A. Purpose And Intent: It is the purpose of this section to apply development standards to lots or parcels with the greatest chance of affecting water quality:
1. Maintain the community's ability to manage stormwater through protection of "critical conveyances".
2. Protect and improve the quality of the Whitefish area's water bodies, including lakes, streams, and the Whitefish River, which are central to the community's identity and values.
3. Protect public safety, public and private property, and water quality from threats of geologic instability and erosion.
4. Protect and preserve the lawful use and enjoyment of private property.
To accomplish these objectives, this section will set forth a series of standards and regulations to maintain the ability of critical conveyances to carry stormwater; to limit sediment, nutrients and other pollutants entering the area's streams and lakes; to properly condition and, where necessary, prohibit development in geologically unstable areas adjacent to water bodies.
The intent of these regulations is to promote lawful and responsible land development. These regulations allow the restoration of streams, stream banks, slopes, and wetlands; sound forest management; and the clearing and removal of hazardous vegetation to protect life and property.
B. Administration:
1. Applicability: Any new or expanded residential, commercial or industrial development proposal within two hundred (200) horizontal feet of a lake, river, wetland, stream or stormwater conveyance must comply with this section. Any lots or parcels that were created by whatever means prior to April 3, 2006, or after March 3, 2008, are required to comply with this section.
The following developments, activities and associated uses are exempt from the provision of this section:
a. Those activities necessary to prevent an immediate threat to public health, safety, or welfare, or pose an immediate risk of damage to private property and that require remedial or preventive action in a time frame too short to allow for compliance with the requirements of this section. After the emergency, the person or agency undertaking the action must report any impacts to the water quality protection area to the director within five (5) days of the activity. The director may require submittal of a water quality protection area report or geotechnical letter to guide restoration or mitigation for these impacts. Final approval of the report, restoration and mitigation will be in accordance with provisions of this section.
b. Operation, maintenance, repair, modification, or addition to existing structures, infrastructure improvements, utilities, public or private roads, dikes, levees, or drainage systems, if the activity applies best management practices and does not further encroach within a water quality protection area or buffer and there is no increased risk to life or property as a result of the action. As applicable, new facilities must comply with section 11-3-33 (erosion control) of this chapter and subsection 11-7-10E (mitigation for impacts) of this title. Operation and maintenance includes minor landscaping, native plant landscaping, buffer restoration, bank stabilization with native plant landscaping and vegetation management, provided that such management actions are part of regular and ongoing maintenance and do not expand farther into the water quality protection area or buffer.
c. Agricultural activities, as defined in Montana Code Annotated 76-2-902. This includes timber harvesting, thinning, and regeneration on land without residential structures. Timber harvesting on forestlands proposed for conversion to other uses must be in compliance with Montana Code Annotated 77-5-301 - 307, the Montana streamside management zone law. Violations of Montana Code Annotated 77-5-301 - 307 must be remediated to the satisfaction of the Montana department of natural resources and conservation prior to submittal of development permits under this section.
d. Educational and research activities that do not degrade the functions and values of a water quality protection area or buffer, and conservation or restoration activities to protect or restore these functions and values.
e. Development of a lot contained within a preliminary plat or planned unit development approved by the Whitefish city council prior to April 2, 2008, pursuant to the approved building site plan or building pad, if the building site plan or building pad are specifically located on the lot, but only to the extent that such development is located within the building site plan or building pad. The zoning administrator may, on a case by case basis, approve minor modifications to the building site plan or building pad. However, this exemption does not exempt a property owner from the requirements of section 11-3-33 of this chapter.
