Tracking California developed the Water Boundary Tool (WBT) in February 2012 to facilitate the creation and collection of customer service area boundaries for public water systems (PWS) in California. Prior to this effort, many systems only had paper maps, and there was no central location where this information was available for the entire state.
Without a statewide digital map of water system customer service areas, it is challenging to answer basic questions about which communities are being served by which systems and what contaminants might they be exposed to. So far, Tracking California has compiled information for water systems that collectively serve about 90% of the total California population.
Tracking California currently operates the WBT, maintains the database, and makes the data publicly available. So far, WBT data has been used to support a range of public health activities, including emergency response, outbreak prevention, exposure investigations, water system management, and research. While WBT data may be integrated into other programs' web tools, the data available on this website are the most up-to-date. Visit our water systems page to access the data or use the tool.
In the past, we had to look up the water system information in Google Earth, find out their sampling maps or distribution maps, compare it between different public water systems side by side.... With the boundary tool, we can verify the service areas in seconds. It improves the efficiency of our work.
The Water Boundary Tool (WBT) was developed by Tracking California to facilitate the creation, collection, and vetting of digital maps for every public water system in California. There is no complete map of 8000-plus public water systems for California, nor is the collection of this essential information required by the state.
Without a statewide digital map of water system customer service areas, it is challenging to answer basic questions, such as:
We aimed to develop a tool that could:
The WBT was initiated by Tracking California in 2012 with goals to:
The WBT project focuses on three main areas:
Water systems and other qualified users can use the tool to input or edit water system service area boundaries. Registration and permissions are required. If you would like to contribute data, please review the instructions and FAQs for tool users before getting started.
Tracking California makes water system service area data accessible to the public in two ways:
Since 2012, over 4,600 service area boundaries that represent approximately 90% of California's population have been collected by the WBT through crowdsourcing efforts. The WBT data have been used extensively for a variety of public health activities in California by a range of users, including:
Impacts and uses of the WBT data have included:
Tracking California has also provided guidance and shared lessons learned about the WBT to other states, some of which have subsequently initiated and modeled their own tools after ours.
While Tracking California is solely responsible for the development and maintenance of the WBT tool and data, we want to acknowledge our partners who have played an important role in the continued collection of data.
Development of a Web-based tool to collect and display water system customer service areas for public health action  Wong M, Wolff C, Collins N, Guo L, Meltzer D, English P
The initial development of the tool was supported by a grant from the CDC National Environmental Public Health Tracking Program. The CDC continues to provide support for the maintenance of overall Tracking California web portal, where this tool resides.
More recently, Tracking California received funding from the Office of Environmental Health Hazard Assessment (OEHHA) to support data collection efforts, maintenance of the WBT, and limited enhancements through June 2019.