A tropical moisture surge has dumped some of Tasmania’s heaviest May rainfall on record, with the deluge now expected to see water restrictions lifted across most of the state as early as next week.
In the 24 hours to 9am on Thursday, the rural area of Gray near St Marys on the east coast recorded 222mm of rain, making it the fourth-wettest May day on record at any Tasmanian site.
Kunanyi/Mt Wellington above Hobart copped 134.6mm, while St Patricks Head just north of Gray saw 124.2mm.
Longley, on the foothills of Kuannyi/Mt Wellington, collected 122.6mm.
Even the Hobart CBD picked up 25.6mm, its heaviest daily total in 10 months.
The difference between Hobart’s 25.6mm and the mountain’s 134.6mm came down to what’s called the orographic effect, where air rises and cools as wind pushes it into elevated terrain, wringing out far more rain at higher altitudes.
While kunanyi/Mt Wellington typically gets more rain than the city in westerly systems, this time the weather came from the east and northeast, meaning Hobart still got a decent soaking but the mountain got a much bigger one.
Launceston itself only saw 10mm, but the South Esk River rises on the Ben Lomond Plateau near east coast stations that recorded well over 100mm, pushing river levels up.
TasWater says it is confident water restrictions will be eased in several communities as a result of the rainfall.
Orford, Triabunna, Oatlands, Scamander and Whitemark are expected to come off restrictions.
TasWater’s head of communications and engagement Liz Hafner said the outlook was promising.
“The recent rain has been extremely welcome, and improvements to supply levels in most of our catchments are looking extremely positive,” Hafner said.
“However, after such an extended dry period and heavy rainfall, we want to make sure systems have recovered properly and that water quality remains at the standard our communities expect before any further decisions are made.”
She said heavy rain and runoff after long dry spells can affect water quality and strain treatment facilities.
“We know restrictions have been challenging for many communities and we want to sincerely thank Tasmanians for the way they responded,” she said.
Lady Barron on Flinders Island will stay on stage one water restrictions until further notice.
TasWater is asking residents in previously restricted areas to keep being mindful of their water use while final checks wrap up over the weekend.
