Australian authorities were concerned on Friday that bushfires could jeopardize Sydney's drinking water supply.

Firefighters capitalized on cooler conditions to establish containment lines but about 70 fires continued to burn across the state of New South Wales (NSW) — half of them uncontained.

Temperatures are expected to rise to 41 degrees Celsius (106 F) in some parts of the state on Sunday and the fire danger remains very high.

Emergency services are focusing on protecting water plants, pumping stations, pipes and other infrastructure from fires around Sydney.

Two fires are burning near Warragamba Dam, which provides water to about 80% of Sydney's 5 million residents. As well as fire damage to infrastructure, it faces contamination risks from ash run-off and debris.

"In recent days up to the cool change, the fires had been a potential threat to supply and assets, particularly in Warragamba and in the Blue Mountains," a spokesman for the state's water authority, WaterNSW, told Reuters news agency. "With the coming very hot conditions the fire situation may escalate in both those fronts and possibly elsewhere."

The dam is 65 kilometers (40 miles) west of Sydney and is at 44.8% capacity due to a prolonged drought. So far, the state's water infrastructure has avoided major damage. The Sydney Morning Herald reported that the lake and dam were almost completely surrounded by the Green Wattle Creek and Ruined Castle fires.

Read more: Australia fires: Prime minister defends climate policy after Greta Thunberg criticism

In pictures: Australia 'mega fire' blankets Sydney with smoke More than just a bushfire Several bushfires have combined to form what is being called a 'mega fire' in a national park forest north of Australia's biggest city, Sydney. Firefighters warned late Friday that they are struggling to contain the blaze, which continues to burn across at least 300,000 hectares (741,000 acres) of land and has spewed smoke and haze over the city.

In pictures: Australia 'mega fire' blankets Sydney with smoke Sydney can't breathe Outdoor sports have been canceled and health authorities in the state of New South Wales (NSW) reported a spike in respiratory illness as smoke from the fires blanketed Sydney. Public health experts are warning people in fire-affected areas to prepare for a prolonged period of poor air quality.

In pictures: Australia 'mega fire' blankets Sydney with smoke Bushfire could burn 'for weeks' The NSW Rural Fire Service said firefighters can do little more than try to get residents out of the way, protect property and wait for dry and windy conditions to subside before they can begin containing the fires. An official warned that, without "flooding rain," the mega fire could burn for weeks. A 3-month-long drought has turned eastern Australia into a tinderbox.

In pictures: Australia 'mega fire' blankets Sydney with smoke Struggling to protect property Fires have threatened properties, including in Werombi, south-west of Sydney. The Rural Fire Service said Friday that more than 680 homes have been destroyed and 250 others have been damaged by bushfires in the state since early October.

In pictures: Australia 'mega fire' blankets Sydney with smoke An endless battle On Saturday, an estimated 2,800 firefighters were struggling to extinguish more than 100 wildfires across NSW. The closest wildfire to Sydney is burning 75 kilometers (46 miles) northwest of the city center.

In pictures: Australia 'mega fire' blankets Sydney with smoke A tough summer ahead Smoke from the fires can be seen from space. Wildfires are common in Australia's summer, which begins in December. This year, however, the fires started in October, driven by persistent high temperatures and dry winds. In the coming days, temperatures in NSW are forecast to crack 40 degrees Celsius (104 Fahrenheit), and meteorologists say no meaningful rainfall is expected until late January.



Army called in

The Australian Defense Force announced on Friday that the army had been called upon to help firefighters. Specialist military personnel will be immediately deployed to 14 Rural Fire Service command centers throughout the state, it said.

Meanwhile, NSW Emergency Services Minister David Elliott was criticized for plans to go on a family vacation to Europe after the prime minister was widely condemned for a holiday in Hawaii while Australia burned.

In the state of South Australia, temperatures hit 42 degrees on Friday after a brief respite over Christmas, prompting authorities to declare a code red. The designation is meant to help protect residents from the heat.

Most of the state had a fire danger rating between high and very high.

Across the country, about 5 million hectares (12.35 million acres) of land have burned this fire season. Almost 1,000 homes have been destroyed.

aw/sms (AP, Reuters, dpa)

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