 He reported that there was some subsidence, there were leaks in the clay core and at least one of the outlet pipes through the dam was broken.Repairs were carried out, with all of the outlet pipes being renewed, and as the valve in the valve house was no longer operational, a new valve was installed on the upstream side of the dam, with control rods running up the stone cladding of the dam to a control wheel on its crest.One unexpected consequence of moving the control valve to the upstream side of the dam was that the rectangular culvert which carried water between the reservoir and the original cut-off valve well, near the core of the dam, was now pressurised in a way for which it had not been designed, and the entrance to the culvert collapsed in 1964.