FLOODPLAIN MANAGEMENT:
ACCESSORY STRUCTURE: | A structure, as defined in this section, that is on the same parcel of property as, and incidental to, the principal structure or use; an accessory structure specifically excludes structures used for human habitation. |
BASE FLOOD: | Flood having a one-percent chance of being equaled or exceeded in any given year. “Base flood” is synonymous with the term “regional flood” used in Minnesota Rules Part 6120.5000. |
BASE FLOOD ELEVATION (BFE): | The elevation of the base flood, regional flood, or one-percent annual chance flood. The term “base flood elevation” is used in the flood insurance study. |
BASEMENT: | Any area of a structure, including crawl spaces, having its floor subgrade (below ground level) on all four sides, regardless of the depth of excavation below ground level. |
BUILDING: | See Structure. |
CHANNEL: | A natural or artificial depression of perceptible extent, with definite beds and banks to confine and conduct flowing water either continuously or periodically. |
CONDITIONAL USE: | A land use or development that would not be appropriate generally but may be allowed with appropriate restrictions upon a finding that certain conditions as detailed in the zoning ordinance exist, the use or development conforms to the comprehensive land use plan of the community, and the use is compatible with the existing neighborhood. |
CRITICAL FACILITIES: | Buildings and structures that contain essential facilities and services necessary for emergency response and recovery, or that pose a substantial risk to the public in the event of failure, disruption of function, or damage by flooding. Specifically, this includes facilities identified as Flood Design Class 4 in ASCE 24-14, Flood Resistant Design and Construction, as amended. Examples include health care facilities, facilities required for emergency response, power generating stations, communications towers, or electrical substations. |
DEVELOPMENT: | Any manmade change to improved or unimproved real estate, including, but not limited to buildings, or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials. |
EQUAL DEGREE OF ENCROACHMENT: | A method of determining the location of floodway boundaries so that floodplain lands on both sides of a stream are capable of conveying a proportionate share of flood flows. |
FARM FENCE: | An open type of fence of posts and horizontally run wire, further specified in Minnesota Statutes, Section 344.02, Subdivision 1(a-d). |
FEMA: | Federal Emergency Management Agency. |
FLOOD: | A temporary rise in the stream flow or water surface elevation from any source that results in the inundation of normally dry land area. |
FLOOD FRINGE: | The portion of the one-percent annual change floodplain located outside of the floodway. This district shall be extended laterally to the 0.2-percent annual change floodplain, where mapped. |
FLOOD INSURANCE RATE MAP (FIRM): | An official map on which the Federal Insurance Administrator has delineated both the special flood hazard areas and the risk premium zones applicable to the community. A FIRM that has been made available digitally is called a Digital Flood Insurance Rate Map (DFIRM). |
FLOOD INSURANCE STUDY (FIS): | The study referenced in Paragraph D, which is an examination, evaluation, and determination of flood hazards, and if appropriate, corresponding surface elevations, or an examination, evaluation, and determination of mudslide (i.e. mudflow) and/or flood-related erosion hazards. |
FLOODPLAIN: | The beds, channel and the areas adjoining a wetland, lake or watercourse, or other source which have been or hereafter may be inundated by the base flood. |
FLOODPROOFING: | A combination of structural and non-structural additions, changes, or adjustments to properties and structures subject to flooding, primarily for the reduction or elimination of flood damages. |
FLOODWAY: | The bed of a wetland or lake and the channel of a watercourse and those portions of the adjoining floodplain which must be reserved to carry or store the base flood discharge without cumulatively increasing the water surface elevation more than one-half foot. |
GENERAL FLOODPLAIN: | Those floodplains designated on the Flood Insurance Rate Maps referenced in Paragraph C.2, but that do not have a delineated floodway. |
LIGHT DUTY TRUCK: | Any motor vehicle that has all three of the following: a) 8,500 pounds gross vehicle weight rating or less; b) vehicle curb weight of 6,000 pounds or less; and c) basic vehicle frontal area less than 45 square feet. |
LOWEST FLOOD: | The lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, used solely for parking of vehicles, building access, or storage in an area other than a basement area, is not considered a building’s lowest floor; provided, that such enclosure is not built to render the structure in violation of the applicable non-elevation design requirements of 44 CFR § 60.3. |
MANUFACTURED HOME: | A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term “manufactured home” does not include the term “recreational vehicle.” |
