| Nilwala River | |
|---|---|
  | |
| Location | |
| Country | Sri Lanka |
| Physical characteristics | |
| Source | Sinharaja Forest Reserve |
| Mouth | |
• location | Matara |
• coordinates | 5°57′N80°32′E / 5.950°N 80.533°E |
| Length | 72 km (45 mi) |
| Basin size | 922 km2 (356 sq mi) |
The Nilwala is a river in Southern Province in Sri Lanka. It originates in Sinharaja Forest Reserve [1] and discharges into the sea at Matara.
The river is 72 km (45 mi) [1] [2] long and has a drainage basin of 922 km2 (356 sq mi). [3]
Matara is a major city in Sri Lanka, on the southern coast of Southern Province. It is the second largest city in Southern Province. It is 160 km (99 mi) from Colombo. It is a major commercial hub, and it is the administrative capital and largest city of Matara District.
The Mahaweli River, is a 335 km (208 mi) long river, ranking as the longest river in Sri Lanka. It has a drainage basin of 10,448 km2 (4,034 sq mi), the largest in the country, which covers almost one-fifth of the total area of the island. The Mahaweli Ganga starts at Polwathura, a remote village of Nuwara-Eliya District in bank Nawalapitiya of Kandy District by further joining of Hatton Oya and Kotmale Oya. The river reaches the Bay of Bengal on the southwestern side of Trincomalee Bay. The bay includes the first of a number submarine canyons, making Trincomalee one of the finest natural deep-sea harbours in the world.
The Malwathu Oya is the second longest river in Sri Lanka. The river originates in the North Central Province of Sri Lanka and enters the sea on the northwest coast, into the Gulf of Mannar, near Vankalai. It is a seasonal river that spans over 164 km (102 mi) through paddy and forest lands, which are used by the inhabitants to cultivate for their survival.
Pinnawala Elephant Orphanage, is a captive breeding and conservation institute for wild Asian elephants located at Pinnawala village, 13 km (8.1 mi) northeast of Kegalle town in Sabaragamuwa Province of Sri Lanka. Pinnawala has the largest herd of captive elephants in the world. In 2023, there were 71 elephants, including 30 males and 41 females from 3 generations, living in Pinnawala.
Kanneliya–Dediyagala–Nakiyadeniya or KDN is a forest complex in southern Sri Lanka. The forest complex designated as a biosphere reserve in 2004 by UNESCO. The KDN complex is the last large remaining rainforest in Sri Lanka other than Sinharaja. This forest area has been identified as one of the floristically richest areas in South Asia. The forest complex is situated 35 km northwest of city of Galle. The rain forest is a major catchment area for two of the most important rivers in southern Sri Lanka, the Gin and Nilwala Rivers. This biosphere reserve harbors many plants and animal species endemic to Sri Lanka.
The Puttalam Lagoon is a large 327 km2 (126 sq mi) lagoon in the Puttalam District, western Sri Lanka.
The Kirila Kelle wetlands are found a short distance inland from the southern Sri Lankan city of Matara. The wetlands are a part of the Nilwala River basin. They comprise some 750 acres of wetlands. Canals were built by Portuguese Colonialists to mitigate flooding of the Nilwala river into Matara township and aid in the cropping of a further surrounding 6000 acres of rice and other farming. A failed attempt at flood mitigation in the early 1990s has meant that the once arable 6000 acres has now become un-farmable. This reduction in historically arable land has resulted in widespread poverty and associated social and environmental problems for some 35,000 people.
The Kehelgamu Oya is a major upstream tributary of the Kelani River. The tributary measures 50 km (31 mi) in length, originating in the hills of the Horton Plains National Park, before passing through the Castlereigh Reservoir. Kehelgamu Oya converges with the Maskeliya Oya at Kalugala, forming the 100 km (62 mi) long Kelani River. The river is heavily used for hydroelectric power generation.
