Preheat oven to 350 degrees

Combine wild blueberries, 3/4 cup white sugar, water, and lemon rind in a baking dish

Bring to boil and simmer for 2 minutes

Meanwhile, mix rest of white sugar (1/4 cup) with brown sugar, flour, cinnamon, and baking powder

Cut in butter until mixture is crumbly

Sprinkle crumbs over blueberry mixture

Bake about 25 minutes or until top is brown

Serve warm with vanilla ice cream