Ethimale tank bund is situated in the Uva province of Sri Lanka across the upper part of the Wila Oya catchment. It was built by Brother Saddhatissa of King Dutugamunu (161-137 AD) using advanced technology. The earthen bund made to retain water was constructed in three sections joining four different mountain hills. The water from the reservoir was not released to the paddy fields directly but to the Wila Oya stream and at an anicut 4.5 km downstream, it was diverted through a canal system to the fields. The main canal still runs 2 km parallel to Wila Oya stream and only after that the water is released to fields through distributary canals. The water thus distributed is retained by few small tanks along the canal and thereafter released to adjoining fields from these tanks.

Ethimale tank has its catchment area of 9.50 sq miles, gets an annual rainfall between 1400 to 1600 mm and stores 5510 Ac.ft (6.8 MCM) of water at its full supply level with 500 Ac.ft as dead storage. This tank bund consists of 3 sections of homogeneous earth fill interconnecting four mountains. The length of the dam is 1100 m and the bund top elevation is 371 ft above MSL. With a catchment area of 2460 ha, the Ethimale tank issues water for 406 ha of paddy fields in the Ethimale irrigation scheme. In addition, this tank is utilized for domestic purposes as well as fisheries and tourism industries.

Ethimale tank belongs to the Monaragala irrigation region and it is located in Siyambalanduwa divisional secretariat division in the Monaragala district in Uva Province. The main spillway discharges to the Wila Oya stream. This tank is the main water source in this area and gets water during mainly Maha season falling from October to December every year. The full extent is cultivated in Maha season whereas a portion of farmland is selected in Yala season with calculating available water volume. About 60 % of the command area would benefit from the Yala season averagely according to the past records.

According to folklore, King Dutugemunu had entrusted his brother Saddhathissa with the development of the East and South-east areas of the country. Prince Saddhathissa had developed the water resources in the area and had created an environment where people did not have to face food shortages. King wanted to check the progress achieved and had sent a person with a bag full of paddy and wanted him to sell it. The person had walked in the entire area but could not find anyone who wanted to buy and had finally reported it to the King. King has realized all are self-sufficient and had called back his brother with the message “enough brother” which means Ethi Male in Sinhala. After that area has been known as Ethimale and the tank was last built as Ethimale. However, this area had been deserted over many centuries later, until the Irrigation Department commenced the development of the water resources at the beginning of the 1950s. In 1958 restoration work of Ethimale had commenced and 334 families selected from Badulla, Welimada and Moneragala were given land. By 1964 on completion of the canal systems water was released for cultivation.

Ethimale tank is to be rehabilitated and augmented under the proposed Kumbukkan Oya reservoir project funded by GOSL. Identified major rehabilitation are such as raising of spill level, renovation of rip rap, strengthening of the dam, establishment of bathing steps, establishment of tor filter & toe drain, installation of piezometers on d/s slope of the dam, construction of access road for inspection, installation of levelling monuments and installation of boundary stones.