Last Chance Irrigation chairman Gavin Dann inspects damaged caused by vandals on Conroys dam, near Alexandra, in April. Photo by Diane Brown.
Between March 25 and April 3, vandals dropped large rocks over the dam wall, smashing six of nine planks protecting outlet valve controls.
The dam, which is situated below the Department of Conservation's Aldinga Conservation Area, remains closed to the public.
Doc community relations programme manager Amanda Ware said the department was working with land owners to determine when, and how, repair work would take place.
Doc hoped to have the work completed before Christmas and public access to the area restored for summer, she said.
The dam was fully functional despite damage to the structure, as valves had not been broken.
Conroys dam has been used to store water for irrigation since 1935.
