Saturday, August 22, 2015

San Mateo County Survey Marker GIS Part 2- Tools and Instructions

This post will highlight the maps main functions and provide tips for best use.

The GIS can be found here or through our Surveying and Map Checking website.

Bottom Toolbar
Listed below from left to right

Zoom buttons and 'My Location'

  • + zooms in / - zooms out
  • locator button shows your location (optimized for mobile users)

Text search
  • type address or intersection; auto complete capable


Turn layers on/off

  • check boxes to turn on/off available layers

Change basemap views

  • choose from 12 different basemaps

Driving directions

  • type or click on the locations for a route

Measuring tools

  • measure lines and routes for linear feet
  • measure areas
  • obtain the lat / long for a location

Simple drawing tools

  • enhance any map view by adding objects and text

Additional Tools

Overview map

  • toggle on/off by clicking on the arrow in the top right of the map window
Data in Table Format
  • launch a data table by clicking the small black arrow below toolbar

  • drag the table up for an expanded view
  • explore the 'Options' menu to hide columns, filter and export data

San Mateo County Survey Marker GIS Part 1- Purpose and Intended Use

This post explains the purpose and intended use of the San Mateo County (SMCO) survey marker GIS map and what kind of information can be found for monuments.

The GIS can be found here or through our Surveying and Map Checking website.

Default view of the SMCO Survey Marker GIS

Purpose & Intended Use

This is an ongoing inventory of survey monuments for the unincorporated areas of San Mateo County.  Some locations within City limits are available because we've chosen to crowd source some of the data.

It is meant to be a planning tool for San Mateo County Public Works projects as well as private surveys for firms wishing to participate.

It is not meant to be a precise network and is considered GIS grade.

Finding Survey Markers

This map acts much like any GIS when panning, zooming, and selecting objects.  Once you locate a point of interest, a single left click will open a window containing the unique data for that location.

Available Survey Marker Information

The minimum data we capture for each location include:
  • Date collected
  • Description
  • Is it tagged?
  • Tag number?
Additional notes can be added to further describe the survey marker or its location.

This GIS includes photos of the monuments as well and are found in the "Attachments" section of the window.
Typical data available and survey marker photo

Thursday, August 6, 2015

San Mateo County - Unrecorded Subdivision Maps

This is a brief post to spread the word about a set of old subdivision maps that our team has recently encountered. These are maps that aren't available through our map research website but may be referenced in old deeds or maybe in the margins of the Assessors Parcel Maps (see image below). I'm positive this isn't every unrecorded subdivision map in San Mateo County but because we found them, we thought we'd share.

See the "UNREC" reference on the Assessors map in the lower right?

This is the Unrecorded Corbett Subdivision Map from Book 5

We had no idea what we were going to find on this mission so when we found so many (50 books in all) we just snapped pictures and assembled a collection of only the index pages. The information is available at our website and in spreadsheet format you can download.

Please pass this along to anyone that I left out. Feel free to email if you've got questions or need more information about these maps. Thanks for reading.