Pour it with a clear conscience - that water is the villain of the story, not the treasure.
Boiling exists to pull the BITTERNESS out of the peel, and that bitterness is now dissolved in the water. Keep it and you keep the bitterness. Some preparations even boil in fresh water more than once for thick-skinned fruit, draining every round.
The flavour you're protecting comes later - from the syrup the blanched peel slowly candies in. That syrup you absolutely keep... it ends up orange-perfumed and lovely brushed on cakes. Drain the bitter water, hoard the sweet syrup 🍊