NEW CONSTRUCTION: | Structures for which the start of construction commenced on or after the effective date of an adopted floodplain management regulation and includes any subsequent improvements to such structures. |
PRINCIPAL STRUCTURE: | The main building or other structure on a lot that is utilized for the property’s principal use. |
REACH: | A hydraulic engineering term to describe a longitudinal segment of a stream or river influenced by a natural or man-made obstruction. In an urban area, the segment of a stream or river between two consecutive bridge crossings would most typically constitute a reach. |
RECREATIONAL VEHICLE: | A vehicle that is built on a single chassis, is 400 square feet or less when measured at the largest horizontal projection, is designed to be self-propelled or permanently towable by a light duty truck and is designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. Those vehicles not meeting this definition shall be considered a structure for the purposes of this section. For the purposes of this section, the term recreational vehicle is synonymous with the term “travel trailer/travel vehicle.” |
REGULATORY FLOOD PROTECTIONS ELEVATION (RFPE): | An elevation that is one foot above the elevation of the base flood plus any increases in the water surface elevation caused by encroachments on the floodplain that result from designation of a floodway. These increases in water surface elevations are typically identified in Floodway Data Tables, found in the Flood Insurance Study. |
REPETITIVE LOSS: | Flood related damages sustained by a structure on two separate occasions during a ten-year period for which the cost of repairs at the time of such flood event on the average equals or exceeds 25% of the market value of the structure before the damage occurred. |
STAGE INCREASE: | Any increase in the water surface elevation during the one-percent annual chance flood caused by encroachments on the floodplain. |
START OF CONSTRUCTION: | Includes substantial improvement, and means the date the permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement, or other improvement was within 180 days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, foundations, or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building. |
STRUCTURE: | A roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. Recreational vehicles not considered travel ready, as detailed in Paragraph L.2.b.(2), shall also be considered a structure for the purposes of this section. |
SUBDIVISION: | Land that has been divided for the purpose of sale, rent, or lease, including planned unit developments. |
SUBSTANTIAL DAMAGE: | Damage of any origin sustained by a structure where the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred. |
SUBSTANTIAL IMPROVEMENT: | Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the “start of construction” of the improvement. This term includes structures that have incurred “substantial damage”, regardless of the actual repair work performed. The term does not, however, include either: |
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 the local code enforcement official and which are the minimum necessary to assure safe living 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”. For the purpose of this section, “historic structure” is defined in 44 CFR § 59.1. | |
VARIANCE: | Means the same as that defined in 44 CFR § 59.1 and Minnesota Statutes, Section 462.357, Subdivision 6(2). |
WATER COURSE: | A channel in which a flow of water occurs either continuously or intermittently in a definitive direction. The term applied to either natural or artificially constructed channels. |

Table 1. Summary of Permitting Requirements for Structures | |||
Structure Type | Floodway | Flood Fringe | Standards* |
Table 1. Summary of Permitting Requirements for Structures | |||
Structure Type | Floodway | Flood Fringe | Standards* |
Accessory Structures - on fill | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.2. |
Accessory Structures - Alt. Elevation Methods | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.3. |
Accessory Structures - Wet Floodproofing | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.1. |
Accessory Structures - Dry (watertight) Floodproofing | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.4. |
Residential - on fill | Not allowed | Allowed with Permit | Paragraph F.2.a.1. |
Residential - Alt. Elevation Methods | Not allowed | Allowed with CUP | Paragraph F.4.a. |
Residential - Dry (watertight) Floodproofing and/or Basement Construction below RFPE | Not allowed | Not allowed | N/A |
Non-Residential - on fill | Not allowed | Allowed with Permit | Paragraph F.2.b. |
Non-Residential - Alt. Elevation Methods | Not allowed | Allowed with Permit | Paragraph F.2.b. |
Non-Residential - Dry (watertight) Floodproofing and/or Basement Construction below RFPE | Not allowed | Allowed with Permit | Paragraph F.2.C. |
*Note - many of these standards are cross-referenced | |||


FLOODPLAIN MANAGEMENT:
