Preheat oven to 350 degrees. Combine Maine wild blueberries, 3/4 cup white sugar, water, and lemon rind in a baking dish. Bring to boil and simmer for 2 minutes. Meanwhile, combine reserved 1/4 cup white sugar with brown sugar, flour baking powder, and cinnamon. Cut in butter until mixture is crumbly. Sprinkle crumbs over blueberry mixture. Bake approximately 25 minutes or until top is brown. Serve warm with heavy cream or vanilla ice cream.