Palace have scored just seven goals in 10 Premier League games this season, with Wilfried Zaha providing much of the attacking spark.
Townsend told Sky Sports: "He's the main man for us, when he's not there you need other players, like myself, to step up and get assists and get goals.
"When he wasn't there last season we've done that, but we maybe didn't get the rub of the green to get over the line and get results on the board.
"I could have had one or two [goals] this season, could or should have had two or three assists, but, like the rest of the team, for some reason it's just not going in for us. But, listen, that'll soon change and the assists and the goals, not just for me but the rest of the team, will start going in."