SOME SURVEYS OF RIVERS IN CEYLON

Abstract

The city of Colombo, capital of Ceylon, is situated at the mouth of the Kelani Ganga and about 25 miles north of another considerable river, the Kalu Ganga, which enters the sea at Kalutara. Though its proximity to two of the largest of the perennial rivers of Ceylon provides some advantages of inland water transport by river craft, it also places it in the zone of periodical floods which cause damage to buildings, communications and agriculture within the city limits and over extensive areas of low-lying paddy fields and gardens beyond. Except for a spur of high land running roughly parallel to the eastern shore of the harbour through Hultsdorp, Blomendahl and Kotahena to the loop of the Kelani Ganga near its mouth, the greater part of the city is very flat and only a matter of 20 feet elevation above sea-level. On its eastern flank lies a series of connected shallow lakes, marshes and paddy fields which extend in a loop from the banks of the Kelani Ganga at Ambatalenpahala to Dehiwela on the city's southern limit; there are, in addition, canals through this area with two outlets into the sea at Wellawatta and Dehiwela. Navigable canals connect the Kelani Ganga with the Beira Lake and Colombo Harbour and, with the canals already mentioned, form a continuous waterway which, in fact, extends northwards as far as Puttalam, 80 miles from Colombo, and southwards to the Kalu Ganga and Kalutara. About half a mile east of Mount Lavinia another series of shallow lakes, marshes and paddy fields spreads its irregular shape roughly parallel to the coast through the Bolgoda Lakes to a low ridge north of the Kalu Ganga and close to its right bank. The whole of these lowlands is referred to as the Bolgoda Basin. A canal called the Kepu Ela, constructed by the Dutch during their occupation of Ceylon, passes through it to join the Kalu Ganga at Diyagama about 5 miles from the river mouth.