Rehabilitation and Modernization of Islam Barrage

Islam Barrage Pictorial View

Barrage Data

Project Objectives

1. Rehabilitation of Existing Barrage Structure
2. Improve Flood Management
3. Rehabilitation of Barrage Gates & Hoisting Machinery Instrumentation

Engineering Studies

Safety Evaluation Study
( M/S EGC )

1. Subsidiary weir needs rehabilitation;
2. Flood passing capacity of the barrage be enhanced;
3. Improvement of training works; and
4. Gates and Hoists need rehabilitation.
5. The consultants concluded that barrage is unsafe and desired a priority attention for its safe operation.

Concept Clearance

1. On the recommendation of Safety Evaluation Consultants “Punjab Barrages Rehabilitation and Modernization Project” was prepared for rehabilitation of six number barrages for an amount of Rs. 29 billion.
2. The project was cleared by ECNEC for an amount of Rs. 745 million for feasibility studies of six barrages and detail design of two barrages  along with emergent repair on seven barrages
3. The project of rehabilitation of barrages was conceptually cleared with the direction that individual project should be submitted after completing feasibility study and detail design.
4. Taunsa Barrage project was taken first being the most sick barrage

Recommendations of Feasibility Consultants
(M/s Barrages Consultants -- Joint venture of ACE-EGC & ARCADIS EUROCONSULT)

General Layout of Spillway Site

Plan of Existing Barrage

Detailed Design
(JV-NESPAK-NDC in association with ICS)

1. Consultants were entrusted to:
1. Review of the feasibility study;
2. Prepare detailed design with complete drawings;
3. Finalize bidding documents; and
4. Assist in procurement of contractors etc.
2. Main tasks carried out by the consultants are:
1. Field surveys (topographic, bathymetric and condition surveys of gates)
2. Geotechnical and geophysical investigations
3. Model testing (sectional and comprehensive)
4. GIS studies (Data development and Analyses)

1. Reported Discharges at Islam barrage are not correct and are on higher side.
1. Design Discharge for 100 year Return Period - 332,000 Cs against 3,70,000 Cs
2. Barrage Capacity 311,000 Cs against 3,30,000 Cs

1. 311,000 cusecs from main barrage and 21,000 cusecs through bypass arrangements (fuse plug & bridge). Existing operating condition (15ft head across)
2. Raising of HFL from 457 ft to 457.6 ft to pass the design flood. This option will have adverse social and environmental and hence is not recommended.
3. 100 year flood (332,000 cusecs) through Barrage by lowering subsidiary weir crest by 1ft & No flood bypass arrangement.

1. Repairs of Cracks and Grouting underneath the floor of subsidiary weir and barrage;
2. Lowering of subsidiary weir by 1ft and passing 100 yr flood (332,000 cusecs) through Barrage and alteration of downstream slope from 1:3 to 1:3.75 to account for thickness deficiencies against unbalanced head;
3. Overlaying of 1ft concrete layer on subsidiary weir stilling basin and relaying of upstream and downstream slope of subsidiary weir;
4. Shortening of divide walls of existing barrage;
5. Strengthening of flood embankments and provision of Wetting channels;
6. Harnessing dunes upstream of barrage;
7. Installation of piezometers;
8. Rehabilitation and motorization of gates and hoisting system.