Lake Parramatta was formerly Hunts Creek. The dam foundation stone was laid in 1855, with all sandstone used for its construction being quarried from Hunts Creek. The dam is historically important as it was only the twelfth engineered (second arch) dam built in the western world.
Lake Parramatta is located at Bourke St, NORTH PARRAMATTA, just off Pennant Hills Road. I would have included a map but after half an hour of trying I gave up, so an address will have to do.
But here is a link for the brochure of the reserve if you would like to know more.