Horizontal Datum

The horizontal datum in use by the City is NAD83/98 (North American Datum of 1983/98). In 2004, the City hired professional surveyors to establish a primary network of seven highly accurate control monuments tied to the National Geodetic Survey (NGS). In the few years following, these NGS monuments were used as a base to densify and expand the network. This current datum is the base for survey work done for our capital improvement projects and other miscellaneous projects.

Modernization of Horizontal Datum to NAD83/98

In 2007, the Record of Survey for the City of Bellingham’s 2005 Horizontal Control Network (4.2MB PDF) was filed with the Whatcom County Auditor and is now on record with the DNR Public Land Survey Office. The Survey documents a survey control network of over 600 points in and around the City, depicted in the City’s NAD83/98 Control Network Survey Map (2MB PDF). This event was the culmination of a four-year project to update the City from the 1973 Cadastral Survey datum (close to NAD27) to a current datum consistent with the Port, County, State, and Federal agencies.

PHASE I: First Order Geodetic Survey & NGS Blue Book process

  • 2004: Established seven primary control stations for the network and contracted with a professional surveyor who established the monuments, performed the control survey and submitted the data to the National Geodetic Survey (NGS).
  • 2005: Data was published by the NGS, which is available via the NGS Datasheet Page.

PHASE II: Densify the NGS network by establishing local control points and divided the City and vicinity into nine areas, targeting existing PLSS sectional monumentation and right-of-way intersection monuments and setting new reference monuments off of the roadways in heavy-traffic situations (both GPS and conventional survey methods were used).

  • 2005-2007: All nine densification areas were completed.
  • October 2007: Record of survey prepared and filed (combined effort of all three surveyors).

Survey Control Network for Waterfront Redevelopment Site

In 2008, the Waterfront Control Record of Survey (420K PDF) was completed. The Survey, conducted in and around the New Whatcom Waterfront Redevelopment site using the NAD83/98 Horizontal Datum and the NAVD88 Vertical Datum, provides a common basis for use in all phases of the waterfront redevelopment. The goal was to provide access to convenient and intervisible reference points for use by all surveyors participating in the redevelopment over an extended period of time. The Survey provides an explanation of the relationship between the NAVD88 Datum and City of Bellingham, NGVD29, Tidal MLLW.