The Survey Section of the Department of Public Works provides surveying services to most Harford County agencies for County projects.
These services include preparing right-of-way plats and easement plats for road widening or drainage improvements, or conducting topographic surveys for the design of new roadways or storm drains.
The Survey Section is also responsible for maintaining the Harford County Survey Control System of survey monuments. These monuments establish permanent locations on earth that can be used to locate new features such as storm drains, water and sewer lines, and buildings.
A plat is a graphic representation showing the correct size and shape of a property to a scale. Along with a property shape, a plat usually shows dimensional data and some physical features of a property.
A right-of-way plat shows a strip of land for legal use by others as a passage. Rights-of-way may be either public or private. Many public rights of way are granted to municipalities as a fee title.
An easement plat is a plat showing a piece of property in which someone other than the owner of that piece of property has a lawful right to use it for a particular purpose. Easements may be either public or private.
A topographic survey is a survey performed to map physical and manmade features with their elevations of a particular area. The GIS Division provides topographic information to the public for a fee.
The Harford County Survey Control System consists of approximately 300 concrete monuments throughout Harford County.
Each monument has an x-coordinate, or easting, and a y-coordinate, or northing, based on the Maryland Coordinate System (North American Datum of 1983). This Datum was adjusted in 1991 and designated as NAD83/1991.
Additionally, each monument has a z-coordinate or elevation based on either the National Geodetic Vertical Datum of 1929 (NGVD 29) or the North American Vertical Datum of 1988 (NAVD 88). The set of three coordinates for each monument establishes a permanent location of the monument on the earth. The National Geodetic Survey is responsible for establishing these datums.
The main reasons for survey monuments are:
Surveyors can re-establish control in an area where construction has destroyed control previously set
To allow surveyors to return to points previously tied to the Maryland Coordinate System. Ease of searching for property corners and construction baselines.