HomeMy WebLinkAbout20100607 - VI-02To: Honorable Mayor and City Council
From: Tom Montgomery
Date: May 27, 2010
Re: 1st Reading and Order Public Hearing — New Storm Water Management
Ordinance
Council is requested to approve the first reading of the proposed new Storm
Water Management ordinance and order a public hearing on the proposed new
ordinance for the June 21 Council meeting.
In order to assume full development permitting authority, the City of Hastings is
required to revise our ordinances to conform to the Vermillion River Watershed
Joint Powers Organization (VRWJPO) rules and regulations. If the City were to
chose not to conform to the VRWJPO rules and regulations, all developments
disturbing one or more acres would have to be reviewed and permitted by the
VRWJPO, in accordance with the VRWJPO rules and regulations.
The proposed new Storm Water Ordinance has few substantive changes from the
existing ordinance other than instituting runoff volume control. Under the storm
water runoff volume control provisions, improvements that create one acre or
more of additional impervious surface must hold any increase in runoff volume
from a 2 year /24 hr storm. Typically this runoff volume increase would be
controlled through the use of infiltration basins.
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CITY OF HASTINGS, MINNESOTA
ORDINANCE NO. 2010- , THIRD SERIES
AN ORDINANCE OF THE CITY OF HASTINGS, MINNESOTA
REPLACING CHAPTER 152 OF THE HASTINGS CITY CODE PERTAINING TO
STORM WATER MANAGEMENT
BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF HASTINGS AS
FOLLOWS.
Chapter 152 of the Hastings City Code is hereby replaced in its entirety with the following:
CHAPTER 152: STORM WATER MANAGEMENT
Section
152.01 Statutory authorization
152.02 Findings
152.03 Purpose -
152.04 Definitions
152.05 Scope and effect
152.06 Storm water management plan approval procedures
152.07 Plan review procedure
152.08 Approval standards
152.09 Other controls
152.98 Violations
§ 152.01 STATUTORY AUTHORIZATION.
This chapter is adopted pursuant to M.S. § 462.351, as it may be amended from time
to time.
(Prior Code, § 15.01)
§ 152.02 FINDINGS.
The City of Hastings hereby finds that uncontrolled and inadequately planned use of
wetlands, woodlands, natural habitat areas, areas subject to soil erosion, and areas
containing restrictive soils adversely affects the public health, safety, and general welfare
by impacting water quality and contributing to other environmental problems, creating
nuisances, impairing other beneficial uses of environmental resources, and hindering the
ability of the City of Hastings to provide adequate water, sewage, flood control, and other
community services. In addition, extraordinary public expenditures may be required for
the protection of persons and property in the areas and in areas which may be affected by
unplanned land usage.
(Prior Code, § 15.02)
§ 152.03 PURPOSE.
The purpose of this chapter is to promote, preserve, and enhance the natural
resources within the City of Hastings and protect them from adverse effects occasioned
by poorly sited development or incompatible activities by regulating land disturbing or
development activities that would have an adverse and potentially irreversible impact on
water quality and unique and fragile environmentally sensitive land; by minimi
conflicts and encouraging compatibility between land disturbing and development
activities and water quality and environmentally sensitive lands; and by requiring detailed
review standards and procedures for land disturbing or development activities proposed
for the areas, thereby achieving a balance between urban growth and development and
protection of water quality and natural areas.
(Prior Code, § 15.03)
§ 152.04 DEFINITIONS.
For the purpose of this chapter, the following definitions shall apply unless the
context clearly indicates or requires a different meaning.
APPLICANT. Any person who wishes to obtain a building permit, zoning or subdivision
approval.
CONTROL MEASURE. A practice or combination of practices to control erosion and
attendant pollution.
DETENTION FACILITY. A permanent natural or human-made structure, including
wetlands, for the temporary storage of runoff which has a storm water outlet and may
have a permanent pool of water.
DUAL PURPOSE POND. A detention facility without a permanent pool that functions
as both a storm water ponding basin and as a sedimentation basin. Sediment removal is
accomplished through the use of filter media surrounding a slotted outlet pipe, with an
overflow outlet set at an elevation that provides for minimum required run off volume
and sediment storage.
