Flood Plains National Park - Sri Lanka

Flood Plains National Park is one of the four national parks set aside under the Mahaweli River development project. The park was created on 7 August 1984. The national park is situated along the Mahaweli flood plain and is considered a rich feeding ground for elephants. Flood Plains National Park is considered an elephant corridor for the elephants migrate between Wasgamuwa and Somawathiya national parks. The park is situated 222 kilometers (138 mi) north-east of Colombo.

The park's elevation range from 20–60 meters (66–197 ft.) with sparse rock outcrop. The Mahaweli River flows from south to north through the centre of the park. The rich alluvial soil flood plains situated beside the river are featured by a number of shallow swampy depressions called 'villus'. Around 38 villus have been recorded from the floodplains. The villus system of Mahaweli River has received protected status from Flood Plains and Somawathiya National Parks. The extended inundation of these low-lying areas, along with the nutrients carried in by the water, are the cause of the high level of net primary productivity. Furthermore to being flooded in the wet season, the villus are also inundated during the dry season because the headwaters of the Mahaweli River experience the south-west monsoon at that time. Unto the recent diversion of the river for irrigational purposes, the villus were important as dry season grazing grounds. The park is situated in the dry zone, therefore there is only a north-east monsoon from October to late-January and the wet season is followed up by a dry lasting from March to September. Mainly temperature is around 27 °C (81 °F) and mean rainfall is around 1,650 millimeters (65 in). Relative humidity range from 60-90% depending on the rainfall patterns and the area experience strong seasonal windy periods.

Mahaweli River in this section was connected to the nearby ancient irrigation network. On the right bank of the river, at the edge of the Mutugalla Villu, ruins of an ancient cave monastery with inscriptions dating back to between 2nd and 7th century BC have been found. Flood Plains National Park which declared in 1984 is in the upper flood plains of Mahaweli River and Somawathiya National Park declared in 1986 is situated in the downstream. These two parks, along with Wasgamuwa National Park to the southwest and the Trikonamadu Nature Reserve to the northeast forms a system of contiguous protected areas. It has been proposed to link all these national parks together to form a single protected area.

The floodplains of the Mahaweli forest are made up of diverse ecological zones consisting of river channels, riverine marshes, villus, seasonally flooded grasslands, and swamp forests. The flood plain in general and associated villus in particular have a high diversity of both smaller and larger plant species. There are 231 plant species that have recorded from Handapan and Bendiya villus and marsh forests, which is the largest villu of 796 hectares (3.07 sq mi) within the Mahaweli River floodplain. Saturated soil and flooding hinder tree growth and enhance the growth of water-tolerant grasses and aquatic plants.

The flood plains are abundant in supply of water and grasslands and therefore is an important habitat for elephant. In 2011, estimated elephant population of the park is around 50-100. Other frequently seen mammals are Fishing Cat, Jungle Cat Rusty-spotted Cat jackal, wild boar, Indian Muntjac, sambar, spotted deer and Water Buffalo. European Otter, Sri Lankan Spotted Chevrotain, and Sri Lankan Leopard are also been recorded from the park. Flood Plains National Park is one of the recorded habitats of Grey Slender Loris.

The flood plains are especially important for the diversity and richness of their avifauna, particularly migrant birds. The rare species Lesser Adjutant and variety of other species inhabit the floodplains. It has been estimated that around 75 species winter in the swamps of the flood plains. Frequently seen residents are Marsh Sandpiper, Wood Sandpiper, Asiatic Golden Plover, garganey, osprey, and Black-tailed Godwit Common residents are eastern large egret Cattle Egret, Painted Stork, Pond Heron, eastern grey heron, Pheasant-tailed Jacana, Purple Coot, Indian darter, Little Cormorant, Indian Shag P., Indian Cormorant, Brahminy Kite, Painted snipe, Black-winged Stilt, and Red-wattled Lapwing.