Project Profile: Reliable Activations for the Saluda River Warning System in Columbia, SC

The South Carolina Electric and Gas Company operates a series of hydroelectric generators on the Saluda River about 6 miles upstream of Columbia. The section of the river between these generators and Columbia is used recreationally for many purposes (wading, swimming, fishing, rafting, canoeing, etc.). DDi, with support from Telos Services, has provided design and implementation services for a warning system made up of 10 remote siren and/or strobe sites along the river.

There are two control points for automatically triggering activations of the sirens and strobes and three base stations that monitor the system performance and display current status and alarm conditions. Being a fully automated system (no human intervention), it was vital that the system be reliable for ensuring activations when appropriate and not generate false activations.

Activations for the upper section of the river (immediately below the dam) are triggered when there is an increase of 800 cubic feet per second being released through any of the generators. The warning system for the lower segment of the river is triggered when a rise of 0.08 feet is detected in any five-minute interval. Individual site activations are acknowledged back to the control station that triggered the activation. Then at specified intervals after the activation, each station reports a current status to all three base stations providing voltages, current draws, and activation state.

In the event of a failure to receive “expected” information, the base stations generate an alarm condition with an assigned priority for follow-up. After hundreds of monitored activations, no false activations have occurred.