To make the blueberry lavender syrup

1. Combine the blueberries, water, and sugar in a heavy bottomed sauce pan. Crush the berries with a potato masher then add the lemon juice and lavender to the pot. Bring the mixture to a boil over medium-high heat then reduce the heat to medium and simmer for 30 minutes, stirring occasionally until the liquid has reduced and the mixture has thickened.
2. Place a fine mesh strainer over a large bowl and pour the blueberry mixture into the strainer. Gently press on the solids with a spatula to extract all of the syrup then discard the solids. Allow the syrup to cool then store in the refrigerator for up to a week.

To make a drink

1. Fill a tall glass with ice. 
2. Add 1/4 cup of the blueberry lavender syrup, squeeze in the lime wedge, and fill to the top of the glass with sparkling water. Garnish with lime wheels or blueberries if desired.