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HomeMy WebLinkAboutA026 - Third reading and adoption of ORDINANCE NO. 4547 to the Conservation Subdivision Standards of Chapter 23 of the Municipal CodeTo:Mayor & City Council From:Planning & Housing Department Date:Febraury 7, 2025 Subject:Third reading and Adoption of ORDINANCE NO. 4547 Item No. 28 MEMO The ordinance relating to Conservation Subdivision Standards of Chapter 23 of the Municipal Code is attached for your review and consideration of third reading and adoption. ATTACHMENT(S): Ordinance_Stormwater_ConservationSubdivision_Standards.pdf City Clerk's Office 515.239.5105 main 515.239.5142 fax 515 Clark Ave. P.O. Box 811 Ames, IA 50010 www.CityofAmes.org 1 ORDINANCE NO.________ AN ORDINANCE TO AMEND THE MUNICIPAL CODE OF THE CITY OF AMES, IOWA, BY AMENDING AND RENUMBERING SECTIONS 23.201, 23.600, 23.601, 23.602, 23.603, 23.604, 23.604, AND 23.605 THEREOF, FOR THE PURPOSE OF AMENDING CONSERVATION SUBDIVISION STANDARDS, REPEALING ANY AND ALL ORDINANCES OR PARTS OF ORDINANCES IN CONFLICT TO THE EXTENT OF SUCH CONFLICT; AND ESTABLISHING AN EFFECTIVE DATE. BE IT ENACTED, by the City Council for the City of Ames, Iowa, that: Section One. The Municipal Code of the City of Ames, Iowa shall be and the same is hereby amended by amending and renumbering Sections 23.201, 23.600, 23.601, 23.602, 23.603, 23.604, 23.604, and 23.605 follows: “DIVISION II DEFINITIONS AND RULES OF CONSTRUCTION Sec. 23.201. DEFINITIONS. . . . (7) BMPs: Best Management Practices. Those practices most appropriate for land management. A practice or series of practices used to manage stormwater in accordance with City stormwater requirements in Chapter 5B Post Construction Stormwater Management Ordinance. . . . (19) Conservation Subdivision: A housing development which is characterized by compact and cluster lots designed around environmentally sensitive areas and dedication of environmentally sensitive areas as conservation areas to preserve and enhance natural features and dedicated conservation areas where the natural and/or restored features of the land are maintained. . . . (36) Low Impact Development: an approach to stormwater management that attempts to mimic pre- development conditions by compensating for losses of rainfall abstraction through infiltration, evapotranspiration, surface storage, and increased travel time to reduce excess runoff. . . . (53) Stormwater Treatment Train: A combination of stormwater management practices that are constructed or planted to convey, cleanse, and enhance stormwater quality and address quantity to manage the rate of stormwater before the remaining water is discharged to receiving waters. … DIVISION VI LOW IMPACT DEVELOPMENT AND CONSERVATION SUBDIVISIONS 23.600. CONSERVATION DEVELOPMENT FOR SUBDIVISIONS 23.6001. APPLICABILITY. Low Impact and Conservation Subdivisions are alternative sets of design objectives and standards primarily for single-family residential subdivisions development. These objectives and standards can be used as an alternative to common residential subdivision development patterns in Ames. However, they shall apply, at least in part, to all residential subdivision development in the undeveloped areas of Ada Hayden Watershed north of Bloomington Road. City Council may also require conformance to this Section when there are unique environmental protection priorities for a site or area. (Ord No. 4042, 8- 10-10) 23.6012. INTENT. The intent of these standards for Low Impact and Conservation Subdivisions is to preserve the existing natural features of the site, to preserve the natural drainage features and hydrologic characteristics of the landscape, and to reduce the impacts of development on the landscape; and 2 (1) To maintain and protect in perpetuity Ames area natural character by preserving these important landscape elements including but not limited to those areas containing unique and environmentally sensitive natural features as prairie, woodlands, stream buffers and corridors, drainageways, wetlands, floodplains, ridgetops, steep slopes, critical species habitat, and by setting them aside from development; (2) To promote interconnected greenways and environmental corridors throughout Ames; (3) To provide commonly-owned open space and conservation areas for passive and/or active recreational use by residents of the development and, where specified, the larger community; (4) To permit various means for owning conservation areas, preserved landscape elements, and to protect such areas from development in perpetuity; (5) To provide greater flexibility in site dwellings and other development features than would be permitted by the application of standard use regulations in order to minimize the disturbance of natural landscape elements and sensitive areas, scenic quality, and overall aesthetic value of the landscape; (6) To protect and restore environmentally sensitive areas and biological diversity, by minimizing disturbance to existing soils, vegetation, and maintaining environmental corridors;, and (7) To preserve significant archaeological sites, historic buildings and their settings. (Ord No. 4042, 810-10); and (8) To provide enhanced stormwater management to prevent and minimize the release of pollutants of concern from stormwater runoff off-site with the Ada Hayden Watershed. 