Dealing with an Aging System

Many SWP facilities are 30 years or older. Aging from the wear and tear of stopping and starting pumps and changing water elevations in canals and pipelines has begun to present certain challenges for DWR maintenance staff.

All structures that fall under civil maintenance-- roads, bridges, roofs, dams, canals, pipelines, buildings -- are inspected every other year by Headquarters and field division staff. Minor repairs are made quickly by the field division, while larger (non emergency) ones must sometimes wait several years as repair contracts are prepared.

Field division personnel, on an almost daily basis, inspect the Project for leaks, settlement, cracking, and other obvious signs that something may be wrong. An obvious sign in the late spring, when the grass begins to dry and turn brown, is a green patch of vegetation, indicating a possible leak.

Other O&M staff in water operations, sometimes called “water dogs,” traverse the Project daily. They do water measurements and collect water samples for analysis. They also keep a close eye, looking for new seeps and monitor exisiting seepage locations.

In recent years, several canal failures have occurred--some that were monitored for several months and some that were unexpected. Such failures can often be attributed to the unexpected settling of high earth embankments on weak foundations. These differential settlments cause cracking in the embankment and the concrete lining. This situation has been the cause of many of our canal leaks and continues to be a place where more problems are expected in the future.

Another problem is the potential hydrostatic water pressures behind the lining when a canal section is dewatered for repair or inspection. Only a few feet of hydrostatic pressure can cause lining or slope failure if the rate of dewatering is too rapid.

When repairs are needed, outages are scheduled or needed repairs are performed during previously scheduled outages. To complete the repair, Division of Engineering staff work with O&M to design the project and bid the job out to potential contractors. The actual work is overseen by DOE.

One repair project under way by O&M, and which will continue for at least the next two years, is refurbishing the radial gates that control the flow along the California Aqueduct. The gates are removed, taken to a facility where they can be cleaned, sandblasted, and repaired and repainted, and then replaced. Gates in the San Joaquin and San Luis field divisions still need attention, but the work can only be done during the non-flood season, a six-month period.

SWP power and pumping plants also are inspected regularly by Headquarters staff, while routine maintenance and repairs are done by the field division’s electricians and mechanics (many trained by DWR’s own apprenticeship program). When major repairs are required, HQ staff administers service repair contracts with outside vendors.

Since the 1970s, technology has changed for pumps and generators, and the Department has installed new equipment and replaced older technology such as the computer systems and circuit breakers. Each year, millions of dollars are budgeted to keep the system in service with as few unexpected outages as possible.

SWP’s operational flexibility (pumping water at night when power rates are cheapest and generating power during the day when it can be sold or exchange at a higher rate) has its trade-off when it comes to some electrical equipment. Thermal cycling, like turning lights off and on, takes a physical toll on the huge circuit breakers in SWP plants.

The Project’s earthfill dams are other facilities that must be routinely watched. O&M staff monitors the settlement in the dams through precise surveys to insure that it is within anticipated limits.