WATERFALLS IN SRI LANKA

Waterfalls have fascinated human beings from the beginning. They are of the most beautiful of natural phenomena. From ancient times waterfalls have struck awe to those who see them and several have various legends and historical events associated with them.

Sri Lanka in comparison to its size has perhaps the largest number of waterfalls of any country in the world. They constitute about a hundred' some of great height and others only' a few meters' Perhaps no country has neglected its waterfalls as much that they are in jungles without even a foot – path leading to them. The vegetation round many falls has been denuded. Sri Lanka's highest waterfall. The Bambarakande Falls (263 m), a sight of the most exquisite beauty is still known only to a few, even though it is a bare 4 miles off the main road from Colombo to Bandarawela. Meny still believe that Diyaluma (220 m) is the highest waterfall in Sri Lanka.

Several geographical factors are necessary for there to be an abundance of waterfalls in any Country. Sri Lanka is fortunate in that all these factors are found in the central highlands  of the island. Firstly, the geological formation of the land has to be such  that there is a sharp upthrust of  the earth's surface resulting in several clearly defined peneplains with precipitous edges. Secondly, there should be plenty of rainfall so that the rivers with the, waterfalls are always carrying a large amount of water. A fall is at its best when there is a large volume of water rushing over its lip. Finally, a thick vegetation surrounding a waterfall always adds to its beauty. These factors are dealt  with in detail in the following paragraphs.

The geological structure of Ceylon shows  three distinct peneplains a coastel penepl of about 1,500 feet above sea level. A second peneplain at about 4,400 feet and a third peneplain about 6,000 feet. These peneplains are very marked and have been caused by a series of upward thrusts of the land surface millions of years ago. Two different theories have been advanced as to how and when these upward thrusts took place. Whatever its origins Sri lanka's tree peneplains are sharply divided from each other.

The division between the second and third peneplains is sharply marked particularly on the southern and eastern edges of the third peneplain. The is an almost wall like escarpment rising to over 3,500 feet above the low lands of the second peneplain on the southern part of the central highlands. This escarpment starts at the foot of Adam's Peak (7,300 feet) and proceeds to Wellawaya at the foot of the great Haputale scarp (5,000 feet). Some of our highest waterfalls are over this cliff wall, e.g., Aberdeen. Laxapana,Kirindi Ella. Bambaralanda, Diyaluma, Rawanella, etc. This horst or upward thrust land mass surrounded by depressed land is also evident on the eastern border of the highlands at a lesser height falling abruptly into the Uma Oya, a tributary of the Mahaweli. The Dunhinda. Manawela. Kurundu and Victoria falls are features of this escarpment. There are no waterfalls on the northern face of the horst. There is also an internal faulting in the central horst in the watawala Ragala area on the third or highest peneplain. Here we find the Devon Ramboda. Elgin, Parawella and St. Claire falls.

Where waterfalls are concerned it is very important greologically that the peneplains should have been formed by a sharp upward thrust or by a sharp depression of the earth's crust. Normally mountains are formed by the folding action of the earth's crustand in such cases peneplains do not occur and consequently there is a lack of waterfalls. It is when faulting of the earth's crust takes place that plateaus and peneplains are usually formed.

Heights of the Waterfalls of Sri Lanka in meters and Feet

Sometimes a waterfall falls from over very hard rock but there are layers of softer rock or soil below it. In such cases the tendency is for the softer layers at the bottom to wear out faster and to undermine the top layer of hard rocks causing it to collapse. The Niagara Falls is a typical example of this action. The Niagara and Horseshoe falls fall over a hard rock lip, but there are layers of softer limestone below it. The water eats into the soft rock casing the lip of the waterfall to collapse periodically. It has been measured that the falls of the Niagara and the Horseshoe recede at the rate of 4 feet a year. The Horseshoe falls has cut a gorge seven and a half miles in length by this process of recession by undermining.

Usually  a waterfall falls into a pool. A typical example of this in Sri lanka is the Dunhinda Falls. In certain cases where the waterfall is very high and the volume of water carried is small then the water disintegrates into mist or spray before it reaches the bottom. Many of sri Lanka's waterfalls particularly during the dry season fall into this category. Some waterfalls have massive rocks at the base so that the weight of the waterfall is broken on them. A typical example of this I Sri Lanka is the Diyaluma falls.

In Constructing such artificial spill dams however, the dam is built at an outward siope so that the water sliders down the spilt, while there is a concrete platform at the bottom which shoots the water horizontally down stream. Thus there can be no under­mining. Needless to say waterfalls of this nature are not perennial and can be seen only when the rivers are in spate. and the reservoirs are overflowing. Many of the artificial reservoirs built in the twentieth century in other parts of the world also have such waterfalls over the spill dams. The Tennessee river which was one of the earliest multi purpose river development projects has as many as 27 such waterfalls along its length.

The Hunas Falls is an artificial fall of another kind. Here a stream coming from the Hunasgiriya mountain has been dammed to form a lake and the overflow is diverted over a steep rock ledge 60 meters in height to create an exceptionally beautiful waterfall.

Waterfalls serve another purpose in providing hydro electric power. Only' a fall with a great height can usually be used for this purpose. It is also necessary that it should carry a large volume of water. Fortunately none of Sri Lanka's falls carry any great quantity of water which makes them useful for generating hydro power. Many of the large waterfalls or cataracts in the world have however been harnessed for this purpose. The Niagara falls which drains four of the Great Lakes of North America has been harnessed for generating electricity though the quantity of water used for this purpose is regulated so that the beauty of the falls is maintained.

In comparison with Sri Lanka's waterfalls the highest water­fall known in the world is the Angel in Venezuela, its drop is more than 3.200 feet. so great a height in fact that it makes little contact with the cliff side on its way down and the water dissolves in mist. The other exceptionally high waterfalls in order of height are the Kukenaam in Venezuela of 2,000 feet the Sutherland in South Island, New Zealand of 1,900 feet. the Tugella Falls in Natal. South Africa of 1.800 feet. the Ribbon Waterfall in Yosemite, California of 1,620 feet. the Upper Yosemite of 1.430 feet and the Garvarni in France of 1,384 feet

The term 'cataract" is used when a waterfall carries an enor­mous amount of water. The best known 'cataract" is the Niagara falls which discharges 200,000 cubic feet of water per second throughout the year. The largest mean discharge of water of any 

waterfall in the world is however that of the Guatra Or Sete Quedas on the Parana River between Brazil and Paraguay, It is estimated that 470,000 cubic feet of water per second goes OVer the falls which is only 30 feet less in height than the Niagara. The Khom cataract on the Mekong River in Vietnam has an annual flow of between 400,000 and 420,000 cUbic feet per second.

This brief note on waterfalls will serve to introduce the Sri Lanka reader to a subject which has not been comprehensively dealt with earlier. No one has listed Our Waterfalls or provided a guide to What is one of the most beautiful aspects of Our scenic beauty.