ACCESSORY STRUCTURE: | A structure, as defined in this section, that is on the same parcel of property as, and incidental to, the principal structure or use; an accessory structure specifically excludes structures used for human habitation. |
BASE FLOOD: | Flood having a one-percent chance of being equaled or exceeded in any given year. “Base flood” is synonymous with the term “regional flood” used in Minnesota Rules Part 6120.5000. |
BASE FLOOD ELEVATION (BFE): | The elevation of the base flood, regional flood, or one-percent annual chance flood. The term “base flood elevation” is used in the flood insurance study. |
BASEMENT: | Any area of a structure, including crawl spaces, having its floor subgrade (below ground level) on all four sides, regardless of the depth of excavation below ground level. |
BUILDING: | See Structure. |
CHANNEL: | A natural or artificial depression of perceptible extent, with definite beds and banks to confine and conduct flowing water either continuously or periodically. |
CONDITIONAL USE: | A land use or development that would not be appropriate generally but may be allowed with appropriate restrictions upon a finding that certain conditions as detailed in the zoning ordinance exist, the use or development conforms to the comprehensive land use plan of the community, and the use is compatible with the existing neighborhood. |
CRITICAL FACILITIES: | Buildings and structures that contain essential facilities and services necessary for emergency response and recovery, or that pose a substantial risk to the public in the event of failure, disruption of function, or damage by flooding. Specifically, this includes facilities identified as Flood Design Class 4 in ASCE 24-14, Flood Resistant Design and Construction, as amended. Examples include health care facilities, facilities required for emergency response, power generating stations, communications towers, or electrical substations. |
DEVELOPMENT: | Any manmade change to improved or unimproved real estate, including, but not limited to buildings, or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations, or storage of equipment or materials. |
EQUAL DEGREE OF ENCROACHMENT: | A method of determining the location of floodway boundaries so that floodplain lands on both sides of a stream are capable of conveying a proportionate share of flood flows. |
FARM FENCE: | An open type of fence of posts and horizontally run wire, further specified in Minnesota Statutes, Section 344.02, Subdivision 1(a-d). |
FEMA: | Federal Emergency Management Agency. |
FLOOD: | A temporary rise in the stream flow or water surface elevation from any source that results in the inundation of normally dry land area. |
FLOOD FRINGE: | The portion of the one-percent annual change floodplain located outside of the floodway. This district shall be extended laterally to the 0.2-percent annual change floodplain, where mapped. |
FLOOD INSURANCE RATE MAP (FIRM): | An official map on which the Federal Insurance Administrator has delineated both the special flood hazard areas and the risk premium zones applicable to the community. A FIRM that has been made available digitally is called a Digital Flood Insurance Rate Map (DFIRM). |
FLOOD INSURANCE STUDY (FIS): | The study referenced in Paragraph D, which is an examination, evaluation, and determination of flood hazards, and if appropriate, corresponding surface elevations, or an examination, evaluation, and determination of mudslide (i.e. mudflow) and/or flood-related erosion hazards. |
FLOODPLAIN: | The beds, channel and the areas adjoining a wetland, lake or watercourse, or other source which have been or hereafter may be inundated by the base flood. |
FLOODPROOFING: | A combination of structural and non-structural additions, changes, or adjustments to properties and structures subject to flooding, primarily for the reduction or elimination of flood damages. |
FLOODWAY: | The bed of a wetland or lake and the channel of a watercourse and those portions of the adjoining floodplain which must be reserved to carry or store the base flood discharge without cumulatively increasing the water surface elevation more than one-half foot. |
GENERAL FLOODPLAIN: | Those floodplains designated on the Flood Insurance Rate Maps referenced in Paragraph C.2, but that do not have a delineated floodway. |
LIGHT DUTY TRUCK: | Any motor vehicle that has all three of the following: a) 8,500 pounds gross vehicle weight rating or less; b) vehicle curb weight of 6,000 pounds or less; and c) basic vehicle frontal area less than 45 square feet. |
LOWEST FLOOD: | The lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, used solely for parking of vehicles, building access, or storage in an area other than a basement area, is not considered a building’s lowest floor; provided, that such enclosure is not built to render the structure in violation of the applicable non-elevation design requirements of 44 CFR § 60.3. |
MANUFACTURED HOME: | A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term “manufactured home” does not include the term “recreational vehicle.” |
