Yes — Havering encourages residents to report fly-tipping, and the council’s published information doesn’t say you must give your name. If you want to report it, use the council’s Report dumped rubbish page.
One thing to note: if you know who is responsible, Havering says to let them know, but you can still report the fly-tip itself. If it’s an immediate danger between 5pm and 9am on weekdays, or at weekends, call the out-of-hours emergency line on 01708 433999.