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Water Data Information System (WDIS) Historic Data Set

The Department of Water Resources once maintained a very large database of water quality measurements collected by agencies throughout California. The data were collected between approximately 1903 and 1990. These data were once published by DWR on microfiche and kept in an early database called the Water Data Information System. The data were used for planning and for publications, such as Bulletin 132 and the California Water Plan. Over the past few years, DWR has worked to convert electronic records from WDIS into a format compatible with the Water Data Library.

The project was divided into two parts. The first part represents over 42,600 stations and 3.6 million field and laboratory measurements. The data were collected by myriad agencies, plus DWR Regional Offices. The data have been carefully reviewed for obvious errors, but it is expected that some errors remain.

If you choose to check the 'Historic Data' box, you will have many more stations to choose from. You'll also find that while some locations have a long record, the majority have been sampled only a few times, perhaps half a century ago. This information can be useful for historical purposes, but if you are interested in modern measurements, leave the box unchecked. Also note that most of these analyses were performed using unknown analytical methods so may not compare with modern data.

The second project covered State Water Project data collected by the DWR Division of Operations and Maintenance (O&M) between 1960 and 1998. These data were compiled by comparing historic WDIS and O&M data sets and verified using original lab reports. Because there is a record of the actual methods used by DWR Bryte and Castaic labs, method information is incorporated. The O&M data represents about 380,000 field and laboratory measurements and is available as of September, 2013. These data may be searched in the normal way, i.e. there is no need to check the 'Historic Data' box.