Inequitable Water Supply in Developing Countries - Factors and Feasible Solutions

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1 IWA Water Loss Conference Water Loss 218, Cape Town, South Africa Inequitable Water Supply in Developing Countries - Factors and Feasible Solutions 7 th May, 218 Roshni Gopal, Avi Anthony Cornelio Research & Development Center, Hitachi India Pvt. Ltd. Hitachi India Pvt. Ltd All rights reserved.

1.1 Scenario in India (1/2) Water utilities in India are spread across regions with service level benchmarks mandated by the Government of India Mathura Bhopal Varanasi Ahmedabad ajkot Jodhpur Indore

4 1.1 Scenario in India (1/2) Water utilities in India are spread across regions with service level benchmarks mandated by the Government of India Mathura Bhopal Varanasi Ahmedabad ajkot Jodhpur Indore Kolkata Surat Nagpur Vishakhapatnam Nasik Mumbai Vijayawada Bangalore Chennai Some water utility locations across India Amritsar Chandigarh NRW : Non-Revenue Water lpcd : litres per capita per day 1 2 Indicator Coverage of water supply connections Per capita supply of water Benchmark 1% 135 lpcd 3 Extent of NRW 2% 4 Extent of metering 1% 5 6 Continuity of water supplied Efficiency in redressal of customer complaints 24 hours 8% 7 Quality of water supplied 1% 8 Cost recovery 1% 9 Efficiency in collection of water charges Source: (1) (2) Improving urban services through service level benchmarking document, Ministry of Urban Development, Govt. of India, 21 (3) 27 Benchmarking and data book of water utilities in India 9% 3

Litres per capita per day (lpcd) Bhopal Bangalore Amritsar Indore Chennai Nashik Rajkot Vishakhapatnam Kolkata Varanasi Chandigarh Ahmedabad Mumbai 1.

5 Litres per capita per day (lpcd) Bhopal Bangalore Amritsar Indore Chennai Nashik Rajkot Vishakhapatnam Kolkata Varanasi Chandigarh Ahmedabad Mumbai 1.2 Scenario in India (2/2) Litres per capita per day (lpcd) in water utilities differs from the service level benchmark of 135 lpcd 2 15 Service level benchmark = 135 lpcd Water utilities Utilities with < 135 lpcd Utilities with > 135 lpcd Source: 27 Benchmarking and Data Book of Water Utilities in India lpcd : litres per capita per person 4

6 1.3 Objective of Study Issue Inequitable supply in water distribution network during intermittent supply Objective Identify factors and feasible solutions for achieving equity during intermittent supply 5

2.1 Inequitable Water Supply (1/2) Inequitable supply is the condition when (a) some areas get supplied with more or less water than the required demand (b) lpcd of distribution areas is less or more

8 2.1 Inequitable Water Supply (1/2) Inequitable supply is the condition when (a) some areas get supplied with more or less water than the required demand (b) lpcd of distribution areas is less or more than target (135) S = 1 m 3 /d D = 12 m 3 /d Area-1 Water P Treatment Flow control Plant Pump Reservoir valve Note : Representative network & values S : Supply; D : Demand; lpcd : Litres per capita per day S = 12 m 3 /d S = 11 m 3 /d D = 13 m 3 /d Area-2 D = 9 m 3 /d Area-3 Area Demand (m 3 /d) Supply (m 3 /d) Remarks Inequity present Supply < Demand Yes Supply < Demand Yes Supply > Demand Yes 7

10 3.1 Topography Topography or elevation in distribution network affects equitable supply Area Reservoir 1 E = 74m E = 725m 2 E = 735m Area Elevation (E) Inequity reason 1 2 > 3 > 1 F, P affected F : Flow; P : Pressure; E : Elevation 3 E = 73m Note : Representative network 9

3.2 Bulk Supply Shortage Bulk supply shortage affects equitable supply At design stage

demand of 7 MLD Production capacity = 85 MLD P Pump Valve Note : Representative network

supply shortage Water Treatment Plant P Pump Valve Flow Pressure Population increase

11 3.2 Bulk Supply Shortage Bulk supply shortage affects equitable supply At design stage Water Treatment Plant Production capacity designed considering 15% losses of projected demand of 7 MLD Production capacity = 85 MLD P Pump Valve Note : Representative network & values Supply Area Flow Pressure Demand = 7 MLD After few years Supply Area Bulk supply shortage Water Treatment Plant P Pump Valve Flow Pressure Population increase Leakage present Production capacity = 85 MLD MLD : Million Litres per Day Inequity Demand = 9 MLD 1

