The Station Fire Memorial Foundation made the announcement Friday.
A makeshift memorial including crosses and other mementoes has been at the site for the past decade.
The foundation is alerting those whose loved ones died in the fire that they have until September 15 to retrieve any items they wish to keep.
Anything there after that date will be respectfully removed and placed in a time capsule as part of the permanent memorial.
The site is currently open, but fences will be put up during construction.
The February 20, 2003, fire at The Station was started by pyrotechnics for the rock band Great White.