The blocked Gamtoos River Mouth was opened by the authorities on Tuesday after flooding cut off an estuary resort and overflowed deep into nearby farmland.
Drone footage by besieged residents of the Kingsway Resort earlier in the day showed floodwaters covering jetties and their only access road, and lapping against garden fences and pushing into pastures.
But by Tuesday afternoon, a 30m trench was being dug across the beach and through the banked dunes at the Gamtoos mouth to link the estuary to the marine high water mark.
Dramatic footage showed the estuary water pressing to the lip of the trench, and seeping in – and by 4pm it was gushing through into the sea.
Early on Tuesday, Yolande Ferreira sent out a distress call from the Kingsway Resort, between the N2 and the ocean.
With last week’s heavy rains, the river had flooded its banks and the water was just a few metres from residents’ gardens and homeowners were trapped, she said.
“Because we’re on a bend, it has also flooded around the back of us across the access road and we can’t get out.
“The water rose 120mm more overnight, so we’re getting very worried.”
Much of the pressure on the Gamtoos is coming upriver from the Loerie Dam, which is overflowing into Loerie Spruit, a tributary of the Gamtoos.
Rudolf Rose, who farms on the west of the spruit north of the R102, said it had pushed into some of his oat fields.
The Gamtoos is typically alkaline because of the inflow upriver of the Groot River and its heavily mineralised water from the Karoo.
Despite the addition of new volumes of rainwater, this salinity could have been exacerbated by the trapped seawater from the blockage at the mouth, he said.
“It may cause some damage to that flooded land and I’ll only know when it recedes.
“But I’ll still take this flooding rather than the drought.”
His neighbour on the east side of the spruit, dairy farmer Helgaard van der Watt, said although the floods had receded slightly by Tuesday, 80% of his pastures had been covered at one point over the weekend.
“It was 1.5m deep, the depth of a tractor wheel, and we couldn’t get into the fields.”
There were also no dry pastures for his 900 cattle so he was having to find extra food for them, he said.
“It’s costing thousands of rands every day and when the water recedes the pastures will be dead. But after 20 years of farming here I’m used to these floods.”
The Gamtoos Estuary closed in July for the first time in nearly 70 years as a result of the drought.
NMU estuarine ecologist Prof Tris Wooldridge was on the beach on Tuesday to guide the Kouga team on where and how best to make the breach.
Normally it was not a good idea to artificially breach an estuary because unless the blocking berm of sand was properly scoured out it would quickly reform, Wooldridge said.
“But in this case it’s very close to breaking through naturally, so it will make no difference,” he said.
“Permission has been received from regional environmental manager Jeff Govender allowing for us to go ahead.”