The City Council of the City of Dayton finds that wetlands serve a variety of beneficial functions. Wetlands maintain water quality, reduce flooding and erosion, provide food and habitat for wildlife, provide open space, and are an integral part of the City's environment. Wetlands are also important physical, educational, ecological, aesthetic, recreational and economic assets to the City. They are critical to the City's stormwater management and other aspects of the public health, safety and general welfare. Regulating wetlands and the land uses around them is therefore in the public interest.

   For the purposes of this Section, the following terms shall have the meanings given to them.

   The individual or entity submitting a land use application to the City.

   Locations identified by the Minnesota Department of Natural Resources (DNR) as high quality natural areas and/or sites of biodiversity significance.

   Plant species indigenous to or naturalized to the Hennepin County region of the State of Minnesota or plant species classified by the Minnesota Department of Natural Resources as native in the Minnesota Native Plant Database. Native Vegetation does not include weeds as defined by this Section.

   Species not indigenous to or naturalized to the Hennepin County region of the State of Minnesota by the Department of Natural Resources or plant species.

   This is an elevation that is defined by the Department of Natural Resources as the top of bank. The OHWL at a location along the watercourse is determined by averaging the elevations of the top of channel banks, with consideration given to the degree of slope (gradient) of the watercourse and the character of the channel and channel banks.

   The minimum horizontal distance between a structure and the nearest edge of the upland buffer zone.

   An area or areas of vegetated ground cover around the perimeter of a wetland that, either in its natural condition or through intervention, is critical to the protection of that wetland. An Upland Buffer Zone protects the edge of a wetland from erosion and filter sediment, chemicals and other nutrients from the runoff that drains into the wetland. An Upland Buffer Zone also provides wildlife habitat and assists in maintaining diversity of both plant and animal species within the City. It also reduces human disturbances to the wetland by providing a visual and physical transition area from a yard to a wetland.

   Noxious weeds as defined and designated pursuant to the Minnesota Noxious Weed Law, M.S. §§ 18.76 through 18.88, as amended from time to time, or any volunteer plants, including, but not limited to, spotted knapweed (Centaurea Maculosa) or burdock (Arctium Minus). For the purposes of this Section, Weeds shall not include dandelions or clover. The City Weed Inspector and/or Assistant City Weed Inspector shall maintain a current list of plants that are defined as Weeds for purposes of this Section.

   A land that is 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. For purposes of this Section, in order for a land to be considered a Wetland, it must have all of the following characteristics:

      (a)   A predominance of hydric soils;

      (b)   Be 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

      (c)   Under normal circumstances, support a prevalence of hydrophytic vegetation.

   (1)   In order to protect wetlands, this Section incorporates by reference the WCA and any future amendments to the WCA that are adopted by the Legislature. In the event that any requirements of this Section are inconsistent with the WCA, the stricter provision that provides the most protection for wetlands shall apply.

   (2)   Applicability. This Section shall apply to all property containing wetlands in the following circumstances:

      a.   When any new development activity occurs on the property. For purposes of this Section, New Development Activity means:

         1.   Any subdivision or minor subdivision which results in a net increase in the number of lots.

         2.   Construction of a principal structure on an existing vacant lot.

   (3)   Exemptions. The upland buffer zone and setback requirements of this Section shall not apply to the following:

      a.   Any land use application that has received final or preliminary plat approval by the City Council prior to the effective date of this Section;

      b.   Any previously buildable parcel existing prior to the effective date of this Section which is rendered unbuildable under City Code because of the implementation of the upland buffer zone and buffer setbacks as required by this Section and other restrictions in the Zoning Ordinance.

   An applicant shall submit the following information to the City along with all other materials required by City Code with respect to any land use application or permit application:

   (1)   A grading plan (if grading is proposed), including the area and volume of land disturbance.

   (2)   The square footage of the proposed structure and any impervious surface.

