Metalwork from the sluice replaced in c.1991. Flows in the mill race, serving Ollerton Mill, are normally regulated by both the sluice gate and the weir situated upstream of the mill. The mill race has various kinds of bank protection including timber, brick/blockwork, bagwork, and more recently, loose stonework. Some sections of the bank have no protection. It is believed that the mill race was originally constructed with a clay lining… Prior to the sluice being replaced/refurbished it is believed that one of the sluice gates was missing and hence water levels were relatively low… Temporary remedial works have been undertaken by the Environment Agency…on 29 October 1996. The scour hole in the channel bed was filled with rock, as was the area behind the sluice wall where erosion had occurred. A level and measured survey of the sluice was undertaken by Carl Bro Group on 20 Nov 1996. The sluice…suffered a partial collapse in Oct 1996 and water from the mill race was seen to be forcing its way under the sluice structure into the adjacent channel. Temporary remedial works have been undertaken by the Environment Agency to plug this breach and restore water levels to the mill race. Investigations into the possible causes of the collapse (concluded that)…underseepage at the weir upstream…is likely to have been the prime cause of the failure at the sluice.(1)

Carl Bro Ltd, 1996, Report on Ollerton Mill - Sluice Collapse (Unpublished document). SNT5678.