(a)   The Legislature of the State of South Dakota has in SDCL 9-36-15 and 7-18-14 authorized local governmental units to adopt regulations designed to minimize flood losses.

   (b)   The city elects to comply with the requirements of the National Flood Insurance Act of 1968, being 42 U.S.C. §§ 4001 et seq. (Pub. L. No. 90-488, as amended). The National Flood Insurance Program, established in the aforesaid act, provides that areas of the town having a special flood hazard be identified by the Federal Emergency Management Agency and that floodplain management measures be applied in the flood hazard areas. The National Flood Insurance Program was broadened and modified with the passage of the Flood Disaster Protection Act of 1973, being 42 U.S.C. §§ 4001 et seq. and other legislative measures. It was further modified by the National Flood Insurance Reform Act of 1994, being 42 U.S.C. §§ 4001 et seq. The National Flood Insurance Program is administered by the Federal Emergency Management Agency, a component of the United States Department of Homeland Security.

(1992 Code, § 45-1) (Ord. 70-09, passed 8-3- 2009)

   (a)   The flood hazard areas of Sioux Falls, South Dakota, are subject to periodic inundation which results in damage to persons and property, health and safety hazards, disruption of commerce and governmental services, and extraordinary public expenditures for flood protection and relief, all of which adversely affect the public health, safety and general welfare.

   (b)   These flood impacts are created by the unusual and rapid accumulation or runoff of surface waters from any source, the cumulative effect of obstructions in floodplains which cause an increase in flood heights and velocities, and by the occupancy of flood hazards areas by uses vulnerable to floods and hazardous to other lands because they are inadequately elevated, or otherwise protected from flood damage.

(1992 Code, § 45-2) (Ord. 70-09, passed 8-3-2009)

   It is the purpose of this chapter to promote the public health, safety and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:

   (a)   Protect human life and health;

   (b)   Minimize expenditure of public money for costly flood control projects;

   (c)   Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

   (d)   Minimize prolonged business interruptions;

   (e)   Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, streets and bridges located in floodplains;

   (f)   Help maintain a stable tax base by providing for the sound use and development of flood-prone areas in a manner as to minimize future flood blight areas; and

   (g)   Ensure that potential buyers are notified that property is in a flood area.

   (h)   Qualify the city of Sioux Falls for participation in the National Flood Insurance Program and Community Rating System program, thereby giving citizens and businesses the opportunity to purchase flood insurance, potentially at discounted rates;

   (i)   Work with existing city ordinances in stormwater and health to maintain the quality of water in rivers, streams, lakes, estuaries, and marine areas and their floodplains so as to protect public water supplies, areas of the public trust, and wildlife habitat protected by the Endangered Species Act;

   (j)   Retain the natural channel, shoreline, and floodplain creation processes and other natural floodplain functions that protect, create, and maintain habitat for threatened and endangered species; and

   (k)   Prevent or minimize loss of hydraulic, geomorphic, and ecological functions of floodplains and stream channels.

(1992 Code, § 45-3) (Ord. 70-09, passed 8-3-2009; Ord. 77-21, passed 7-6-2021)

   In order to accomplish its purposes, this chapter uses the following methods:

   (a)   Restrict or prohibit uses that are dangerous to health, safety or property in times of flood, or cause excessive increases in flood heights or velocities;

   (b)   Require those uses vulnerable to floods, including facilities which serve those uses, be protected against flood damage at the time of initial construction;

   (c)   Control the alteration of natural floodplains, stream channels and natural protective barriers, which are involved in the accommodation of flood waters;

   (d)   Control filling, grading, dredging and other development which may increase flood damage; and

   (e)   Prevent or regulate the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards to other lands.

(1992 Code, § 45-4) (Ord. 70-09, passed 8-3-2009)

   For the purposes of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning:

      (1)   A non-basement building:

         A.   Built, in the case of a building in Zones A1-30, AE, A, A99, AO, AH, B, C, X, and D, to have the top of the elevated floor, or in the case of a building in Zones V1-30, VE, or V, to have the bottom of the lowest horizontal structure member of the elevated floor elevated above the ground level by means of pilings, columns (posts and piers), or shear walls parallel to the floor of the water; and

         B.   Adequately anchored so as not to impair the structural integrity of the building during a flood of up to the magnitude of the base flood. In the case of Zones A1-30, AE, A, A99, AO, AH, B, C, X, and D.

   EXISTING MANUFACTURED HOME PARK OR SUBDIVISION. A manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed before the effective date of the floodplain management regulations adopted by a community.

      (1)   The overflow of inland or tidal waters; and

      (2)   The unusual and rapid accumulation or runoff of surface waters from any source.

      (1)   Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register;

      (2)   Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district;

      (3)   Individually listed on a state inventory of historic places in states with historic preservation programs which have been approved by the Secretary of Interior; or

      (4)   Individually listed on a local inventory or historic places in communities with historic preservation programs that have been certified either:

         A.   By an approved state program as determined by the Secretary of the Interior; or

         B.   Directly by the Secretary of the Interior in states without approved programs.

      (1)   Built on a single chassis;

      (2)   Four hundred square feet or less when measured at the largest horizontal projections;

      (3)   Designed to be self-propelled or permanently towable by a light duty truck; and

      (4)   Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

      (1)   Damage of any origin sustained by a structure whereby the three-year running cumulative (starting after December 31, 2022) cost of restoring the structure to its before damaged condition would equal or exceed 45% of the market value of the structure before the damage occurred.

