost of maintaining and implementing erosion and sediment control required by the
permit;
(c) The cost of completing buffer strip landscaping in accordance with Paragraph 108(a) of
Rule J; and
(d) The cost of remedying damage resulting from noncompliance with the permit or these
Rules or for which the permittee is otherwise responsible.
4. FORM AND CONDITIONS.
(a) A performance bond or letter of credit must be in a form acceptable to the District and
from a bank or surety licensed to do business in Minnesota.
(b) The security shall be in favor of the District and conditioned upon the applicant’s
performance of the authorized activity in compliance with the permit and applicable laws,
including these Rules, and the payment when due of any fees or other charges authorized
or required by the permit, and these Rules.
(c) The security shall be issued for a minimum term of one year. Security with a shorter
term may be deposited with the District provided it is replaced at least 30 days before its
expiration.
(d) The District shall be authorized to make a claim or draw against the security after any
default by the permittee under the permit or these Rules, or if the permittee fails to
replace any security at least 30 days before its expiration.
5. POLITICAL SUBDIVISIONS. The general contractor for activities of a political
subdivision shall provide any security required by the permit and these Rules.
6. RELEASE. Any security may be released by the District pursuant to Paragraph 14 of Rule
B.
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RULE M - VARIANCES
1. WHEN AUTHORIZED. The managers may grant variances from the literal provisions of
these Rules. A variance shall only be granted when in harmony with the general purpose and
intent of the Rules in cases where strict enforcement of the Rules will cause undue hardship,
and when the terms of the variance are consistent with the District’s water resources
management plan and Minnesota Statutes, chapter 103D.
2. HARDSHIP. “Hardship” as used in connection with the granting of a variance means the
land in question cannot be put to a reasonable use if used under the conditions allowed by
these Rules; the plight of the applicant is due to circumstances unique to the land and not
created by the applicant; and the variance, if granted, will not adversely affect the essential
character of the locality and other adjacent land. Economic considerations alone shall not
constitute a hardship if a reasonable use for the land exists under the terms of these Rules.
Conditions may be imposed in the granting of a variance to insure compliance and to protect
adjacent land and the public health and general welfare of the District.
3. PROCEDURE. An application for a variance shall describe the practical difficulty or
particular hardship claimed as the basis for the variance. The application shall be
accompanied with such surveys, plans, data and other information as may be required by the
managers to consider the application.
4. TERM. A variance shall expire one year after it is granted, unless used by the applicant
within the one-year period.
5. VIOLATION: A violation of any condition imposed in the granting of a variance shall be a
violation of these Rules and shall automatically terminate the variance.
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RULE N - APPEALS
1. INTERESTED PARTY. For the purposes of this Rule N, “interested party” means a person
or political subdivision with an interest in the pending subject matter.
2. APPEALS. An interested party may appeal a rule, permit decision or order made by the
managers by a declaratory judgment action brought under Minnesota Statutes, Chapter 555.
3. PROCEDURES. The decision on appeal must be based on the record made in the
proceeding before the managers. An appeal of a permit decision or order must be filed
within 30 days of the managers’ decision.
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RULE O - ENFORCEMENT
1. MISDEMEANOR. A violation of these Rules, a stipulation agreement made or permit or
order issued by the managers pursuant to these Rules, is a misdemeanor subject to a penalty
as provided by law.
2. ACTIONS. The District may exercise all powers conferred upon it by Minnesota Statutes,
chapter 103D, in enforcing these Rules, or a stipulation agreement made or permit or order
issued by the managers under these Rules, including criminal prosecution, injunction, or an
action to compel performance, restoration or abatement, or other appropriate action.
3. ADMINISTRATIVE ORDER. The District may issue a cease and desist order when it finds
that a proposed or initiated activity or project presents a serious threat of flooding, erosion,
sedimentation, an adverse effect upon water quality, or otherwise violates these Rules.
4. ATTORNEYS’ FEES AND COSTS. In any civil action arising from or related to these
Rules, an order or a stipulation agreement made or a permit issued or denied by the managers
under these Rules, the court may award the prevailing party reasonable attorneys’ fees and
costs.
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RULE P – ILLICIT DISCHARGE
1. POLICY. It is the policy o f the managers to prohibit illicit discharges to the Prior Lake Outlet
Channel.
2. DEFINITIONS: For the purposes of this Rule P, unless the context otherwise requires, the
following words and terms shall have the meanings set forth below. Words and terms not
defined in this Rule shall have the meanings set forth in Rule A.
Illicit Connection – an illicit connection is defined as either of the following:
1. Any drain or conveyance, whether on the surface or subsurface, which allows an
illegal discharge to enter the MS4 system, including, but not limited to any
conveyances which allow any non-stormwater discharge including sewage, process
wastewater, and wash water to enter the system and any connections to the system
from indoor drains and sinks, regardless of whether said drain or connection has been
previously allowed, permitted, or approved by political subdivision.
2. Any drain or conveyance connected from a commercial or industrial land use to the
MS4 system that has not been documented in plans, maps, or equivalent records and
approved by a political subdivision.
Illicit Discharge – any discharge to the MS4 that is not composed entirely of stormwater
except discharges pursuant to a NPDES permit (other than NPDES permit for discharges
from the municipal separate storm sewer) and discharges resulting from firefighting
activities.
Non-Stormwater Discharge – any discharge to the MS4 system that is not composed
entirely of stormwater.
