1In a sauce pan, over medium-low heat, add water, sugar and lime leaves. Heat until sugar dissolves and remove from heat; pour in a large bowl and allow to cool.
Remove watermelon rinds and place water melon chunks into a food processor and pulse until it becomes slushy. Add watermelon slush to the sugar mixture.
Chill 4 hours. Strain and freeze until firm.
Thaw in the refrigerator for 1/2-hour before serving.