      (2)   This includes the costs of, but are not necessarily limited to, all materials, labor, built-in appliances, overhead, profit, and repairs to damaged portions of the building that are done concurrent with the subject improvements. This term does not, however, include the costs of the improvement associated with post-storm debris removal; permitting; fees, preparation of surveys, costs, plans, and/or specifications; or improvements outside of the structure, such as landscaping, sidewalks, fences, or detached structures; or work exempted from building permit requirements.

      (1)   Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by a local code enforcement official and which are the minimum necessary conditions; or

      (2)   Any alteration of a “historic structure,” provided that the alteration will not preclude the structure’s continued designation as a “historic structure.”

      (3)   The costs of the improvement associated with post-storm debris removal; permitting; fees, preparation of surveys, costs, plans, and/or specifications; or improvements outside of the structure, such as landscaping, sidewalks, fences, or detached structures; or work exempted from building permit requirements.

(1992 Code, § 45-5) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016; Ord. 78-17, passed 8-15-2017; Ord. 32-18, passed 5-2- 2018; Ord. 77-21, passed 7-6-2021)

   This chapter shall apply to all areas of regulatory floodplain, which is comprised of the special flood hazard area and all protected areas within the jurisdiction of Sioux Falls, South Dakota.

(1992 Code, § 45-6) (Ord. 70-09, passed 8-3-2009; Ord. 77-21, passed 7-6-2021)

   The areas of special flood hazard identified by the Federal Emergency Management Agency in a scientific and engineering report entitled, “The Flood Insurance Study for Minnehaha County, South Dakota and Incorporated Areas” dated September 2, 2009; March 7, 2017; or October 5, 2017, with accompanying Flood Insurance Rate Maps (FIRM), and any revisions thereto are hereby adopted by reference and declared to be a part of this chapter. Any areas annexed by the city of Sioux Falls will continue to use the latest effective Flood Insurance Study and map panel. Any information that meets FEMA specifications for best available information will be applicable in setting floodplain restrictions.

(1992 Code, § 45-7) (Ord. 70-09, passed 8-3-2009; Ord. 85-11, passed 11-14-2011; Ord. 94- 16, passed 8-2-2016; Ord. 78-17, passed 8-15-2017; Ord. 77-21, passed 7-6-2021)

      (1)   Identify and describe the development to be covered by the permit;

      (2)   Describe the land on which the proposed development is to be conducted by legal description, street address, or similar description that will readily identify and definitely locate the site;

      (3)   Include a site plan showing the delineation of special flood hazard areas, floodway boundaries, flood zones, base flood elevations, ground elevations, proposed fill and excavation, and drainage patterns and facilities;

      (4)   Indicate the use and occupancy for which the proposed development is intended;

      (5)   Be accompanied by construction documents, grading and filling plans, and other information deemed appropriate by the floodplain administrator;

      (6)   State the valuation of the proposed work when required; and

      (7)   Be signed by the owner or the owner’s authorized agent.

      (1)   Elevation certificate upon the placement of the lowest floor, including basement, prepared by a registered professional engineer or land surveyor, of the elevation of the lowest floor, including basement. The floodplain administrator may require submission upon the placement of the lowest floor, including basement, prior to further vertical construction;

      (2)   Designed opening certificate prepared by a registered professional engineer for fully enclosed areas below the base flood elevation where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in § 156.066(c);

      (3)   “No-rise” certificate along with supporting hydraulic computations, prepared by a registered professional engineer, that development in a designated floodway will result in no increase in the base flood heights during the occurrence of a base flood (100-year) discharge;

      (4)   Fill placement certification prepared by a registered professional engineer when required by the floodplain administrator to ensure proper compaction and slope protection for fill placed in the floodplain;

      (5)   Manufactured home foundation design certification by a registered professional engineer to meet the requirements in § 156.066(d); and

      (6)   Hydraulic and hydrologic analyses requirements within § 156.060.

(1992 Code, § 45-8) (Ord. 70-09, passed 8-3-2009; Ord. 85-11, passed 11-14-2011; Ord. 94- 16, passed 8-2-2016; Ord. 77-21, passed 7-6-2021)

   No structure or parcel shall hereafter be located, altered, or have its use changed without full compliance with the terms of this chapter and other applicable regulations.

(1992 Code, § 45-9) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016)

   This chapter is not intended to repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this chapter and another ordinance, easement, covenant or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

(1992 Code, § 45-10) (Ord. 70-09, passed 8-3-2009)

   In the interpretation and application of this chapter, all provisions shall be:

   (a)   Considered as minimum requirements;

   (b)   Liberally construed in favor of the governing body; and

   (c)   Deemed neither to limit nor repeal any other powers granted under state statutes.

(1992 Code, § 45-11) (Ord. 70-09, passed 8-3-2009)

   The degree of flood protection required by this chapter is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. On rare occasions, greater floods can and will occur and flood heights may be increased by human-made or natural causes. This chapter does not imply that land outside the areas of special flood hazards or uses permitted within the areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the community or any official or employee thereof for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.

(1992 Code, § 45-12) (Ord. 70-09, passed 8-3-2009)

   If any section, provision or portion of this chapter is adjudicated unconstitutional or invalid by a court, the remainder of the chapter shall not be affected.

(1992 Code, § 45-13) (Ord. 70-09, passed 8-3-2009)

   The chief building official is hereby appointed the floodplain administrator to administer and implement the provisions of this chapter and other appropriate sections of title 44 of the Code of Federal Regulations (National Flood Insurance Program regulations) pertaining to floodplain management.

