The first weir was erected on the Waingongoro River in the earl 1900s to raise th water level to provide enough fall to feed the rams which pumped the water to the factory. In 1917 work began on building a new concrete factory, and a secound ram was installed at that time. A lower weir was built in the 1930s to lessen the scouring (visible today) from underneath the apron of the main weir.