Gal Oya National Park is located in the boundary of Uva and Eastern Provinces surrounding Inginiyagala reservoir AKA Senanayaka Samudraya  the largest reservoir in Sri Lanka Senanayaka Samudraya is created by constructing a dam across the water stream called “Gala Oya” which later became “Gal oya” under Galoya project to distribute water to Uva and eastern provinces for irrigation purposes