The Maskeliya Oya is a major upstream tributary of the Kelani River. This 40 km (25 mi) long tributary originates in the hills of the Peak Wilderness Sanctuary, before passing through the Maskeliya Reservoir. The Maskeliya Oya converges with the Kehelgamu Oya at Kalugala, forming the 100 km (62 mi) long Kelani River. The river is heavily used for hydroelectric power generation.
The Gal Oya is a 108 km (67 mi) long river, in southeast Sri Lanka. It is the 16th longest river in Sri Lanka. It begins in the hills east of Badulla and flows northeast, emptying into the Indian Ocean south of Kalmunai.
The Deduru Oya Dam is an embankment dam built across the Deduru River in Kurunegala District of Sri Lanka. Built in 2014, the primary purpose of the dam is to retain for irrigation purposes approximately a billion cubic metres of water, which would otherwise flow out to sea. Site studies of the dam began in 2006 and construction started in 2008. It was ceremonially completed in 2014, with the presence of then President Mahinda Rajapaksa.
Nanu Oya is a 27 km (17 mi) long stream in the Central Province of Sri Lanka. It originates at an elevation of over 2,000 m (6,562 ft) on Pidurutalagala, the highest mountain in Sri Lanka, flowing into the Kotmale Oya at an elevation of approximately 1,200 m (3,937 ft). The Kotmale Oya is a tributary of the Mahaweli River, the longest river in Sri Lanka, which finally discharges at Trincomalee after a combined distance of nearly 350 km (217 mi). The river was dammed in 1873 to create the popular Lake Gregory in Nuwara Eliya. The Nanu Oya discharges into the Kotmale Oya 2.5 km (1.6 mi) upstream of the Upper Kotmale Dam.
The Uma Oya Hydropower Complex (also internally called Uma Oya Multipurpose Development Project or UOMDP) is an irrigation and hydroelectric complex currently under construction in the Badulla District of Sri Lanka. Early assessments of project dates back to 1989, when the first studies was conducted by the country's Central Engineering and Consultancy Bureau. The complex involves building a dam across Dalgolla Oya, and channelling water over a 3,975 m (13,041 ft) tunnel to Mathatilla Oya, both of which are tributaries of the Uma Oya. At Mathatilla Oya, another dam is constructed to channel 145,000,000 m3 (5.1×109 cu ft) of water per annum, via a 15,290 m (50,160 ft) headrace tunnel to the Uma Oya Power Station, where water then discharged to the Alikota Aru via a 3,335 m (10,942 ft) tailrace tunnel. The Alikota Aru is a tributary of the Kirindi Oya.
The Kala Oya is the third longest river in Sri Lanka. The 145 km (90 mi) long river has a basin size of 2,873 km2 (1,109 sq mi), and more than 400,000 rural population live by the river basin.
Rekawa Lagoon is a coastal waterbody located in Hambantota Districtt in the Southern Province, Sri Lanka and it is located 200 km (120 mi) south of Colombo. The lagoon possesses a rich biodiversity with a variety of flora and fauna.
The Attanagalu Oya is a river in Gampaha District, Sri Lanka.
2018 Sri Lanka floods and landslides caused from an annual heavy southwest monsoon beginning around 19 May. As of 26 May 2018; the monsoon floods affected in about 19 districts, killed at least 21 people, about 150, 000 people were affected and further left approximately 23 people missing. The death casualties were reported from 22 May onwards in the provinces including South, Northwest, North and East. About 4 people were reported dead due to lightning, 5 people were killed due to floods and lightning, 8 people died due to drowning and further left 4 people dead resulting from fallen trees. The DMC report claimed about 400, 000 people have been displaced to safer locations. About 105 houses were reported to have fully damaged and over 4832 houses have been partially damaged.
Kirindi Oya is a river in Sri Lanka. Starting in Bandarawela, it flows for 117 km (73 mi) down to Bundala.