(1992 Code, § 45-14) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016; Ord. 30-19, passed 3-19-2019)

   Duties and responsibilities of the floodplain administrator and designated staff shall include, but not be limited to, the following:

   (a)   Maintain and hold open for public inspection all records pertaining to the provisions of §§ 156.051 and 156.052;

   (b)   Review floodplain development permit application to determine whether proposed building site, including the placement of manufactured homes, will be reasonably safe from flooding;

   (c)   Review, approve, or deny all applications for floodplain development permits required by adoption of this chapter;

   (d)   Review permits for proposed development to assure that all necessary permits have been obtained from those federal, state or local governmental agencies (including § 404 of the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. § 1334, and the Endangered Species Act (ESA) of 1973) from which prior approval is required;

   (e)   Where interpretation is needed as to the exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be a conflict between a mapped boundary and actual field conditions), the floodplain administrator or designated staff shall make the necessary interpretation;

   (f)   Notify, in riverine situations, adjacent communities and the state coordinating agency which is the water management board authorized by SDCL 46-1-6, prior to any alteration or relocation of a watercourse, and submit evidence of the notification to the Federal Emergency Management Agency;

   (g)   Assure that the flood-carrying capacity within the altered or relocated portion of any watercourse is maintained;

   (h)   When base flood elevation data has not been provided in accordance with § 156.031, the floodplain administrator or designated staff shall obtain, review, and reasonably utilize any base flood elevation data and floodway data available from a federal, state, or other source in order to administer the provisions of §§ 156.060 through 156.068;

   (i)   When a regulatory floodway has not been designated, the floodplain administrator or designated staff must require that no new construction, substantial improvements, or other development (including fill) shall be permitted within Zones A1-30 and AE on the community’s FIRM, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community;

   (j)   Under the provisions of 44 C.F.R. Chapter 1, § 65.12, of the National Flood Insurance Program regulations, a community may approve certain development in Zones A1-30, AE, AH on the community’s FIRM which increases the water surface elevation of the base flood by more than one foot, provided that the applicant first applies for a conditional FIRM revision through FEMA (conditional letter of map revision).

   (k)   Upon receipt of a floodplain development permit request, the floodplain administrator or designated staff shall compare the elevation of the site to the base flood elevation. A development project is not subject to the requirements of this chapter (with the exceptions of restrictions specifically set by this chapter for areas outside the regulated floodplain) if the development project is entirely located on a portion of the land that can be shown to be:

      (1)   Outside the protected area; and

      (2)   Higher than the base flood elevation.

   (l)   The floodplain administrator or designated staff shall inform the applicant that the project, permit, or development may still be subject to the flood insurance purchase requirements unless the owner receives a Letter of Map Amendment from FEMA.

(1992 Code, § 45-15) (Ord. 70-09, passed 8-3-2009; Ord. 85-11, passed 11-14-2011; Ord. 94- 16, passed 8-2-2016; Ord. 77-21, passed 7-6-2021)

   (a)   Application for a floodplain development permit shall be presented to the floodplain administrator or designated staff on forms furnished by them and may include, but not be limited to, plans drawn to scale showing the location, dimensions, and elevation of proposed landscape alterations, existing and proposed structures, including the placement of manufactured homes, and the location of the foregoing in relation to areas of special flood hazard.

   (b)   Additionally, the following information is required:

      (1)   Elevation (in relation to mean sea level) of the lowest floor (including basement) of all new and substantially improved structures;

      (2)   Elevation in relation to mean sea level to which any nonresidential structure shall be “floodproofed;”

      (3)   A certificate from a registered professional engineer or architect that the nonresidential floodproofed structure shall meet the floodproofing criteria of § 156.066(b);

      (4)   Description of the extent to which any watercourse or natural drainage will be altered or relocated as a result of proposed development;

      (5)   Maintain a record of all information in accordance with § 156.051(a);

      (6)   If along an approximate Zone A or AE, a BFE will need to be determined using either a detailed study or best available data through FEMA;

      (7)   The elevations of the ten-, 50-, 100-, and 500-year floods where the data is available;

      (8)   The boundaries of the regulatory floodplain, SFHA, floodway, and channel migration area delineated in accordance with 156.065(j)(3);

      (9)   The proposed drainage system including, but not limited to, storm sewers, overland flow paths, detention facilities, and roads;

      (10)   Existing and proposed structures, fill, pavement and other impervious surfaces, and sites for storage of materials;

      (11)   All wetlands;

      (12)   Habitat areas identified for conservation or protection under state or federal or local laws or regulations (e.g., Endangered Species Act, Magnuson-Stevens Fishery Conservation and Management Act, Growth Management Act, Shorelines Management Act, Priority Habitat and Species List); and

      (13)   Existing native vegetation and proposed revegetation.

   (c)   If the proposed project includes a new structure, substantial improvement, or repairs to a substantially damaged structure that will be elevated, the application shall include the Flood Protection Elevation for the building site and the proposed elevations of the following:

      (1)   The top of the bottom floor (including basement, crawl space, or enclosure floor);

      (2)   The top of the next higher floor;

      (3)   The top of the slab of an attached garage;

      (4)   The lowest elevation of machinery or equipment servicing the structure;

      (5)   The lowest adjacent (finished) grade next to structure;

      (6)   The highest adjacent (finished) grade next to structure; and

      (7)   The lowest adjacent grade at the lowest elevation of a deck or stairs, including structural support.