2. Relationship to Other Regulations:
a. These water quality protection regulations apply as an overlay and in addition to zoning and other regulations adopted by the city.
b. Any individual water quality protection area adjoined by another type of water quality protection area will have the buffer and meet the requirements providing the most protection to the water quality protection areas involved. When any provision of this section or any existing regulation, easement, covenant, or deed restriction conflicts with this section, that which provides more protection to the water quality protection areas apply.
c. The city will not approve any permit or otherwise issue any authorization to alter the condition of any land, water, or vegetation, or to construct or alter any structure or improvement in, over, or on a water quality protection area or associated buffer, without first ensuring compliance with the requirements of this section.
d. Compliance with the provisions of this section does not constitute compliance with other federal, state, and local regulations and permits that may be required, nor does it relieve an applicant from the duty to avoid harm to neighboring or downstream properties or create a duty to neighboring or downstream properties on the part of the city. The applicant is responsible for complying with these other requirements and duties, apart from the process established in this section.
3. Administrative Rules: Applicable departments within the city are authorized to adopt such administrative rules and regulations as are necessary and appropriate to implement this section and to prepare and require the use of such forms as are necessary for its administration.
4. Permitting: Development within two hundred feet (200') of a water quality protection area that is not exempt under subsection B1 of this section must obtain a permit prior to the start of any proposed activity pursuant to section 11-7-10 of this title.
5. Reasonable Use Exception: When the requirements of this section, or these requirements in combination with zoning and other development standards, would render a legally existing lot or parcel of record incapable of providing any legal and reasonable use, as defined in this subsection, a reasonable use exception (RUE) will be issued by the director if the criteria in this subsection are met. A “legal and reasonable use” is defined as one allowed by the applicable zoning district and consistent with similar uses in the same general area, taking into account the most recent construction trends in the general area. For dwelling units, a legal and reasonable use may disturb no more than five thousand (5,000) square feet or fifteen percent (15%) of the parcel, whichever is greater, by structures or other land alteration, including grading, utility installations and landscaping, but not including the area used for an on site sewage disposal system.
a. An application for a reasonable use exception must be made to the city and must include a water quality protection area identification form; water quality protection area report or geotechnical letter, as applicable; and any other related project documents, such as permit applications to other agencies. The application must document what can be developed on the property in compliance with the strict provisions of this section and other zoning and development standards, and must explain why this would not permit any reasonable use of the property. It must include the date the applicant purchased the property or otherwise obtained the right to develop or use it, and restrictions or conditions on use or development in existence on that date. The burden of proof is on the applicant to bring forth evidence in support of the application and to provide sufficient information on which any decision has to be made on the application.
b. Following receipt of a complete and accurate submittal, within thirty (30) days the director will grant or deny a request for an RUE in writing with findings of fact pursuant to the determinations set forth in subsection B5c of this section.
c. In reviewing applications for RUEs, the director shall determine that all of the following criteria are met:
(1) The lot, tract, or parcel is a legal lot of record.
(2) All reasonable use of the property is preempted under the strict provisions of this section, or the combination of this section and zoning and development standards, for reasons other than actions by the applicant after the effective date hereof.
(3) There are no reasonable development alternatives readily available to the applicant that meet the standards of these regulations.
(4) The RUE does not pose a threat of significant injury to occupiers of the land, other properties, or the natural resources protected by this section.
(5) Impacts associated with the RUE are the minimum necessary to allow for reasonable use of the property, and will be reasonably and effectively mitigated through conditions of approval.
d. An RUE will not be approved solely to improve views and vistas or proximity to amenities when viable alternatives exist. Preference will be given to modifying or waiving development standards that do not impact water quality protection areas or the safety of the occupiers of the land or other properties.
e. Approval or denial of any RUE may be appealed to the community development board pursuant to section 11-7-5 of this title. An approved RUE must be recorded with the Flathead County clerk and recorder prior to any construction activity. The RUE is valid for three (3) years and the director may approve up to two (2) 1-year extensions, provided the applicant can demonstrate progress is being made on the project. If construction has not begun during the approval period, the RUE will expire.
6. Variances: A variance from the requirements of this section may be authorized through a planned unit development or a neighborhood plan or, in other cases, by the director, in conjunction with the public works department, if the applicant provides clear and compelling evidence that the result would better protect or restore the functions and values of affected water quality protection areas than would application of standard criteria or in the case where these regulations conflict with state or federal regulations.
