Before 1750, roads were an impractical way of transporting heavy goods and water transport on the rivers was the accepted method. The number of suitable rivers was limited. Power to drive machinery was also derived from water but this needed fast-flowing streams where a head could be built up to turn the waterwheels. Finding the two types of water at the same locality was rare. Castlefield could use the River Medlock, as it fell to join the River Irwell to turn the wheels, but the Irwell needed to be improved to make it a safe river to navigate.