Benchmarks

The City of Clive originally created a survey control network in 2006 in order to provide a consistent vertical and horizontal datum for all potential users including City personnel, area consultants and developers. After the most recent update in the spring of 2020, the network now consists of forty eight (48) primary control points set at strategic locations and constructed by the City of Clive. Each control point is protected in an in-ground system with an access cover flush to existing ground.

The NGS (National Geodetic Survey) HARN (High Accuracy Reference Network) was used as the baseline for the creation of the network. The following coordinate system specifications were used:

  • Coordinate System: NAD Iowa State Plane South Zone (1402) (US Survey Feet)
  • Projection: Lambert Conformed Conic
  • Vertical: NAVD88 (US Survey Feet)

Please use the interactive mapping below to obtain the relevant control point data at a specific location by clicking on the corresponding benchmark icon. A complete listing of survey data for all points in the network is also available here.

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