Pollutant - Anything which causes or contributes to pollution. Pollutants may include, but
are not limited to: paints, varnishes, and solvents; oil and other automotive fluids; non-
hazardous liquid and solid wastes and yard wastes; refuse, rubbish, garbage, litter, or other
discarded or abandoned objects, ordnances, and accumulations, so that same may cause or
contribute to pollution; floatables; pesticides, herbicides, and fertilizers; hazardous
substances and wastes; sewage, fecal coliform and pathogens; dissolved and particulate
metals; animal wastes; wastes and residues that result from constructing a building or
structure; and noxious or offensive matter of any kind.
Stormwater – means stormwater runoff, snow melt runoff, and surface runoff and drainage
(Minn. R. 7090.0080, subp.12.).
3. REGULATION.
(a) No person or polit ical subdivisio n shall throw, drain, or otherwise discharge, cause, or
allow ot hers under it s control to throw, drain, or otherwise discharge into the Prior Lake
Out let Channel any po llutants or waters containing any po llutants, other than stormwater,
unless specifically exempted by Paragraph 3 below.
(b) The const ruction, use, maintenance or continued existence of illicit connect ions to the
Prior Lake Outlet Channel is prohibited.
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(i) This prohibit io n expressly includes, without limitation, illicit connections made in
the past, regardless of whether the connect ion was per missible under law, rule, or
pract ices applicable or prevailing at the time of connect ion.
(ii) A person is considered to be in vio lation o f this ordinance if the person connects a
line conveying sewage to the Prior Lake Outlet Channel, or allows such a
connect ion t o continue.
(iii) Improper connect ions in vio lat ion of this ordinance must be disconnected and
redirected, if necessar y, to an approved onsite wastewater management s yst em or
the sanit ar y sewer s ystem.
(iv) Any drain or conveyance that has not been documented in plans, maps or
equivalent, and which may be connected to the storm sewer system, shall be located
by t he owner or occupant of that propert y upon receipt of written notice of vio lat ion
fro m the Dist rict requir ing that such locating be completed. Such notice will specify
a reasonable t ime period within which the location of the drain or conveyance is to
be det ermined, that the drain or conveyance be ident ified as storm sewer, sanitary
sewer or other, and that the outfall locat ion or point of connect ion to the storm
sewer syst em, sanitar y sewer system or other discharge point be ident ified. Results
of t hese invest igat ions are to be documented and provided to the Distr ict.
4. SUSPENSION OF MS4 ACCESS. The District may, without prior notice, suspend MS4
discharge access when such suspension is necessary:
(a) Suspension due to Illicit Discharges in Emergency Situations. The District may, without
prior notice, suspend MS4 discharge access when such suspension is necessary to stop an
actual or threatened discharge which presents or may present imminent and substantial
danger to the environment, or to the health or welfare of persons, or to the District’s MS4
or Waters of the United States. If the violator fails to comply with a suspension order
issued in an emergency, the District may take such steps as deemed necessary to prevent
or minimize damage to the District’s MS4 or Waters of the United States, or to minimize
danger to persons or the environment.
(b) Suspension due to the Detection of Illicit Discharge. Any person discharging to the
District’s MS4 in violation of this Rule may have their MS4 access terminated if such
termination would abate or reduce an illicit discharge. The District may issue an
administrative order or pursue other enforcement action as provided in the District’s Rule
O to compel performance, restoration, abatement, and other appropriate action.
5. MONITORING OF DISCHARGES. This section applies to all facilities that have
stormwater discharges associated with industrial activity, including construction activity.
(a) Access to Facilities. The District shall gain consent or obtain a search warrant to enter
buildings subject to regulation under this Rule to determine compliance with this Rule.
The discharger shall make the necessary arrangements to allow access to representatives
of the District.
(b) Access to Records. The District may examine and copy records that must be kept under
the conditions of an NPDES Permit to discharge stormwater or that concern the
performance of any duties as defined by state or federal stormwater laws.
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(c) If the District has been refused access to any part of the premises from which stormwater
is discharged, then the District may seek issuance of a search warrant from any court of
competent jurisdiction.
6. WATERCOURSE PROTECTION. Every person owning property, through which a
watercourse passes, shall keep and maintain that part of the watercourse within the property
free of trash, debris, and other obstacles that would pollute, contaminate, or significantly
retard the flow of water through the watercourse. In addition, the owner or lessee shall
maintain existing privately owned structures within or adjacent to a watercourse, so that such
structures will not become a hazard to the use, function, or physical integrity of the
watercourse.
7. NOTIFICATION OF SPILLS. It is the duty of every person to notify the District
immediately of the discharge, accidental or otherwise, of any substance or material under its
control which, if not recovered, may cause pollution of the Prior Lake Outlet Channel, and
the responsible person shall recover as rapidly and as thoroughly as possible such substance
or material and take immediately such other action as may be reasonably possible to
minimize or abate pollution.
8. ENFORCEMENT. In addition to pursuing enforcement actions as provided in the District’s
Rule O, the District may utilize the following measures to enforce the provisions of this rule:
(a) Notice of Violation. Whenever the District finds that a person has violated a prohibition
or failed to meet a requirement of this Rule, the District may order compliance by written
notice of violation to the responsible person. Such notice may require without limitation:
(i) The performance of monitoring, analysis and/or reporting;
(ii) The elimination of illicit connections or discharges;
(iii) That violating discharges, practices or operations will cease and desist;
(iv) The abatement or remediation of stormwater pollution or contamination hazards and
the restoration of any affected property;
(v) Payment of District costs of administrative and remediation;
(vi) The implementation of source control or treatment BMPs.