FLOOD FRINGE. The portion of the flood plain outside of the floodway. FLOOD
FRINGE is synonymous with the term FLOODWAYFRINGE used in the Flood
Insurance Study for the City of Hastings.
FLOOD PLAIN. The beds proper and the areas adjoining a wetland, lake, or
watercourse, which have been or hereafter may be covered by the regional flood (The
critical 100 -year storm).
FLOODWAY. The bed of a wetland or lake and the channel of the watercourse and
those portions of the adjoining flood plains which are reasonably required to carry or
store the regional flood discharge.
HYDRIC SOILS Soils that are saturated, flooded, or ponded long enough during the
growing season to develop anaerobic conditions in the upper part.
HYDROPHYTIC VEGETATION. Macrophytic plant life growing in water, soil, or on a
substrate that is at least periodically deficient in oxygen as a result of excessive water
content.
LAND DISTURBING OR DEVELOPMENT ACTIVITIES Any change of the land
surface including removing vegetative cover, excavating, filling, grading, and the
construction of any structure.
PERSON. Any individual, firm, corporation, partnership, franchisee, association, or
governmental entity.
PUBLIC WATERS Waters of the state as defined in M.S. § 103G.005, Subdivision 15,
as amended.
REGIONAL FLOOD. A flood which is representative of large floods known to have
occurred generally in Minnesota and reasonably characteristic of what can be expected to
occur on an average frequency in the magnitude of the critical 100 -year recurrence
interval. REGIONAL FLOOD is synonymous with the term BASE FLOOD in the
Flood Insurance Study.
RETENTION FACILITY. A permanent natural or man made structure that provides for
the storage of storm water runoff by means of a permanent pool of water.
SEDIMENT. Solid matter carried by water, sewage, or other liquids.
STRUCTURE. Anything constructed or erected on the ground or attached to the ground,
including, but not limited to, buildings, factories, sheds, cabins, mobile or manufactured
homes, and other similar items.
47
WETLANDS Lands transitional between terrestrial and aquatic systems where the water
table is usually at or near the surface or the land is covered by shallow water no deeper
than 6 feet. For purposes of this definition, wetlands must have the following 3
attributes:
(1) Have a predominance of hydric soils;
(2) Are inundated or saturated by surface or ground water at a frequency and
duration sufficient to support a prevalence of hydrophytic vegetation
typically adapted for life in saturated soil conditions; and
(3) Under normal circumstances support a prevalence of the vegetation.
(Prior Code, § 15.04)
§ 162.05 SCOPE AND EFFECT.
(A) Applicability. Every applicant for a building permit, subdivision approval, or a
permit to allow land disturbing activities must submit a storm water management
plan to the Public Works Department. No building permit, subdivision approval, or
permit to allow land disturbing activities shall be issued until approval of the storm
water management plan or a waiver of the approval requirements has been obtained
in strict conformance with the provisions of this chapter. The provisions of
§ 152.09 apply to all land, public or private, located within the City of Hastings.
(B) Exemptions. The provisions of this chapter do not apply to:
(1) Any part of a subdivision if a plat for the subdivision has been approved by
the City Council on or before the effective date of this chapter;
(2) Any land disturbing activity for which plans have been approved by the
watershed management organization within 6 months prior to the effective
date of this chapter;
(3) A lot for which a building permit has been approved on or before the
effective date of this chapter;
(4) Installation of fence, sign, telephone, and electric poles and other kinds of
posts or poles gardening, tree planting, deck construction, and other types of
construction disturbing 113 acre or less; or
(5) Emergency work to protect life, limb, or property.
(C) Waiver. The City Council may waive any requirement of this chapter upon making a
finding that compliance with the requirement will involve an unnecessary hardship
and the waiver of the requirement will not adversely affect the standards and
requirements set forth in § 152.06. The City Council may require as a condition of
the waiver, the dedication or construction, or agreement to dedicate or construct as
may be necessary to adequately meet the standards and requirements.
(Prior Code, § 15.05)
§ 152.06 STORM WATER MANAGEMENT PLAN APPROVAL PROCEDURES.
(A) Application.
