A $3.5 million all-weather training track will be installed at Hawkesbury to replace the sand circuit.

The synthetic Polytrack surface is the same used for racing at Pakenham in Victoria.

Work on the track is expected to start before the end of winter and take about four months.

"Our No.2 grass really gets knocked around with trackwork and trials, especially during the winter months," Hawkesbury chief executive Greg Rudolph said in statement on Tuesday.

"With 250-300 horses in work at Hawkesbury, the addition of the Polytrack will undoubtedly ease the pressure on that circuit."

The 1900m Hawkesbury track will be designed to withstand extreme temperatures from 45 degrees down to minus 20 and provide a cushioning effect for horses during trackwork.