(b) Enforcement Measures. If a violation is not corrected pursuant to the Notice of Violation
and subsequent District order, the District may seek enforcement of the Rule
requirements and/or order through criminal prosecution, injunction, action to compel
performance, restoration, abatement, and other appropriate action. The District may avail
itself of any and all measures necessary to abate the violation and/or restore the property.
9. EXCEPTIONS. The fo llo wing materials may be discharged to the Prior Lake Outlet Channel
operated by t he District:
(a) Stormwater from a Municipal Separate Storm Sewer System connected to the Prior Lake
Out let Channel operated by the District, as specified in the Jo int Powers Agreement /
Memorandum of Agreement that governs the operation of the Pr ior Lake Outlet Channel.
(b) Discharges fro m public waters, including Prior Lake, Pike Lake, and Dean lakesWetland.
(c) The fo llowing minor discharges:
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(i) Water line flushing
(ii) Landscape irr igat ion
(iii) Divert ed stream flows
(iv) Rising ground waters
(v) Uncont aminated ground water infilt ration
(vi) Uncontaminat ed pumped ground water
(vii) Discharges fro m potable water sources
(viii) Foundat ion drains
(ix) Air condit ioning condensat ion
(x) Irrigat ion wat er
(xi) Springs
(xii) Water fro m crawl space pumps
(xiii) Foot ing drains
(xiv) Lawn wat ering
(xv) Individual resident ial car washing
(xvi) Flows fro m riparian habitats and wetlands
(xvii) Dechlorinated swimming pool discharges
(xviii) Street wash water
(d) Discharge permitted under an NPDES permit, waiver, or waste discharge order issued to
t he discharger and administered under the author ity o f the United States Environmental
Protect ion Agenc y (EPA), provided that the discharger is in full compliance wit h all
requirements of t he permit, waiver, or order and other applicable laws and regulations,
and provided that a permit has been received fro m the Distr ict under all applicable rules.
(e) Discharges or flow from firefight ing, and other discharges specified in writ ing by the
Prior Lake Watershed District as being necessar y t o protect public health and safet y.
(f) Dye testing is an allowable discharge, but requires a verbal notification to the District
prior to the time of the test.
Response to Comments matching 45-Day Review Draft 9/3/2019
1
Commenter Comments on March 9, 2018 Draft Redlines Discussion and proposed revisions
General Comments
1 PL, SV, SC,
[SC]
Current revision is inconsistent with stated goals:
-Updating rules before updates of the Construction
Stormwater Permit and the MPCA MS4 Permit in 2019
will lead to further inconsistencies.
-PLSLWD rules differ from Scott WMO and state rules.
[District standards is or was either ½ inch or 1 inch, we
don’t understand how using 1-inch, consistent with the
NPDES permit, is relaxing stormwater standards.
Additionally, MPCA has found that the NPDES
standards meet anti-degradation, or non-degradation.
Please clarify. County is supportive of doing what is
shown to be needed, but questions the cost and
efficiency of doing things just “because.” Our
experience in the long run is that we stand to lose
more ground requiring things that don’t have solid
justification because of the animosity created with the
regulated community.]
Goals were framed in 2013 when the District's volume standard was less
than 1.0-inch and Scott WMOs rules were substantively different as well.
The Construction Stormwater Permit is updated and Scott WMO draft rules
defer in large part to NPDES.
The PLSLWD Board has provided clear direction to staff not to relax
stormwater standards to NPDES standards for new development, however
the District is proposing to relax standards for road reconstruction and
redevelopment projects. Currently the stormwater standards are the same
for all development, whether new, redevelopment or road reconstruction
including: 1) peak rate control, 2) volume control (1.0-inch), 3) and water
quality treatment – BMPs sized to retain, filter or detain the 2-year, 24-hour
event (2.8-inches). The proposed rule revisions relax stormwater
management standards for redevelopment and road reconstruction by
striking the requirement to meet the water quality treatment standard.
2 SC Draft revision are confusing and complicated. Opinion noted.
3 SC, [SC] A well-defined and transparent process of problem
definition, future planning and needs assessment is
need before modifying rules.
[Yes we realize that there have been conversations for
5 years, but we haven’t received documentation of the
need for making some of these changes despite asking.
County has also pointed out a number of times that
how land use is now guided in the unincorporated
areas of much of Spring Lake Township will result in
some improvements, but we have yet to hear clear
acknowledgement of that by the District and its
engineer through policies and programs of the District.]
The majority of issues and respective rule modifications have been
identified for well over 5-years during which time the TAC was engaged.
With renewed efforts in starting in 2017 the rule revision process has
engaged the TAC at 5 meetings, local road authorities at 3 additional
meetings, and the District's 2020 Plan Public Engagement Process for issues
identification.
4 ST Initial discussions have led to the question of what is
the basis/need for these changes. Present clear need
for rule changes, the desired outcome, and show how
the rule changes accomplish goal.
See response to comment #3.
Response to Comments matching 45-Day Review Draft 9/3/2019
2
5 ST Examples should be given of how the new rules would
be applied to some recent/proposed developments, to
show how these new rule changes would compare to
the current rules. This should be done for various sized
developments, like a lot split (2 lots) or smaller
development with no new infrastructure, and for a
larger 12+ lot development with new roads/
stormwater systems. These examples could be used to
show the differences in review process, plans/permits,
cost of infrastructure/ponding requirements, and
added water quality benefits.