23.602 APPLICATION PROCEDURE. In addition to the standard subdivision application requirements, all applications shall include a complete inventory and mapping of natural resources with the preliminary plat as described herein. (1) Inventory and Mapping of Natural Resources. An inventory of natural resources of the proposed development site shall be conducted by experts in the field such as biologists, ecologists, soil scientists, hydrologists, geologists or those credentialed in a manner acceptable to the City. The inventory must include, but is not limited to, the following information mapped at a scale of no less than one inch equals 50 feet and with topographic contours at 2-foot intervals. (a) United States Department of Agriculture-Natural Resource Conservation Service soil type locations and identification of soil type characteristics such as percolation rates, suitability for infiltration-based stormwater management practices, hydric soils, depth to water table, and suitability for wastewater disposal systems if applicable. (b) Hydrologic characteristics, including surface water bodies, floodplains, groundwater recharge and discharge areas, wetlands, natural swales, drainage ways, and slopes 10% or greater. (c) Land cover on the site including, but not limited to, prairie, woodland, forest, wetland and general cover type (pasture, woodland, etc.), and stand-alone trees with a caliper of more than 12 inches measured four feet off the ground unless, in the discretion of the Planning Director, it is not necessary to include all trees meeting said size requirements. The inventory shall include comments on the health and condition of the natural resources. (d) Known critical habitat areas for rare, threatened or endangered species using existing documented inventories. (e) Cultural resources shall be identified by a brief description of historic character of buildings and structures, historically important landscapes, and archeological features using a review of existing, documented inventories. 23.603. GENERAL REQUIREMENTS. (1) Design and Standards for Residential Lot Layout. Conservation Area Set-Asides (a) The subdivision layout shall include conservation areas that incorporate site features identified in the natural resources inventory required by Section 23.602 that, as native species in good condition, have particular preservation or restoration value. These conservation areas shall be evaluated for acceptability by the Public Works Director. At a minimum, the following features and defined buffers must be included in conservation areas: (i) All jurisdictional wetlands, floodways, and/or identified wildlife habitat areas. Non-jurisdictional wetlands are encouraged to be retained. 3 (ii) A 25-foot landscape buffer around the perimeter of a subdivision adjacent to major roadways. Walkways, other incidental encroachments, and variations of buffer depth are permitted, provided that they meet the intent of this Division. The buffer shall be established with and maintained with natural vegetation utilizing native plants. (iii) Natural Feature Buffers. The following features as identified in the natural resources inventory Section 23.602 and their required buffer measures. Buffer area widths may be reduced when restoration activities or enhancements to the area are included with the subdivision design and approved by the Public Works Director. (1) Open water areas - A 50-foot native vegetative buffer shall be maintained around open water areas such as ponds and lakes unless a specific common use area is identified. (2) Stream buffers with native vegetation shall be maintained along stream areas using the following requirements based on stream order, with the final classification by the Public Works Director: (a) Streams exceeding 3rd order and above, the City requires sketches, maps, studies, engineering reports, tests, profiles, cross-sections, construction plans and specifications to determine adequate buffer widths. (b) Perennial streams (1st and 2nd order). The total required stream buffer width is one hundred (100) feet on each side perpendicular to the waterway measured from the outer wet edge of the channel during base flows. (c) Intermittent streams. The total required stream buffer width is fifty (50) feet on each side perpendicular to the water way measured from the centerline of the channel. (d) Waterways and/or dry channels that have a contributing drainage area of fifty (50) acres or greater. The total required stream buffer width is thirty (30) feet on each side perpendicular to the waterway measured from the centerline of the waterway. (e) Waterways and/or dry channels with a contributing drainage area of less than 50 acres. The total required stream buffer width is twenty (20) feet on each side perpendicular to the waterway measured from the centerline of the waterway. (3) Jurisdictional wetlands shall also be provided with a buffer appropriately sized based on size and quality, including quality as habitat and diversity of plant and animal communities. The buffer size shall be acceptable to the Public Works Director. (2) Conservation Area Design. (a) Conservation area design shall promote minimal disturbance and include primarily