   (3)   A wetland delineation report. It is the responsibility of the applicant to determine whether wetlands exist on the property by completing a wetland delineation and submitting a wetland delineation report. The following shall apply to the wetland delineation report:

      a.   The report shall delineate and document the boundaries of any wetlands on the property in accordance with the WCA requirements.

      b.   The City will require that the wetland delineation be performed by a certified wetland delineator. The wetland delineation must be performed according to the 1987 U.S. Army Corps of Engineers Wetland Delineation Manual and subsequent amendments, and be acceptable to the City Engineer. The City Engineer shall have complete discretion in determining whether the wetland delineation report is acceptable.

      c.   Wetland delineations shall be completed by the applicant between April 20 and October 20 of the given year and must be submitted to the City for review no later than November 1. A wetland delineation completed outside these dates or submitted later than November 1 may be considered to be incomplete.

   (4)   A certificate of survey or site plan describing the proposed activity and showing the upland buffer zones to the wetlands on the property.

   (5)   An upland buffer zone landscaping plan, if required.

   (6)   Any submittals required by the WCA.

   (7)   Legal descriptions of the upslope edge of the upland buffer zones to be used for the conservation easement. Wetlands and upland buffer zones shall be protected by a conservation easement to be granted to the City; and

   (8)   Deposit funds in an amount to be determined by the City to be used for any expenses incurred by the City in completing its review of the wetland delineation report, wetland ordinance compliance, and, if appropriate, developing a wetland boundary estimate and determining if the upland buffer zones proposed by the applicant meet the requirements of this Section.

   (1)   If a new development activity, as defined in Subdivision 3(2)a. of this Section, is proposed, the following upland buffer zone and structure setbacks shall be required for each wetland within or adjacent to the subject property:

      The upland buffer zone adjacent to wetlands is required to have an average width of 25 feet, with a minimum width of 10 feet. The principal structure setback from the upland buffer zone is required to be 15 feet.

      A minimum 50-foot upland buffer zone and 20-foot principal structure setback from the upland buffer zone is required adjacent to Elm Creek, Rush Creek, North Fork Rush Creek and Diamond Creek. The upland buffer zone will be taken from the delineated wetland edge or ordinary high water level as defined by the Department of Natural Resources if there is not an adjacent wetland.

   If approved by City staff, the width of the upland buffer zone may vary along the wetland's boundaries, so long as the following conditions are met:

      a.   The upland buffer zone's width does not fall below the minimum upland buffer zone width at any location;

      b.   The total area of the upland buffer zone meets or exceeds the total area which would be required if the upland buffer zone average width was utilized; and

      c.   Areas that are within an upland buffer zone with a preconstruction slope exceeding 12% must meet or exceed the upland buffer zone average width requirement.

   (2)   All upland buffer zones shall be measured from the edge of the delineated wetland, as approved by the City, into the adjacent upland area.

   (3)   The total area required for an upland buffer zone is not required to exceed 300% of the area of the adjacent wetland unless the wetland is adjacent to Elm Creek, Rush Creek, North Fork Rush Creek and Diamond Creek. If it is adjacent to these creeks it will need to meet the 50-foot requirement.

   (4)   Where existing structures or impervious surfaces are located within an area that would be required to be included in an upland buffer zone, alternative methods to protect the wetland may be approved by the City staff in order to avoid creating unreasonable impacts on the existing use of the property. Such methods may include, but are not limited to, upland buffer zone width averaging below the minimum required, redirection of drainage to a different area where an upland buffer zone is feasible while still maintaining the drainage to the wetland, or the use of rainwater gardens, vegetated swales or other best management practices for treating runoff.

   (5)   For roadways, trails, and driveways, or portions thereof that are routed across a wetland pursuant to an approved WCA permit application, upland buffer zones will be required on the till slope but fill shall not be expanded to accommodate the upland buffer zone requirement. Mitigation of the upland buffer zone will be required as described in Subdivision 10 of this Section.

   (1)   The area within wetlands and upland buffer zones shall be preserved predominately in their natural states, except to the extent set forth below. Wetlands and upland buffer zones must be protected by a conservation easement granted to the City by the applicant in a form provided by the City. The conservation easement will preserve the natural state of the wetland and upland buffer zones by restricting the activities that are allowed within the easement areas. The easement will give the City the authority to enforce the conservation easement restrictions. Additional public uses within the conservation easement, such as a trail, will not be required by the City for these purposes but may be required pursuant to other applicable City requirements.