Examples were provided for recently permitted municipal road
reconstruction projects. The examples illustrated how the proposed
revisions relax stormwater management requirements. New development
stormwater management standards remain largely unchanged.
Rule A - Definitions
6 PL, SV Eliminate definitions that differ from MS4 Permit or
Construction Stormwater Permit and reference Permit
definitions.
Review of and revision to proposed definitions have been made, as
appropriate.
7 SV Impervious Surface: The rule states "open decks with
joints at least 1/4 inch wide shall not constitute and
impervious surface". All decks constructed in the City
of Savage would have this spacing and the addition of
this language is unnecessary.
This language has been eliminated.
8 SP Impervious Surface: Use the general permit language:
"Impervious Surface" means a constructed hard surface
that either prevents or retards the entry of water into
the soil and causes water to run off the surface in
greater quantities and at an increased rate of flow than
prior to development. Examples include rooftops,
sidewalks, driveways, parking lots, and concrete,
asphalt, or gravel roads. Bridges over surface waters
are considered impervious surfaces.
Proposed draft is revised as suggested.
9 SV Memorandum of Understanding (MOU): A definition
shall be added that identifies that an MOU will be
established with the local jurisdiction and the PLSLWD.
The local jurisdiction will be responsible for adopting
and enforcing the requirements of the PLSLWD.
Language has been added to the Relationship with Municipalities and
County section of the Rules.
Response to Comments matching 45-Day Review Draft 9/3/2019
3
10 SP New Development: Definition is not clear, consider:
"Any construction activity that is not defined as
redevelopment."
Proposed draft is revised as suggested.
11 SP Redevelopment: Definition is not clear, consider: "Any
construction activity where, prior to the start of
construction, the areas to be disturbed have 15% or
more of impervious surface."
Definition for redevelopment is proposed to remain as draft in order to
extend redevelopment standards to razed sites.
12 SC, [SC] Mill, reclamation and overlay – further clarification
needed on whether base layer (class V) would be
considered one of the top layer(s)
[Based on the response then it should not be a
problem for the District to add “gravel” to the
parenthetical list of impervious surfaces included in
this sentence.]
By definition, gravel is impervious surface. The definition as drafted states,
"without disturbance of the underlying native soil".
13 MnDOT Impervious Surface – Please add that the trails must be
greater than 10 feet wide and not bordered by a 5 foot
vegetated buffer strip to be considered impervious
surfaces.
This has been added at an exception to Rule D.
14 MnDOT New Development – Please confirm that new
development and any requirements for new
development is not applicable to linear development.
For example, confirm that criteria 3, e, i of the Rules is
not applicable to linear development.
New Development standards do not apply to Linear Projects. Rule D.3(e)(i)
starts with, “For New Development only…”.
15 MnDOT Reconstructed Impervious Surface: Please clarify that
catch basin and pipe/culvert repair/replacement with
the same capacity infrastructure does not constitute
triggering the Stormwater rules even if the underlying
soil is disturbed.
This clarification is included in the definition.
Rule D - Stormwater Management
16 PL 1.(c) Add a definition for the term "Directly connected
impervious surface".
This has been added to Rule A: Directly Connected Impervious Surface – an
impervious surface that is hydraulically connected to a conveyance system
(i.e. streets, curb and gutter, catch basins, storm drains, etc.) without
flowing over pervious areas.
Response to Comments matching 45-Day Review Draft 9/3/2019
4
17 SV 2.(a) Rule should be revised to allow flexibility for local
jurisdictions to enforce their current rules. The City of
Savage requests that for sites less than 1 acre the
permitting thresholds be left to the local permitting
authority.
It was our understanding that the TAC recommended adopting the lowest
threshold of its partners.
18 SP 2.(a) Replace "Development" with "New development". Proposed draft is revised as suggested.
19 SP, SC, [SC] 2.(a) Consider simplifying, change to impervious area,
instead of meeting both disturbed and impervious
area. What is the basis for 3,500 sf of impervious?
[Thank you for the clarification, and thank you for the
exception for Single Family Homes. However, as noted
below we recommend making this about the base
zoning, not homes. ]
The basis of this language is the City of Prior Lake regulations. Paragraph 8.
Exception (g) has been revised to exempt development of Rural Residential
Reserve.
20 PL 2.(b) Eliminate rule and replace with reference to MS4
Permit requirements.
Per Board direction, the Public Linear Project regulation will remain as
drafted.
21 SP 2.(b) Change language to "net increase" of 10,000 sf of
impervious area.
Per Board Direction, the Public Linear Project regulation will remain as
drafted.
22 MnDOT 2.(b) Please consider 1 acre of net new and
reconstructed impervious surface as the trigger for
treatment, rather than 10,000 square feet or new or
reconstructed impervious.
Per Board Direction, the Public Linear Project regulation will remain as
drafted.
23 PL 2.(c) This rule would require lots that are generally less
than ¼ acre to provide stormwater management.
Additional information requested:
-Will the PLSLWD review applications and stormwater
management calculations?
-Will the PLSLWD take conservation easements for
BMPs under this rule?
-Will the PLSLWD provide compliance checks to ensure
that these private BMPs are functioning as they should
be and enforcement if they are not?
