Recognizing the importance of good large-scale maps to sound community development and redevelopment, the Southeastern Wisconsin Regional Planning Commission (referred to below as “the Commission”) has, for two decades, encouraged the preparation of large-scale topographic and cadastral maps within its 2689-square-mile region. These maps are based on a unique system of survey control that combines the best features of the U.S. Public Land Survey System and State Plane Coordinate Systems. The large-scale maps and attendant survey control system provide, in a highly cost-effective manner, the technical foundation for the eventual creation of a multipurpose cadastre within the region.
The Commission is committed to the concept that any accurate mapping project requires the establishment of a basic system of survey control. This control consists of a framework of points whose interrelationships and whose horizontal and vertical positions on the surface of the Earth have been accurately established by field surveys and to which the map details are adjusted and against which they can be checked.
At present, new large-scale topographic mapping in most urban areas is usually based on third- or lower-order control nets having, at best, temporarily monumented stations. These control nets are usually largely unrecoverable and, as a practical matter, unusable by local engineers and surveyors. These control nets are generally tied to the national geodetic datum, and the finished maps are compiled on a state plane coordinate grid. Property boundary-line maps are, on the other hand, most