The Udawalawe National Park is next only in popularity to the Yala National Park in the Southern region, where elephants can usually be observed even at mid-day.  The availability of water, during the driest periods, accounts for such visibility.  The Park has a resident population of about 150 elephants with more animals ranging in during the dry season from habitats to the East and North of Uda Walawe making this an important conservation area.

Besides the elephant, recent investigations have recorded 21 species of fish, 12 species of amphibian, 18 species of snakes, 15 species of tetra pod reptiles, 184 species of birds and 39 species of mammals.  Of the scores of plant species recorded, 3 are endemic and one is considered as threatened (i.e. Mandora-Hopea cordifolia).  As such the site score from a bio-diversity point of view is quite high, despite the much degraded forest cover.

Other significance of this Park is that it forms the immediate catchment of Uda Walawe reservoir, which provides water to a command area of 32,000 ha, of paddy and sugarcane lands and has the potential to generate 6 MW of hydro-electricity.  At full supply level, the tank covers about 3400 ha and the maximum depth is then about 20 m at the dam site.  The reservoir has been made to provide irrigation to 12,000 ha on the river's right bank and 20,000 ha on the left bank.  The Park was established to conserve wildlife and forest as well as protect the immediate upstream catchment from erosion.  At the time of the park demarcation, there were many settlements inside the area concerned and a major part of the Park was cleared for shifting cultivation.