-This rule will not meet the goal stated in 8/8/17
Memo, “Promoting consistency with other regulations
such as the NPDES Construction Permit to minimize the
regulatory burden on developers.”
Per Board Direction, this standard is proposed to remain as drafted and the
District is willing to take on review, design guidance, and inspection and
enforcement for the few projects that would be regulated under this
criteria.
Response to Comments matching 45-Day Review Draft 9/3/2019
5
24 SP 2.(c) Replace "Development" with "New development". Proposed draft is revised as suggested.
25 PL, SV, SC,
[SC]
3.(a) Rate control requirements should not be changed
from storm event-based to flood event-based.
[Thank you]
Proposed draft is revised as suggested.
26 PL, SV 3.(a) Rate control requirements in existing rules are
sufficient and do not need updated (in reference to
requiring rate control at each point of site discharge).
Can the rule be revised to allow for an increase in one
area if the ultimate receiving water is the same,
providing there is an adequate conveyance?
Clarifying language has been added to accommodate this request.
27 MnDOT 3.(a) Peak Runoff Rates – Says “Peak runoff rates for
the developed condition shall not exceed pre-
development peak runoff rates at each point of site
discharge for the 2-year, 10-year and 100-year critical
duration flood events.” Linear projects have numerous
points of site discharge. Can averaging of runoff rates
within each drainage area be allowed for linear
projects?
See response to comment #26.
28 PL, SV 3.(b) Volume control requirements in existing rules are
sufficient and do not need updated to require volume
control at each point of site discharge. Changing the
rule eliminates flexibility for unique site topographical
features. Can the rule be revised to allow for an
increase in one area if the ultimate receiving water is
the same?
“at each point of site discharge” has been removed from the criteria.
29 MnDOT 3.(b) Stormwater Volume – Can averaging of volume
control within each drainage area also be allowed for
linear projects.
See response to comment #28.
30 SC, [SC] 3.(b) Why 1.1” and 0.55” in the respective categories
for development, redevelopment and linear? These
are different than other entities. Provide rationale and
need.
[Documentation of “need” is still not addressed. While
MIDS is an option for compliance under the MS4 there
is no preference given to this standard.]
1.1” and 0.55” has been revised to 1.0” and 0.5”, respectively, to be
consistent with the Draft MS4 Permit language dated 5.7.2019.
Response to Comments matching 45-Day Review Draft 9/3/2019
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31 PL, SV, SP,
SC, [SC]
3.(b)(i) Changing this rule is inconsistent with local
jurisdictions and rationale for change is not provided.
[Documentation of “need” is still not addressed. While
MIDS is an option for compliance under the MS4 there
is no preference given to this standard.]
This paragraph has been revised to be consistent with the Draft MS4 Permit
language dated 5.7.2019.
32 PL, SV 3.(b)(i) Keep 0.5-inch volume control requirement for
sites creating less than 1-acre of new impervious.
Savage and Prior Lake have this provision, Shakopee does not. The PLSLWD
Board is of the opinion that stormwater management standards should
remain high for new development.
33 PL, [SC] 3.(b)(ii) Remove this rule and reference MS4 Permit
requirements. Rationale for change has not been
provided.
[Documentation of “need” is still not addressed. While
MIDS is an option for compliance under the MS4 there
is no preference given to this standard.]
The PLSLWD Board has provided clear direction to staff to provide flexibility
to Redevelopment (which per existing rule is treated as new development)
but not to relax stormwater standards to NPDES standards.
34 SV 3.(b)(ii) Remove rule and allow local permitting
authorities to enforce their current standards. Consider
a lower threshold for sites less than 1 acre.
See response to comment #32.
35 PL, [SC] 3.(b)(iii) Remove this rule and reference MS4 Permit
requirements for linear projects. Rationale for change
has not been provided.
[Documentation of “need” is still not addressed]
The PLSLWD Board has provided clear direction to staff to provide flexibility
to Linear Projects (which per existing rule is treated as new development)
but not to relax stormwater standards to NPDES standards.
36 SP, [SC] 3.(b)(iii) Too complicated, reconsider volume
calculation to 1-inch over impervious area triggered by
area.
[Documentation of “need” to follow MIDS standards is
still not addressed.]
1.1” and 0.55” has been revised to 1.0” and 0.5”, respectively, to be
consistent with the Draft MS4 Permit language dated 5.7.2019.
37 PL 3.(c) Delete this section and replace with reference to
MPCA Stormwater Manual.
This section has been has been revised to reference the Minnesota
Stormwater Manual.
38 SC, [SC] 3.(d) – Why would iron or other additives affect
volume?
[Response is still confusing as the title of this section is
“Alternative Volume Control Criteria” (emphasis
added).]
The section title and language has been revised to clarify intent.
Response to Comments matching 45-Day Review Draft 9/3/2019
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39 SP, SC, [SC] 3.(e)(i) Unclear if additional water quality
requirements/analysis beyond volume reduction
requirement is needed. Consider adding clarifying
language. Are the proposed reductions based on
existing or reduction of proposed loading?
[Suggest clarifying that volume infiltrated counts as
being treated.]
The intent of this criteria is to maintain the same level of water quality
treatment for New Development, by requiring treatment of the 2-year, 24-
hour event. Clarifying language has been added.
40 SC, [SC] 3.(e)(ii) – Is this additional treatment beyond volume
and water quality? Also, is sediment (TSS) a
documented problem in the PLSLWD that this is
required?