native vegetation and landscaping in accordance with Section 23.603(5). Features identified by the natural resources inventory Section 23.602 and located in Conservation Areas shall be maintained in their natural condition or an enhanced condition. (b) Access easements sufficient for maintenance vehicles shall be provided to conservation areas. (c) Conservation areas may include greenways, shared use paths, walking paths, and other trails for access to environmental resources, parks, and other amenities for the benefit of the subdivision residents and general public. All developments shall provide for pedestrian access and circulation for connectivity of development areas and for enjoyment of significant conservation area set asides. Conservation areas are not required to serve as passive or active recreation area in addition to the required percentage of common open space to be set-aside by Zoning Ordinance standards. 4 (d) Grading, removal of topsoil, and other disturbance of features identified by the natural resources inventory required by Section 23.602 and located in Conservation Areas is not permitted. The Public Works Director may authorize a modification of the conservation area to improve the appearance of natural features or to restore the overall condition and natural processes, in compliance with an approved management plan, as described in Section 23.605. The Public Works Director may also authorize impacts to the conservation area for essential infrastructure. (e) Conservation areas shall be managed in accordance with a Conservation Area Management Plan as outlined in Section 23.605 and applicable landscaping standards in Section 23.603(5). (f) The conservation area shall be designated as a Conservation Easement as detailed in the definition section of this ordinance. (a) All residential units should be in cluster groups unless the site has been designed to preserve sensitive areas and maintain a stormwater treatment train. (b) All lots shall take access from interior roads. (c) All separation areas for residential lots along existing roads shall be landscaped in accordance with the conservation area landscaping requirements in Section 23.603(2)(f). d) Eighty percent (80%) of residential lots shall abut a conservation area or open pace to the front or rear. Open space and conservation area across a road shall qualify for this requirement. (e) Cluster groups shall be located to avoid or mitigate directly disturbing existing native prairie, woodlands, wetlands and other natural features identified in the site inventory of natural resources (3) Residential Lot Layout. (a) The use of cluster groups, smaller lots, or other unique residential lot layouts that support reduced impervious area along with maximizing conservation areas and open space are highly encouraged. Lot layout design shall minimize overall mass grading of site and be situated in a manner that maintains the general topography and natural site features such as drainage ways. (b) In support of reduced impervious areas and larger conservation areas within a development, use of limited connectivity street networks such as loop streets and cul-de- sacs may be appropriate. These designs shall be shown to provide for convenient circulation routes, and to otherwise meet the intent of Section 23.401(1)(d) regarding minimizing dead-end streets. Limited connectivity street networks shall still provide for access to significant conservation areas and for convenient pedestrian circulation routes with signage where appropriate. (c) All lots shall take access from interior roads. (d) Shared driveways to reduce impervious surfaces are encouraged. (e) Residential lots shall not contain large stormwater flowage easements to serve regional detention and treatment measures. (f) All single-family residential subdivisions shall incorporate an element of open spaces in order to meet the intent of subdivision of dispersed and connected conservation areas with a natural setting that supports a treatment train approach to stormwater management. For example, if all conservation areas are at one remote area of the site, other open space features would be required to meet the intent of connected large open spaces. However, not all areas must strictly be linked together. (4) Commercial Lot Layout. Commercial lots shall be sited to ensure runoff is treated through a treatment train approach. Shared access is preferred to reduce impervious surfaces. (5) Connectivity and Roadway Design. (a) Roadway design, subdivision layout, and use of sidewalks and trails shall provide for an interconnected neighborhood while minimizing impacts to natural areas and reducing total impervious area within the development. (b) Roadways are encouraged to follow natural contours and slopes to minimize disturbance of drainage patterns. 