The paper begins with a brief examination of the concepts of irrigation, of a development project and of monitoring. The features of irrigation development are then presented, highlighting the characteristics which have hitherto made project monitoring difficult.
Cost comparisons between different solutions for planning problems are frequently based on 'present costs' or 'constant prices'. The comparisons can be expected to result in correct decisions when costs do not change with time; when costs escalate the decisions may not necessarily be correct. It is therefore necessary to establish, firstly, whether the use of present costs results in good planning decisions when costs increase and, secondly, what adjustments have to be made when increasing costs are to be taken into account.
The paper dealt the results of a geotechnical investigation into the instability of a cutting (in the Ecca Series) between Paul Pietersburg and Vryheid on the new Broodsnyersplaas - Richards Bay railway line.