In a saucepan over medium heat, mix sugar and water until sugar dissolves. Add blueberries and lemon zest, bringing the mixture to a boil. Reduce heat and let it simmer until the blueberries burst, about 5 minutes.
Remove from heat and let it cool for 10 minutes, then strain the mixture into a clean jar. Let it cool completely.
Pour about a tablespoon of blueberry syrup into each champagne flute, followed by 1/4 cup of lemonade. Top off each flute with Champagne.