Place water and sugar in a medium saucepan, add lavender and bring to a boil.
Turn burner off and let "simple syrup" cool.
Squeeze lemons and strain out pits.
Pour syrup into a 1/2 gallon container straining out the lavender, add lemon juice and water, then stir.
Serve over ice.
If you are serving it in a drink dispenser for a party, you can add more fresh lavender on top as it will stay purple in color and look pretty and add lemon slices if desired.