California Division of Water Resources Seismic Network

The Earthquake Engineering section of the California Department of Water Resources (DWR) operates a seismic network for monitoring DWR critical facilities. Data from some of these sites is shared with the USGS Menlo Park and is integrated with other data of the Northern California Seismic System (NCSS). The earthquake epicenters and magnitudes are reported to the Project Operations Center, USBR, Department of Transportation, Division of Safety of Dams, US Corps of Engineers, and PG&E. The magnitudes and epicenters are used to determine the geographical area of the State Water Project requiring inspections after an earthquake. Facilities such as dams, pumping and power plants, switchyards, oil and gas pipelines, pipeline crossings, canal and pipeline, tunnels, intake structures, check structures, and office and maintenance buildings all are inspected based on this data. The uses of the strong motion data are for structural response studies following an earthquake, seismic stability evaluation of Sacramento Delta levees, and dynamic structural analysis of structures on DWR facilities.

The DWR owns and operates 23 seismographic sites throughout California with a total of 82 channels. The real-time data from these sites is transmitted to Sacramento via fiber optic, leased telephone lines, microwave, and radio. The network is actively upgrading short-period, vertical, analog instrumentation. Over half of the sites now consist of digital dataloggers with tri-axial accelerometers.

Network Code: WR

Typical Station Equipment

DWR stations fall into 2 categories: short-period, and strong-motion. Each station type has its own equipment.

Short-period DWR stations

• Vertical-component velocity sensor (Ranger SS-1, Baby and Large Benioff, and Teledyne SD212)
• Central site digitization and timing if analog
• Continuous telemetry to the Sacramento

Strong-motion DWR sensors

• 3-component accelerometer (Kinemetrics EpiSensor or FBA-23)
• Kinemetrics Makalu and Etna
• Continuous telemetry
• Backup power supply

Typical Recorded Channels

Station and Channel Information

• WR Information Directory, including
  • List of station locations
  • List of available channels
    • Year/month/day format
    • Year,doy format
  • Instrument Response
    • SEED format
    • Simplified Responses

Data access

Several tools provide access to SEED format data at the NCEDC, both in terms of querying the archives and allowing data requests:

• Querying the archives
  • SeismiQuery at the NCEDC
• Access data through NCEDC web services