Water from Mother Nature in the form of torrential downpours plus some assistance from U.S. water-bombing planes has provided a few days of relief to weary firefighters in Australia. Friday’s rains will keep some of the fires at bay, but many bushfires are still burning with about 30 of them not yet contained.

The water, however, comes at a steep cost with flash floods, power outages, muddy roads and downed trees hampering the continued efforts to put out the blazes. The area has suffered through a three-year drought and the dry-caked soil cannot absorb the water. It will obey the laws of gravity and flow downhill.

Another consequence of the run-off water comes in the form of a chemistry lesson from Mother Nature. When hot ash from the scorched areas mix with water, the result is an alkaline solution of sodium hydroxide (NaOH), commonly known as lye. Your great-great-grandmother may have made her lye soap with it and it is the main ingredient in common household drain and oven cleaners.  

The muddy alkaline run-off water is a weak solution, but it is still potent enough to poison the waters as it flows into the rivers and creeks. Local media have reported that many fish have been killed by the toxic waters that probably contain other run-off contaminants in addition to the lye.

The rain is still welcome news to the area. A tweet by the New South Wales (NSW) Rural Fire Service said, "Rain has fallen across most firegrounds over the last 24 hours which is great news!” 82 fires are still burning across NSW and 30 are still not contained.

Rural Fire Service deputy commissioner Rob Rogers told Channel Seven television Friday, "It won't put all these fires out but certainly it's slowed them right down and I think it's given a significant morale boost.”  Dozens of fires were still burning in the neighboring state of Victoria.

Since September, 29 people have been killed, thousands of homes destroyed and an estimated one billion deaths in livestock and wildlife have occurred. Some areas may never recover.

To help in the battle, the first of four water-bombing aircraft has arrived from the United States to help combat the bushfires that have scorched almost 11 million hectares. The first one, an Erickson Aero MD 87, can drop more than 11,000 liters (3,000 gallons) of fire retardant in a matter of seconds. The planes that will follow include two McDonnell Douglas DC-10s capable of dropping 35,600 liters (9,405 gallons) of water.

While impressive, consider that a typical 1-inch rainstorm will drop nearly 110,000 liters (about 30,000 gallons) on one acre. The water bombers can brag, however, that they have a better aim than natural rainfall.

The forecast is for more rain this weekend in the states of NSW, Queensland, and Victoria offering more hope to the fire weary citizens of Australia.