Open Hamilton

Case study: San Mateo, California

San Mateo County, California, located in the heart of Silicon Valley, takes open data seriously.

The county government went beyond simply unlocking information. It believes open data plays a key role in its long-term vision for the community and its operations. With the launch of its open data, performance and expenditure portals, the county is moving closer to becoming an open government and transforming its relationship with local residents.

Metro Ideas Project spoke with John Ridener, open data officer about how the county is democratizing data.

The push began in fall 2008 when the Board of Supervisors approved Shared Vision 2025, San Mateo County’s long-term strategic blueprint. After a series of public meetings and surveys, the county outlined five goals to help guide future policy decisions. One goal was a more collaborative community. Open data became a way to help achieve this outcome and support an open, responsive and effective government.


The state of California does not require local governments to publish their data. The San Mateo mayor’s office and Information Services Department led the push for transparency by developing an open data policy. A March 2013 memo encouraged departments to share data, but did not make it mandatory.

The memo established clear reporting guidelines and created a County Open Data Committee to develop standards and methods to report data. It also outlined several county responsibilities:

  • Designate an open data manager to be responsible for coordinating with departments
  • Build and maintain an open data portal
  • Designate department contacts to work with auditors on submitted data
  • Conduct quarterly reviews of data quality and progress of releasing datasets


The county launched its open performance platform the same month the administrative memo was approved. The open data portal followed six months later.

Performance data was published first. This data was in a ready-to-release format, and the initiative had strong backing from Reyna Farrales, deputy county manager for performance management. Once the portal passed the proof-of-concept stage, ISD began to focus on other datasets.

ISD focused on identifying and publishing the datasets that would be most compelling to users. Data was prioritized by themes like education and community service. Departments also contributed datasets they believed to be of community interest. High-value datasets were selected based on a list of top datasets from Socrata, the vendor that houses the open data portal.

ISD worked with other departments to ensure data was high quality and to help automate future updates. It provided a data quality checklist to help guide and standardize the process. Other departments were responsible for the accuracy of their data.

The platform now includes three main features.

An open performance dashboard allows citizens and other departments to track services, performance indicators and progress on Shared Vision 2025 community goals.

An open expenditures dashboard lists all payments of $5,000 or more for goods and services. This dashboard includes information on vendors, purchasing agency, type of expenditure and total expenditures over time.

The open data portal includes 861 datasets from 24 departments. The datasets have received more than 460,000 views.


The county raised around $400,000 to cover the initial cost of a Socrata subscription, an open data community liaison position and other data-related activities.


Here are some ways government and developers have used the data portals.

The county compiled data on the age of its fleet of fire vehicles. Officials realized that older vehicles that had exceeded their lifespan were costing more in maintenance. The county used this data to make the case for purchasing new vehicles and cut maintenance costs.

OpenSMC, the county’s Code for America brigade, uses the open data portal for software development. One of the brigade s apps helps citizens locate nearby flu shot clinics.


Here are some of the challenges faced during implementation.

Departments didn’t know they had useful data. Changing this perception took demonstrating the ways data can be used, visualized and shared.

It wasn’t enough to tell departments that open data is a smart policy. They needed to be sold on how it could directly benefit their work.

Politics can get in the way of opening data. Certain datasets have political challenges. For example, as of summer 2016, San Mateo County does not publish crime data. Navigating these challenges requires perseverance and the ability to show open data’s return on investment.

Lessons learned

Here are some of the lessons learned from implementation.

Not all data is created equal. San Mateo sought to publish as much data as possible upon the initial launch. But after the first year, officials learned which datasets were more valuable. For example, data on water can take a year to update, which isn’t particularly helpful when drought conditions set in. The county began to take a closer look at the usefulness of certain datasets and started to prioritize high-value data.

Data has to have utility beyond the portal. It’s most useful when it’s integrated into existing applications. For example, the county’s restaurant health ratings are synchronized with Yelp restaurant reviews.

Departments need to get granular. High-level data provides a general overview of what a department does. But to analyze policy impact and drive decisions, granular data provides more value.

Steps forward

San Mateo County is focused on releasing more valuable datasets, helping department use open data and actively engaging with local residents. The county is working to publish property tax bill data to better measure the fiscal impact of new development.

The county’s Code for America brigade is working with departments to launch new apps driven by open data. One recent example is a transportation department app for cyclists to track and measure route information.

Finally, the county is engaging the public through open data events like an annual hackathon. Hack-SMC provides an opportunity for programmers, technologists, designers and residents to use the open data portal to create solutions to community problems.

Jacqueline Homann

Policy research director

Jacqueline Homann has worked at a number of international and federal institutions. She is a graduate of the LBJ School of Public Affairs at the University of Texas at Austin and holds an M.A. in policy studies.