   (d)   If the proposed project will result in a new elevated building, substantial improvements to an elevated building, or repairs that require the building become elevated, a non-conversion agreement will need to be signed by the permit applicant and filed at the county register of deeds office. The non-conversion agreement shall:

      (1)   Acknowledge the risk associated with this building practice;

      (2)   Acknowledge the use of the area that was permitted as an enclosure will be used solely on nonresidential accessory or appurtenant structure of low value whose usage is only for building access, parking, or storage;

      (3)   Allow for community, state, and/or federal officials to conduct periodic inspections to ensure compliance; and

      (4)   Prior to issuance of certificate of occupancy or final inspection, whichever occurs last, the property owner must execute a non-conversion agreement and the agreement must be recorded with the county real estate records. The agreement will be in the form of a restrictive covenant or other county-approved binding instrument, where the benefits of the covenant run in favor of the city of Sioux Falls. The covenant must be drafted to run with the land and bind successors in perpetuity. The purpose of the covenant is to document the current owner's understanding of the limitations on construction and use of the enclosed area in accordance with the provisions of this chapter, and to put prospective purchasers on notice of such restrictions. The covenant will also reference retrofitting criteria necessary to properly convert accessory buildings or structures to habitable space, should the owner choose to do so. In addition to any other enforcement mechanisms available, violation of the agreement will be considered a violation of this chapter and subject to all applicable zoning enforcement procedures.

   (e)   For any nonresidential construction that has been wet floodproofed, a non-conversion agreement must be completed as part of the permitting process. The non-conversion agreement:

      (1)   Acknowledges the risk associated with this building practice;

      (2)   Acknowledges the use of the area that was wet floodproofed will be used solely on nonresidential accessory or appurtenant structure of low value whose usage is only for building access, parking, or storage;

      (3)   Allows for community, state, and/or federal officials to conduct periodic inspections to ensure compliance; and

      (4)   Prior to issuance of certificate of occupancy or final inspection, whichever occurs last, the property owner must execute a non-conversion agreement and the agreement must be recorded with the county real estate records. The agreement will be in the form of a restrictive covenant or other county-approved binding instrument, where the benefits of the covenant run in favor of the city of Sioux Falls. The covenant must be drafted to run with the land and bind successors in perpetuity. The purpose of the covenant is to document the current owner's understanding of the limitations on construction and use of the enclosed area in accordance with the provisions of this chapter, and to put prospective purchasers on notice of such restrictions. The covenant will also reference retrofitting criteria necessary to properly convert accessory buildings or structures to habitable space, should the owner choose to do so. In addition to any other enforcement mechanisms available, violation of the agreement will be considered a violation of this chapter and subject to all applicable zoning enforcement procedures.

(1992 Code, § 45-16) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016; Ord. 77-21, passed 7-6-2021)

   Approval or denial of a floodplain development permit by the floodplain administrator shall be based on all of the provisions of this chapter and the following relevant factors:

   (a)   The danger to life and property due to flooding or erosion damage;

   (b)   The susceptibility of the proposed facility and its contents to flood damage and the effect of the damage on the individual owner;

   (c)   The danger that materials may be swept onto other lands to the injury of others;

   (d)   The compatibility of the proposed use with existing and anticipated development;

   (e)   The safety of access to the property in times of flood for ordinary and emergency vehicles;

   (f)   The costs of providing governmental services during and after flood conditions including maintenance and repair of streets and bridges, and public utilities and facilities such as sewer, gas, electrical and water systems;

   (g)   The expected heights, velocity, duration, rate of rise and sediment transport of the flood waters, and the effects of wave action, if applicable, expected at the site;

   (h)   The necessity to the facility of a waterfront location, where applicable;

   (i)   The availability of alternative locations, not subject to flooding or erosion damage, for the proposed use; and

   (j)   The relationship of the proposed use to the comprehensive plan for that area.

(1992 Code, § 45-17) (Ord. 70-09, passed 8-3-2009)

   The building board of appeals as established by the community shall hear and render judgment on requests for variances from the requirements of this chapter.

   (a)   Any person or persons aggrieved by the decision of the building board of appeals may appeal the decision in the courts of competent jurisdiction.

   (b)   The floodplain administrator shall request an opinion letter from the Federal Emergency Management Agency and the state Office of Emergency Management prior to hearing any variance. Additionally, the floodplain administrator shall maintain a record of all actions involving an appeal and shall report variances to the Federal Emergency Management Agency and the state Office of Emergency Management upon issuing a variance.

   (c)   Variances may be issued for:

      (1)   New construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing the relevant factors in division (f)(2) below have been fully considered. As the lot size increases beyond the one-half acre, the technical justification required for issuing the variance increases.

      (2)   The repair or rehabilitation of historic structures upon a determination that the proposed repair or rehabilitation will not preclude the structure’s continued designation as a historic structure and the variance is the minimum necessary to preserve the historic character and design of the structure.

   (d)   Upon consideration of the factors noted above and the intent of this chapter, the building board of appeals may attach those conditions to the granting of variances as it deems necessary to further the purpose and objectives of this chapter. (See § 156.003.)

   (e)   Variances shall not be issued:

      (1)   A.   To habitable structures within any designated floodway that impacts upstream and downstream per requirements within 44 C.F.R. § 60.6 (a) (1) and 44 C.F.R.§ 60.3 that need to be addressed to eliminate any increase in flood levels during the base flood discharge.

