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Storm Water Related Definitions (2)Storm Water Related Definitions This list of terms is intended to include those that have specific meaning to the National Flood Insurance Program (NFIP). In a few instances, standard industry terms have been added for additional focus and emphasis. Act --The National Flood Insurance Act of 1968 and any amendments to it. Anchored --Adequately secured to prevent flotation, collapse, or lateral movement. Appurtenant Structure --A detached garage or carport servicing a 1-4 family dwelling. Base Flood --The flood having a one percent chance of being equaled or exceeded in any given year. Basin-- The entire area of land which drains into a particular design point via natural flow or manmade improvements. Sometimes also referred to as, “Watershed”. Benchmark-- An elevation reference mark. Base Flood Elevation (BFE) -- The elevation shown on the Flood Insurance Rate Map for Zones AE, AH, A1-A30, AR, AR/A, AR/AE, AR/A1-A30, AR/AH, AR/AO, V1-V30, and VE that indicates the water surface elevation resulting from a flood that has a one percent chance of equaling or exceeding that level in any given year. Basement-- Any area of the building, including any sunken room or sunken portion of a room, having its floor below ground level (subgrade) on all sides. Building-- A structure with two or more outside rigid walls and a fully secured o roof, that is affixed to a permanent site; or A manufactured home (a "manufactured home," also known as a o mobile home, is a structure built on a permanent chassis, transported to its site in one or more sections, and affixed to a permanent foundation); or A travel trailer without wheels, built on a chassis and affixed to a o permanent foundation, that is regulated under the community's floodplain management and building ordinances or laws. "Building" does not mean a gas or liquid storage tank or a o recreational vehicle, park trailer, or other similar vehicle, except as described above. Cancellation --The ending of the insurance coverage provided by a policy before the expiration date. “CA” Factor-- A multiplicative coefficient achieved by multiplying the coefficient of runoff “C”, by the area in acres “A” that is tributary to the point of design. “cfs”-- Cubic feet per second. A measure of the volume of water. Critical Structures-- An integral and readily identifiable part of a drainage system, without which the efficiency of the drainage system is compromised. Cistern-- Covered cisterns and the water in them are defined as an integral part of an insurable building, meaning under the building or above ground and physically attached to a side of the building with one of the walls of the building and cistern being common to each other. Closed Basin Lak e--A natural lake from which water leaves primarily through evaporation and whose surface area exceeds or has exceeded one square mile at any time in the recorded past. NFIP-insured buildings that are subject to continuous lake flooding from a closed basin lake are covered under the provisions of Standard Flood Insurance Policy. Community --A political entity that has the authority to adopt and enforce floodplain ordinances for the area under its jurisdiction. Community Number --A 6-digit designation identifying each NFIP community. The first two numbers are the state code. The next four are the FIMA-assigned community number. An alphabetical suffix is added to a community number to identify revisions in the Flood Insurance Rate Map for that community. Community Rating System (CRS) --A program developed by FIMA to provide incentives for those communities in the Regular Program that have gone beyond the minimum floodplain management requirements to develop extra measures to provide protection from flooding. Condominium --That form of ownership of real property in which each unit owner has an undivided interest in common elements. Condominium Association --The entity made up of the unit owners responsible for the maintenance and operation of: Common elements owned in undivided shares by unit owners; o Other real property in which the unit owners have use rights; o where membership in the entity is a required condition of unit ownership. Countywide Map --A Flood Insurance Rate Map that shows flooding information for the entire geographic area of a county, including the incorporated communities within the county. Date of Construction --The date that the building permit was issued provided the actual start of construction, repair, reconstruction, or improvement was within 180 days of the permit date. Detention-- The detention of storm water on a site, or within a project shall be interpreted as a temporary restrainment of runoff with anticipation of normal runoff over an extended period of time. 