It has led to pleas from the club for authorities to immediately restrict entry to the course from the footbridge, built as part of the new 240-hectare Werribee River Regional Park.

The project's first stage, which is nearing completion, will include the footbridge, a new entrance from New Farm Road, and cycling and walking trails.

It will be linked to Werribee Park by the footbridge, which crosses the river and a path through a woodland area, of which the golf club is a neighbour.

The new regional park will wind its way from the west bank of the river near the zoo to Werribee South.

Club president Wayne Byrne said the riders had entered the course via the footbridge and pathways, which are not yet open to the public.

"This is something we've been dreading. It's now possible for the public to access the entire course from the footbridge.

"Access needs to be restricted not only to protect the course but also for safety reasons. We don't want anybody to get hit by a golf ball."

Course staff worked around the clock to repair the damage, which has cost the club about $4000.

Parks Victoria chief ranger Rocky Barca said the agency had agreed to provide a fence between the new path and the golf course as part of the initial works.

Following discussions with the club, Parks Victoria would bring forward construction of the barrier.