5 (d) Sidewalks may be only required on one side of street for short block lengths with less than four dwellings not have a public sidewalk. However, all lots shall have direct access to sidewalks or the pathway system. (e) Typical driveway approach sections, Chapter 7 of SUDAS specifications, shall be used. (2) Site Requirements (a) Open water areas - A 50-foot native vegetative buffer shall be maintained around open water areas such as ponds and lakes unless a specific common use area is identified. (b) Stream buffers - Stream buffers with native vegetation shall be maintained along stream areas using the following requirements based on stream order: (i) Streams exceeding 3rd order and above, the City requires sketches, maps, studies, engineering reports, tests, profiles, cross-sections, construction plans and specifications to determine adequate buffer widths. (ii) Perennial streams (1st and 2nd order). The total required stream buffer width is one hundred (l00) feet on each side perpendicular to the waterway measured from the outer wet edge of the channel during base flows. (iii) Intermittent streams. The total required stream buffer width is fifty (50) feet on each side perpendicular to the water way measured from the centerline of the channel. (iv) Waterways and/or dry channels that have a contributing drainage area of fifty (50) acres or greater. The total required stream buffer width is thirty (30) feet on each side perpendicular to the waterway measured from the centerline of the waterway. (v) Waterways and/or dry channels with a contributing drainage area of less than 50 acres. The total required stream buffer width is twenty (20) feet on each side perpendicular to the waterway measured from the centerline of the waterway. (4c) Stormwater management Design. (a) Development is subject to all requirements of Ames Municipal Code Chapters 5A and 5B for minimum stormwater management requirements. (b) The stormwater management design shall utilize low-impact development principles and best management practices in a treatment train to address water quality. This includes, but is not limited to, the following: (i) Minimize the use of storm sewer piping and maximize the use of swales. (ii) Use curb cuts in lieu of storm sewer intakes when appropriate when adjacent to conservation areas to divert street water to a stormwater conveyance or treatment system. (iii) Sump pump discharge can be dDischarged sump pumps where possible into a stormwater conveyance or treatment system. (iv) Use conservation areas for Oon-site treatment and storage of stormwater generated by the development shall occur in conservation area if it is consistent with the environmental functions of the conservation area. Individual lot on-site stormwater management may also be used in conservation subdivisions in conjunction with open space and conservation area management of stormwater. (v) Select a variety of targeted stormwater management best practices and facilities to use in a series to reduce off-site discharge of pollutants including Total Suspended Solids (TSS), phosphorous, nitrogen, E. coli, and metals. A singular stormwater treatment measure of a detention pond will not meet this standard. (vi) Provide pre-treatment for stormwater runoff through practices such as swales, bioretention cells, and vegetative buffers. Forebays are required prior to surface- stormwater practices such as constructed wetlands and wet and dry ponds. (vvii) Include detailed design information for the stormwater management practices in accordance with City stormwater requirements in Chapter 5B Post Construction Stormwater Management Ordinance following the design information provided in the Iowa Stormwater Management Manual. including The stormwater treatment train approach shall be used where appropriate to capture, treat and release stormwatera total pollution reduction summary for Total Suspended Solids (TSS), phosphorous, nitrogen, and metals showing reductions achieved by discharge point and practice in 6 the treatment train. The Public Works Director may require additional practices to protect water quality based on reductions shown. (viii) Submit a grading plan that shows the location of features identified by the natural resources inventory Section 23.602 in conservation where grading is not proposed and on-site protection measures. (ix) For longer duration buildout of a subdivision, sediment basins shall be provided until final stabilization. Their location and storage capacity per acre drained shall be indicated on the grading plan. The approved plan shall be incorporated into the SWPPP required by Chapter 5A. (d) Shared use paths, sidewalks, and driveway (i) An accessible and interconnected shared use path system shall be developed to connect residential areas with open space/conservation areas within or adjacent to the site. (ii) Sidewalks shall only be required on one side of streets; however, all lots shall have direct access to sidewalks or the pathway system. (iii) Typical driveway approach sections, Chapter 7 of SUDAS specifications, shall be used. (e) Conservation Area Requirements (i) The conservation area shall be designated as a Conservation Easement as detailed in the definition section of this ordinance. (ii) Applicants must provide an explanation of the conservation area objectives achieved with their proposed development and identify the percentage of the total development area that this area occupies. (iii) All conservation areas shall be part of a larger continuous and integrated system except for conservation areas that are naturally isolated from other conservation areas on or near the site. For the purposes of this section, continuous shall be defined as either physically touching