         B.   Regarding floodway variances: The structures must be accessory buildings and represent a low cost in potential to damage to building materials as well as public expense;

      (2)   To reduce the base flood elevation requirement within § 156.066(a) Residential construction; or

      (3)   To reduce the freeboard and/or base flood elevation requirement within § 156.066(b) Nonresidential construction.

      (1)   Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.

      (2)   Variances shall only be issued upon:

         A.   Showing a good and sufficient cause;

         B.   A determination that failure to grant the variance would result in exceptional hardship to the applicant; and

         C.   A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing local laws or ordinances.

      (3)   Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with the lowest floor elevation below the base flood elevation, and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation.

(1992 Code, § 45-18) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016; Ord. 78-17, passed 8-15-2017; Ord. 32-18, passed 5-2-2018; Ord. 77-21, passed 7-6-2021)

   (a)   A fee of $75 shall be charged for the issuance of a floodplain development permit pertaining to individual lots.

   (b)   A fee of $250 shall be charged for the issuance of a floodplain development permit pertaining to a group of lots or subdivisions (either platted or preliminary).

   (c)   Fee will be administratively voided by staff for the following exceptions:

      (1)   If the improvement is not a substantial improvement;

      (2)   For zoning permits (fence, sheds, paving, and the like); and/or

      (3)   For any organization identified under § 41.007.

(Ord. 94-16, passed 8-2-2016; Ord. 78-17, passed 8-15-2017; Ord. 30-19, passed 3-19-2019; Ord. 77-21, passed 7-6-2021)

   The city of Sioux Falls shall review all floodplain development permit applications to determine whether proposed development areas will be reasonably safe from flooding.

      (1)   No development shall:

         A.   Obstruct flow, defined as development which blocks the conveyance of floodwaters by itself or with other development, causing any increase in the BFE flood height; or

         B.   Cause any increase in the BFE flood height due to floodplain storage area lost.

      (2)   The floodplain administrator and/or designated staff shall deny permits if it is determined the proposed development will obstruct flow or cause any increase in the BFE flood height, based on the officially adopted FIRM or other adopted map.

      (3)   The city of Sioux Falls Engineering Design Standards, Chapter 11, Drainage Improvements, shall regulate the hydraulic and hydrologic analyses standards and compliance.

(Ord. 94-16, passed 8-2-2016; Ord. 77-21, passed 7-6-2021)

   (a)   All requests to revise or change the flood hazard data, including requests for a Letter of Map Revision and a Conditional Letter of Map Revision, shall be reviewed by the floodplain administrator and/or designated staff.

      (1)   The floodplain administrator shall not sign the community acknowledgment form for any requests based on filling or other development, unless the applicant for the letter documents that such filling or development is in compliance with this chapter.

      (2)   The floodplain administrator shall not approve a request to revise or change a floodway delineation until FEMA has issued a Conditional Letter of Map Revision that approves the change.

   (b)   If an applicant disagrees with the regulatory data prescribed by this section, they may submit a detailed technical study needed to replace existing data with better data in accordance with FEMA mapping guidelines. If the data in question are shown on the published FIRM, the submittal must also include a request to FEMA for a Letter of Map Revision to correct the flood risk in the area based on existing conditions.

   (c)   Where base flood elevation data are not available in accordance with this section, applicants for approval of new subdivisions and other proposed developments (including proposals for manufactured home parks and subdivisions) greater than 50 lots or five acres, whichever is the lesser, shall include such data when submitting for their permit.

   (d)   Where floodway delineation is not available in accordance with this section, the floodway will be designated to be one-half the distance of the mapped 100-year floodplain at any point, and the prohibition on floodway development adheres, unless a floodway study indicates otherwise. This provision applies to any floodplain development permit, including those for substantial improvements.

   (e)   The floodplain administrator and/or designated staff shall use the most restrictive data available for the channel migration zone, floodways, and future conditions.

(Ord. 77-21, passed 7-6-2021)

   All temporary storage of materials or equipment on sites within Zones A1-30, AE, AH, AO, and A on the community's FIRM or area that has been identified as a flood hazard area through the use of best available data are required to:

   (a)   For commercial, industrial, or government uses:

      (1)   Obtain an annual floodplain development permit prior to temporary storage; and

      (2)   Provide a city-approved response flood plan to detail what activities will take place if a flood warning is issued to ensure that materials aren't swept away by the flood; and

      (3)   Provide an erosion control plan for all feasible levels of water events.

   (b)   For all other uses:

      (1)   Obtain a floodplain development permit prior to temporary storage; and

      (2)   Be on the site for fewer than 90 consecutive days and no more than 180 cumulative days within a calendar year; and

      (3)   Have a plan in place for the removal of the equipment or materials including a list of necessary supplies, tools, and resources needed to achieve the removal; and

      (4)   Have proper documentation to support when the materials or equipment are moved on and off the site.

(Ord. 77-21, passed 7-6-2021)

   The floodplain administrator or designated staff can allow a non-conversion agreement to be removed if the owner of a property can show that based on the most current information that the property no longer qualifies for floodplain restrictions that would require the non-conversion agreement.