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. Development Permit-- A permit required before development shall begin in an area designated as within the limits of the base flood. Drainage Easement-- A delineated portion of land set aside for the overland or underground transfer of storm water. This area shall not have any permanent structures, fences, or other obstacles hindering the safe transfer of water through the easement. Drainage Improvements-- All elements of a storm drainage system consisting of streets, alleys, storm sewers, channels, culverts, bridges, swales, and any other facility through which, or over which storm water flows. Dwelling --A building designed for use as a residence for no more than four families or a single-family unit in building under a condominium form of ownership. Elevated Building --A building that has no basement and has its lowest elevated floor raised above the ground level by foundation walls, shear walls, posts, piers, pilings, or columns. Solid foundation perimeter walls are not an acceptable means of elevating buildings in V and VE zones. Emergency Program --The initial phase of a community's participation in the National Flood Insurance Program. During this phase, only limited amounts of insurance are available under the Act. Enclosure --That portion of an elevated building below the lowest elevated floor that is either partially or fully shut-in by rigid walls. Erosion --The collapse, undermining, or subsidence of land along the shore of a lake or other body of water. Erosion is a covered peril if it is caused by waves or currents of water exceeding their cyclical levels which result in flooding. Federal Emergency Management Agency (FEMA) --The federal agency under which the National Flood Insurance Program is administered. Flood -- A general and temporary condition of partial or complete inundation of two or more acres of normally dry land area or of two or more properties (at least one of which is the policyholder's property) from: --Overflow of inland or tidal waters; or --Unusual and rapid accumulation or runoff of surface waters from any source; or --Mudflow; or Collapse or subsidence of land along the shore of a lake or similar body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels that result in a flood as defined above. Flood Hazard Boundary Map (FHBM) --Official map of a community issued by the Administrator, where the boundaries of the flood, mudflow, and related erosion areas having special hazards have been designated. Flood Insurance Rate Map (FIRM) --Official map of a community on which the FIMA Administrator has delineated both the special hazard areas and the risk premium zones applicable to the community. Floodplain --Any land area susceptible to being inundated by flood waters from any source. Floodplain Management --The operation of an overall program of corrective and preventive measures for reducing flood damage, including but not limited to, emergency preparedness plans, flood control works, and floodplain management regulations. Floodproofing --Any combination of structural and nonstructural additions, changes, or adjustments to structures, which reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitation facilities, or structures with their contents. Freeboard-- An additional amount of height above the Base Flood Elevation used as a factor of safety (e.g., 2 feet above the Base Flood) in determining the level at which a structure's lowest floor must be elevated or floodproofed to be in accordance with State or community floodplain management regulations. FEMA-- Abbreviation for “Federal Emergency Management Agency” FIRM Map-- A map produced by the U.S. Department of Housing and Urban Development, which has the purpose of a Flood Insurance Rate Map and on which the Federal Emergency Management Agency has delineated both the areas of special flood hazards and the risk premium zones applicable to the community. Flood-- A general and temporary condition of partial, or complete inundation of normally dry land areas from the overflow of inland, or tidal waters; the usual and rapid accumulation of runoff, or surface waters from any source; or mudslides which are caused, or precipitated by accumulations of water on, or under the ground. Flood, “100 Year”-- A flood that, on the average, is likely to occur once every 100 years, (i.e., that has a one-percent chance of occurring each year). Also referred to as “100 Year Storm” and/or, as the “Base Flood”. Flood Plain-- The area of land inundated with water in a 100 Year Storm. Floodway-- The channel of a river or the watercourse and the adjacent land areas that must be reserved in order to discharge the Base Flood without cumulatively increasing the water surface elevation more than one foot. Floodway Map-- A map produced by FEMA which delineates the flood boundary and floodway. Fort Worth Drainage Manual-- The City of Fort Worth Storm Drainage Criteria and Design Manual. Freeboard-- A factor of safety usually expressed in feet above a flood level for purposes of flood plain management. Frequency-- The average frequency statistically determined for which it is expected that a specific flood level