During the construction of the Lee Scheme, the ESB saw that the contract was getting into trouble and there was a possibility it might never be finished or that it would run well over budget. This was pointed out to the contractors, and, after much intense discussion, it was decided to put Maurice Sweeney, a very capable engineer, in charge. From then on the work progressed very favourably.

Considering the size of the development, the numbers employed and the type of work involved, the number of deaths during construction was relatively low. In all, four people were killed - two at Carrigadrohid and two at Inniscarra. As a matter of fact, the two who died at Inniscarra were not directly employed on dam construction - they were employees of CIE.

November 9, 1954: James O'Mahony, Mangerton Terrace, Blarney. He was employed by CIE and was sent to the site at Inniscarra with a load of pipes. As he descended the steep incline to the dam site, he applied the brakes. These did not function on the trailer. He swerved to avoid a dumper and struck a bank. In an effort to save himself he jumped out of the cab and struck his head on a concrete block, which killed him instantly. The irony about this incident was that the lorry continued on down the slope and came to a stop, right side up, at the bottom.

June 9, 1956: Thomas Walsh, aged forty-seven, Middle Road, Whitegate. He was a helper on a CIE Road Freight Department lorry. The lorry, with a trailer attached, had delivered a load of cement to the dam site at Inniscarra. As he was uncoupling the trailer, he was pinned between the lorry and the trailer. He suffered abdominal injuries and was dead on admission to the North Infirmary.

August 24, 1956: John O'Leary, twenty-two, unmarried, Knockroe, Ballyvoige, Kilnamartyra, Macroom. The accident happened at Carrigadrohid. A joint connecting a steel pipe and a cylinder at the top of the dam was leaking and the deceased was helping to repair it. He was on a platform of two loose planks with no special protection. The job needed only a few minutes' work to repair it. It was difficult to tighten the joint so he used both hands on the spanner. The spanner slipped and he fell forty feet on to a steel gate. He suffered a fracture of the skull and a penetration of one lung. He died in hospital six days later.

19 November 1956: John O'Sullivan, 38 Barrett's Place, Macroom. He was engaged in dismantling some scaffolding at Carrigadrohid when he slipped and fell twenty feet on to a concrete surface, sustaining severe head injuries. He was attended on the spot by Dr J K Moynihan and the Rev J O'Donnell, Macroom. He was then removed to St Finbarr's Hospital where he succumbed to his injuries later in the day.