[Second half of our comment has not been addressed.]
This is a minimum performance measure if applicant cannot meet
stormwater management standards onsite.
41 SC, [SC] Item 3.(f) – Given all the other volume and runoff
regulation, is this still needed?
[Volume control not being realized on-site has not
been our experience.]
Yes, volume control may not be realized onsite and these bounce and
inundation standards are commonly referenced by municipalities and
watershed districts to minimize impacts on wetlands.
42 PL 3.(f) Modify wetland bounce and inundation table to
remove 100-year event.
Consistent with other watershed district rules, the 100-year event criteria is
proposed to remain.
Response to Comments matching 45-Day Review Draft 9/3/2019
8
43 PL, SC, [SC] 3.(g) Remove the first paragraph and table. Start the
second paragraph by saying, "All projects, curve
numbers…"
[Response does not make sense since the language in
the Rule is that the policy stated in the Rules is to
“Require that peak runoff rates for new development
not exceed pre-development conditions and the
capacity of downstream conveyance facilities.”
(emphasis added), not “pre-settlement”. Additionally,
the language in criteria 3(a) also states pre-
development, not pre-settlement, and definitions
includes one for pre-development (given as the
condition prior to the proposal) but not pre-
settlement. So why are runoff curve numbers that
more closely reflect pre-settlement being used? As for
comparison with the County’s numbers the point was
that ours are intended to be pre-settlement, not pre-
development. Plus, the County numbers (based on
Scott WMO standards) were intended for
unincorporated areas where there is more space with
the type of development planned, ability to meet pre-
settlement, and we don’t operate a stormwater utility.
The Scott WMO does not force cities to use pre-
settlement because they have stormwater utilities and
more active management of stormwater infrastructure
and were less likely to experience problems that the
county was having with drainage systems being
natural, largely private, and frequently cobbled
together to support agriculture. If it is the intent of the
District to go pre-settlement then use consistent
language, and if the numbers are close to what the
county uses why not just use the same ones?]
This would result in departure from the goal of pre-settlement rates for
New Development. Curve numbers have been revised to match Scott
WMO standards. Could consider further revision to apply these curve
numbers only to New Development in unincorporated areas but arguably
there is plenty of space in New Development in incorporated areas,
especially those areas that will be annexed.
Response to Comments matching 45-Day Review Draft 9/3/2019
9
44 SC, [SC] 3(g) (last paragraph) – Proof of need? Already using
pretty low Curve Numbers. What if the starting
condition is ag.?
[Response does not address our comment or concerns.
This requirement seems to double down to create a
very restrictive standard. The table already has very
low curve numbers such that applicants are forced to
show very low runoff amounts pre-development (or
pre-settlement?) and then forced to go to artificially
higher curve number because of the soil group criteria
for the proposed condition. We suggest if you are
making them go to pre-settlement as reflected in the
curve number in the table that is already pretty
restrictive, piling more on top of that is probably not
effective. In addition, with respect to our question
about agriculture it is well documented that soils over
the long term exposed to repeated row crop
agriculture tend to lose organic matter, and can
become compacted or development a hard pan, or lose
some of their structure. Plus, there is not vegetation
for a good portion of the year. Development of
agricultural lands as rural residential presents an
opportunity to establish year around vegetation that
over time can improve soil and infiltration. This
particular transition should be recognized and
embraced, not penalized with curve number
adjustments as it will improve soils over time.]
Last paragraph recognizes the impact of grading on soil structure (i.e.
compaction) and the last sentence has been amended to acknowledge the
impacts of agriculture on soil structure.
45 PL 3.(h) Per the Flood Study results, this rule should
exempt properties within the floodplain of Prior Lake
based on model assumptions and other areas where
stormwater modeling can show no adverse impacts.
This has been clarified to exempt the floodplain of Prior Lake.
Response to Comments matching 45-Day Review Draft 9/3/2019
10
46 PL, SP, SV,
[SC]
3.(i) Delete this section and replace with referenced to
MPCA Stormwater Manual, relating to stormwater
infiltration feature design considerations.
[Please justify the need for this additional analysis.
Provide an analysis of general cost and time increase to
developers to have this analysis done, the number of
times the district has run into this problem, and the
benefit that will be gained.]
The additional cost is negligible ($300) to the insight gained and pitfalls
avoided by assuming infiltration performance based on soil borings alone.
47 SC 3.(i)(i) – Exact location for boring is impracticable. Changed "exact" to "at the". The intent is to indicate to the applicant that
site specific borings at the location of the proposed BMP is required.
48 SC 3.(k)(iii) – Which type of waterbodies, public? Any that would impact the performance of the wet pond by regularly
inundating the water quality storage of the NURP basin rendering it
ineffective.
49 SC, [SC] 3.(l) – How are regional and local being defined?
Language regarding landlocked basin for the overflow
elevation and runout elevation being different is
confusing. 2ft for low floor freeboard under 100 yr.
regional elevations has safety factor built in, so why the
need for 2’ instead of a lesser amount?
[Please clarify these terms in the table.]
Regional is FEMA based or in absence of FEMA flood elevation, District
SWMM model elevation. 2-ft is from existing rule, no proposed change.
Footnote has been added to clarify.
50 PL 3.(o) Add a Fee in Lieu option for projects that have no
space for BMPs.
Fee in Lieu has been added to Section (q).
