The Directorate General of Water Resources Development (DGWRD) of the ministry of Public Works, Government of Indonesia (GOI) contracted PRC Engineering Consultants, Inc. (PRC/ECI) to provide consulting engineering service for preparir3 an integrated development plan for the Tuntang/Jragung Rivers in the Jratunseluna Basin. The study for the preparation of the plan started on May 16, 1979 and was originally scheduled to be completed on November 30, 1979. An interim report on the study was submitted by PRC/ECI on August 15, 1979 which was reviewed by all the concerned agencies and later discussed on September 24, 1979 in a meeting held by the DGWRD at Jakarta. In that meeting and in subsequent discussions between PRC/ECI and DGWRD, it was the consensus of opinion of all the participants that it would be very beneficial if the study on the Tuntang/Jragung Rivers could be modified by including the entire Jratunseluna Basin in certain aspects of the study. In that modified study the interrelationships of the existing, proposed and the potential development works of the Tuntang/Jragung subbasins and those of the adjoining subbasins within the Jratunseluna Basin should be examined. Thus, the master plan for the development of the Jratunseluna Basin which was prepared earlier by NEDECO in the year 1973, would be reviewed and updated. The changes in criteria and constraints which have occurred and the large amount of new data which have become available since preparation of the original master plan would be incorporated in the modified study for formulating a conceptual optimized development plan. The original contract between GOI and PRC/ECI for the engineering services was, therefore, amended to include the revised scope of work for the modified study. For the preparation of the integrated development plan for the Tuntang/Jragung Rivers, as contemplated originally, a report was prepared on Hydrology for supporting the proposed plan. That report is being produced as Part I Appendix A -Hydrology, related to the Tuntang/Jragung Rivers Basins Integrated Development Plan. The above mentioned modified study to update the Master Plan for the Jratunseluna Basin was started in December 1979 and completed in May 1980. The results of that study pertinent to the hydrological investigations done by the consultant to support the proposed plan are reported in this document as Part II Appendix A - Hydrology, related to the Tuntang and Related Rivers Basins Development Plan.