It has rained and yet the water reservoir has not been filled. How is that possible?

Published 14 Mar 2022

It has rained and yet the water reservoir has not been filled. How is that possible?

It is a common misconception that large amounts of rain will fill up Council’s water storage dams and reservoirs. Rain can stir up a lot of mud, silt and sediments in rivers. When this happens, river water can become murky which limits the amount of water that can be taken out to replenish the water reservoir.

Most of our water treatment plants can manage murky water up to a certain degree, but not if it gets too much. Often, taking water from the river can increase only once river levels drop and mud, silts and sediments have settled down.

Furthermore, when river levels drop too low, there are regulations in place which restrict the amount of water that can be taken out. The lower the river levels are, the less water can be extracted.

In other words, when rain has caused high river flows, water intake can be limited due to murky waters, and during low river flows water intake can be limited due to regulations.