or located across a public right-of-way, for example, on opposite sides of an internal road. (iv) Conservation areas, in accordance with the Conservation Area Management and Ownership outlined in Section 23.605, shall protect site features identified in the site natural resources inventory Section 23.604 (1) and analysis as having particular value in preserving and/or restoring the natural character and conserving natural resources in compliance with the intent of this ordinance and consistent with the goals and objectives of this ordinance. (v) Healthy natural features such as woodlands, prairie, wetlands, and streambanks shall generally be maintained in their natural condition. If recommended by a professional with pertinent qualifications, the Municipal Engineer may authorize a modification to improve the natural features’ appearance or restore the overall condition and natural processes, in compliance with an approved management plan, as described in Section 23.605. (vi) All wetlands, floodways, and/or identified wildlife habitat areas shall be contained in conservation areas. (vii) Conservation areas and open space shall be distributed throughout the development and combined shall comprise at least twenty-five (25) percent of the total area of the subdivision. An area comprised of conservation areas and open space greater than twenty- five percent of the total area of the subdivision may be required if necessary to maintain health features such as woodlands, prairie, wetlands and streambanks in their natural condition as provided in 23.603(2)(v). (viii) Safe and convenient pedestrian access and access easements sufficient for maintenance vehicles shall be provided to conservation areas. (f5) Landscaping. for Conservation Subdivisions – The layout and design of a subdivision includes a variety of conservation and open space areas. A landscaping plan shall be prepared that identifies all proposed landscaping within common areas and conforms to the following: (i) The preservation of existing native, non-invasive vegetation as identified in the natural resources inventory Section 23.604(1) 23.602 as being in good condition and of good quality shall generally be preferred to the installation of new plant material. (ii) Mass grading of sites shall be minimized in order to preserve the natural features of the site. 7 (iii) Within all required separation areas between residential lots and external roads and site boundaries, existing woodlands with desirable tree species shall be retained. (iiiv) All new landscaping in conservation areas to be installed and existing native vegetation to be preserved shall be protected through a conservation easement. Native landscaping shall be installed according to the guidelines provided in the Iowa Stormwater Management Manual Section 2E-6. (iv) Trees of native species as indicated by the Iowa Department of Natural Resources and approved by the City shall be planted along internal roads within cluster groups in a total amount equivalent to the standard subdivision requirements. Trees may be planted, but are not required, along internal roads passing through conservation areas. (vi) Informal, irregular, or natural arrangement is required for newly planted trees and other landscaped areas to avoid the urban appearance that regular spacing may evoke. (vii) Trees shall be located so as not to interfere with the installation and maintenance of utilities, shared use paths, or sidewalks that may parallel the road. (viii) Within all conservation areas, separation between external roads and residential lots, a vegetated buffer area at least 25 feet in width shall be maintained or established. Where no natural trees and/or shrubs exist, native plant materials shall be planted. (ixvii) Conservation areas required to meet Section 23.603(1)(d) Conservation areas shall be planted using native species to enhance privacy and a natural appearance. (xviii) Required buffers around wetlands, all water bodies and drainageways must be naturally vegetated or planted with native plant species appropriate to the surrounding landscape. (ixi) Buffers consisting of an informal, irregular or natural arrangement of native plant species, combined with infrequent or prescriptive mowing are required to create a low- maintenance, naturalized landscape. (xii) In addition to the above, land management practices minimizing the impact of nutrients shall be used and demonstrated in Ada Hayden Watershed; minimal fertilization of lawns including the use of phosphorus-free fertilizers is recommended. APPLICATION PROCEDURE. In addition to the standard subdivision application requirements, an inventory and mapping of natural resources shall be conducted prior to the initial submittal. (1) Inventory and Mapping of Natural Resources. An inventory of natural resources of the proposed development site shall be conducted by experts in the field such as biologists, ecologists, soil scientists, hydrologists, geologists or those credentialed in a manner acceptable to the Municipal Engineer and must be submitted with the conservation subdivision application. The inventory must include, but is not limited to the following information mapped at a scale of no less than one inch equals 50 feet: (a) Topographic contours at 2-foot