Carry out dam safety surveillance and prepare the monthly report

What is going on

Gallery drain D-14 at the Mitta Ranges concrete gravity dam has increased from 0.4 to 0.9 litres per minute over two months. The reading is below the alert level but the trend concerns the dam safety engineer, who wants a full instrument reading set and a written report this month. The storage is at 71 percent after winter rain and the hydro unit is out of service for governor work under OUT-26-09, so environmental flow is being released through the bypass valve. The weekly walkover, the piezometers, the seepage weirs and the survey points are all due. Two people must attend the gallery and the downstream toe.

Your brief

Complete the walkover inspection and the full instrument reading set to the dam safety surveillance procedure, record everything in the Operations Log, update the hazard in the incident register, raise or update the work order for D-14 and prepare the monthly surveillance report for the Renewables Manager.

Work through it

You do not need to do it all. Doing a few of these will show you what the work is like. Your ticks and notes stay on this device.

• Read the Procedure: Dam Safety Surveillance and prepare the inspection checklist and the reading schedule for the walkover, piezometers, seepage weirs and survey points.
• Record the walkover observations for the crest, downstream face, toe, abutments, spillway and gallery drains as Reading entries in the Operations Log with photograph references.
• Record the D-14 reading and at least four piezometer and weir readings in the Operations Log, each compared to the last reading and the alert level.
• Update INC-26-0145 in the HSE Incident Register with the new reading, the trend and the actions agreed with the dam safety engineer.
• Update WO-26-5142 in Maintenance Work Orders and Defects with the drain clearing plan and set a monitoring frequency.
• Describe the environmental flow release through the bypass and how you confirm and log it each day while the unit is out.
• Prepare the monthly surveillance report with observations, readings, trends, conclusions and recommendations for the Renewables Manager.
• State the triggers for a post-event inspection and what you would do if D-14 reached the alert level during the inspection.

What someone in this role would produce

• Inspection checklist and reading schedule
• Operations Log entries
• Updated incident register and work order records
• Monthly surveillance report