7. Public Agencies And Utilities: If the application of this section would prohibit a development proposal by a public agency or public utility, the agency or utility may apply for a reasonable use exception, which must follow the procedures and criteria of subsection B5 of this section, as applicable, and demonstrate that application of this section would otherwise unreasonably restrict the ability to provide services to the public.
8. Mapping: The city must maintain planning level maps indicating the best available information as to the location of water quality protection areas. In addition to these maps, the following may be used as a guide for locating water quality protection areas:
a. Topographic maps published by the U.S. geological survey;
b. Flood insurance rate maps published by the federal emergency management agency;
c. Surficial geologic map of the upper Flathead River Valley (Kalispell Valley) area, Flathead County, northwestern Montana, published by the Montana bureau of mines and geology;
d. Soil survey of the upper Flathead Valley area, Montana, published by the U.S. soil conservation service; and
e. Soil survey of Flathead National Forest area, published by the U.S. forest service and the natural resource conservation service, in cooperation with Montana agricultural experiment station.
f. Topographic mapping through the Flathead Basin mapping project, 2009, maintained by Montana natural resource information system.
All of these sources are to be used for planning purposes by the city, project applicants and property owners, but may be superseded by new data and do not eliminate the need for on site evaluation for the presence of water quality protection areas.
9. Density Calculation: Density must be calculated based on the gross acreage of the site. Land restricted from development within water quality protection areas or their buffers may be used to meet requirements for open space other than active recreation under section 12-4-11 of this code. Where development is partly prohibited due to the presence of water quality protection areas, as defined in this section, an applicant may be permitted to transfer up to one hundred percent (100%) of the density attributable to the undevelopable area of the property to another portion of the same property, where the director finds this is consistent with the city’s growth policy and that the following standards are met:
a. The increased density does not significantly harm the water quality protection areas on site or on adjacent properties;
b. The increased density does not significantly harm wildlife habitat, including migration corridors;
c. The increased density does not significantly harm the character and qualities of the existing neighborhood; and
d. Where applicable, the increased density makes efficient use of infill property.
Where the above standards are met, the normal standards of the underlying zoning district for minimum lot size, setbacks, and lot coverage may be modified to accommodate the increased density.
10. Enforcement And Penalties:
a. Reasonable access to the site will be provided to the city for the purpose of inspections during any proposal review, restoration, emergency action, or monitoring period. The director must present proper credentials and make a reasonable effort to contact any property owner before entering onto private property. Except in emergencies or when the director determines there may be an imminent threat to environmental resources, such reasonable effort includes written notice by certified letter seven (7) days in advance of a planned site inspection.
b. When a water quality protection area or its buffer has been altered in violation of this section, all ongoing development work must stop and the water quality protection area or buffer shall be restored. The city has the authority to issue a stop work order to cease all ongoing development work, and order restoration, rehabilitation, or replacement measures at the owner’s or other responsible party’s expense to compensate for violation of provisions of this section. All development work must remain stopped until a restoration plan is prepared and approved by the city.
c. If development work continues, the city has the authority to seek all legal and equitable relief necessary to enforce this section. Restoration plans shall be prepared by a qualified professional using the best available science and shall describe how the actions proposed meet the minimum requirements described in subsection B10d of this section. As necessary, the director can, at the violator’s expense, seek expert advice in determining the adequacy of the plan. Inadequate plans will be returned to the applicant or violator for revision and resubmittal.
d. At a minimum, performance standards for restoration are as follows:
(1) For alterations to critical stormwater conveyances, or streams, wetlands, and lakes and their buffers, restoration must return the affected environment to the historic conditions or the conditions existing at the time of the initiation of the project; if that is infeasible, restoration must replace, enhance, or provide substitute resources or environments, following the criteria for mitigation in subsection 11-7-10D of this title, where applicable.