(Ord. 77-21, passed 7-6-2021)

   In all areas of special flood hazards, the following provisions are required for all new construction and substantial improvements:

   (a)   All new construction or substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;

   (b)   All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;

   (c)   All new construction or substantial improvements shall be constructed with materials resistant to flood damage;

   (d)   New and replacement electrical equipment, heating, ventilating, air conditioning, plumbing connections, and other service equipment shall be located at least two feet above the base flood elevation. Electrical wiring and outlets, switches, junction boxes, and panels shall be elevated at least two feet above the base flood elevation unless they conform to the provisions of the electrical code for location of such items in wet locations. Duct systems shall not be installed below two feet above the base flood elevation;

   (e)   All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;

   (f)   New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from the systems into flood waters;

   (g)   On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding;

   (h)   The flood protection elevation (FPE) shall be the base flood elevation plus two feet;

   (i)   Where base flood elevation and floodway data have not been provided in special flood hazard areas, the floodplain administrator shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a federal, state, or other source; and

      (1)   The protected area is comprised of those lands that lie within the boundaries of the floodway and the channel migration area.

      (2)   In riverine areas where a floodway has not been designated in accordance with this chapter, the protected area is comprised of those lands that lie within the boundaries of the channel migration area and the SFHA;

         A.   The channel migration area shall be the channel migration zone as delineated on Sioux Falls Floodplain Protection Area Map plus 25 feet.

         B.   Where more than one channel migration zone has been delineated, the floodplain administrator shall use the delineation that has been adopted for other local regulatory purposes.

         C.   Where a channel migration zone has not yet been mapped, it is designated as the entire SFHA as the channel migration zone.

(1992 Code, § 45-19) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016; Ord. 77-21, passed 7-6-2021)

   In all areas of special flood hazards where base flood elevation data has been provided, the following provisions are required:

      (1)   Site plans for new residential structures are required to specify the minimum ground elevation (MGE) which designates the elevation of the top of the black dirt under the grass, or the top of the landscape rock or other landscape material at the lowest exposed part of the house.

      (2)   Exception: Structures on areas removed from areas of special flood hazard with a FEMA-approved LOMR-F may proceed with construction per standards listed in FEMA Technical Bulletin 10-01, Ensuring That Structures Built on Fill In or Near Special Flood Hazard Areas Are Reasonably Safe From Flooding.

      (3)   Structures on areas removed from areas of special flood hazard with a FEMA-approved LOMR-F, and per the community acknowledgment form submitted with Letter of Map Change, shall have elevation drawings at the time of application for a building permit and must be signed and sealed by a licensed professional engineer or surveyor.

The professional is verifying that no new construction or substantial improvement is allowed unless the lowest floor elevation is two feet or more above the BFE. The elevation drawing shall include the following:

         A.   Lowest floor elevation (including basement);

         B.   The lowest ground elevation touching the building (entry point); and

         C.   Base flood elevation.

      (1)   A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided;

      (2)   The bottom of all openings shall be no higher than one foot above grade; and

      (3)   Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.

      (1)   Require that all manufactured homes to be placed within Zone A on a community’s FHBM or FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.

      (2)   Require that manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the community’s FIRM on sites:

         A.   Outside of a manufactured home park or subdivision;

         B.   In a new manufactured home park or subdivision;

         C.   In an expansion to an existing manufactured home park or subdivision; or

         D.   In an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated two feet above the base flood elevation, and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.

      (1)   Require that recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community’s FIRM either:

         A.   Be on the site for fewer than 180 consecutive days;

         B.   Be fully licensed and ready for highway use; or

         C.   Meet the elevation certificate requirements of § 156.052(b)(1), and the elevation and anchoring requirements for manufactured homes in division (d) above.

      (2)   A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions.

      (1)   The structure must be affixed to a permanent foundation, designed and adequately anchored to resist flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Because of hydrodynamic loads, crawl space construction is not allowed in areas with flood velocities greater than five feet per second unless the design is reviewed by a qualified design professional, such as a registered architect or professional engineer.

      (2)   The crawl space is an enclosed area below the BFE and, as such, must have openings that equalize hydrostatic pressures by allowing the automatic entry and exit of floodwaters. The bottom of each flood vent opening can be no more than one foot above the LAG.

      (3)   The crawl space enclosure must have proper openings that allow equalization of hydrostatic pressure by allowing automatic entry and exit of floodwaters. To achieve this, a minimum of one square inch of flood opening is required per one square foot, or smaller openings if they are approved engineered openings of the enclosed area subject to flooding.

      (4)   Portions of the building below the BFE must be constructed with materials resistant to flood damage. This includes not only the foundation walls of the crawl space used to elevate the building, but also any joists, insulation, piers, or other materials that extend below the BFE. Ductwork, in particular, must either be placed two feet above the BFE or sealed from floodwaters.

      (5)   Any building utility systems within the crawl space must be elevated above the BFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions.

      (6)   The interior grade of a crawl space below the BFE must not be more than two feet below the LAG.

      (7)   The height of the below-grade crawl space, measured from the lowest interior grade of the crawl space floor to the bottom of the floor joist of the next higher floor cannot exceed four feet at any point.

      (8)   There must be an adequate drainage system that removes floodwaters from the interior area of the crawl space. The enclosed area should be drained within a reasonable time after a flood event.

      (9)   Buildings with below-grade crawl spaces will have higher flood insurance premiums than buildings that have the preferred crawl space construction with the interior elevation at or above the LAG.

(1992 Code, § 45-20) (Ord. 70-09, passed 8-3-2009; Ord. 85-11, passed 11-14-2011; Ord. 94-16, passed 8-2-2016; Ord. 78-17, passed 8-15-2017; Ord. 77-21, passed 7-6-2021)

   (a)   All subdivision proposals including the placement of manufactured home parks and subdivisions shall be consistent with provisions of this chapter.

