The Domesday Book records the name of Rochdale as Recedham, formed from Old Englishreced "hall", and ham "homestead". The name of the river is a back-formation from this Old English name. With time, the town's name changed to Rachedale and eventually Rochdale. The name of the river Roch is /ˈroʊtʃ/, with a long o. The name of the town, however, is pronounced /ˈrɒtʃdeɪl/, with a short o.
The river has been culverted in Rochdale town centre since the early 20th century. This was built by the joining together of seven bridges to form one large bridge, making it one of the widest bridges in the world. Maintenance work was carried out on the bridge in the 1990s and the river was uncovered temporarily. In 2015 work began on opening the bridge again in a multi million pound project. On Boxing Day 2015, following heavy rain, the Roch burst its banks causing flooding in the town centre.