Make It Make Sense With Ayanda Nyathi - What Happens When Dams Overflow? 

According to the Daily Maverick, authorities at the Vaal Dam have opened a fifth sluice gate yesterday, as inflows surge at an alarming rate. Sunday morning's rainfall in the area was noted at about 200 cubic metres per second. The Department of Water and Sanitation has issued an evacuation warning for residents near the Vaal Triangle, Parys and tributaries around the Vaal River, as well as farmers with pumps and equipment at the riverside. When Dams reach this severe point of overflowing, why do sluice gates need to be opened? What does this help with? Spokesperson for the Department of Water & Sanitation, Wisane Mavasa helps us Make Sense of this.