To prepare the simple syrup:
Combine the sugar, water, lime juice, and zest in a small saucepan. Bring to a boil, stirring to dissolve the sugar. Remove from heat and chill thoroughly.
To prepare the soda:
In a blender, food processor, or juicer, puree the watermelon chunks. Pass through strainer to remove seeds and pulp.
In a pitcher, combine the watermelon juice, simple syrup, and sparkling water or club soda. Add additional simple syrup to taste, if needed. Pour into glasses filled with ice. Garnish with lime wedges, if desired.
Note: Make this a cocktail by adding an ounce of your liquor of choice to each glass, vodka, gin, rum, etc.
Calories: 292kcal, Carbohydrates: 75g, Protein: 2g, Fat: 1g, Saturated Fat: 1g, Sodium: 6mg, Potassium: 376mg, Fiber: 1g, Sugar: 69g, Vitamin A: 1730IU, Vitamin C: 34mg, Calcium: 21mg, Iron: 1mg