Dams feel pinch after long dry
THE REGION'S dams are beginning to show signs of the extended dry spell, and there appears to be no relief on the horizon.
The Bureau of Meteorology's extended outlook for the nation indicates a very low chance of southeast Queensland exceeding its already very low average rainfall for the period from August to October.
Traditionally a dry period for Ipswich and surrounds, the next three months are also likely to be warmer than average, according the the bureau's seasonal outlook.
That could mean an already depleted Wivenhoe Dam continues to drop.
Bureau of Meteorology forecaster David Crock said although there was no El Nino in effect at the moment, the dry conditions were being influenced by ocean temperatures on the other side of the continent.
"Earlier this year, ocean temperatures in the Pacific looked like they would develop in an El Nino but it did not eventuate,” Mr Crock said.
"Indian Ocean temperatures also have an impact on our weather, in particular our rainfall. The Indian Ocean dipole refers to patterns in the Indian Ocean, and currently we are seeing a positive dipole, where the temperatures are cooler on our side of the Indian Ocean and warmer over towards Africa.
"That is probably the major ocean influence at the moment. It is a dry long-term outlook for Australia as a whole and particularly for Queensland.”
Wivenhoe is one of several storages in the region that has not had decent in-flows for many months.
The last time Wivenhoe Dam had a significant top-up was in late February, 2018, when heavy rainfall resulted in a boost of 10 per cent in the dam level, from 68 to 78 per cent. Since then, it has been on a steady decline, and currently sits at 54 per cent.
Seqwater has previously stated that it will not activate the recycled water pipeline, built more than a decade ago as a drought resilience measure, until the combined level of the region's water grid drops to 40 per cent. It is estimated dam levels will not decrease to that level until March next year, meaning a wet summer could save us from having to recycle treated sewerage into the drinking water supply.
Upstream at Somerset, things are a little better, with the current level at just over 77 per cent. Aerial photographs taken earlier this week show the results of the extended dry across the region.
The Lockyer Valley is feeling it the worst, with Laidley's Bill Gunn Dam dropping to an abject puddle at 2.8 per cent.
Atkinson Dam is sitting at just over five per cent.
Down in the Scenic Rim, Moogerah Dam has dropped to 56 per cent, while Maroon is a bit healthier at 74 per cent.
Lake Manchester, barely 15km north of Ipswich, has bucked the trend, sitting at 94 per cent.
The dam is not used for drinking water and is only about one-fiftieth the size of Lake Wivenhoe.