Combine flour, sugar, baking powder, and salt in a bowl. Rub in margarine until mixture is crumbly. Add milk and mix until a smooth dough forms.
Combine maple syrup and water in a large saucepan over medium-high heat and bring to a boil. Scoop dough into dumplings using an ice cream scoop and drop gently into the boiling syrup. Reduce heat to low and simmer, keeping saucepan covered, until dumplings are cooked but not gooey and syrup has thickened, 10 to 15 minutes.