      (1)   Preliminary plans and development engineering plans shall include the special flood hazard area and drainage data as required by engineering design standards.

      (2)   Residential building lots shall be provided with adequate buildable area outside the floodway.

      (3)   Streets and sidewalks shall be designed to minimize potential for increasing or aggravating flood levels.

   (b)   All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet floodplain development permit requirements of §§ 156.032, 156.052, and 156.065 through 156.068.

   (c)   Base flood elevation data shall be determined and shown on subdivision proposals and other proposed development including the placement of manufactured home parks and subdivisions which are greater than 50 lots or five acres, whichever is lesser.

   (d)   (1)   All subdivision proposals including the placement of manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.

         A.   The minimum setback distance from the edge of a flood hazard area to the nearest wall of a basement shall be 20 feet;

         B.   The lowest floor level elevation (including basement) shall be no more than five feet below the closest adjacent base flood elevation;

         C.   The lowest opening shall be no less than one foot above the base flood elevation;

         D.   Additional requirements in conformance with the provisions of FEMA/FIA-Technical Bulletin 10-01 may be required to ensure that a structure is reasonably safe from flooding.

   (e)   All subdivision proposals including the placement of manufactured home parks and subdivisions shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize or eliminate flood damage.

   (f)    Any subdivision proposals along any regulated floodplain are required to determine the BFE through a study or best available data through FEMA and provide that information with the first subdivision submittals.

   (g)   Base flood elevation data shall be provided for all subdivision proposals where a flood hazard exists as illustrated on a floodplain map (FIRM map or best available information data). The property owner(s) or designated representatives of any subdivision which proposes changes to the 100-year floodplain limits shall have a licensed professional prepare, request the city to sign a community acknowledgment form, and submit for a conditional Letter of Map Change directly to the Federal Emergency Management Agency (FEMA). Building permits for any areas of the subdivision affected by proposed changes shall not be approved by the city prior to acceptance of the Letter of Map Change by FEMA. Upon verification of the FEMA acceptance, the city floodplain administrator shall issue a floodplain development permit.

(1992 Code, § 45-21) (Ord. 70-09, passed 8-3-2009; Ord. 94-16, passed 8-2-2016; Ord. 78-17, passed 8-15-2017; Ord. 77-21, passed 7-6-2021)

   (a)   Floodways located within areas of special flood hazard established in § 156.031 are areas designated as floodways.

   (b)   Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles and erosion potential, the following provisions shall apply:

      (1)   Designate a regulatory floodway which will not increase the base flood level more than one foot; and

      (2)   Encroachments are prohibited, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway (except for public works projects such as bridges, culverts, low water crossings, roads, public utilities, and the like); and

      (3)   Under the provisions of 44 C.F.R. Chapter 1, § 65.12, of the National Flood Insurance Program regulations, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the applicant first applies for a conditional FIRM and floodway revision through FEMA; and

      (4)   Pipeline river or stream crossings shall be buried in the stream bed and banks or otherwise sufficiently protected to prevent rupture due to channel degradation and meandering or due to the action of flood flows; and

      (5)   The maintenance of existing levees is permissible; and

      (6)   Residential development is prohibited within the regulated floodway portion of the regularity floodplain; and

      (7)   Any work exempted and allowed is required to show a no-rise for any floodway and floodplain up and downstream from the project area.

(1992 Code, § 45-22) (Ord. 70-09, passed 8-3-2009; Ord. 85-11, passed 11-14-2011; Ord. 77-21, passed 7-6-2021)

      (1)   Withstand flood pressures, depths, velocities, uplift and impact forces, and other regional flood factors;

      (2)   Protect structures to the flood protection elevation;

      (3)   Anchor structures to foundations to resist flotation and lateral movement;

      (4)   Minimize or eliminate infiltration of flood waters; and

      (5)   Minimize or eliminate discharges into flood waters.

      (1)   The structure is strictly a nonresidential structure used for parking or storage only;

      (2)   The accessory building or structure must represent a maximum investment of less than 10% of the value of the principal building on the property, or a maximum floor area of 600 square feet;

      (3)   Designed to allow for the automatic entry and exit of flood waters through the use of openings;

      (4)   Be constructed of flood-resistant materials;

      (5)   Be properly anchored to resist flotation, collapse, and lateral movement;

      (6)   Mechanical and utility equipment, outlets, and switches must be elevated or floodproofed to or above the BFE plus two feet;

      (7)   Must comply with the floodway encroachment provisions of the NFIP and this chapter; and

      (8)   Designed and built to adhere to FEMA Technical Bulletins 1, 2, and 7.

   (c)   A registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this division. A record of such certification that includes the specific elevation (in relation to mean sea level) to which such structures are floodproofed shall be maintained by the floodplain administrator. If the use or occupancy of the building changes in the future to residential, then the wet floodproofing of the structure cannot be used when determining compliance of the structure to the residential construction of this chapter.

(Ord. 94-16, passed 8-2-2016; Ord. 77-21, passed 7-6-2021)

   (a)   Where base flood elevation data have been obtained pursuant to this chapter, the floodplain administrator or designated staff shall obtain, record, and maintain the actual "finished construction" elevations for the locations listed in § 156.052(c). This information shall be recorded on a current FEMA elevation certificate (FEMA Form 81-31), signed and sealed by a professional land surveyor, currently licensed in the state of South Dakota.