51 SC Item 3.(o) – What if the overall zoning by the land use
authority is resulting in reduction over time? What are
the limitations for areas the credits can be transferred
within?
If land use decision reduce runoff volume, all the better, but applicants are
still responsible for meeting stormwater volume standards under
developed conditions. Limits for credit transfer will be defined when
approved, but generally speaking credits will be transferable within three
areas – 1) tributary to Prior Lake, 2) the Prior Lake Outlet Channel, or 3)
other areas not tributary to 1 or 2 (i.e. Cates Lake drainage area, other
landlocked areas, etc.).
Response to Comments matching 45-Day Review Draft 9/3/2019
11
52 SC, [SC] 3.(p) – Overall this does not seem to be an efficient use
of public dollars.
[Please provide an example of the amount of
calculations and analysis that would need to be shown
to gain approval by the Board for this requirement.
How often do other watershed districts with this type
of regulation approve a cost cap project? What
information will the Board be considering in setting the
cost cap each term?]
This came at the request of the road authorities and is not intended to be
onerous. If a municipality were to exercise this option, the District would
lean on other watershed districts that have been implementing this cap for
years for guidance.
53 MnDOT 3.(p) Please allow for the unit costs for the various
project components to be developed by the applicant
and approved by the Watershed District Engineer, not
set by the Board. MnDOT uses past project average bid
unit cost prices in our project cost estimates.
Paragraph 3.(p) has been revised to accommodate this request.
54 PL, SC, [SC] 3.(r) It is not realistic to expect as-built drawings to be
completed within 35 days of substantial completion of
construction.
[The County defers to the experience and
recommendation of the City of Prior Lake.]
The District is open to an alternate timeframe – please suggest timeframe
with 45-day review comments.
55 MnDOT 4. Allow an MS4 to use its’ SWPPP instead of preparing
a separate maintenance schedule.
This is acceptable, Paragraph 4(i) has been clarified.
56 SC, [SC] 4. Flowage and drainage easements that are recorded
will be reviewed by the County Surveyor, why does
District need them? D&U Easements go to the cities or
townships.
[Then please limit the review to the cases the PLSLWD
is the recipient of the easement. Otherwise this is
additional redundant review. In unincorporated areas
of the County, the townships accept the D&U
easements, but they are reviewed by the County
Surveyor (who is licensed) as part of signing off on
plats. Also note Conservation Easements are not the
same as flowage and drainage easements.]
This is not always the case. Duplication it not the District’s intent. This is
language that predates these proposed revision.
Response to Comments matching 45-Day Review Draft 9/3/2019
12
57 SC Item 5 – “Applicant” is used under Maintenance;
however, D & U easements go to the cities and
townships. Suggest something accepting Developers
Agreement approved by cities and twps.
This is for privately maintained BMPs.
58 SC 8.(e) – Consider removal of the word "gravel”. What
portion of the road needs to treat areas that directly
discharge into a wetland? Could you define "direct
discharge" and “rural section”? Would vegetation in
the road ditch count as credit?
Paragraph 8.(e) has been revised as, “The reconstructed impervious surface
of a road that will remain rural-section that is bordered downgradient by
vegetated open space or a vegetated filter strip with a minimum width of 5
feet with a slope less than 2 percent is exempt from the requirements of
Paragraph 3(b)(iii).”
59 SC, [SC] 8.(g) Consider the inclusion of accessory structures,
pools, additions, etc. These would typically be smaller
in disturbance area and impervious surface than single
family homes. PUDs can go as low as 1 acre in
unincorporated areas of the watershed can this be
lowered to 1 acre size lots?
[We recommend not making this about a home and
accessories, but the base zoning. That it would be
exempt if a Rural Residential Lot developed in
conformance with county requirements, or PUD
developed in conformance with approved plans. If this
approach is not acceptable to the District we will send
over a variety of typical permit applications we get in
the rural area requesting District interpretation of how
the Rules would be applied to these various cases.]
Paragraph 8.(g) has been revised as, “Land zoned as RR-1 Rural Residential
Reserve District developed in conformance with County requirements.”
60 ST 8. Exemption for rural roadways with swale/ditch
systems. These types of roadways do not present a
point discharge or collection system that can be
treated in one location.
See response to comment #58 and also note that there is flexibility added
for roads in Sections 3 (b), (d), (e)(ii), and (m) thru (q).
Response to Comments matching 45-Day Review Draft 9/3/2019
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61 ST 8.(g) Exemption for rural parcels; the initial low
threshold for impervious surface increases on
individuals lots is geared more towards urban
development and should be exempt to account for the
current zoning of rural residential nature (larger lots
means longer driveways, larger homes, outbuildings,
etc.). Revise Exception 8.g to cover all land zoned as
rural residential. This would take out parcel size
requirements as well as the activities/structures
associated. This would help to keep the exemption
more clearly defined as it is applied in the future.
See response to comment #59.
62 MnDOT 8.(h) Please keep the fence, signs, posts and poles in as
exceptions to Rule D. These areas should not be
counted as impervious surfaces.
This exception has been unstricken.
63 SP Appendix D.1 Reference the table in the stormwater
manual instead of including here. Design rates do not
follow the guidance in the stormwater manual and it is
not clear why that would be needed.
Design rates are per the state stormwater manual with the exception of SM
soils, which is predominant in PLSLWD and often misclassified in the field.
