Malankara Dam
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Operation and Maintenance Manual for Malankara Dam (KL07HH0049) Water Resources Department Government of Kerala O&M Manual of Malankara Dam August 2020 Operation and Maintenance Manual for Malankara Dam (Prepared By) KERALA WATER RESOURCES DEPARTMENT STATE OF KERALA August 2020 i O&M Manual of Malankara Dam August 2020 Government of Kerala Operation and Maintenance Manual Malankara Dam ii O&M Manual of Malankara Dam August 2020 KERALA WATER RESOURCES DEPARTMENT Disclaimer This Operation and Maintenance Manual for Malankara Dam in no way restricts the dam operators in digressing from her/his responsibilities. The Dam Operators must exercise appropriate discretion and good judgment based on actual site condition when implementing and using the operation and maintenance manual for managing the workings of the dams and appurtenant structures. The manual was developed for the purpose of organising and managing the operation, inspection and maintenance of the dams for reducing risk and optimizing performance of the dams as a general guide. For any information, please contact: THE CHIEF ENGINEER PROJECT II KERALA STATE WATER RESOURCE DEPARTMENT THIRUVANANTHAPURAM, KERALA Email: [email protected] iii O&M Manual of Malankara Dam August 2020 FOREWARD Globally, the Operation and Maintenance (O&M) Manual of a dam/barrage is one of the most important documents which is supposed to be put in practice right from the initial filling of reservoirs. In order to address the operation and maintenance aspects, ongoing Dam Rehabilitation and Improvement Project (DRIP) has requisite scope to prepare new or update existing O&M manuals for all DRIP dams, which will become very helpful to Dam/Barrage Owners in addressing the dam specific issues comprehensively in future. This Operation and Maintenance (O & M) Manual developed is a detailed set of written descriptions with step-by-step procedures for ensuring that the dam is safely operated, frequently inspected and properly maintained. Timely inspection and preventative maintenance is necessary for the safe functioning of the dam and continued productive use of the dam and reservoir. The format of this manual is prepared following the principles published in 2018 CWC Guidelines for Operation and Maintenance of dams for the use by all Dam/Barrage Owners in developing their own site-specific manuals. Each section of the document provides the necessary instructions to operate inspect and maintain their dams. It is recommended that all dam officials in charge to use this manual for ensuring that the dam is operated and maintained in a sustainable manner and will continue to derive benefits. Chief Engineer Projects – II Thiruvananthapuram iv O&M Manual of Malankara Dam August 2020 PREFACE Malankara Dam and Reservoir are owned and operated by Irrigation Department, Kerala. The Malankara dam is an earth cum masonry dam across Thodupuzha river, a tributary of Muvattupuzha river. It is located at Muttom in Idukki district near Thodupuzha- Moolamattom road and was constructed for the Muvattupuzha Valley Irrigation Project (MVIP). The dam site is about 27 Km from Muvattupuzha town and 8 Km from Thodupuzha town. There is a network of canal system consisting of two main canals on either banks, its branches and distributaries. It utilizes the tailrace discharge of Idukki Hydroelectric project by inter basin transfer and the runoff from the catchment area of Thodupuzha river up to Malankara. The Project was started in 1974 and completed in 1994 and the project envisages an ayacut of 18173 Ha of land in Kottayam, Ernakulam & Idukki Districts. The project also caters to the water needs of the Hindustan News Print factory at Velloor, near Piravom and providing drinking water facility to KWA Schemes and production of 10.5 MW of electricity at mini Hydro Electric station at Malankara. Malankara Dam acts as a diversion structure and fully opened in rainy season and inflow into dam is not predictable as it mainly depends on KSEB power generation at Moolamattom. The out flowing water from KSEB Power house at Moolamattom after power generation is stored in this dam for irrigation and small scale power generation purposes at Malankara. However in rainy seasons 2 rivers namely Nachar and Vadakkanar in the catchment area also contributes to the inflowing water to this dam. Since the storage capacity of dam is low, dam shutters are opened in a controlled manner in order to control the inflowing huge amount of water from above mentioned 3 areas. Also if the power generation at KSEB Moolamattom is at its maximum its tail discharge is enough to take the dam to its full storage level. The O&M Manual is prepared based on the available data from existing DPR and from mechanical department as per the