Dokan & Derbendikhan Dam Inspections
Document / Report Control Form
Project Name:Dokan and Derbendikhan Dam Inspections
Project number:5062018
Report for:World Bank
PREPARATION, REVIEW AND AUTHORISATION
Revision #
Date
Prepared by
Reviewed by
Approved for Issue by
First Draft
21 June 2006
M C Cordell
D Kenneally
B Minhinick
Second Draft
27 June 2006
M C Cordell
D Kenneally
B Minhinick
Final Report
31 July 2006
M C Cordell
D Kenneally
B Minhinick
ISSUE REGISTER
Distribution List
Date Issued
Number of Copies
World Bank
31 July 2006
1 (Electronic)
SMEC staff:M C Cordell
31 July 2006
1
Associates:
-
-
Melbourne Office Library:
31 July 2006
1
Report Project File: 5062018
31 July 2006
1
SMEC International Pty. Ltd.
133 Waverley Road, Malvern East, VIC. 3145
PO Box 559, Carnegie, VIC. 3163
Tel:61 3 9573 8100Fax:61 3 9573 8199Email:[email protected]
www.smec.com.au
The information within this document is and shall remain property of SMEC International Pty. Ltd.
Contents
11Introduction
11.1Background
21.2Project Objective
21.3Scope of SMEC Consultancy Assignment
21.4Consultancy Assignment Programme
31.5Format of Report
31.6Acknowledgements
42Dam Safety Management
42.1Overview
42.2Dam Safety Standards
42.3Significance of Hazard and Risk in Dam Safety Management
52.4Dam Hazard Category
62.5Dam Safety Management System
83Derbendikhan Dam
83.1General Description and History
113.2Geology
123.3Seismicity
133.4Hydrology
153.5Previous Studies and Reports
163.6Aspects Relating to Dam Safety
263.7Aspects Relating to Operational Efficiency
273.8Maintenance Issues
283.9Other Issues
294Dokan Dam
294.1General Description and History
324.2Geology
324.3Seismicity
334.4Hydrology
354.5Previous Studies and Reports
364.6Aspects Relating to Dam Safety
434.7Aspects Relating to Operational Efficiency
454.8Maintenance Issues
454.9Other Issues
465Proposed Emergency Actions
465.1Prioritisation of Required Actions
465.2Derbendikhan Dam
495.3Dokan Dam
Appendix 1Dokan and Derbendikhan Emergency Hydropower Project Description
Appendix 2Terms of Reference
Appendix 3Available Reports and Documents
Appendix 4Dam Monitoring Instrumentation at Derbendikhan Dam
Appendix 5Dam Monitoring Instrumentation at DokanDam
1 Introduction1.1 Background
The Government of Iraq has requested funding from the World Bank (through IDA) for emergency repairs of Dokan and Derbendikhan hydropower plants, both located in the Kurdistan Region of Iraq. A Project Information Document (PID) Concept Stage was prepared by the World Bank for the proposed Dokan and Derbendikhan Emergency Hydropower Project (P099059) at the end of March 2006 and discussed with representatives of the Ministry of Planning and Development Corporation and the Ministry of Electricity of the Central Iraqi Government during the week of 15 April 2006. To continue the preparation of the proposed project, a Preparation Mission was undertaken between 20-25 April 2006, when a team of representatives from the Ministry of Electricity (MoE) of the Kurdistan Regional Government (KRG) met with the World Bank Team to further discuss and agree on the technical and other aspects of project design, initiate procurement documentation preparation, implementation arrangements, environmental and fiduciary requirements.
Dokan and Derbendikhan, with a capacity of 400 MW and 249 MW respectively, are the two largest power stations in the Kurdistan Regional Governorate, and are connected to the national power grid. Each power station is part of a multipurpose scheme for power production and irrigation at each of the locations.
The Dokan Dam is located on the Lesser Zab River, approximately 220km upstream from its confluence with the Tigris River. The site is located adjacent to the town of Dokan and approximately 295km north of Baghdad and 65km northwest of Sulaimaniyah city.
The Derbendikhan Dam is located on the Diyala River, immediately upstream of the town of Derbendikhan. It is approximately 150km upstream of the Hemren Dam. The site is approximately 420km by road northeast of Baghdad and 65km southeast of Sulaimaniyah city. It is also within 15km of Iranian border to the southwest.