(2) For alterations to steep or unstable slopes, the following minimum performance standards must be met for restoration:
(A) The hazard must be reduced to a level equal to, or less than, the predevelopment hazard;
(B) Any risk to public safety or other water quality protection areas resulting from the alteration must be eliminated or minimized; and
(C) To the extent feasible, the hazard area and buffers must be replanted with native vegetation sufficient to minimize the hazard.
e. Any person convicted of violating any of the provisions of this section will be guilty of a misdemeanor. Each day or portion of a day during which a violation of this section is committed or continued will constitute a separate offense. Any development carried out contrary to the provisions of this section will constitute a public nuisance and may be enjoined as provided by the statutes of the state of Montana. The city may levy civil penalties against any person, party, firm, corporation, or other legal entity for violation of any of the provisions of this section. The civil penalty will be assessed at a maximum rate of one thousand dollars ($1,000.00) per day per violation.
C. Stream, Lake and Wetland Buffers and Setbacks:
1. Standard Buffers And Setbacks: A buffer is an area of land adjacent to a lake, wetland or stream, including the Whitefish River intended to protect the water quality area, while a setback is a smaller area of land adjacent to the buffer intended to protect buffers from human disturbance where structures are prohibited and only limited alterations are allowed.
Except where modified through a reasonable use exception under subsection B5 of this section or a variance under subsection B6 of this section, buffers and setbacks for streams, wetlands, and lakes are hereby established as follows. All buffers include the entire floodplain. Widths will be measured on the horizontal plane perpendicular to the edge of the water quality protection area. Developments in compliance with buffer and setback requirements or allowed uses in this section will not be required to submit a water quality protection area report unless specifically noted below.
Waterbody | Buffer | Setback |
Whitefish River Subsection C1a of this section | 75' or top of bank, whichever is greater | Variable, but no less than 20' |
Other perennial streams Subsection C1b of this section | 100' with 25' increase/decrease for high/low intensity land use | 10' |
Intermittent streams Subsection C1c of this section | 50' | 10' |
Wetlands Subsection C1d of this section | 100', with 25' increase/decrease for high/low intensity land use | 10' |
Whitefish Lake Subsection C1f of this section | 20' with water quality plan to meet performance standard of 75' buffer | 10' |
Other lakes Subsection C1g of this section | 75' | 10' |
a. Whitefish River: The buffer is the top of bank (where evident) or seventy five feet (75') from the ordinary high water mark, whichever is greater. If there is an associated wetland along the river, the seventy five feet (75') is measured from the edge of the wetland. If any structure is proposed within two hundred feet (200') of the buffer on a property that abuts the river, a geotechnical letter consistent with subsection D of this section shall be required. Such an analysis may also be required if the director of public works determines, based on field observation and in consultation with the applicant, that a proposed structure beyond this setback may be damaged by slope failure, slumping or other geologic instability, or that it may contribute to such instability on other properties. Unless an approved geotechnical letter concludes a larger setback is necessary, the setback must equal the rear yard setback in the applicable zone, but in no case will it be less than twenty feet (20').
b. All Other Perennial Reaches of Streams: All other perennial reaches of streams, including, but not limited to, Beaver, Cow, Eagle, Haskill, Hellroaring, Lazy, Smith, Swift, Viking, and Walker Creeks and their tributaries: The buffer must extend one hundred feet (100') from the ordinary high water mark, except that the buffer for Second Creek upstream of the city’s water supply intake must be two hundred feet (200'). These buffers shall be increased by twenty five feet (25') for multi-family, industrial and commercial development; they will be reduced by twenty five feet (25') for passive recreational uses such as parks or for low density residential development on lots 2.5 acres or greater and cannot be subdivided into lots less than 2.5 acres. There will be no permitted reduction in the buffers for Second Creek. The setback will be ten feet (10'), with no encroachment on the buffer allowed.