   (2)   Any alterations within the wetland and upland buffer zone, except those stated below, shall be prohibited, including, but not limited to, the installation or placement of structures and impervious surfaces, the destruction or removal of trees, shrubs or other vegetation, the introduction of any non-native vegetation, any mowing, dredging or excavation activities and the placement or storage of any fill material or trash and the application of fertilizer. The following activities are permitted:

      a.   Activities described within an upland buffer zone landscaping or mitigation plan that was approved by the City;

      b.   The removal of non-native vegetation;

      c.   The removal of dead or diseased trees that pose a hazard;

      d.   The installation of utility poles, underground utility lines, light poles, traffic regulatory signs and signals, mailboxes, and other equipment that is determined by the City to provide an essential public service;

      e.   The installation of public and private flood control structures, ponding and drainage facilities and associated accessory appurtenances as approved by the City;

      f.   The installation of environmental monitoring or control facilities, including those related to water quality and wildlife regulation;

      g.   The mowing of or installation of permeable pathways not to exceed 4 feet in width to allow reasonable access to the wetland;

      h.   The installation of boardwalks, docks or other structures to allow reasonable access to the wetland or lake. These structures shall not exceed 4 feet in width or have poles greater than 2 feet in diameter;

      i.   The installation of public trails, if required. The temporary and permanent trail disturbance shall not exceed 9 feet in width and must be located outside of the minimum width of the required upland buffer zone.

   All upland buffer zones shall identified with markers. The applicant shall be responsible for the costs of obtaining and installing the markers. At a minimum, 1 marker shall be placed per lot at the upslope edge of the upland buffer zone and then placed every 250 feet thereafter and on all common lot lines.

   (1)   Proposed locations of the markers shall be shown on the grading or site plan for the property. The location of the markers shall capture the portion of the upland buffer zone that extends the furthest upslope into the lot. A plan that shows the location of the marker shall be provided to the City for its review and approval.

   (2)   Artwork and verbiage on the sign shall face away from the wetland.

   (3)   Sign dimensions, specifications, verbiage, and artwork shall be specified by the City and provided to the applicant.

   Upland buffer zones shall meet the following vegetation performance standards:

   (1)   Where acceptable natural vegetation exists in an upland buffer zone, disturbance is allowed only with approval from the City. An upland buffer zone will be considered to have acceptable natural vegetation if it:

      a.   Is composed of less than 25% weeds; and

      b.   Is covered by native vegetation with less than 5% exposed soil; unless exposed soil is due to native canopy cover; and

      c.   Does not contain maintained turf grass.

   (2)   Where an upland buffer zone or a portion thereof is not considered acceptable or is to be disturbed, an upland buffer zone landscaping plan must be submitted to the City Engineer for approval. At a minimum, the landscaping plan shall include the following information:

      a.   A plan sheet that shows the location of the upland buffer zones. The plan sheet must also show upland buffer zones that are considered to be acceptable in their current state and identify them as areas that will not be disturbed during grading. The City may require silt fencing around these areas in order to protect them from erosion and disturbance during grading and construction;

      b.   The species, planting and seeding locations for upland buffer zones that were determined to be unacceptable by the City. This shall involve the seeding or planting of a minimum of at least 4 species of native grasses and 5 species of native forbs and a cover crop. The seed mix shall consist of at least 15 pounds of pure live seed (PLS) per acre and the cover crop shall be at least 20 pounds per acre. If planting is proposed, spacing between plants shall not exceed 3 feet unless otherwise approved by the City Engineer; and

      c.   Detailed specifications that describe sequencing, scheduling, materials, installation and maintenance execution for the seeding, planting, or weed removal within the upland buffer zones.

   (3)   In cases where an upland buffer zone landscaping plan is required, the City may require an approved form of a financial guarantee equal to 150% of the estimated cost of the vegetation installation. The financial guarantee shall be valid for 2 years and may be used by the City for compliance inspections and establishment of the required vegetation if not completed by applicant or if deemed unsuccessful by the City. Vegetation will be deemed by the City to be successful if the area has a minimum of 1 plant per square foot from the specified seed mix or planting plan and less than 25% of the area is inhabited by weeds.

   The property owner or homeowners' association shall be responsible for maintaining the upland buffer zones on the property. Maintenance shall include the following:

   (1)   Maintain and repair any damage to the wetland buffer zone caused by activities such as mowing, cutting or grading, unless the activities are approved by the City.

