The river has a catchment area of 1,773 square kilometres (685 sq mi),[1] and a mean annual flow of 95 cubic metres per second (3,400 cu ft/s) at Klondyke.
The entry point has New Zealand's first acoustic fish fence, keeping salmon smolt in the river and preventing them ending up on farmland.
This system rums through a static fish screen on its way into 7 man made dams, holding a total of 18,000,000 m3 of water to distribute across 16,000ha of formerly dry land farming area.
[citation needed] On 23 December 1999, Fish and Game New Zealand lodged an application for a water conservation order on the Rangitata River.
[9][10] A locomotive, DC 4686, ended up completely submerged in the river on 4 January 2002, after floodwater undermined a stopbank supporting the railway line, causing a derailment.