12 3.3 Leakage in Transition Network Leakage in transition network affects equitable water supply When supply at same time to areas, Rehabilitated area-1 (new network) Non-rehabilitated area-2 (old network with leakage) Reservoir Valve S : Supply D : Demand L : Leakage Rehabilitated area-3 (new network) Area Status Inequity reason 2 Non-rehabilitated S = D + L, S 1,3 Rehabilitated S, S D 11

14 4.1 Solutions for Achieving Equitable Supply Solutions to achieve equity Supply rotation Flow control using flow control valve (FCV) Pressure management using pressure relief valve (PRV) Check for solution feasibility using intermittent supply PDD hydraulic model PDD : Pressure Driven Demand 13

15 Pressure (H) Supply Supply 4.2 Intermittent Supply PDD Hydraulic Model Pressure Driven Demand (PDD) concept helps to analyze intermittent water supply over conventional scenario Continuous Water Supply Demand Time 24h Service Pipe WDN Junction Intermittent Water Supply Tank Time 24h WDN Junction 14

5.1 Network Considered in Study (Base PDD Model) The pressure driven network considered in this study consists of 3 areas Area-1 Area-2 Source tank Consumer tanks introduced Area-3 Sr.

17 5.1 Network Considered in Study (Base PDD Model) The pressure driven network considered in this study consists of 3 areas Area-1 Area-2 Source tank Consumer tanks introduced Area-3 Sr. No Simulation Condition Supply period Head loss equation Consumer tanks 3 hours (6 a.m. to 9. a.m.) Hazen - Williams Height = 1 m Virtual network 4 Source tank Height = 6 m Area 1 Area 2 Area 3 No of nodes No of connections No of consumers Demand required (m 3 /day) PDD : Pressure driven demand 16

5.2 Base PDD Model Analysis Representative PDD model is developed to analyze feasibility of equity solutions Base PDD network before solution Area-1 Demand 15 [VAL 135 UE] Area-1 satisfaction(%) 1 5

18 5.2 Base PDD Model Analysis Representative PDD model is developed to analyze feasibility of equity solutions Base PDD network before solution Area-1 Demand 15 [VAL 135 UE] Area-1 satisfaction(%) Area-2 Supply lpcd 8 (m3/day) 3 /d) 99 Target Actual Area-3 Inequity present 2 Area Supply (m3/day) 3 /d) Target 135 lpcd Inequity present Actual PDD : Pressure driven demand Area-3 Supply (m3/day) 3 /d) 135 lpcd Inequity present Target Actual Inequity exists in all 3 areas Lpcd : Litres per capita per day; PDD : Pressure driven demand 17

19 Equity achieved Equity achieved Equity achieved 5.3 Case-1 Supply Rotation Solution Inequity in the network can be solved by supply rotation solution Network at 7 a.m. Supply only to area 1 15 Area Supply period : 6-7 a.m 5 Supply Network at 8 a.m (m3/day) /d) Demand 2 Area-2 satisfaction (%) 1 81 Supply to area-2 6 Supply period : 7-8 a.m. 7 Supply 8 (m3/day) /d) Network at 9 a.m Area Supply only to area-3 Supply period : 8-9 a.m Target lpcd lpcd Supply lpcd (m3/day) 3 /d) Before solution After solution 18

20 5.4 Case-2 FCV Solution Flow control valves (FCV) are used to solve inequity in the network [VAL Area Network after FCV solution UE] Area-1 Supply (m3/day) 3 /d) lpcd Equity achieved Area-2 Demand satisfaction (%) FCV Area Area Supply lpcd (m3/day) 3 /d) Equity achieved 2 1 Area Supply (m3/day) 3 /d) 135 lpcd Equity achieved Target Before solution After solution 19

21 5.5 Case-3 Pressure Management using PRV When leakage of 34% is introduced in area-3, PRV is used to reduce leakage and also to maintain demand satisfaction in the zone Network after PRV solution Demand satisfaction (%) Target Before solution After solution PRV Zone-3 [VAL UE] [VAL UE] 6.75 Supply (m3/day) 3 /d) leakage(%) Equity maintained in all zones Leakage reduced from 34% to 22% using PRV PRV : Pressure Relief Valve 2

23 6.1 Conclusion Equitable water supply is a service level benchmark for water utilities in India In this study, some factors causing inequity such as topography, bulk supply shortage, presence of leakage in transition network are discussed With the proposed pressure driven hydraulic modeling technique, equity and demand satisfaction at each consumer junction can be visualized Feasible solutions to achieve equitable water supply proposed are Case 1: Supply rotation technique Case 2: FCV Case 3: PRV Though prior arts are available, such as equity in intermittent supply through optimal tank sizing, layout, the proposed equitable water solutions are with minimum network intervention identified from PDD hydraulic modelling technique with storage tank With equitable water supply, the benefit to the utility is better customer service and meeting service level benchmark mandated by Government of India 22