NEW CONSTRUCTION: | Structures for which the start of construction commenced on or after the effective date of an adopted floodplain management regulation and includes any subsequent improvements to such structures. |
PRINCIPAL STRUCTURE: | The main building or other structure on a lot that is utilized for the property’s principal use. |
REACH: | A hydraulic engineering term to describe a longitudinal segment of a stream or river influenced by a natural or man-made obstruction. In an urban area, the segment of a stream or river between two consecutive bridge crossings would most typically constitute a reach. |
RECREATIONAL VEHICLE: | A vehicle that is built on a single chassis, is 400 square feet or less when measured at the largest horizontal projection, is designed to be self-propelled or permanently towable by a light duty truck and is designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. Those vehicles not meeting this definition shall be considered a structure for the purposes of this section. For the purposes of this section, the term recreational vehicle is synonymous with the term “travel trailer/travel vehicle.” |
REGULATORY FLOOD PROTECTIONS ELEVATION (RFPE): | An elevation that is one foot above the elevation of the base flood plus any increases in the water surface elevation caused by encroachments on the floodplain that result from designation of a floodway. These increases in water surface elevations are typically identified in Floodway Data Tables, found in the Flood Insurance Study. |
REPETITIVE LOSS: | Flood related damages sustained by a structure on two separate occasions during a ten-year period for which the cost of repairs at the time of such flood event on the average equals or exceeds 25% of the market value of the structure before the damage occurred. |
STAGE INCREASE: | Any increase in the water surface elevation during the one-percent annual chance flood caused by encroachments on the floodplain. |
START OF CONSTRUCTION: | Includes substantial improvement, and means the date the permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition placement, or other improvement was within 180 days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, foundations, or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building. |
STRUCTURE: | A roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured home. Recreational vehicles not considered travel ready, as detailed in Paragraph L.2.b.(2), shall also be considered a structure for the purposes of this section. |
SUBDIVISION: | Land that has been divided for the purpose of sale, rent, or lease, including planned unit developments. |
SUBSTANTIAL DAMAGE: | Damage of any origin sustained by a structure where the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred. |
SUBSTANTIAL IMPROVEMENT: | Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the “start of construction” of the improvement. This term includes structures that have incurred “substantial damage”, regardless of the actual repair work performed. The term does not, however, include either: |
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 the local code enforcement official and which are the minimum necessary to assure safe living 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”. For the purpose of this section, “historic structure” is defined in 44 CFR § 59.1. | |
VARIANCE: | Means the same as that defined in 44 CFR § 59.1 and Minnesota Statutes, Section 462.357, Subdivision 6(2). |
WATER COURSE: | A channel in which a flow of water occurs either continuously or intermittently in a definitive direction. The term applied to either natural or artificially constructed channels. |

Table 1. Summary of Permitting Requirements for Structures | |||
Structure Type | Floodway | Flood Fringe | Standards* |
Table 1. Summary of Permitting Requirements for Structures | |||
Structure Type | Floodway | Flood Fringe | Standards* |
Accessory Structures - on fill | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.2. |
Accessory Structures - Alt. Elevation Methods | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.3. |
Accessory Structures - Wet Floodproofing | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.1. |
Accessory Structures - Dry (watertight) Floodproofing | Only specific uses and types allowed - with CUP | Allowed with Permit | Paragraph F.3.d.4. |
Residential - on fill | Not allowed | Allowed with Permit | Paragraph F.2.a.1. |
Residential - Alt. Elevation Methods | Not allowed | Allowed with CUP | Paragraph F.4.a. |
Residential - Dry (watertight) Floodproofing and/or Basement Construction below RFPE | Not allowed | Not allowed | N/A |
Non-Residential - on fill | Not allowed | Allowed with Permit | Paragraph F.2.b. |
Non-Residential - Alt. Elevation Methods | Not allowed | Allowed with Permit | Paragraph F.2.b. |
Non-Residential - Dry (watertight) Floodproofing and/or Basement Construction below RFPE | Not allowed | Allowed with Permit | Paragraph F.2.C. |
*Note - many of these standards are cross-referenced | |||

