Superstar Winx is unlikely to be around to grace the turf at the new Valley - she would be nine in the spring of 2020 when work on the grandstand is due to begin after the centenary running of the Plate - but whoever does win the 100th running of Australia's greatest weight-for-age classic will always be a footnote in the race's history.

Should building works make it impossible to race at the venue then negotiations would take place with either Flemington or Caulfield to stage the race as a one-off venture.

But Valley officials are hopeful the jewel in their crown, a race now synonymous with triple champions Kingston Town and Winx, will not have to be shifted.

"There will be 10-11 months when we don't race here after the 2020 Plate, but we are hopeful that we will be able to stage the race in 2021. But if that's not possible we will look to stage it elsewhere for one year," said Valley CEO Michael Browell.

Dubbed "Vision for the Valley" the massive redevelopment of the racecourse precinct is one of the most ambitious rebuilds undertaken at a Melbourne racecourse, combining not just racing but also leisure, residential and commercial activities on the site now occupied by just the racetrack.

As a result, the iconic shape of the Valley course will be changed, particularly the short straight, which often leads to dramatic finishes as horses crank into full gear long before they make the home turn.

The circuit, when the redevelopment is complete, will be 1702 metres in circumference, with the home straight extended from the current 173 metres to 317 metres. At present, the course is about 100 metres longer, at 1805 metres.

The track will be widened, allowing field sizes to increase (the current maximum is 14). The extra width will also allow the ground staff to manage the turf better, providing capacity to stage up to 35 race meetings each year.

Traditionalists will be pleased to hear that all key starting positions, including the famous Cox Plate 2040-metre start at the top of the home straight, will be retained.

Valley officials say the project will now move into detailed design and construction phase, with marketing of the first residential precinct scheduled to commence in mid-2018, with the grandstand redevelopment and reconfiguration of the racecourse start after the running of the 100th Cox Plate in 2020.

MVRC chairman Don Casboult said the club would be making the next phase of its history with this initiative..

"It will deliver a huge range of benefits for the entire community over the next century. The scale and ambition of this project is unparalleled," he said.

"This place has been the setting for so many iconic moments in Australian thoroughbred racing - the place where legends are made. Now a brilliant new chapter has been opened on the Valley story."

Planning has been undertaken by MVRC in consultation with members, the community, state and local government over the past decade and plans were accelerated after rezoning of the racecourse land by the appointed planning advisory panel in 2015.