The Toffees have enjoyed a superb start under Benitez this term and sit in fifth spot in the Premier League, just two points off league leaders Chelsea.
Everton started well under Carlo Ancelotti last season, but then fell away and ended the season without being able to qualify for Europe, something Townsend is specifically targeting this term.
Townsend is hopeful Everton will not fade again and is sure Benitez will work day and night to make sure that does not happen.
“We’ve had a good start, similar to last season, but last season results tailed off for one reason or another”, Townsend told his club’s official site.
“We have the players this year and a manager who will work tirelessly to not let us make the same mistakes.
“It’s too early to start looking at the table – everyone knows Everton need to be in the top six or seven places and playing in Europe.
“For me, a successful season has to be finishing in those European places.”
Townsend has so far featured in all of Everton’s seven league games, scoring three goals and setting up two more for his team-mates; he joined the Toffees in the summer on a free transfer.