intervals. (b) United States Department of Agriculture, Natural Resource Conservation Service soil type locations and identification of soil type characteristics such as percolation rates, suitability for infiltration-based stormwater management practices, hydric soils, depth to water table, and suitability for wastewater disposal systems if applicable. (c) Hydrologic characteristics, including surface water bodies, floodplains, groundwater recharge and discharge areas, wetlands, natural swales, drainage ways, and slopes 10% or greater. (d) Land cover on the site including but not limited to prairie, woodland, forest, wetland and general cover type (pasture, woodland, etc.), and stand-alone trees with a caliper of more than [24] inches measured four feet off the ground. The inventory shall include comments on the health and condition of the natural resources. (e) Known critical habitat areas for rare, threatened or endangered species using existing documented inventories. (f) Cultural resources shall be identified by a brief description of historic character of buildings and structures, historically important landscapes, and archeological features using a review of existing, documented inventories. 8 (2) Education and Outreach Plan for the Development. An educational plan shall be developed and distributed to all perspective lot owners that describes the characteristics of the conservation subdivision including the development concept, conservation areas management practices that will be used to manage these areas, and benefits of the natural features. They shall also include information on lawn care strategies that reduce nutrient and pesticide inputs and pollution to local water bodies. Lot owners shall be made aware of the wildlife aspects of a conservation subdivision. Deer, birds, and other animals and insects will be attracted to the natural areas. 23.6054. CONSERVATION AREA MANAGEMENT AND OWNERSHIP. (1) Conservation Area Management Plan. Every development conservation subdivision must include a plan that provides evidence of a means to properly manage the conservation areas and open space areas in perpetuity through a conservation easement for conservation areas or common ownership for open space areas and evidence of the long-term means to properly manage and maintain all common facilities, including any stormwater facilities. The plan shall be approved by the Public Works Director Municipal Engineer prior to plat approval. (a) A conservation area management plan shall be submitted with the following components during the following approval stages: (2) Preliminary Plat: (a) Include a conservation area management plan specifically focusing on the long-term management of conservation areas. The conservation area management plan shall include a narrative, based on the site analysis required in Section 23.604(1), describing: (i) Existing conditions including all natural, cultural, historic, and scenic elements in the landscape. (ii) The proposed completed condition for each conservation area; and the measures proposed for achieving the end state. (iii) Proposed restoration measures, including: measures for correcting increasingly destructive conditions, such as erosion, and measures for restoring habitats, ecosystems, and historic features. (3) Final Plat: (a) The conservation area management plan shall include the following items for final plat approval: (i) Provide a copy of the conservation easement acceptable to the City in a recordable format. (ii) Designate the ownership of the conservation area and common facilities. (iii) Establish necessary regular and periodic operation and maintenance responsibilities. (iv) Estimate staffing needs, insurance requirements, and other associated costs and define the means for funding the same on an on-going basis. (v) The operations needed for maintaining the stability of the resources, including: mowing schedules; native vegetation burns; weed control; planting schedules; clearing and cleanup; the applicant shall be required to provide financial security in a form acceptable to the city for the maintenance and operation costs of conservation areas for a two-year period of time at time of the plat. (vi) A proposed Education and Outreach Plan for the Development. An educational plan shall be developed to be distributed to all prospective lot owners that describes the characteristics of conservation subdivision including the development concept, conservation areas management practices that will be used to manage these areas, and benefits of the natural features. It shall also include information on lawn care strategies that reduce nutrient and pesticide inputs and pollution to local water bodies. Lot owners shall be made aware of the wildlife aspects of a conservation subdivision. Deer, birds, and other animals and insects will be attracted to the natural areas.” 9 Section Two. All ordinances, or parts of ordinances, in conflict herewith are hereby repealed to the extent of such conflict, if any. Section Three. This ordinance shall be in full force and effect from and after its passage and publication as required by law. Passed this day of , 2025. ______________________________________ _______________________________________ Renee Hall, City Clerk John A. Haila, Mayor 10