The Udawalawa dam stands up as a concrete giant which owns a ferocious and majestic look depicting the modern architectural stupendous skills of hydro-engineers being the largest irrigation dam in the Southern Province of Sri Lanka. It has been constructed with two sections known as embarkment section and gravity section. The total length of the dam is approximately 3.9km and used as a power station in which generated hydroelectric power that was established in 1969.

Udawalawa Reservior or Udawalawa Lake Stands for the total surface area of 34 square kilometres and it measures 8.5 km in the length and roughly 4.5km to the width and the reservoir is situated entirely within the National Park premises and it is highlighted as its centrepiece and complete land area is gently vegetated.