(1) A written application for storm water management plan approval, along with
the proposed storm water management plan, shall be filed with the Public
Works Department and shall include a statement indicating the grounds
upon which the approval is requested, that the proposed use is permitted by
right or as an exception in the underlying zoning district, and adequate
evidence showing that the proposed use will conform to the standards set
forth in this chapter. Prior to applying for approval of a storm water
management plan, an applicant may bave the storm water management plans
reviewed by the appropriate departments of the city.
(2) Two sets of clearly legible blue or black lined copies of drawings and
required information shall be submitted to the Public Works Department and
shall be accompanied by all required fees for processing and approval as set
forth in § 152.07(E), and a bond when required by § 152,07(D) in the
amount to be calculated in accordance with that section. Drawings shall be
prepared to a scale appropriate to the site of the project and suitable for the
review to be performed. The drawing size shall be limited to a maximum of
22 inches by 34 inches and the drawing scale may range from a maximum
of 1 inch equals 20 feet to a minimum of I inch equals 100 feet.
(B) Storm water management plan. At a minimum, the storm water management plan
shall contain the following information:
(1) Existing site map. A map of existing site conditions showing the site and
immediately adjacent areas, including:
(a) The name and address of the applicant, the section, township and range,
north direction arrow, date and scale of drawing and number of sheets;
(b) Location of the tract by an insert map at a scale sufficient to clearly
identify the location of the property and giving the information as the
names and numbers of adjoining roads, utilities, subdivisions, towns
and districts or other landmarks;
(c) Existing topography with a contour interval appropriate to the
topography of the land but in no case having a contour interval greater
than 2 feet;
(d) A delineation of all streams, rivers, public waters, and wetlands located
on and immediately adjacent to the site, including depth of water, a
description of all vegetation which may be found in the water, a
statement of general water quality and any classification given to the
water body or wetland by the Minnesota Department of Natural
Resources, the Minnesota Pollution Control Agency, the Dakota
County Soil and Water Conservation District, Vermillion River
Watershed Joint Powers Organization, and/or the United States Army
Corps of Engineers;
(e) Location and dimensions of existing storm water drainage systems and
natural drainage patterns on and immediately adjacent to the site
delineating in which direction and at what rate storm water is
conveyed from the site, identifying the receiving stream, ever, public
water, or wetland, and setting forth those areas of the unaltered site
where storm water collects;
(f) A description of the soils of the site, including a map indicating soil
types of areas to be disturbed as well as a soil report containing
information on the suitability of the soils for the type of development
proposed and for the type of sewage disposal proposed and describing
any remedial steps to be taken by the developer to render the soils
suitable including special rotations locating where erosion soils exist
on the site;
(g) Vegetative cover and clearly delineating any vegetation proposed for
removal; and
(h) One hundred -year flood plain, flood fringes and floodways.
(2) Site construction plan. A site construction plan including:
(a) Locations and dimensions of all proposed land disturbing activities and
any phasing and phasing time frame of those activities;
(b) Locations and dimensions of all temporary soil or dirt stockpiles;
(c) Locations and dimensions of all construction site erosion control
measures necessary to meet the requirements of this chapter;
(d) Schedule of anticipated starting and completion date of each land
disturbing activity including the installation of construction site
erosion control measures needed to meet the requirements of this
chapter (in general the erosion control measure shall be installed prior
to any grading activity); and
(e) Provisions for maintenance of the construction site erosion control
measures during construction.
(3) Plan of final site conditions. A plan of final site conditions on the same
scale as the existing site map showing the site changes including:
(a) Finished grading shown at contours at the same interval as provided
above or as required to clearly indicate the relationship of proposed
changes to existing topography and remaining features;
(b) A landscape plan, drawn to an appropriate scale, including dimensions
and distances and the location, type, size, and description of all
proposed landscape materials which will be added to the site as part of
the development;
(c) A drainage plan of the developed site delineating in which direction
and at what rate storm water will be conveyed from the site and setting
forth the areas of the site where storm water will be allowed to collect;
(d) The proposed size, alignment, and intended use of any structures to be
erected on the site;
(e) A clear delineation and tabulation of all areas which shall be paved or
surfaced, including a description of the surfacing material to be used;
and
(f) Any other information pertinent to the particular project which in the
opinion of the applicant and/or the city is necessary for the review of
the project.
