Eng_Water_Details_Benchmark_Datum_trtThe height of a benchmark is calculated relative to the heights of nearby benchmarks in a network extending from a fundamental benchmark. A fundamental benchmark is a point with a precisely known relationship to the vertical datum of the area, typically mean sea level.

City of Marshfield Benchmarks Sea level datum with origin at W7 of U.S. Coast & Geodetic Survey first order leveling. Unless otherwise noted, benchmarks are located on fire hydrants. They consist of a one inch stainless steel disc stamped with the number of the benchmark and the letters "BM".  The disc is fastened to the hydrant with a steel drive pin. The elevation is read on the head of the drive pin. Do not use if the disc is not affixed to the hydrant or does not clearly indicate the benchmark number, or the disc does not match the benchmark location as described. The City of Marshfield is not responsible for incorrect data or improper/illegal use of the data.

City of Marshfield Benchmarks
This list of benchmarks is updated every hour and by entering our benchmarks portal, you hereby agree to use the correct datum when submitting plans to the City for review.  Incorrect datum may result in rejection of plans submitted for review.