framework of CWC on ‘Guidelines for preparing Operation and Maintenance Manual for Dams dated Jan 2018. v O&M Manual of Malankara Dam August 2020 CONTENTS Sl.no Details Page 1 General Information 1 1.1 Purpose, Location, Description of dam 1 1.2 Assignment of responsibility 11 1.3 Collection & Reporting of Dam and Reservoir Data 16 1.4 Public Utilities and Safety 17 1.5 Restricted Areas 17 1.6 Staff position, Communication & Warning System 18 1.7 Distribution of Operation & Maintenance Manuals 18 1.8 Supporting Documents & Reference Material 20 1.9 Typical Schedule of Duties 20 1.10 Hydro mechanical Inspections/ checks 24 2 Project Operation 25 2.1 Operation Plan 25 2.2 Normal Operation 25 2.2.1 Instructions for Operating Control Mechanisms 25 2.2.2 Operation of the Reservoir 29 2.2.3 Safety Aspects 30 2.2.4 Flood Release Procedure 31 2.2.5 Reservoir Capacities 31 2.2.6 Inflow forecasting 33 2.3 Emergency Operation 35 2.3.1 Flood communication system 35 2.4 Drawdown Facility 36 2.5 Record Keeping 36 3 Project Inspection 38 3.1 Types of Inspections 38 3.2 Informal Inspections 38 3.3 Scheduled Inspections 39 3.4 Special (Unscheduled) Inspections 40 3.5 Comprehensive Evaluation Inspections 41 3.5.1 General. 41 3.5.2 Details to be provided to DSRP before inspection 42 3.5.3 Field Inspection – Observations & Recommendations 43 regarding Remedial Measures 3.5.4 Components involved 45 4 Project Maintenance 47 4.1 Maintenance Plan 47 4.2 Maintenance Priorities 47 4.2.1 Immediate Maintenance 48 4.2.2 Preventive Maintenance 48 4.3 Maintenance Items 50 4.3.1 Earthwork 50 vi O&M Manual of Malankara Dam August 2020 4.3.2 Upstream Riprap 52 4.3.3 Controlling Vegetation 53 4.3.4 Controlling Animal Damage 54 4.3.5 Controlling Ants and Termites (White Ants) 54 4.3.6 Controlling Damage from Vehicular Traffic 55 4.3.7 Masonry/Concrete dams & Spillways 55 4.3.8 Outlet Works 56 4.3.9 Trash Racks 57 4.3.10 Gates & Hoisting Equipment 57 4.3.11 Electrical System 74 4.3.12 Metal Component Maintenance 75 4.3.13 Access Roads 75 4.3.14 General Cleaning 75 4.4 Materials requirements for maintenance during monsoon period 76 4.5 Establishment Requirements 76 4.6 Preparation of O&M budget 77 4.7 Maintenance Records 80 5 Instrumentation and Monitoring 82 5.1 General Instrument Type 83 5.2 Instrumentation at Malankara Dam 83 5.3 Frequency of Monitoring 83 5.4 Data Processing and Evaluation 83 5.4.1 Data Collection 83 5.4.2 Data Presentation 83 5.4.3 Data Interpretation 83 5.4.4 Dam Performance Evaluation 84 5.4.5 Methods of Behavior Prediction 85 5.5 Visual Observations 85 6 Previous Rehabilitation reports 86 7 Updating the Manual 93 Annexure A-Basic Drawing 94 Annexure B-Hydrologic Review Report 96 Annexure C- Gate Manufacturer’s Manual 110 Annexure D- Check list for Inspection 110 Annexure E- DSRP Inspection Report 147 Annexure F- Pre monsoon Inspection Report 240 Annexure G-notification for strengthening of alarm and warning system 276 for safety of people from sudden release of water from dams issued by National Disaster Management Authority (October 2015) Annexure H-Glossary 280 vii O&M Manual of Malankara Dam August 2020 LIST OF FIGURES Figure 1. 1. Location Map of Malnakara Dam ....................................................................................... 3 Figure 1. 2. Vicinity Map ....................................................................................................................... 4 Figure 1. 3. Catchment area of Malankara dam ................................................................................... 5 Figure 1. 4. Google Map ........................................................................................................................ 6 Figure 1. 5. View from river side with all shutters open ....................................................................... 7 Figure 1. 6. Platform for shutter operations ......................................................................................... 8 Figure 1. 7. Spillway gate ...................................................................................................................... 8 Figure 1. 8. Stilling basin ( View from dam top ) ................................................................................... 9 Figure 1. 9. Toe Drain ............................................................................................................................ 9 Figure 1. 10. View inside Gallery ( V notch and drain ) ....................................................................... 10 Figure 6. 1. OFFICE BUILDING ............................................................................................................. 87 Figure 6. 2.FENCING ...........................................................................................................................