Wainuiomata Water Collection Area

The lush native forests and clear rivers of the Wainuiomata and Orongorongo catchment areas were recognised early on for their water supply potential.  In 1880 an earth dam was constructed and a pipeline laid to Wellington. Since this time further developments have taken place. These include the construction of the Morton Dam in 1912, and construction of a weir and pipeline from the Orongorongo Catchment in 1926. 

By the late 1980s the system had reached the end of its useful working life. Morton Dam was decommissioned and emptied of its water. In 1993 a new state-of-the-art treatment plant was built. Water is now taken directly from weirs in both the Wainuiomata and Orongorongo catchments. The new plant produces up to 60 million litres of high quality water per day and supplies about 15 percent of the water used by greater Wellington.