Cumbum Lake, also known as Gundalakamma Lake, built on Gundalakamma rivulet upon Nallamala hills, is one of the oldest manmade lakes of Asia. It is said that the lake was built by sage Jamadagni at the opening between two hills of Nallamala range. But history records that the anicut (dam) was built by the Gajapati, kings of Orissa in 15th Century AD while the area was under their control. It was subsequently renovated by the Vijayanagar Princess Varadharajamma.
The lake in its present form is about 7 km long and on average, about 3.5 km wide. The Imperial Gazette of India, at the turn of 20th century, puts the height of the dam at 57 feet (17 m) and the drainage area at 430 square miles (1,100 km2). The directly irrigated land was about 10,300 acres (42 km2) in all.
Water Colour Painting of Cumbum Tank
Cumbum lake is accessible both by the rail from Cumbum railway station and by road from Nandyal, Ongole and Kadapa. It is one of the most picturesque valleys in the Guntur-Nandyal-Guntakal section of South Central Railway. The Bogada and Chelama rail tunnel, one of the longest in broad gauge line, (1.6 km)are situated near this station. Cumbum tank, formed by damming the Gundlakamma river by earthen bund, which is the highest in the Presidency (80 ft), with 100 yards length. The tank spreads over an area of 9 square miles (23 km2), and irrigates 6,944 acres (28.10 km2) with over 3,500 acres (14 km2) being second cropped in a good year. A more successful work is the Cumbum tank, formed under native rule by damming a gorge of the Gundlakamma river.
A water-colour painting of Cumbum tank on the Gundlakamma River painted by an unknown artist in March 1794 is still preserved at the British Library.