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    Water Distribution System Rehabilitation

    Uploaded by

    Youssef
    The document discusses a pilot project in Bangalore, India to reduce unaccounted for water (UFW) through rehabilitation of the water distribution system. Key points: 1. UFW in Bangalore is approximately 50% of water supply volume, resulting in high costs and low water pressure. 2. The pilot project covers 30 km2 and will establish district metering areas, inspect/replace meters and connections, detect leaks, and rehabilitate pipelines to reduce UFW. 3. Initial results are promising, with UFW reduced to 53-70% in some areas through leak detection and network restructuring based on hydraulic analysis.

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    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd

    Water Distribution System Rehabilitation

    Uploaded by

    Youssef
    502 views5 pages
    The document discusses a pilot project in Bangalore, India to reduce unaccounted for water (UFW) through rehabilitation of the water distribution system. Key points: 1. UFW in Bangalore is approximately 50% of water supply volume, resulting in high costs and low water pressure. 2. The pilot project covers 30 km2 and will establish district metering areas, inspect/replace meters and connections, detect leaks, and rehabilitate pipelines to reduce UFW. 3. Initial results are promising, with UFW reduced to 53-70% in some areas through leak detection and network restructuring based on hydraulic analysis.

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    WATER DISTRIBUTION SYSTEM REHABILITATION

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    © Attribution Non-Commercial (BY-NC)

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    The document discusses a pilot project in Bangalore, India to reduce unaccounted for water (UFW) through rehabilitation of the water distribution system. Key points: 1. UFW in Bangalore is approximately 50% of water supply volume, resulting in high costs and low water pressure. 2. The pilot project covers 30 km2 and will establish district metering areas, inspect/replace meters and connections, detect leaks, and rehabilitate pipelines to reduce UFW. 3. Initial results are promising, with UFW reduced to 53-70% in some areas through leak detection and network restructuring based on hydraulic analysis.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    502 views5 pages

    Water Distribution System Rehabilitation

    Uploaded by

    Youssef
    The document discusses a pilot project in Bangalore, India to reduce unaccounted for water (UFW) through rehabilitation of the water distribution system. Key points: 1. UFW in Bangalore is approximately 50% of water supply volume, resulting in high costs and low water pressure. 2. The pilot project covers 30 km2 and will establish district metering areas, inspect/replace meters and connections, detect leaks, and rehabilitate pipelines to reduce UFW. 3. Initial results are promising, with UFW reduced to 53-70% in some areas through leak detection and network restructuring based on hydraulic analysis.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd
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    of 5

    UNACCOUNTED FOR WATER (UFW) REDUCTION & CONTROL

    AND
    WATER DISTRIBUTION SYSTEM REHABILITATION (WDSR)

    Mr. Takeru Tsuchiya


    Engineer, Advisor, Division 3, Sector Strategy Development Department
    Japan Bank for International Cooperation
    1. Background
    Bangalore Water Supply and Sewerage Board (BWSSB) proposes to draw the final
    installment of allocated water from River Cauvery under Cauvery Water Supply
    Scheme(CWSS) Stage Ⅳ , Phase Ⅱ . Government of Karnataka (GoK) in India has
    allocated 1,469 Mld of Cauvery Water to BWSSB. Under CWSS Stages Ⅰ, Ⅱ, and Ⅲ,
    BWSSB is drawing about 614 Mld of raw water. OEFF funded, now known as Japanese
    Bank for International Cooperation(JBIC), CWSSB Stage Ⅳ, Phase Ⅰat the final stages of
    completion. Water supply components have been already commissioned and an additional
    315 Mld is being drawn from Cauvery river. Under CWSS Stage Ⅳ Phase Ⅱ, BWSSB
    proposes to draw the balance 540 Mld.
    Bangalore, the capital city of Katnataka state, is one of the fastest growing cities in India.
    The present population of about 5,7 million is expected to increase to over 7 million by the
    year 2011 and the area covered by the city is projected to increase from the present 446 km2
    to 594 km2 in the same period.

    Meanwhile, the major problem BWSSB is facing at present is the high level of
    unaccounted-for water (UFW). UFW rate is estimated at approximately 50 % of water supply.
    These high losses increase the cost of supply and contribute to the substantial operating
    subsidies required from GoK. As a consequence of high UFW, especially due to leakage,
    consumers are not able to obtain sufficient quantity of water with adequate pressure for their
    needs. The water supply duration in the project area is around 6 hours on alternative days.
    Hence it is essential that UFW levels be reduced to acceptable levels as rapidly as possible.
    The additional revenue generated because of reduced leakage/UFW will improve financial
    status and ensure sustainability of waterworks.