Figure 1. Project Location Map
Dokan Power Station became fully operational in 1979. Repair and maintenance have been substandard because of unavailability of spares and equipment. These factors have contributed to long outages and unreliable performance. Moreover, due to the long operational period (29 years) the power plant is now due for rehabilitation. This would need to be preceded by a detailed assessment of the plants condition and the safety of the Dokan Dam. The work would also explore the feasibility of redesign of some of the equipment, in particular the turbine and generator, in order to increase the overall efficiency of the power plant. It would also take into account the unavailability of spares from the original manufacturer.
The construction of Derbendikhan Power Station was completed in 1983 but operation commenced in 1990 due to a delay in construction of the overhead line to connect the power plant to the national grid. Only one unit was commissioned by the contractor, who had to leave the site because of the Second Gulf War. The other two units came into operation without proper commissioning. A combination of this and faulty design of the hydraulic system are considered to have contributed to unsatisfactory performance of this power plant since its commissioning. The plant suffers from severe cavitation of the runners and draft tubes. It also needs complete rehabilitation preceded by investigation of the cause of cavitation and redesign.
The Derbendikhan Dam has also suffered in its early days from a large slope failure on the right bank, approximately 100m upstream of the dam. As a result, subsequent modifications have been done since, and monitoring has indicated that additional slope movement is minimal, but the data record is scarce; and accordingly the operating restriction on the minimum pool level will be maintained during the project.
Due to shortage of power generation it is necessary that both power plants continue to operate. Therefore the rehabilitation work would be implemented in two phases. This project would constitute the first phase, consisting of urgent repairs to keep the two power plants operational, as well as studies and designs for the second phase which would involve rehabilitation.
1.2 Project Objective
The objective of the project is to help alleviate the current power supply shortfall through urgent repair works, and prepare for the subsequent rehabilitation of the Dokan and Derbendikhan hydropower plants to restore their original capacity 400 and 249MW respectively.
Details of the proposed project components are presented in Appendix 1.
1.3 Scope of SMEC Consultancy Assignment
Snowy Mountains Engineering Corporation (SMEC) were engaged by the World Bank to provide a Dam Safety Expert, Mr. Mark Cordell, to update the earlier condition assessments carried out for Dokan and Derbendikhan Dams and recommend works, if any, of an emergency nature, that should be financed under the proposed Dokan and Derbendikhan Emergency Hydropower Project.
The Terms of Reference of the Consultancy Assignment are given in Appendix 2.
1.4 Consultancy Assignment Programme
Following receipt of the Contract for the Consultancy Assignment on Friday 5 May 2006, SMEC immediately mobilised Mr. Mark Cordell to undertake the inspections of Dokan and Derbendikhan Dams on 8-17 May 2006. A broad outline of Mr. Cordells visit to KRG is summarised in Table 1.
Table 1. Summary of Consultancy assignment Activities
Date
Activity
Monday 8 May 2006
Departed Melbourne to Erbil (via Dubai)
Tuesday 9 May 2006
Arrived in Erbil and overland transfer to Sulaimaniyah
Wednesday 10 May 2006
Kick-off Meeting with Mr. Fatih Salih
Initial Visit to Derbendikhan Dam and discussions with Mr. Abdulrahman Khani, Dam Manager and his staff
Thursday 11 May 2006
Inspection of Derbendikhan Dam
Friday 12 May 2006
Inspection of Derbendikhan Dam
Saturday 13 May 2006
Initial Visit to Dokan Dam and discussions with Mr. Hama Tahir, Dam Manager and his staff
Sunday 14 May 2006
Inspection of Dokan Dam
Monday 15 May 2006
Inspection of Dokan Dam
Overland transfer to Erbil
Tuesday 16 May 2006
Departed Erbil to Melbourne (via Dubai)
Wednesday 17 May 2006
Arrived back in Melbourne
Thursday 18 May 2006 Friday 16 June 2006
Preparation of Consultancy Assignment Draft Report
Monday 19 June 2006 Wednesday 28 June 2006
World Bank Review and Comment on Draft Report
Monday 31 July 2006
Finalisation and Issue of Final Report
1.5 Format of Report
The Terms of Reference originally envisaged the Consultancy assignment to be carried out in two stages, with the submission of a report at the end of each stage:
1. Inception report advising
