A former WA mayor has been acquitted of assaulting his neighbour over a “childish” driveway dispute which saw the pair hurl insults at one another and have a water fight.

Troy Pickard, who was Mayor of the City of Joondalup for 11 years to 2017, was accused of throwing a mug of hot coffee into his neighbour, Mark Wild's, face in January 2018 after Mr Wild confronted him about spraying dirt onto his drive.

Former City of Joondalup Mayor, Troy Pickard. Credit:AAP

He appeared in Joondalup Magistrates Court on Monday where Magistrate Jennifer Hawkins handed down her verdict, determing he should be acquitted on the assault charge.

"I'm obviously delighted with the outcome after a 15-month saga," Mr Pickard said.