(Prior Code, § 15.06)
§ 132.07 PLAN REVIEW PROCEDURE.
(A)Process. Applicant prepared storm water management plans meeting the
requirements of § 152.06 shall be submitted to the Public Works Department for
review in accordance with the standards of § 152.08. City Council action on the
storm management plan must be accomplished within 120 days following the date the
application for approval is filed with the Public Works Department.
(B) Duration. Approval of a plan submitted under the provisions of this chapter shall
expire 1 year after the date of approval unless construction has comunenced in
accordance with the plan. However, if prior to the expiration of the approval, the
applicant makes a written request to the Public Works Department for an extension of
time to commence construction setting forth the reasons for the requested extension,
the Public Works Department may grant an extension of not greater than 1 single
year_ Receipt of any request for extension shall be acknowledged by the Public
Works Department within 15 days. The Public Works Department shall make a
decision on the extension within 30 days of receipt. Any plan may be revised in the
same manner as originally approved.
(C) Conditions. A storm water management plan may be approved subject to compliance
with conditions reasonable and necessary to insure that the requirements contained in
this chapter are met. The conditions may, among other matters, limit the size, kind or
character of the proposed development, require the construction of structures,
drainage facilities, storage basins and other facilities, require placement of vegetation,
establish required monitoring procedures, stage the work over time, require alteration
of the site design to insure buffering, and require the conveyance to the City of
Hastings or other public entity of certain lands or interests herein.
(D)Performance bond. Prior to approval of any storm water management plan, the
applicant shall submit an agreement to construct the required physical improvements,
to dedicate property or easements, or to comply with the conditions as may have been
agreed to. The agreement shall be accompanied by a performance bond to cover the
amount of the established cost of complying with the agreement. The agreement and
performance bond shall guarantee completion and compliance with conditions within
a specific time, which time may be extended in accordance with division (B) above.
The performance bond amount shall be determined by the Director of Public Works,
and shall be set at 125% of the estimated cost of the required improvement. The
adequacy, conditions and acceptability of any agreement and performance bond shall
be determined by the Hastings City Council or any official of the City of Hastings as
may be designated by resolution of the City Council.
(E) Fees. All applications for storm water management plan approval shall be
accompanied by a processing and approval fee as required by ordinance.
(Prior Code, § 15.07)
§ 152.08 APPROVAL STANDARDS.
(A) Site dewatering. Water pumped from the site shall be treated by temporary
sedimentation basins, grit chambers, sand filters, upflow chambers, hydro - cyclones,
swirl concentrators or other appropriate controls as appropriate. Water may not be
discharged in a manner that causes erosion or flooding of the site or receiving
channels or a wetland.
(B) Waste and material disposal. All waste and unused building materials (including
garbage, debris, cleaning wastes, wastewater, toxic materials or hazardous materials)
shall be properly disposed of off -site and not allowed to be carried off by runoff into a
receiving channel or storm sewer system.
(C) Tracking. Each site shall have graveled roads, access drives, and parking areas of
sufficient width and a length providing a minimum of SO feet of maintained graveled
surface both from the edge of the public or private roadway to prevent sediment from
being tracked onto public or private roadways. Any sediment reaching a public or
private road shall be removed by street cleaning (not flushing) before the end of each
workday. Failure to keep the public or private roadway clean may result in the city
ordering construction halted until the time as the roadways are properly clean.
(D) Drain inlet protection. All storm drain inlets shall be protected during construction
until control measures are in place with a straw bale, silt fence, or equivalent barrier
meeting accepted design criteria, standards and specifications included in the City's
Builders Handbook and Public Works Design Manual or otherwise approved by the
City
(E) Site erosion control.
(1) Construction Erosion Control
(a) Erosion and sediment control measures shall be consistent with Best
Management Practices (BMPs), included in the City's Builders
Handbook and Public Works Design Manual or otherwise approved by
the City, and shall be sufficient to retain sediment on site. The City
may at its discretion use turbidity measurements as an indicator of
potential non - compliance with erosion and sediment control measures
taken. Turbidity measurements will be in accordance with VRWJPO
Standards.
(b) All temporary erosion and sediment controls shall be installed on all
down gradient perimeters before commencing the land disturbing
activity, and left in place and maintained as needed until removal is
approved by the City after the site had been stabilized.. All permanent
erosion control measures shall be installed and operational per the
design and as approved by the City.