c. All Intermittent Streams: The buffer must extend fifty feet (50') from the ordinary high water mark. The setback will be ten feet (10'), with no encroachment on the buffer allowed.
d. Wetlands: For single-family residential development, the buffer must be one hundred feet (100') for all wetlands not exempted under subsection C1e of this section. These buffers will be increased by twenty five feet (25') for multi-family, industrial, and commercial development; they will be reduced by twenty five feet (25') for passive recreational uses such as parks or for low density residential development on lots 2.5 acres or greater and cannot be subdivided into lots less than 2.5 acres. The setback will be ten feet (10'), with no encroachment on the buffer allowed.
e. Exempt Wetlands: All isolated wetlands rated as category III or category IV using the Montana wetland assessment method, as developed and updated by the Montana department of transportation, and that are less than one thousand (1,000) square feet shall be exempt from these regulations. All such wetlands between one thousand (1,000) square feet and ten thousand (10,000) square feet shall have no buffer and setback restrictions and may be filled or otherwise degraded, if impacts are fully mitigated based on section 11-7-10 of this title. Existing storm ponds that were former wetlands, provided a fifteen foot (15') setback is maintained from the edge of the pond, are exempt.
f. Whitefish Lake: The buffer and setback will be regulated under title 13 of this code. All development of property within seventy five feet (75') of the lake must submit a water quality protection plan developed by a qualified professional, which must make recommendations regarding stormwater management, impervious surface, grading and filling, and vegetation protection and restoration so that the estimated discharge of sediment, nutrients, and other pollutants to the lake during and after construction would be no greater than if the site had a seventy five foot (75') buffer, using a methodology approved by the director of public works. This plan may reference or incorporate other documentation required by the city. Requirements for a water quality plan may be waived by the public works director for minor disturbances.
g. All Other Lake Shorelines That Are Not Wetlands: The buffer is seventy five feet (75') from the mean annual high water elevation. The setback is ten feet (10'), with no encroachment on the buffer allowed.
2. Restriction on Subdividing: Land located wholly within a wetland or its buffer may not be subdivided. Land located partially within a wetland or its buffer may be divided provided that each resulting lot has sufficient buildable area outside of, and will not affect, the wetland or its buffer.
3. Restoration Incentive: Except for Whitefish Lake, buffer widths may be reduced up to twenty five percent (25%) if the buffer is restored or enhanced from a preproject condition that is disturbed (e.g., dominated by invasive species), so that functions of the postproject buffer are equal or greater. For single-family homes on existing lots of record, the restoration plan must be developed by a qualified professional for the relevant water quality protection area and must be approved by the director. For all other development, the restoration plan must also meet requirements in section 11-7-10 of this title.
4. Buffer Averaging: Except for Whitefish Lake, the director has the authority to average buffer widths on a case by case basis, where a qualified professional demonstrates to the director’s satisfaction that all of the following criteria are met:
a. The total area contained in the buffer after averaging is no less than that contained within the buffer prior to averaging;
b. Decreases in width are generally located where riparian functions may be less sensitive to adjacent land uses, and increases are generally located where riparian functions may be more sensitive to adjacent land uses, to achieve no net loss or a net gain in functions; and
c. The averaged buffer, at its narrowest point, shall never be less than fifty percent (50%) of the standard width or fifty feet (50') for the Whitefish River.
5. Allowed Activities in Buffers: The director may permit the following uses within a stream, wetland, or lake buffer, provided they meet the standards set forth below and are not prohibited by any other applicable law. Certain allowed activities require a water quality protection plan approval. Activities along perennial streams, including the Whitefish River, may also require review and approval from the Flathead conservation district:
a. Authorized Activities: For lake buffers, activities specifically authorized under title 13, “Lake And Lakeshore Protection Regulations”, of this code.
b. Viewing Structures: Viewing structures and gazebos, if they are no greater than one hundred (100) square feet, have no permanent foundation other than concrete blocks, and have impacts mitigated by planting an area with native vegetation at least equal in size to the area disturbed by the structure, preferably in the same buffer.
