Benchmark- a marked point of known or assumed elevation from which other elevations may be established. Benchmark information is available at the Public Works Department Engineering Division, located on the second floor of City Hall, 303 W. Commonwealth Avenue, at the corner of Commonwealth and Highland Ave
All City drawings for public improvements need to be designed using City of Fullerton Datum. Datum- a reference from which measurements are made.
Use of Alternate Vertical Datums
If alternate vertical datums are utilized the surveyor in question shall run a closed level loop between a benchmark in the proposed alternate vertical datum and the nearest existing City of Fullerton bench mark. This information shall be submitted with the signature and seal of the responsible surveyor. A conversion factor shall be calculated and provided on all plans in a format like the following sample language.
VERTICAL DATUM AND BENCHMARK
VERTICAL DATUM: NAVD88
BENCHMARK: ORANGE COUNTY SURVEYOR 2B-50-05
ELEVATION: 304.473’ (2005)
DESCRIPTION: DESCRIBED BY OCS 2005 - FOUND 3 3\4" OCS ALUMINUM BENCHMARK DISK STAMPED "2B-50-05", SET IN THE NORTHWESTERLY CORNER OF A 15.0 FT. BY 4.5 FT. CONCRETE CATCH BASIN. MONUMENT IS LOCATED IN THE NORTHEASTERLY CORNER OF THE INTERSECTION OF IMPERIAL HIGHWAY AND PALM AVENUE. 123 FT. NORTHERLY OF THE CENTERLINE OF IMPERIAL HIGHWAY AND 30 FT. EASTERLY OF THE CENTERLINE OF PALM. MONUMENT IS SET LEVEL WITH THE SIDEWALK.
A CLOSED DIFFERENTIAL LEVEL LOOP WAS RUN BETWEEN ORANGE COUNTY SURVEYOR BENCHMARK 2B-50-05 AND CITY OF FULLERTON BENCHMARK 16-37 (291.98’). AT THE PROJECT LOCATION THE DIFFERENCE BETWEEN NAVD88 ESTABLISHED AS DESCRIBED ABOVE AND THE CITY OF FULLERTON VERTICAL DATUM ESTABLISHED BY CITY OF FULLERTON BENCHMARK 16-37 IS -8.04’.
PROJECT ELEVATIONS MAY BE CONVERTED FROM NAVD88 TO CITY OF FULLERTON VERTICAL DATUM BY SUBTRACTING 8.04’.