(c) For proj ects disturbing more than 1 acre,
(1) Erosion and sediment controls, and final stabilization of the site,
shall meet the most current requirements of the General Permit
Authorization to Discharge Storm Water Associated With
Construction Activity Under the National Pollutant Discharge
Elimination System/State Disposal System Permit Program Permit
(NPDES General Construction Permit) issued by the Minnesota
Pollutant Control Agency.
(2) All on -site stonnwater conveyance channels shall be designed and
constructed to withstand the expected velocity of flow from a 10-
year frequency storm without erosion.
(3) If the activity is taking place on a site where soils are currently
disturbed (e.g., a tilled agricultural site that is being developed),
areas that will not be graded as part of the development and areas
that will not be stabilized according to the timeframes specified in
the NPDES General Construction permit Part IV.B.S, shall be
seeded with a temporary or permanent cover before commencing
the proposed land disturbing activity.
(d) All activities on the site shall be phased and/or conducted in a logical
sequence to minimize the area of bare soil exposed at any one time.
(e) All disturbed ground left inactive for 14 or more days shall be stabilized
by seeding and mulching, sodding, coverings, or other equivalent control
measure. Straw, hay, or other vegetative mulch shall be disc anchored.
Geotextile or other approved covering shall be anchored in accordance
with the manufacturer's specifications.
(F) Storm water management criteria for permanent facilities as constructed for new
development in the absence of stormwater infrastructure.
(1) Post Construction Water Quality
(a) Post construction stormwater runoff quality measures shall meet the
standard for the General Permit Authorization to Discharge Storm Water
Associated With Construction Activity Under the National Pollutant
Discharge Elimination System/State Disposal System Permit Program
Permit (NPDES General Construction Permit) issued by the Minnesota
Pollution Control Agency, except where more specific requirements are
provided below.
(b) Infiltration/filtration options are the preferred approach to satisfying the
water quality treatment requirements of the NPDES General
Construction Permit. Given the high vulnerability of the Hastings
municipal water supply acquifer, only filtration will be allowed to treat
stormwater runoff from roadways, parking lots, and large paved surfaces
located within the one year travel zone of a City municipal well as
defined by the Hastings Wellhead Protection Plan.
(2) Peak Runoff Rate
(a) A hydrograph method based on sound hydrologic theory will be used to
analyze runoff for the design or analysis of flows and water levels.
(b) Runoff rates for proposed activities, and development shall:
(1) Existing conditions in runoff calculations shall be the land cover
conditions existing in the year 2005.
(2) Not exceed existing runoff rates for the 1 -year, and 10 -year critical
duration storm events.
(3) Be implemented such that the peak runoff rate for proposed
activities and development, shall not exceed the existing rate for
the 100 -year, 4 day critical duration storm event, or the 100 -year,
24 -hour storm event, whichever is greater.
(3) Volume Runoff Criteria
(a) Development that creates one acre or more of new impervious surface
must incorporate volume control practices into the design sufficient to
prevent an increase in the runoff volume for the 2 -year 24 -hour storm
above pre - development conditions unless waived in accordance with the
Drainage Alternate Rule. Determination of the necessary control volume
to achieve this Standard can be completed by the City on a regional basis
and included in an approved Local Water Plan, or calculated on a site -
by -site basis for each individual proposal.
(b) The water quality control volumes necessary to meet the NPDES
General Construction Permit that are satisfied using infiltration or
filtration technologies within the City's Drinking Water Surface
Management Area (DWSMA) can count toward the Volume Control
requirements of these Rules
(c) Given the high vulnerability of the Hastings municipal water supply
acquifer, only filtration will be allowed to treat stormwater runoff from
roadways, parking lots, and large paved surfaces located within the one
year travel zone of a City municipal well as defined by the Hastings
Wellhead Protection Plan. When permitted, infiltration for volume
control shall meet the following requirements;
(1) Infiltration volumes and facility sizes shall be calculated:
(a) Using the appropriate hydrological soil group classification
and saturated infiltration rate from the current VRWJPO
rules.