c. Walkways and Trails: Walkways and trails, provided pathways minimize adverse impacts on water quality. As applicable, trails must comply with section 11-3-33 (erosion control) of this chapter and section 11-7-10 (mitigation for impacts) of this title. Paths should be designed using the best management practices and obtain permits when necessary. Unless required by the Americans with disabilities act or otherwise approved in the city’s adopted master trails plan, they should generally be parallel to the perimeter of the water body, located in the outer twenty five percent (25%) of the buffer area, avoid removal of mature trees, and be limited to pervious surfaces no more than four feet (4') in width. City paths/trails also require approval of a water quality protection permit. A walking path to a lake, stream, or wetland may be permitted for single-family homes on existing lots of record provided impacts are mitigated based on recommendations by a qualified professional for the relevant water quality protection area, which must be approved by the director. For all other developments, mitigation for such a path must also meet requirements in section 11-7-10 of this title.
d. Pesticides and Fertilizers: Pesticides and fertilizers may be applied in buffers under the following conditions:
(1) Pesticides must be applied according to the manufacturer’s label. There are specific materials labeled for appropriate applications in aquatic, ditch bank/edge areas and upland environments. All others are prohibited. The applicator must ensure that the pesticide application is applied in accordance with the restrictions of the label for its intended use, targeted vegetation and/or area being treated.
(2) No fertilizer will be applied to any buffer unless suggested as part of a buffer enhancement/mitigation plan. Such plan must provide soils sample analysis indicating a need for the fertilizer and the composition of macronutrients (N, P, K), a schedule of application and measures to ensure the fertilizer does not reach adjacent water bodies. Fertilizer applied must be no more than is needed for plant uptake.
e. Forest Management: Tree removal within the buffer area for the following requires the submittal of a tree removal plan to the zoning administrator for review and approval prior to removing trees:
(1) Tree removal for the health of the stand, including fuel reduction, habitat improvement, removal of diseased wood, and thinning for acceleration of multi-age, multi-story characteristics. Trees planted by the current property owner may be removed at the sole discretion of that property owner and need not be replaced unless they were required as mitigation or through an enforcement action under this section.
(2) Tree removal for limited view enhancement, meaning filtered views and/or view corridors from key vantage points, such as decks, balconies, and picture windows, achieved by pruning or limbing or, as a last resort, limited tree removal. Trees removed must be replaced with additional trees at least three inches (3") in trunk diameter as measured eight inches (8") above ground level, unless installation of such trees would create erosion or slope stability hazards that cannot be adequately controlled or mitigated. Conifers removed must be replaced by conifers. Replacement trees and shrubs shall be located in the same general area of the site as the trees removed, to the extent consistent with purposes for removal, and shall be sufficient in number to provide a comparable area of root coverage, once established.
f. Stream Crossings: Stream crossings, if necessary to provide access to property and if impacts are fully mitigated consistent with an approved water quality protection areas report.
g. Stormwater Management Facilities: Stormwater management facilities may be allowed within the outer twenty five percent (25%) of buffers, provided that:
(1) No other location with less impact is feasible; and
(2) Mitigation for impacts is provided to achieve no net loss or a net gain in functions.
h. Connection Lines To Utilities: Connection lines to utilities, if required by the city or utility, with a restoration plan for disturbed soils and vegetation approved by the director.
i. Stream Bank Stabilization: Bioengineering or soft armoring techniques for stream bank stabilization is preferred.
6. Allowed Activities In Setbacks: In addition to activities identified in subsection C5 of this section, the following uses are allowed in a stream, wetland, or lake setback, provided they are not prohibited by any other applicable law:
a. Activities specifically authorized within lake setbacks under section 11-3-27 of this chapter.
b. Recreational structures such as play apparatus or patios at grade and associated safety devices (railings, steps, etc.).
c. Vehicular access for maintenance or essential emergency services.
d. Lawns, gardens, and the application of associated fertilizers, herbicides, and pesticides are allowed.
e. Incidental outdoor storage of nonhazardous materials.
f. Tree removal is not restricted, but tree retention and management are highly encouraged, as is the planting of native trees.