or discharge may be equaled or exceeded. Grade Elevation --The lowest or highest finished ground level that is immediately adjacent to the walls of the building. Use natural (pre-construction), ground level, if available, for Zone AO and Zone A (without BFE). HEC I Analysis-- A computer watershed model developed by the Hydraulic Engineering Center, U.S. Army Corp of Engineers, which contains several methods with which to simulate surface runoff and river reservoir flow in river basins and flows in urban areas. HEC II Analysis-- A computer backwater flood model developed by the Hydraulic Engineering Center, U.S. Army Corps of Engineers, which calculates water surface profiles for steady, gradually varied flows in natural or man-made channels. Improvements --Fixtures, alterations, installations, or additions comprising a part of the insured building, including the units within the insured condominium building. Letter of Map Amendment (LOMA) --An amendment to the currently effective FEMA map which establishes that a property is not located in a Special Flood Hazard Area. A LOMA is issued only by FEMA. Letter of Map Revision (LOMR) --An official amendment to the currently effective FEMA map. It is issued by FEMA and changes flood zones, delineations, and elevations. Lowest Adjacent Grade-- The lowest point of the ground level next to the building. Lowest Floor --The lowest floor of the lowest enclosed area (including a basement). An unfinished or flood-resistant enclosure, usable 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 so as to render the structure in violation of requirements. (Formerly called "reference level" or "reference level floor.") Lowest Floor Elevation (LFE) --The measured distance of a building's lowest floor above the National Geodetic Vertical Datum (NGVD) or other datum specified on the FIRM for that location. Low-Rise Building --Low-rise condominium buildings having fewer than five units regardless of the number of floors or five or more units with fewer than three units including basement. All townhouses/rowhouses, regardless of the number of floors or units, and all single-family detached condominium buildings are classified as low rise. An enclosure below an elevated building, even if it is the lowest floor for rating purposes, cannot be counted as a floor to avoid classifying the building as a low rise. Manufactured (Mobile) Home --A structure built on a permanent chassis, transported to its site in one or more sections, and affixed to a permanent foundation. "Manufactured (mobile) home" does not include recreational vehicles. Manufactured (Mobile) Home Park or Subdivision,Existing --A manufactured (mobile) home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured (mobile) 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 on or before December 31, 1974, or before the effective date of the community's initial FIRM, whichever is later. Manufactured (Mobile) Home Park or Subdivision, Expansion to Existing Site --The preparation of additional sites by the construction of facilities for servicing the lots on which manufactured (mobile) homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads). Map Revision --A change in the FHBM or FIRM for a community which reflects revised zone, base flood, or other information. Mean Sea Level-- The National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which base flood elevations shown on a community’s Flood Insurance Rate Map are referenced. Mudslide-- A general and temporary movement down a slope of a mass of rock or soil, artificial fill, or a combination of these materials caused or precipitated by the accumulation of water on, or under the ground. Mudflow --A river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water. Other earth movements, such as landslide, slope failure, or a saturated soil mass moving by liquidity down a slope, are not mudflows. National Flood Insurance Program (NFIP) --The program of flood insurance coverage and floodplain management administered under the Act and applicable Federal regulations promulgated in Title 44 of the Code of Federal Regulations, Subchapter B. National Geodetic Vertical Datum (NGVD) --National standard reference datum for elevations, formerly referred to as Mean Sea Level (MSL) of 1929. NGVD is used as the reference datum on most FIRMs. Natural Grade --The grade unaffected by construction techniques such as fill, landscaping, or berming. New Construction --Buildings for which the "start of construction" commenced on or after the effective date of an initial FIRM or after December 31, 1974, whichever is later, including any subsequent improvements. Non-Residential --Includes, but is not limited to: small business concerns, churches, schools, farm buildings (including grain bins and silos), poolhouses, clubhouses, recreational buildings, mercantile structures, agricultural and industrial structures, warehouses, hotels and motels with normal room rentals for less than 6 months' duration, and nursing