(b) Using documented, site specific, infiltration or hydraulic
conductivity measurements completed by a licensed soil
scientist or engineer, or
(c) Using the method provided in the current Minnesota
Stormwater Manual as published by the Minnesota
Pollution Control Agency and,
(2) The design shall consider the infiltration rates of the least
permeable horizon within the first five feet below the bottom of the
infiltration practice, and
(3) The system shall be capable of infiltrating the required volume in
72 hours.
(d) Constructed infiltration or filtration facilities, such as basins and
trenches:
(1) Can only be used if there is pretreatment of stormwater runoff
designed to protect such systems from clogging with sediment and
to protect groundwater quality;
(2) Cannot be used within the emergency response area as defined by
the Drinking Water Surface Management Area, within the one year
travel zone of a municipal or other community supply well as
defined in the Hastings Well Head Protection Plan, or within 100
feet of a private well unless specifically allowed by an approved
wellhead protection plan;
(3) Cannot be used for runoff from fueling and vehicle maintenance
areas and industrial areas with exposed materials capable of
leeching into the soil;
(4) Cannot be used on areas with less than 3 feet vertical separation
from the bottom of the infiltration system and the seasonal high
water table;
(5) Cannot be used in Type D soils.
(e) Infiltration and filtration areas must be fenced or otherwise protected
from disturbance before the land disturbing activity starts.
(f) Volume control amounts may be waived by the City for sites with
predominately Type C and D soils, shallow bedrock, or where a shallow
water table prevents construction of infiltration systems, provided the
following are met in order of decreasing preference:
(1) Site design practices to minirnize the creation of connected
impervious surfaces are used to the extent practical.
(2) Underdrains are used to promote filtration instead of infiltration.
(g) Vegetation used in conjunction with infiltration systems must be tolerant
of urban pollutants, and the range of soil moisture conditions
anticipated.
(4) Drainage Alteration Rule
(a) Outlets from landlocked basins with a tributary drainage area of 100
acres or more will be allowed, provided such outlets are consistent with
other portions of these Rules, State and Federal regulations, and the
downstream impacts, riparian impacts, and habitat impacts of such
outlets have been analyzed and no detrimental impacts result. The
analysis and determination of detrimental impacts shall:
(1) Use a hydrograph method based on sound hydrologic theory to
analyze runoff for the design or analysis of flows and water levels;
(2) Ensure a hydrologic regime consistent with the Peak Runoff Rate
Control Criteria and the Runoff Volume Control Criteria of these
Rules;
(3) Ensure the outlet does not create adverse downstream flooding or
water quality conditions, or materially affect stability of
downstream major waterways;
(4) Maintain dead storage within the basin to the extent possible while
preventing damage to property adjacent to the basin;
(5) Ensure that the low floors of new structures adj acent to the basin
are set consistent with the Floodplain Alterations Rule; and,
(6) Ensure that proposed development tributary to the land- locked
basin has incorporated runoff volume control practices to the
extent practical.
(b) Artificial drainage, flow obstruction, and diversions involving
waterways, public waters, public water wetland, wetlands with drainage
areas of 640 acres or more will be allowed provided such alterations or
diversions are consistent with other portions of these Rules, State and
Federal regulations, and the downstream impacts, riparian impacts and
habitat impacts of such alterations or diversions have been analyzed and
no detrimental impacts result. Proposals for drainage alterations and
diversions shall demonstrate that:
(1) There is a reasonable necessity for such drainage alteration or
diversion to improve or protect human health and safety, or to
improve or protect aquatic resources;
(2) Reasonable care has been taken to avoid unnecessary injury to
upstream and downstream land;
(3) 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
(4) The drainage alteration or diversion 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.
(c) Drainage alterations, diversions, and landlocked basin outlets shall be
provided with stable channels and outfall.
(G) Wetlands
(1) General Provisions
(a) Any drainage, filling, excavation, or other alteration of a public waters
wetland or wetland shall be conducted in compliance with Minnesota
Statues, section 103G.245, Wetland Conservation Act (WCA),
Minnesota Rules 8420, and regulations adopted hereunder.
(b) In order to preserve WCA exemption or no loss determination, projects
involving excavation in Types 1, 2, 6, and 7 wetlands must demonstrate
a beneficial purpose, such as habitat or water quality improvements, and
minimize loss of wetland function as determined by the City.