   (b)   For all new or substantially improved dry floodproofed nonresidential structures where base flood elevation data has been obtained pursuant to this chapter, the floodplain administrator and/or designated staff shall obtain, record, and maintain the elevation (in relation to the datum of the effective FIRM) to which the structure was floodproofed. This information shall be recorded on a current FEMA floodproofing certificate (FEMA Form 81-65), signed and sealed by a professional engineer, currently licensed in the state of South Dakota.

(Ord. 77-21, passed 7-6-2021)

   (a)   A certification of use for the property or a certificate of occupancy for a new or substantially improved structure or an addition shall not be issued until:

      (1)   The permit applicant provides a properly completed, signed, and sealed elevation or floodproofing certificate showing finished construction data as required by § 4.6;

      (2)   If a mitigation plan is required by this chapter, all work identified in the plan has been completed according to the plan's schedule;

      (3)   The applicant provides copies of all required federal, state, and local permits noted in the permit application per this chapter;

      (4)   All other provisions of this chapter have been met.

   (b)   The floodplain administrator or designated staff may accept a performance bond or other security that will ensure that unfinished portions of the project will be completed after the certification of use or certificate of occupancy has been issued.

(Ord. 77-21, passed 7-6-2021)

   (a)   No new development shall create a threat to public health, public safety, or water quality. Chemicals, explosives, gasoline, propane, buoyant materials, animal wastes, fertilizers, flammable liquids, pollutants, or other materials that are hazardous, toxic, or a threat to water quality are prohibited from the regulatory floodplain. This prohibition does not apply to small quantities of these materials kept for normal household use. This prohibition does not apply to the continued operations of existing facilities and structures, reuse of existing facilities and structures, or functionally dependent facilities or structures.

   (b)   If the proposed project cannot meet division (a) above, then a habitat assessment must be conducted that includes an assessment of the impact of the project on federal, state, or locally protected species and habitat, water quality, and aquatic habitat. The assessment shall be:

      (1)   A biological evaluation or biological assessment developed per 50 C.F.R. § 402.12 to initiate federal interagency consultation under Endangered Species Act § 7(a)(2); or

      (2)   Documentation that the activity fits within § 4(d) of the Endangered Species Act; or

      (3)   Documentation that the activity fits within a habitat conservation plan approved pursuant to § 10 of the Endangered Species Act, where any such assessment has been prepared or is otherwise made available; or

      (4)   An assessment prepared in accordance with FEMA standards. The assessment shall determine if the project would adversely affect:

         A.   Species that are federal, state, or local listed as threatened or endangered;

         B.   The primary constituent elements for critical habitat, when designated;

         C.   Essential fish habitat designated by the National Marine Fisheries Service;

         D.   Fish and wildlife habitat conservation areas; or

         E.   Other protected areas and elements necessary for species conservation.

         A.   If the assessment conducted under this section concludes the project is expected to have an adverse effect on water quality and/or aquatic habitat or habitat functions, the applicant shall provide a plan to mitigate those impacts in accordance with applicable FEMA regulations.

            1.   If the USFWS or NMFS issues an incidental take permit under § 10 ESA, Biological Opinion under § 7, ESA, then it can be considered to qualify as a plan to mitigate those impacts.

            2.   If the project is located outside the protected area, the mitigation plan shall include such avoidance, minimization, restoration, or compensation measures so that in-direct adverse effects of development in the floodplain (effects to stormwater, riparian vegetation, bank stability, channel migration, hyporheic zones, wetlands, large woody debris, and the like) are mitigated such that equivalent or better habitat protection is provided.

            3.   No new stream crossings are allowed outside the protected area, unless approval has been obtained as stated in this chapter.

            4.   If the project is located in the protected area, the mitigation plan shall stipulate avoidance measures as are needed to ensure that there is no adverse effect during any phase of the project.

         B.   The plan's habitat mitigation activities shall be incorporated into the proposed project. The floodplain development permit shall be based on the redesigned project and its mitigation components.

         C.   As required in this chapter, the floodplain administrator shall not issue a certificate of occupancy until all work identified in the habitat assessment and mitigation plan has been completed or the applicant has provided the necessary assurance that unfinished portions of the project will be completed in accordance with § 156.071(b).

(Ord. 77-21, passed 7-6-2021)

   (a)   Construction of new critical facilities shall be, to the extent possible, located outside the limits of the 500-year floodplain.

   (b)   Construction of new critical facilities in the regulatory floodplain shall be permissible if no feasible alternative site is available, provided:

      (1)   Critical facilities shall have the lowest floor elevated two feet above the base flood elevation or to the height of the 500-year flood, whichever is higher. If there is no available data on the 500-year flood, the permit applicants shall develop the needed data in accordance with FEMA mapping guidelines.

      (2)   Access to and from the critical facility shall be protected to the elevation of the 500-year flood.

(Ord. 77-21, passed 7-6-2021)

   New development shall not reduce the effective flood storage volume of the regulatory floodplain. A development proposal shall provide compensatory storage if grading or other activity eliminates any effective flood storage volume. Compensatory storage shall:

   (a)   Provide equivalent volume at equivalent elevations within the same drainage basin that is being displaced. For this purpose, "equivalent elevation" means having a similar relationship to ordinary high water and to the best available ten-year, 50-year, and 100-year water surface profiles; and

   (b)   Be hydraulically connected to the source of flooding; and

   (c)   Provide compensatory storage in the same construction season as when the displacement of flood storage volume occurs and before the flood season begins; and

   (d)   The newly created storage area shall be graded and vegetated to allow fish access during flood events without creating fish stranding sites.

(Ord. 77-21, passed 7-6-2021)