‘Memoirs of a Water Engineer’- Palitha Manchanayake

by Austin Fernando

I read ‘Memoirs of a Water Engineer,’ a collection of 19 essays by Eng. Palitha Manchanayake, with great pleasure and satisfaction. The essays are on ancient irrigation engineering, water resources, hydrology and flood forecasting covering his personal experiences both here and abroad. He first worked here for the Department of Irrigation and Mahaweli Authority and later, after migrating to Australia, as a Hydrologist serving the Commonwealth Bureau of Meteorology in Sydney.

Firstly, I found that the writer to be a versatile personality compared to many engineering professionals. Manchanayake has authored other works on scientific irrigation, Sinhala poetry, Buddhism, and philosophy as well. To find writers of that versatility and depth is difficult and hence commenting on work by such an author becomes a satisfying pleasure.

As is to be expected, the book devotes itself to technical aspects of irrigation, hydrology, political engagements, and construction issues related to such work. But these are provided simply without technical jargon. I address these aspects, as applicable, by referring to his various articles.

On Biso Kotuwas he covers several areas of technicalities, quoting from earlier historical and technical publications by writers like RL Brohier and Henry Parker. He has also referred to the work of my friend, Prof. WI Siriweera, to state historical findings on Biso Kotuwa. In a comparative study of large reservoirs, he highlights the importance of Biso Kotuwa, supporting the construction of large water bodies coping with high pressures at high heads of water. Hence, his explanation (pages 15 to 17) in plain language and equally simple technical terms of the purpose of a Biso Kotuwa is educative to technical and other personnel.

The author discusses another Sri Lankan hydrological invention, i.e. Keta Sorowwa, the conduit through which outgoing water from small low-head reservoirs were issued in ancient times. He explains here, also in plain language, the make-up of Keta Sorowwa and explains the Ketaya (clay pipe) required during high water levels, permitting enhanced tank capacity. Keta Sorowwa has been helpful to ensure water requirements when rains cease. Manchanyake calls it an engineering marvel and regrets the destroying of Keta Sorrowas by some British rulers, especially during the 1818 Rebellion.

Chapter Three lists how irrigation infrastructure has evolved over the years. Chapter Four also sets out the historical evolution of ancient irrigation, water resources management and the Yodha Ela concept that evolved during the eras of the Sinhala Kings dealing with the Yodha Elas of Kalawewa, Elehara-Minneriya, Minneriya-Kantale, Angamedilla, and Minipe Yodha Elas, and describes some Yodha Elas.

The chapter discussing the devastation caused by the British in the irrigation field narrates the historical aspects, which run through from pages 49-54, that include the Wellassa Rebellion and the destruction of ‘one tank-one village’ ecology. Manchanayake incorporates an emotional description of the beheading of Keppitipola Disawa to highlight the consequences of the criminal devastation by the British in 1818.

The book narrates the personal experiences of the author relating to irrigation feasibility studies, planning, and operating schemes. In Rambakan Oya and Muthukandiya schemes he developed close relationships with political heads, an experience by itself, and he mentions administrative hiccups that occur due to differing personal views on projects.

In the chapter on the Parakrama Samudra floods in 1978, he offers a detailed description of the disaster. I too had personal experience there as the then Government Agent of Polonnaruwa. Manchanayake and a group of engineers took part in another study and submitted a report to the government when a walking path was to be constructed on the Parakrama Samudra bund.

The flood control system in Ratnapura discussed in the relevant chapter could not be achieved through scientific norms and a project had to be abandoned. However, the need and importance of flash flood prediction and management are set out and these could improve flood control systems in any part of the country.

The chapter on Elephant Corridor is interesting as it shows environmental consequences of scientific decisions which are sometimes forgotten by technical officials. How rain gauging was disturbed thrice by elephants and how the concerned officials eventually succeeded teaches a lesson not only for irrigation but also for any other development project involving the environment. Manchanayake’s love for the environment is such that he devotes an entire chapter in his book titled Wahalakada Jungles to this subject. There’s much to learn there of the irrigation and hydrology of Wahalkada as well as wildlife there.

In the subsequent chapter he deals with technical assessments, discussing the water resources of Sri Lanka. The last few chapters running from pages 103 to 142 are the author’s experience in hydrology, floods, etc which would best serve interested engineers. For managers, the experiences could be guidelines for the future development of water management. Of course, some of the stances taken by developed nations may not be feasible here for want of resources. However, exposure to these would be useful to our engineers observes the writer.

This book printed by ‘The Quality Printers’ of Nugegoda will be of interest to laymen, generalists like me as well as to those who serve in the field of irrigation in areas where managing water shortages is an important part of their jobs. The book is written in simple language without technical jargon and with an environment friendly approach.I recommend it to those who are interested in water resources and management. Mostly, let me repeat my appreciation of the interest the author has taken to cover such a wide field.