(c) A high quality (or equivalent value) public waters wetland or wetland
(as determined by methods acceptable to the VRWJPO for vegetative
diversity) may not be used for stormwater management and treatment
unless the use will not adversely affect the function and public value of
the wetland and other alternatives do not exist. Runoff shall not be
discharged directly into a high quality public water wetlands or wetland
(as determined by methods acceptable to the VRWJPO for vegetative
diversity) without pretreatment of the runoff,
(2) No Net Loss and Wetland Alteration
(a) No permits will be granted until the WCA replacement plan is approved
or exemption certificate is obtained. Wetland replacement/mitigation
citing must follow the priority order:
(1) Mitigation on -site
(2) Mitigation within the same minor subwatershed as established by
the Minnesota Department of Natural Resources for the "1979
Watershed Mapping Project" pursuant to Minnesota Laws 1977,
chapter 455, section33, subdivision 7, paragraph (a).
(3) Mitigation within the JPO boundary
(4) Mitigation within Dakota County
(b) Transportation projects shall pursue wetland mitigation projects to the
extent practical using the criteria above. However, this does not preclude
the use of the BWSR Replacement Program.
(3) Wetland Buffer Areas
(a) Application: Buffer areas abutting all rivers, streams, and wetlands as
identified in Figure 4 of City's Water Management Plan.
(b) Classification: A wetlands functional assessment for vegetative diversity
will be completed with each wetland and public waters wetland,
delineated for a project and buffers established according to the
management classification in the following table. Figure 4 and 8 in the
Water Management Plan, as adopted in 2009, delineates three different
duality standards for wetlands. All wetlands shown on Figure 8 not
shown on Figure 4 are considered Low Quality. Buffers on wetlands
begin at the delineated edge of the wetland; (the line where hydrology,
vegetation, and soils indicates a change between upland and wetland).
(1) Exceptional Quality Wetland:
(a) Average Buffer Width: 50ft
(b) Minimum Buffer Width: 3 0ft
(2) High Quality Wetland:
(a) Average Buffer Width: 40ft
(b) Minimum Buffer Width: 30ft
(3) Medium Quality Wetland:
(a) Average Buffer Width: 30ft
(b) Minimum Buffer Width: 25ft
(4) Low Quality Wetland:
(a) Average Buffer Width: 25ft
(b) Minimum Buffer Width: 16.5ft
(c) Buffer area requirements: Where acceptable natural vegetation exists in
buffer areas, the retention of such vegetation in an undisturbed state is
required unless approval to replace such vegetation is received. A buffer
has acceptable vegetation if it:
(1) Has a continuous, dense layer of perennial grasses that has been
uncultivated or unbroken for at least 5 consecutive years; or,
(2) Has an overstory of trees and/or shrubs that has been uncultivated
or unbroken for at least 5 consecutive years; or,
(3) Contains a mixture of the plant communities in Criteria (c)(1) and
(c)(2) above that has been uncultivated or unbroken for at least 5
years.
(d) Maintenance of Buffer Areas: Buffers shall be staked and protected in
the field prior to construction unless the vegetation and the condition of
the buffer are considered inadequate. Existing conditions vegetation will
be considered unacceptable if:
(1) Topography or sparse vegetation tends to channelize the flow of
surface water
(2) Some other reason the vegetation is unlikely to retain nutrients and
sediment
(e) Requirements for Replanting: Where buffer vegetation and conditions
are unacceptable, or where approval has been obtained to replant,
buffers shall be replanted and maintained according to the following
criteria:
(1) Buffers shall be planted with a native seed mix approved by
MnDOT, BWSR, NRCS or the Dakota County SWCD, with the
exception of a one -time planting with an annual nurse or cover
crop. Plantings of native forbs and grasses may be substituted for
seeding. All substitutions must be approved by the City.
Groupings /clusters of native trees and shrubs, of species and at
densities appropriate to site conditions, shall also be planted
throughout the buffer area.
(2) The seed mix and planting shall be broadcastlinstalled according to
MnDOT, BWSR, NRCS or Dakota County SWCD specifications.
The selected seed mixes and plantings for permanent cover shall be
appropriate for the soil site conditions and free of invasive species.
