Celebrating dam safety at IRWD

National Dam Safety Awareness Day is May 31, a day intended to encourage and promote best practices for dam safety, as well as emergency plans. This year’s theme is, “Dam safety is a shared responsibility: Know your risk; know your role; know the benefits of dams and take action.”

IRWD monitors five dams: Sand Canyon, Rattlesnake, Syphon, Santiago Creek and San Joaquin. The California Department of Water Resources Division of Safety of Dams (DSOD) regulates all jurisdictional dams in the state. Reports and emergency action plans related to IRWD facilities are posted on our website at irwd.com/construction/dam-safety-program.

At IRWD, safety is not only a priority but a necessity for the work we do. Here are some recent projects IRWD has implemented to enhance the safety of our dams:

InSAR satellite monitoring

IRWD is contracted for InSAR, an “eyes in the sky” satellite monitoring system that will record small movements in a dam that could be caused for a variety of reasons. The satellite provides thousands of points every 11 days with measurements to the millimeter. This level of monitoring greatly enhances IRWD’s monitoring capabilities from the traditional approach. . InSAR is not required by the DSOD, but IRWD will use it to monitor San Joaquin and Rattlesnake dams for three years due to the history of nearby landslides at these dams.

Instrumentation pilot program

A new instrumentation pilot program was recently begun at Sand Canyon Dam. Similar to Supervisory Control and Data Acquisition (SCADA), it uses cloud-based Automatic Data Acquisition Systems (ADAS) to collect and display technical information in real time. This program includes information on piezometer readings, which monitors seepage through embankment dams and allows for quick response to proactively address potential issues.  

This project, when complete, will substantially decrease the labor involved with manually collecting water-level readings. Instead, it will provide continuous instrument readings that are available at a moment’s notice.

Monthly inspection form

IRWD recently adopted a systematic and disciplined monthly inspection process that includes a scoring system to provide early indications for areas of concern. IRWD continues to fine-tune the system and is developing an electronic version to improve the process for completing the forms and tracking results.

Dam safety program guidelines

An IRWD Dam Safety Committee is dedicated to dam safety. The cross-department committee hosts quarterly meetings that focus on safety at IRWD’s dams following District dam safety guidelines, which include seismic monitoring, movement monitoring, training, and Risk Informed Decision-Making (RIDM). RIDM is a method of dam safety evaluation that goes beyond minimum state requirements to understand risks and further inform important decision-making.

“These recurring Dam Safety Committee meetings bring renewed focus on the importance of the dams and promote accountability,” said Engineering Manager Jacob Moeder, who oversees IRWD’s Dams and Storage team.

National Dam Safety Awareness Day was established to memorialize the 2,220 people who lost their lives in 1889 when the South Fork Dam collapsed in Pennsylvania. To learn more or find out how to get involved with dam safety, visit fema.gov.