A former employee of a small California canal system has been charged with installing unauthorized software and damaging the computer used to divert water from the Sacramento River.

Michael Keehn, 61, former electrical supervisor with Tehama Colusa Canal Authority (TCAA) in Willows, California, faces 10 years in prison on charges that he "intentionally caused damage without authorization to a protected computer," according to Keehn's Nov. 15 indictment. He did this by installing unauthorized software on the TCAA's Supervisory Control and Data Acquisition (SCADA) system, the indictment states.

Keehn accessed the system on or about Aug. 15, according to the indictment. He is set to appear in federal court on Dec. 4 to face charges of computer fraud.

As an electrical supervisor with the authority, he was responsible for computer systems and is still listed as the contact for the organization's Web site.

With a staff of 16, the TCAA operates two canals -- the Tehama Colusa Canal and the Corning Canal -- that provide water for agriculture in central California, near the city of Chico. Both systems are owned by the federal government.

The security of SCADA systems, which are used to control heavy machinery in industry, has become a hot-button topic in recent years. In September, video of an Idaho National Laboratory demonstration of a SCADA attack was aired on CNN, showing how a software bug could be exploited to destroy a power generator.

In the video, the turbine was gradually worn out and left shuddering and smoking. Sources familiar with the hack say this was done by turning the generator off and on while it was out of phase with the power grid, putting excessive stress on the turbine and causing its components to wear out.

It's not clear how much damage the attack on the Authority's SCADA system could have caused, but in 2000 a disgruntled former employee was able to access the SCADA system at Maroochy Water Services in Nambour, Australia, and spill raw sewage into waterways, hotel grounds and canals in the area. That man, Vitek Boden, was eventually sentenced to two years in prison.

Even if an attack were to knock the TCAA's SCADA system offline, the canals could continue to operate, said Robin Taylor, assistant U.S. attorney with the U.S. Department of Justice, which is prosecuting the Keehn case. "When the computer doesn't work they have to go to manual operation," she said.

The intrusion cost the TCAA more than $5,000 in damages, Taylor said.

The IDG News Service is a Network World affiliate.