(3) Buffer vegetation (both natural and created) shall be protected by
erosion and sediment control measures during construction.
(4) During the first five full growing seasons, except where the City
has determined vegetation establishment is acceptable, the owner
or applicant must replant buffer vegetation where the vegetative
cover is less than 90 %. The owner or applicant must assure
reseeding/or replanting if the buffer changes at any time through
human intervention or activities.
(f) Conservation Easement: Where a buffer is required, the City shall
require the protection of the buffer under a conservation easement, or
include the buffer in a dedicated outlot as part of platting and
subdivision approval, except where the buffer is located in a public
transportation right -of -way. Buffer shall also have monumentation to
clearly designate the boundaries of all new buffers within new
residential subdivisions. A monument shall consist of a post and a buffer
strip sign approved by the City.
(g) Usage:
(1) Alterations, including building, storage, paving, routine mowing,
burning, plowing, introduction of noxious vegetation, cutting,
dredging, filing, mining, dumping, grazing livestock, agricultural
production, yard waste disposal, or fertilizer application are
prohibited within any buffer. Periodic mowing or burning, or the
use of fertilizers and pesticides for the purpose of managing and
maintaining native vegetation. may be allowed with approval of
the City. Noxious weeds may be removed and mechanical or spot
herbicide treatments may be used to control noxious weeds, but
aerial or broadcast spraying is not acceptable. Prohibited
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, or as otherwise
clarified in Criteria 3d.
(2) The following activities shall be permitted within any buffer, and
shall not constitute prohibited alterations:
(a) The following activities are allowed within both the minimum
and average buffer width areas:
(1) Use and maintenance of an unimproved access strip
through the buffer, not more than 10 feet in width, for
recreational access to the - major waterway or wetland
and the exercise of riparian rights;
(2) Structures that exist when the buffer is created;
(3) Placement, maintenance, repair, or replacement of
public roads and utility and drainage systems that exist
on creation of the buffer or are required to comply with
any subdivision approval or building permit obtained
from the City, so long as any adverse impacts of public
road, utility, or drainage systems on the function of the
buffer have been avoided or minimized to the extent
practical;
(4) Clearing, grading, and seeding is allowed if part of an
approved Wetland Replacement Plan, or approved
Stream Restoration Plan.
(5) Construction of a multipurpose trail, including
boardwalks and pedestrian bridges, provided it is
constructed to minimize erosion and new impervious
surface, and has an undisturbed area of vegetative
buffer at least ten (10) feet in width between the trail
and the wetland or public waters wetland edge, or the
bank of the major waterway; or where needed to cross
the major waterway, the minimum impact alignment is
used.
(6) The construction of underground utilities such as water,
stormwater, and sanitary sewers and pipelines provided
the minimum impact alignment is used, the area is
stabilized in accordance with Criteria 3d above, and
setbacks established in the Floodplain Alterations Rule,
are met.
(b) The following activities are allowed within those portions of
the average buffer width that exceed the minimum buffer
width:
(1) Stormwater management facilities, provided the land
areas are stabilized in accordance with Criteria (e)(1 -4)
above, and alterations prohibited in Criteria (g)(1)
above are upheld.
(2) The area of shallow vegetated infiltration and
biof ltration facilities, and water quality ponds not to
exceed 50 percent of the pond area, adjacent to
wetlands and major waterways may be included in
buffer averaging provided the facilities do not encroach
into the minimum buffer width, and the land areas are
stabilized in accordance with Criteria 3d above, and
alterations prohibited in Criteria fl above are upheld.
§ 152.09 OTHER CONTROLS.
In the event of any conflict between the provisions of this chapter and the provisions of
an erosion control or shoreland protection ordinance adopted by the City Council, the
more restrictive standard prevails.
(Prior Code, § 15.09)
§ 152.98 VIOLATIONS.
Every person violates a section, subdivision, paragraph, or provision of this chapter when
he or she perfon s an act thereby prohibited or declared unlawful, or fails to act when the
failure is thereby prohibited or declared unlawful, and upon conviction thereof, shall be
punished as for a misdemeanor except as otherwise stated in specific provisions hereof,
(Prior Code, § 15.99) Penalty, see § 10.99