The additional soil analysis recommended and corresponding
supplementary design infiltration rate table is highly recommended given
the wide range of potential infiltration rates.
PL City of Prior Lake
SV City of Savage
SP City of Shakopee
SC Scott County
MnDOT Minnesota Department of Transportation (comments made after the 10/10/18 TAC meeting)
[SC] Scott County comments made after the 10/10/18 TAC meeting
ST Stantec, on behalf of Spring Lake Township (comments made after the 10/10/18 TAC meeting)
[Phone] 952-447-9800 | [Fax] 952-447-4245 | cityofpriorlake.com
4646 Dakota Street SE
Prior Lake, MN 55372
October 21, 2019
Diane Lynch, District Administrator
Prior Lake-Spring Lake Watershed District
4646 Dakota Street SE
Prior Lake, MN 55372
RE: Prior Lake-Spring Lake Watershed District Proposed Rules Revision
Ms. Lynch,
The City of Prior Lake appreciates the time and effort the Prior Lake-Spring Lake Watershed District
(PLSLWD) has dedicated to updating its rules. There have been several iterations of the updated rules
shared with the Technical Advisory Committee (TAC) and a smaller road authority group during 8
meetings, after the effort started in August 2017. The PLSLWD’s stated goals for the rules revision
process included (PLSLWD Memo, 8/8/2017):
• Standards need to be brought into agreement with current state guidance and advances in
stormwater management science.
• Improving water quality while providing flexibility to developers to incorporate new techniques
and technologies.
• Increasing requirements and incentives for volume management.
• Promoting consistency with other regulations such as the NPDES Construction Permit to
minimize the regulatory burden on developers.
• Coordinate regulatory standards and requirements with Scott County and other jurisdictions to
simplify and adopt similar standards where appropriate.
City staff appreciated the opportunity to participate in both the TAC meetings and the road authority
group meetings. While many of goals were met during the revision process, there are also some
significant rules changes that are not supported by the stated goals and we respectfully ask you to
consider making additional updates to the proposed rules. Please consider the following comments:
1. [Rule D, Section 3.b.iii.] The MS4 Permit already provides baseline water quality treatment
requirements on a statewide basis that address anti-degradation. The MS4 Permit does include the
level of treatment required by the proposed PLSLWD rules as an option within the MIDS framework,
but the MS4 permit also provides an exemption for ROW that is not present in the proposed PSLWD
rules. No justification or cost-benefit analysis has been provided to show how making this change
watershed-wide will benefit water quality within Prior Lake. Please consider applying this new rule
only to projects within subwatersheds draining to impaired water bodies, and areas with TMDL Load
Reduction Goals within approved TMDL Implementation Plans. A targeted approach to addressing
water quality will have a better chance of meeting our shared water quality improvement goals,
while also being mindful of taxpayer dollar expenditures.
2. The proposed PLSLWD rules include a Linear Project Cost Cap option [Rule D, Section 3.p.] and
Stormwater Impact Fund [Rule D, Section 3.q.] options. While staff supports these concepts because
they provide flexibility, more information is required before the City would be able to use them as
part of a feasibility study for a new linear project. Please provide additional information, including
annual cost cap amounts and Stormwater Impact Fund amounts and criteria, by December 31, 2019.
3. [Rule D, Section 2.c.] This rule would require that lots generally smaller than ¼ acre provide
stormwater management. Additional information was requested, and in the PLSLWD comment
response document, dated 9/3/2019, the PLSLWD proposes to take on review, design guidance,
inspection, and enforcement for projects regulated under this rule. Additional clarification is
requested, including how PLSLWD will coordinate with City staff during this new review process. Due
to the high percentage of impervious surface coverage on developed shoreland lots, please consider
applying this rule only to sites where the proposed impervious surface coverage exceeds 30% AND
that percentage is higher than the existing impervious cover on the lot. Sites that require a City
variance for proposing a reduction in impervious coverage, but are still above the 30% coverage
threshold (example, small site going from 38% to 32% impervious surface coverage, should not be
required to provide stormwater management.
4. The PLSLWD’s comment response document, dated 9/3/2019, makes references to the “Draft MS4
Permit language dated 5.7.2019”. Please note that the MS4 permit is still in draft form and may be
substantially revised in its final form. Unless the MS4 permit is generally referenced by the PLSLWD
rules, any specific language pulled from the draft MS4 permit will need to be reviewed and
potentially updated when the final version of the updated MS4 permit is released.
5. [Rule D, Section 3.i.] Delete this section and replace with a reference to the Minnesota Stormwater
Manual, for stormwater infiltration feature design considerations. There is already a statewide
standard so making slight modifications locally without further analysis is unwarranted. Please
provide an analysis of cost and time increase to complete this analysis, the number of times the
PLSLWD has run into this problem in the past, and the benefit(s) to water quality realized by making
this change.
6. [Rule D, Section 3.r.] It is not realistic to expect as-built drawings to be completed within 35 days of
substantial completion of a project. Please consider revising this rule to allow 60 days, which is
consistent with typical City development agreements.
Thank you for the opportunity to partner with the PLSLWD on this important effort. We look forward to
continuing to work together towards the development of final rules that are feasible and cost-effective.
Sincerely,
Kirt Briggs Jason Wedel
Mayor City Manager
City of Prior Lake City of Prior Lake
Cc: Prior Lake City Council
Andy Brotzler, PE, Director of Public Works/City Engineer
Pete Young, PE, Water Resources Engineer