homes. Other Residential --Hotels or motels where the normal occupancy of a guest is 6 months or more; a tourist home or rooming house which has more than four roomers. A residential building (excluding hotels and motels with normal room rentals for less than 6 months' duration) containing more than four dwelling units. Incidental occupancies such as office, professional private school, or studio occupancy, are permitted if the total area of such incidental occupancies are limited to less than 25 percent of the total floor area within the building. Participating Community --A community for which the FIMA Administrator has authorized the sale of flood insurance under the NFIP. Policy --The entire written contract between the insured and the insurer. It includes: The printed policy form- The application and Declarations Page; Any endorsement(s) that may be issued; and Any renewal certificate indicating that coverage has been instituted for a new policy and new policy term. Only one dwelling, specifically described by the prospective policyholder in the application, may be insured under a policy. Pollutants --Substances that include, but are not limited to, any solid, liquid, gaseous, or thermal irritant or contaminant, including smoke, vapor, soot, fumes, acids, alkalis, chemicals, and waste. "Waste" includes, but is not limited to, materials to be recycled, reconditioned, or reclaimed. Ponding Hazard --A flood hazard that occurs in flat areas when there are depressions in the ground that collect "ponds" of water. The ponding hazard is represented by the zone designation AH on the FIRM. Post-FIRM Building --a building for which construction or substantial improvement occurred after December 31, 1974, or on or after the effective date of an initial Flood Insurance Rate Map (FIRM), whichever is later. Pre-FIRM Building --a building for which construction or substantial improvement occurred on or before December 31, 1974, or before the effective date of an initial Flood Insurance Rate Map (FIRM). Principal Residence --A single-family dwelling in which, at the time of loss, the named insured or the named insured's spouse has lived for either 80 percent of the 365 days immediately preceding the loss, or 80 percent of the period of ownership, if less than 365 days. Principally Above Ground Building --A building that has at least 51 percent of its actual cash value, including machinery and equipment, above ground. Probation-- A means of formally notifying participating communities of violations and deficiencies in the administration and enforcement of the local floodplain management regulations. Probation Premium --A flat charge that the policyholder must pay on each new or renewal policy issued covering property in a community that the NFIP has placed on probation under the provisions of 44 CFR 59.24. Provisional Rating --A method for placing flood coverage prior to the receipt of a FEMA Elevation Certificate. Regular Program --The final phase of a community's participation in the National Flood Insurance Program. In this phase, a Flood Insurance Rate Map is in effect and full limits of coverage are available under the Act. Regular Program Community --A community wherein a FIRM is in effect and full limits of coverage are available under the Act. Repetitive Loss Structure-- A structure, covered by a contract of flood insurance issued under the NFIP, that has suffered flood damage on two occasions during a 10-year period that ends on the date of the second loss, in which the cost to repair the flood damage, on average, equaled or exceeded 25% of the market value of the structure at the time of each flood loss. Replacement CostValue (RCV) --The cost to replace property with the same kind of material and construction without deduction for depreciation. Residential Condominium Building --A building, owned and administered as a condominium, containing one or more family units and in which at least 75 percent of the floor area is residential. Retention: The retention of storm water on a site or within a project shall be interpreted as a permanent restrainment of runoff with no anticipation of runoff over an extended period of time. Shear Walls --Walls used for structural support but not structurally joined or enclosed at the ends (except by breakaway walls). Shear walls are parallel, or nearly parallel, to the flow of the water and can be used in any flood zone. Sheet Flow Hazard --A type of flood hazard with flooding depths of 1 to 3 feet that occurs in areas of sloping land. The sheet flow hazard is represented by the zone designation AO on the FIRM. Single Building --A building that is separated from other buildings by intervening clear space or solid, vertical, load-bearing division walls. Single-Family Residence --A residential single family dwelling. Incidental office, professional, private school, or studio occupancies, including a small service operation, are permitted if such incidental occupancies are limited to less than 50 percent of the