   (2)   Ensure that all soil surfaces in the wetland buffer zone are planted with native vegetation and that there is less then 5% of open soil surface which may result in erosion.

   (1)   In cases where a wetland permit approval results in upland buffer zone alteration mitigation is required for the upland buffer as well as the wetland.

   (2)   The following shall be required by the City for any upland buffer zone mitigation:

      a.   Upland buffer zones shall be required to be replaced on the fill slope and elsewhere along the edge of the existing wetland to meet the upland buffer areas for the associated classification of the wetland. If a wetland is to be completely filled pursuant to an approved wetland permit, the upland buffer zone area requirement associated with the classification of that wetland will be required for the replacement wetland unless the replacement is occurring adjacent to a wetland with a classification that requires a wider upland buffer zone. In that event, the upland buffer zone requirement for the wider upland buffer zone shall apply.

      b.   Upland buffer zone plantings that are completed for mitigation shall meet the standards for vegetation specified in this section.

      c.   Upland buffer zones may be utilized for wetland mitigation credits if they meet the requirements of the WCA.

   An applicant will be required to provide a hydrologic restoration plan and implementation of the plan for wetlands within a proposed subdivision if all the following criteria are met:

   (1)   The wetland has been hydrologically altered by ditching, drain tile, or a lower outlet elevation but still exists in a partially drained state. Wetlands that have been entirely drained by ditches or tile lines and are no longer jurisdictional wetlands will not have a hydrologic restoration requirement.

   (2)   The wetland, if restored, can be reasonably designed to only impact the hydrology of the property in which it is located. If the restoration will impact the hydrology or drainage of an adjacent landowner, the landowner shall be contacted to determine if they are willing to allow the alteration. If the landowner is not willing to except the alteration, then the wetland restoration will not be required.

   (3)   The hydrologic restoration can be designed in a way to limit the conversion of upland to wetland. If the wetland is restored, the applicant will be allowed to grade up to the delineated wetland edge to maintain the developable upland of the property. If grading to reduce wetland expansion is not practical and there is a net increase of 5% or more of upland converted to wetland the applicant will not be required to restore the basin.

   (4)   All wetlands within a subdivision will be required to be hydrologically restored if they meet criteria (1) through (3) above unless it is proven that it is technically or economically not feasible. The goal of the restoration shall be to restore to the previous (prior to hydrologic alteration) wetland type.

   A variance from the requirements of this Section may be granted by the City Council in accordance with the variance provisions of the City Code, so long as the variance does not violate the Wetland Conservation Act or any other applicable state statutes or rules.

   (1)   Investigation. When a violation of this Section is either discovered by or brought to the attention of the City, the City shall immediately investigate the situation and document the nature and extent of the violation.

   (2)   Notice of the violation. If a violation is found to exist, the City shall notify the offending party of the requirements of this Section, all other applicable official controls and the nature and extent of the suspected violation of these controls. If the structure or use is under construction or development, the City may order the construction or development to be immediately stopped until the property is brought into compliance with this Section. If the construction or development has already been completed, then the City may issue an order identifying the corrective actions that must be made within a specified time period to bring the use or structure into compliance with this Section.

   (3)   Appeal. The offending party may appeal the City's correction order to the City Council. An appeal must be brought in writing no later than 10 days from the date of the notice.

   (4)   Failure to correct. If the offending party does not correct the work within the specified date on the notice and no appeal has been taken within 10 days of the notice, the City may enter the property and perform the corrective work. Any amount incurred by the City in performing the corrective work may be certified by the City to the county for collection with the property taxes.

   (5)   Penalties. Any person who violates any provision of this Section shall be guilty of a misdemeanor and shall be subject to a maximum fine or maximum period of imprisonment, or both, as specified by M.S. § 609.03. Each additional day that the property remains in violation of this Section shall constitute an additional violation of this Section and may be prosecuted accordingly.

   (6)   Nothing contained herein shall prevent the City from taking such other lawful action as is necessary to prevent or remedy any violation of this Section, including, but not limited to, seeking a civil injunction or restraining order.

(Ord. 2008-16, passed 9-8-2008; Am. Ord. 2012-06, passed 4-24-2012; Am. Ord. 2014-04, passed 3-25-2014; Am. Ord. 2017-12, passed 9-25-2017)