California Surveyors Forums

Good morning everyone,

Does anyone know if Contra Costa County has any NAVD88 benchmark data available online? I found the NGVD27 listings, but that won't work for what I need.

Thanks
Bruce Johnson
PLS 7845
Sonoma County

The county did a height modernization project in 2004, the NGS project number is GPS1659. You can search by project number on the NGS datasheet page. I don't know what, if any, updating has been done since 2004.

Jim Frame wrote:The county did a height modernization project in 2004, the NGS project number is GPS1659. You can search by project number on the NGS datasheet page. I don't know what, if any, updating has been done since 2004.

There were a few marks in Contra Costa County included in the 2011 DWR height mod survey. One of them is PID DN4098. I don't have the GPS project number handy, but if you go to that datasheet and click on the link to local and network accuracies to other stations, you will get a list of the marks it is connected to. There doesn't seem to be many, if any, NAVD88 leveled marks in the county using Data Explorer. Knowing where in the county you are interested in would help narrow things considerably.

Have you thought about contacting the County Surveyor, Jim Stein and ask?
jim.stein@pw.cccounty.us