building's total floor area. Solid Foundation Perimeter Walls --Walls that are used as a means of elevating a building in A Zones and that must contain sufficient openings to allow for the unimpeded flow of floodwaters more than 1 foot deep. Special Flood Hazard Area (SFHA) --An area having special flood, mudflow, or flood-related erosion hazards, and shown on a Flood Hazard Boundary Map or a Flood Insurance Rate Map as Zone A, AO, A1-A30, AE, A99, AH, AR, AR/A, AR/AE, AR/AH, AR/AO, AR/A1-A30, V1-V30, VE, or V. For the purpose of determining Community Rating System premium discounts, all AR and A99 zones are treated as non-SFHAs. Standard Flood Insurance Policy--Dwelling Form --Policy issued to insure a building and/or residential contents on a single-family or a 2-4 family dwelling. Standard Flood Insurance Policy--General Property Form --Policy issued to insure a building and/or contents on other residential or non-residential buildings. Start of Construction --For other than new construction or substantial improvements, under the Coastal Barrier Resources Act, this is the date the building permit was issued, provided that the actual start of construction, repair, 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 building on site, such as the pouring of a slab or footing, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured (mobile) home on a foundation. For a substantial improvement, 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. Stock --Merchandise held in storage or for sale, raw materials, and in-process or finished goods, including supplies used in their packing or shipping. "Stock" does not include any property not covered under "Section IV. Property not Covered" of the General Property Form, except the following: Parts and equipment for self-propelled vehicles; Furnishings and equipment for watercraft; Spas and hot-tubs, including their equipment; and Swimming pool equipment. Substantial Damage --Damage of any origin sustained by a building whereby the cost of restoring the building to its before-damaged condition would equal or exceed 50 percent of the market value of the building before the damage occurred. Substantial Improvement --Any reconstruction, rehabilitation, addition, or other improvement of a building, the cost of which equals or exceeds 50 percent of the market value of the building before the "start of construction" of the improvement. Substantial improvement includes buildings that have incurred "substantial damage," regardless of the actual repair work performed. The term does not, however, include either any project for improvement of a building to correct existing state or local code violations or any alteration to a "historic building," provided that the alteration will not preclude the building's continued designation as a "historic building." Suspension --Removal of a participating community from the NFIP because the community has not enacted and/or enforced the proper floodplain management regulations required for participation in the NFIP. Travel Trailer --Under the NFIP, a travel trailer can be considered a building only if it is without wheels, built on a chassis and affixed to a permanent foundation, and regulated under the community's floodplain management and building ordinances or laws. Ultimate Conditions-- The level of development anticipated upon full development of all land with a watershed. Ultimate conditions are typically determined by reference to existing use and projected land uses on vacant or nonconforming properties based upon existing zoning or the City Land Use Plan, whichever is more intense. Unless specifically stated otherwise, all storm water runoff calculations required within this ordinance should be based on ultimate conditions of development. Underground Building --A building for which 50 percent or more of the actual cash value, including machinery and equipment that are part of the building, is below ground. Unfinished Area --An enclosed area that is used only for the parking of vehicles, building access, or storage purposes and that does not meet the definition of a finished (habitable) area. Sheet-rock (drywall) used for fire protection is permitted in unfinished areas. Unit --A single-family unit owned by the policyholder in a condominium building. Valued Policy --A policy in which the insured and the insurer agree on the value of the property insured, that value being payable in the event of a total loss. The Standard Flood Insurance Policy is not a valued policy. Variance --A grant of relief by a participating community from the terms of its floodplain management regulations. Waiting Period --The time between the date of application and the policy effective date. Walled and Roofed --A building that has two or more exterior rigid walls and a fully secured roof and that is affixed to a permanent site. Zone-- A geographical area shown on a Flood Hazard Boundary Map or a Flood Insurance Rate Map that reflects the severity or type of flooding in the area.