    BWSSB has taken up a pilot project in UFW and the estimated cost of the works is
    about Rs 480 Millions. In addition to CWSSB Stage Ⅳ, Phase Ⅰ, JBIC has also funded
    this project , specifically valves, meters and leak detectors, and the consulting services as
    technical assistance.

    1
    2. Description of the Works

    Table. Statistics of the Pilot Project Area


    Pilot Project Area Bangalore
    Area 30 km2 1,279 km 2

    (565 km2 Urban, 714 km2 Greenbelt)


    Population 400,000 4.84 million
    Water supply volume 70 MLD 850 MLD
    No. of connections 32,000 380,000
    Length of mains 302 km -

    The scope of the work includes carrying out UFW survey and remedial measures for
    about 35,000 service connections and 302 km water of Distribution network. The work
    comprises establishment of District Meter Areas (DMAs) within the pilot area for the purpose
    of monitoring of UFW and detection of leakage. Provide bulk meters to measure water
    consumption, inspection of all
    Shut
    Shut! ! Shut
    Shut! !
    consumer meters, fixing of new meters
    on unmetered water connections or on
    connections where meters are not
    working, testing of meters for accuracy,
    recording of consumptions on revenue M
    meter to measure water supplied to
    the consumers. The difference
    DMA
    DMA
    between the input into DMA and water
    Valve Boundary Valve
    supplied to consumers is the total loss
    of water in the DMA. Decide Pipe M District Meter
    DMA is established with boundary valves which make DMA
    permissible loss to get target levels
    hydraulically isolated and limit inflow/outflow points of DMA.
    and carryout leak detection survey, At limited inflow/outflow points, district meter will be installed
    identify leaks, repair leaks and retest to measure inflow volume of DMA accurately. UFW can be
    calculated as shown below.
    the DMA till loss of water is reduced to UFW = [Inflow to DMA] – [Consumption in DMA (billed
    target leakage level. amount)]
    Figure. Concept of DMA
    Also, carryout condition
    assessment survey of water distribution network in the DMA / pilot area and rehabilitate
    water pipelines prone to leaks.

    Work also includes renewals/replacement of service connections using MDPE pipes where
    necessary.

    2
    Design of DMA shall be done with the aid of computer network models, high level model
    covering the project area and low level models for each DMA to ensure and demonstrate
    that the proposed DMA establishment works will be able to maintain adequate hydraulic
    capacity of the DMA under 24 hours satisfied demand conditions as well as ensuring no
    unacceptable detrimental impact on supplies to areas adjacent to the DMA. The boundary of
    the DMA shall be watertight.

    Circulating valves, i.e. those


    valves that are closed in order to
    remove all loops from within the DMA
    thus producing a tree-like mains
    layout, shall be identified and new
    valves installed where necessary,
    which will make leakage detection
    works more easily and efficiently.

    The size and extent of areas


    within the DMA that can be
    progressively isolated in order to
    identify leakage levels across the
    DMA shall be determined to minimize
    the need for step valves
    commensurate with best step-testing Figure. DMA
    practice. New step valves shall be installed where necessary.

    3. Current Status of the Project


    Progress of the project is about 60 % as of the end of May. 2004. The current result is
    encouraging. In progressed DMA (DMA-3A), UFW has been reduced down to 53% of initial
    volume. Besides in DMA-1, UFW has been reduced down to 54%. And in DMA-3C, UFW
    has been reduced down to 70%. The status of the project is based on the data prepared by
    BWSSB and its consultant team.

    3
    Leakage Restructuring distribution networks
    UFW rate is estimated at 50% of water supply volume Based on the hydraulic analysis, restructuring work
    such as re-connection etc, is being done so as to
    ensure optimal water pressure within DMAs.

    Installation work of DM (district meter) Installation work of DM


    Bulk meters, called district meter, are installed at inlet Water flow meter (right) and Pressure gauge (left)
    points of DMAs to measure supply volume to
    eachDMA.

    Revenue meter box


    To prevent physical damage, water meter is installed
    with meter box.

    4
    Site survey
    Confirm the data on existing facilities such as location
    Data logger box
    of valves, junctions of distribution pipes, house
    connections, etc.
    Monitoring actual water flow and pressure, DMA
    design is reviewed.

    Listening stick Pressure gauge


    Checking watertight of boundary valves of DMA. Pressure gauges are installed at strategic points of
    DMA should be hydraulically isolated. DMA in order to know water supply condition. Logged
    data is used for computer simulation model and design
    review.

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