In a saucepan, combine chopped rhubarb, water, and sugar. Bring to a boil over medium heat.

Reduce heat and simmer for about 10 minutes until rhubarb is soft.

Strain the mixture through a fine mesh strainer into a bowl, pressing to extract as much liquid as possible.

In a pitcher, combine the rhubarb syrup and fresh lemon juice.

Add cold water and stir well to combine.

Taste and adjust sweetness if necessary by adding more sugar or water.

Serve over ice and enjoy!