Surveying Glossary

Easement – the privilege of using something that is not your own (as using another’s land as a right of way to your own.) Usually an easement has a special purpose and gives the owner of the easement right to “trespass” on the landowners property in order to maintain the easement or utility covered in the easement.

Encroachment – to intrude unrightfully on someone else’s rights or territory. This is when a building or some portion of it, or a wall or fence, extends beyond the boundary of the owner and illegally intrudes on the land of an adjoining owner.

Floodplain – floodplain or flood plain is the land area adjacent to a river, stream, lake, or other body of water that is subject to flooding. (See “flood” for more information.)

Metes and Bounds Letnl – a land description method that details all of the boundary lines (bounds) of the land, together with the line dimensions & directions (metes). The most common method today is to use bearings and distances.

Drawing – an illustration that is drawn to scale that represents planned or actual features of an area. The survey drawing shows each property line with its distance and bearing, what marks the property corners, the improvements on the property, encroachments, easements, etc. The amount of information shown is dependent of the type of survey or the purpose.

Bearings – defines direction based on the four cardinal directions (north, south, east & west.) A bearing is comprised of three elements 1) the north or south element, 2) the bearing angle, and 3) the east or west element. For example N 24°15’ E is a line that runs in a direction of 24°15’ toward the east from the due north direction, or in a direction that is 24°15’ clockwise from the due north direction. (See figure.)

Monument – a fixed natural or artificial object that is found or set at a property corner to establish the boundaries of the property.

Parcel – a parcel of land is some defined amount of land defined by certain boundaries. Another word for parcel of land could be “piece” of land.

Setback Lines – the distance from the property line or other established line within which no buildings may be constructed. Also known as a building line.

Septic System – an on-site septic system handles the sewage effluent from a home or multiple homes where a municipal sanitary sewer system is not available. This is a common occurrence in rural settings.

Subdivision – dividing a larger tract of land into two or more smaller tracts of land. This might be done to divide land among family members or other individuals. Technically, any further division of a piece of land into smaller portions is a subdivision, but this term has come to mean a tract of land that is divided with roads provided and lots for home construction. This is the most common use of the term.

Onsite Septic System – An onsite septic system is used in rural areas to dispose of household sewage. The system normally contains a septic tank which allows the sewage to be “broken down” and field lines to dispose of the effluent. It may occasionally contain an additional treatment system which “treats” the effluent to a higher level than the septic tank. To find your septic tank and field lines, look for the greenest grass.

FEMA – The Federal Emergency Management Agency – – Fema’s mission is to “reduce the loss of life and property and protect the Nation from all hazards, including natural disasters…” One of the ways that FEMA “protects” us and helps to “reduce the loss of life and property” is through the National Flood Insurance Program (NFIP). The NFIP enables property owners to purchase insurance protection atninst losses from flooding. To establish the insurance rates for each particular home, FEMA identifies flood hazard areas throughout the U.S. by producing Flood Insurance Rate Maps (FIRMs) and Flood Boundary and Floodway Maps (FBFMs). These maps identify the Special Flood Hazard Area (SFHA)

Flood Insurance Rate Map (FIRM) – The official map of a community on which FEMA has delineated both the special hazard areas and the risk premium zones applicable to the community.

1-percent chance storm event – also known as the 100 year flood, the base flood and the Special Flood Hazard Area (SFHA) – the flood that has a one-percent chance of being equaled or exceeded on the average in any given year.

Orthorectification - is the process of removing the effects of image perspective (tilt) and relief (terrain) effects for the purpose of creating a planimetrically correct image. The resultant orthorectified image has a constant scale wherein features are represented in their 'true' positions.

Base Flood Elevation (BFE) – the water-surface elevation associated with the base flood. The computed elevation to which floodwater is anticipated to rise during the base flood. Base Flood Elevations (BFEs) are shown on Flood Insurance Rate Maps (FIRMs) and on the flood profiles.

Participating Community – The community must participate in the National Flood Insurance Program (NFIP) for the property owner to be able to purchase flood insurance. The local community enters into a partnership with FEMA by applying to participate, adopting a resolution of intent to participate and cooperate with FEMA, and adopting a “floodplain management ordinance” that meets minimum NFIP criteria. Normally, there is also a local “coordinator” who acts as a liaison between the community and FEMA. If the community doesn’t participate insurance is not available, disaster assistance is restricted, federal grants or loans are limited, federal mortgage insurance and loan guarantees are limited, among other sanctions. The community is also tasked with enforcing their floodplain management ordinance. If they are found to be lacking in enforcement, they can be removed from the program.

Finished Floor or Lowest Floor – 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. Communities are required to obtain the elevation of the lowest floor (including basement) of all new and substantially improved structures.

Elevation Certificate – a form developed by FEMA to provide an official record that shows the elevations of buildings in identified Special Flood Hazard Areas (SFHA). This form is also used by the property owner to obtain flood insurance.

Letter of Map Amendment (LOMA) – an official amendment, by letter, to an effective NFIP map. A LOMA establishes a property’s location in relation to the Special Flood Hazard Area (SFHA). LOMAs are usually issued because a property has been inadvertently mapped as being in the floodplain, but is actually on natural high ground above the base flood elevation.

An Orthophoto, Orthophotograph or Orthoimage is an aerial photograph or image geometrically corrected ("orthorectified") such that the scale is uniform: the photo has the same lack of distortion as a map.