Flood mapping accuracy has vastly improved following data additions to the Australian Rainfall and Runoff (ARR) national guideline document.

Information from at least 100,000 storms and new weather-related data from more than 30 years of observations have been added to the ARR.

The Bureau of Meteorology’s new Intensity Frequency Duration (IFD) rainfall readings from more than 10,000 gauging stations are also included.

“We’ve also used statistical analysis techniques that weren’t available 30 years ago,” bureau CEO Andrew Johnson said. “The new IFDs more accurately estimate rainfall intensity, frequency and duration in specific locations, which helps Australia to reduce the potential damaging impact of future floods.”

It is the first major upgrade for the ARR, following a previous update almost 30 years ago.

Geoscience Australia and Engineers Australia worked for more than four years on the project.

“More accurate, consistent data sets and guidance means more accurate and consistent flood studies and mapping,” Engineers Australia CEO Stephen Durkin said.

“This is not only good news for engineers and town planners, but also for Australians living in areas with a flood risk.”

Major floods in 2010/11 prompted the ARR upgrade.