D. Slopes and Geologic Instability: If a project is proposed on a lot or parcel with slopes greater than ten percent (10%) and is within two hundred feet (200') of a lake, wetland or intermittent or perennial stream, the applicant must submit a geotechnical letter, as described below.
1. Geotechnical Letter:
a. Assessment of Site Conditions: The letter shall include an assessment of the existing geologic and geotechnical site conditions, including surface water runoff, groundwater, soil types, erosion, and slope stability.
b. Conclusions and Recommendations: The qualified professional must prepare conclusions and recommendations for the proposed development and any mitigation necessary to address existing site conditions that may need to be modified due to the proposed development.
c. Maintenance Responsibility: Perpetual maintenance of all stabilization measures and their design effectiveness is the express responsibility of the property owner and all heirs and assigns. Failure to maintain these measures and their design effectiveness shall constitute a violation of this section pursuant to section 11-7-13 of this title.
2. Exemption: For the following residential development applications within two hundred feet (200') of a lake, wetland or stream, the director may waive the requirements of this subsection:
a. An addition less than two hundred (200) square feet in size.
b. Detached unoccupied auxiliary buildings such as garages and sheds six hundred (600) square feet or less.
c. Decks attached to structures where no additional load bearing weight is added to an adjacent slope.
d. Other small or minor disturbances, as determined by the director.
E. Critical Stormwater Conveyances:
1. Restricted Area: No building, structure, excavation, filling, or development of any kind, and no terrain disturbance that would interfere with stormwater flow will be allowed within critical stormwater conveyances, as defined by this section, unless otherwise approved through a reasonable use exception under subsection B5 of this section, a variance under subsection B6 of this section, or by the director of public works as part of a detailed drainage study.
2. Applicability: This section applies only to identified critical stormwater conveyances on the city’s most current maps, or to critical stormwater conveyances identified by the director of public works based on field observation, with the precise location of the conveyance to be determined on a site by site basis, as described in this subsection E.
3. Location: Precise location of critical stormwater conveyance boundaries will be determined on a site by site basis by the director of public works based on estimated flows for a 25-year storm (having a 4 percent chance of occurring in any given year), in consultation with the property owner and/or project proponent and reviewing the most recent city stormwater conveyance mapping, within thirty (30) days of a request by the property owner. The property owner may hire a qualified professional to establish the precise location of the boundaries and submit the determination for the city’s review and approval.
4. Setback: New structures or terrain disturbance that would interfere with stormwater flow are also prohibited within fifteen feet (15') of designated critical stormwater conveyances. Patios, driveways, and landscaping that would not significantly interfere with stormwater flow are allowed.
5. Property Access: Structures necessary for vehicle access are allowed within critical stormwater conveyances and setback areas if they do not reduce conveyance capacity.
6. Pesticide and Fertilizer Application:
a. Pesticides must be applied according to the manufacturer’s label. There are specific materials labeled for use that are appropriate applications in aquatic, ditch bank/edge areas and upland environments. All others are prohibited. The applicator must ensure the pesticide application is applied in accordance with the restrictions of the label for its intended use, targeted vegetation and/or area being treated.
b. Fertilizer applied must be no more than is needed for plant uptake, taking into account the nutrient content of the soils.
7. Restricted Activities: Removal and/or disturbance of existing ground vegetation and trees within critical stormwater conveyances, and filling and excavation of areas adjacent to critical stormwater conveyances, must not be conducted in such a manner as to negatively impact the conveyance through additional runoff, erosion, or sedimentation. No storage or vehicle parking of any kind will be allowed within a critical stormwater conveyance.
(Ord. 12-04, 2-6-2012; amd. Ord. 23-27, 11-20-2023)