Soil and water

Drought on the Sunshine Coast: does it matter when I use water?

Two months after Stage 4 restrictions began in Chapman’s water system, people want to know: Is it okay to flush the toilet when it’s raining?

“If it’s yellow, let it soften, if it’s brown, rinse it off”, perhaps a popular mantra on the Sunshine Coast these days – but when can we start rinsing the yellow again ?

Sunshine Coast Regional District (SCRD) Area E Director Donna McMahon conveyed a resident’s question at the October 27 SCRD board meeting: “If it rains, can- do I flush the toilet?

Remko Rosenboom, Managing Director of Infrastructure Services at SCRD, was quick to respond: “You are always allowed to flush the toilet – I will never stop anyone from flushing the toilet.”

But Rosenboom went on to say the immediate concern isn’t when it rains – there’s a lot of water flowing through Chapman Creek and into the water system when it rains – it’s when the rain comes. stop that we have to be careful.

The prolonged drought has dried up the Chapman watershed and water needs to saturate the ground and seep into the aquifer. Flows from Chapman Creek, which feeds the water system, drop “extremely rapidly” after a rain event, Rosenboom said. Normally, the return to a lower flow would be gradual as rain absorbed in the watershed is slowly released back into the stream. Instead, the ground is so dry that it doesn’t absorb enough water, but the water runs into the stream all at once.

“That’s why the water restrictions will have to stay in place, because they’re not just about when it’s raining, but also when it’s not raining,” Rosenboom said.

Rather than large dumps of 50mm of rain that are simply flushed through the system, the catchment area requires smaller amounts – 10mm, 20mm – of rain over days or weeks to recharge according to Rosenboom.

The SCRD remains in a local state of emergency and users of the Chapman water system remain subject to Stage 4 restrictions.