The Federal and NT Governments are funding a $77.88 million upgrade of 6.5 kilometres of the Arnhem Highway across the Adelaide River Floodplain.

The project will reduce road closures during the wet season along the Arnhem Highway due to flooding of the Adelaide River, resulting economic and safety benefits for road users.

The upgraded section of the highway will be built next to the existing road alignment, which will include raising the height of the road and the 13 new bridges.

Deputy Prime Minister and Minister for Infrastructure, Transport and Regional Development Michael McCormack said this project was planning for the future of the Territory, by providing approximately 6.6 kilometres of new road alignment and a series of 13 bridges along the length of the floodplain.

"The Adelaide River Flood Plains Upgrade is another critical part of improving our roads and is currently supporting 179 jobs, which is vital during the COVID-19 pandemic," the Deputy Prime Minister said.

"We are continuing to get shovels in the ground on projects like this across Australia under our $110 billion infrastructure investment pipeline, which is laying the foundations for economic recovery from COVID-19 while ensuring we have the transport infrastructure needed to get people home sooner and safer - no matter where they live."

NT Minister for Infrastructure, Planning and Logistics Eva Lawler said this section of the Arnhem Highway, like the current works, also spans the Adelaide River Floodplain and will improve flood immunity, road safety and productivity for a number of industries reliant on road transportation across both sections of works.

"The Adelaide River Flood Plains Upgrade project is a significant investment for the Territory, securing future economic development for the East Arnhem region, while creating jobs for Territorians," Ms Lawler said.

"The Arnhem Highway is a major transport link connecting Darwin and Kakadu National Park - a major tourist attraction to the Northern Territory and the service centre of Jabiru.

"It also connects local primary producers and industry to Darwin, facilitating the export of key resources and produce to Darwin and beyond - these links have proven to be crucial throughout the COVID-19 pandemic."

Senator Sam McMahon said the Arnhem Highway was often closed due to flooding of the Adelaide River.

"This can cause extensive delays of up to 10 days at a time, effecting the economic viability of tourism and other key industries in the area and of much inconvenience for residents and travellers," Senator McMahon said.

"These vital upgrades will improve flood mitigation at the Adelaide River floodplain and increase route reliability and accessibility, while reducing the frequency of road closures throughout the wet season."

Early works on Stage 2 of the Beatrice Hill section started in September ahead of the 2020 wet season, including ground improvement works for the new alignment, such as clearing, construction of a rock drainage layer/working platform and specialist installation of vertical wick drains through the underlying soft soils.

Works will continue into 2021 on the Beatrice Hill section and include construction of approximately 2.8 kilometres of new road alignment including a multi-span bridge.

The Adelaide River Floodplain Upgrade Project started in late 2019 and is expected to be completed by late 2021, weather permitting.

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