A thesis submitted in partial fulfillment of the requirements for degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1992

This study is attempt to develop a methodology for assessing environmental impacts in large irrigation systems. The Progo Irrigation System has been taken as the project under consideration. This method was developed based upon the existing methods proposed by International Commission on Irrigation and Drainage, the Government of Indonesia and field observation. This developed method can be considered as a tool to irrigation staff, planners, and impact assessors with non-specialist in environmental science in identifying and anticipated at an early stage that adverse environmental effects and, if possible avoided or controlled. This proposed method can also be used to assess the environmental effects of a new or existing irrigation systems before the formal environmental impact assessment. The method consider the tertiary unit in an irrigation system and the water balance in each tertiary unit. The method was applied to the Progo Irrigation System in Indonesia, this method appears to give satisfactory results. From the field observations, it can be concluded that the irrigation systems over a period of a time cause several environmental effects. These effects could vary from system to system and also within the system from location to location.