Presented by: Willem Wegelin WRP Consulting Engineers Modified IWA water balance

Transcription

1 Presented by: Willem Wegelin WRP Consulting Engineers Modified IWA water balance 1

2 NO DROP CERTIFICATION Incentive-based regulation BLUE DROP NO DROP GREEN DROP 1 WSP 1 Strategy, planning & implementation 1 W 2 RAP 2 Asset management 2 Asset management 2 Asset management 3 Technical skills 3 Technical skills 3 Technical skills 4 Credibility and accountability 5 Compliance 5 4 Credibility and accountability Compliance & Performance 4 Credibility and accountability 5 Compliance 6 Local regulation 6 Local regulation 7 Customer care 2

3 Objectives of No Drop certification To change behaviour towards improved water use and water demand management by municipalities To reduce water loss and increase water use efficiency To use credible data to report against defined targets To benchmark within defined municipal- and performance clusters and/or contribute to sector-wide benchmarking initiatives STATE OF NRW / WATER LOSSES IN SA (2009/10 data) (2011/12 data) (2011/12 data) (2011/12 data) (2011/12 data) 3

4 STATE OF NRW / WATER LOSSES IN SA (2012/13 data) (2012/13 data) (2012/13 data) 8 (2011/12 Large Systems data) (2014/15 data) (2011/12 data) 8 Large Systems 8 Large Systems Non-delegated (2015/16 data) (Dec 2016 data) (2015/16 data) National (2015/16 data) WATER LOSS BENCHMARKING 4

5 Basic principles The IWA water balance should provide a true reflection of the water use efficiency, water loss and non-revenue water in a distribution system The water balance should be based on actual data with minimum estimation All information must have an audit trail The water balance is based on the potable water supply (system input volume) and does not allow for treatment losses The water balance is a volumetric balance and does not include non-payment Modified IWA water balance 5

6 Authorised connection? - Yes unmetered and informal - Usually installed out of desperation or convenience - No installed by user - Yes utility allows user to continue using the connection Number of connections A connection is defined as any formal or accepted point of water supply = no intension of disconnecting All other connections should be considered unlawful and removed This means all users supplied with potable water must have a metered or unmetered connection Use number of accounts from billing system - No of meters distorted by combination meters - No households no of connections - No stands = no of connections (outdated cadastral) 6

7 Connection decision flow chart Connection Authorised Unauthorised Metered Unmetered Illegal connection Billed Unbilled Remove or formalise Authorised consumption Water losses Mains leakage Metered Billed Water Losses 7

8 Connection leakage (before meter) Metered Billed Water Losses House connection Metered Billed Authorised Metered Billed 8

9 Internal Plumbing Leakage Metered Billed Authorised Metered Unbilled Yard connection Metered Billed Authorised Unmetered Unbilled 9

10 Tanker supply Metered Billed Authorised Metered Unbilled Inefficient water use and wastage Metered Billed Authorised Metered Unbilled 10

11 Live stock watering Metered Billed Unauthorised Connection - Remove Public stand pipe Metered Billed Authorised Metered Unbilled 11

12 Informal connection Metered Billed Authorised Unmetered Unbilled Water loss or Authorised consumption Reticulation (Government) Stand (Consumer) Connection Before connection Water losses Commercial losses Physical losses After connection Authorised consumption Meter or unmetered Billed or unbilled 12

13 Modified IWA water balance After the connection Before the connection EXAMPLES 13

14 Indigent water user (metered) Actual use = 18 kl/month Free Basic Water = 6kl/month Balance = 12 kl/month Metered billed (billed at zero rate) Metered unbilled Flat rate water user (unmetered) Estimated actual use = 22 kl/month Flat rate consumption = 10 kl/month Balance = 12 kl/month Unmetered billed Billed for 10kl/month (Includes FBW) Unmetered unbilled 14

15 KEY PERFORMANCE INDICATORS Key Performance Indicators Litres / capita / day Losses m 3 / connection / day Losses m 3 / km mains / day % Non-revenue water Infrastructure Leakage Index - Current Annual Real Losses Unavoidable Annual Real Losses 15

16 Litres / capita / day 3 Ml/d WTW 4 Ml/d Formal water supply areas water users Formal water supply areas water users 300l/c/d l/c/d 1 Ml/d Informal water supply areas water users 60 l/c/d Unavoidable Annual Real Losses UARL = ( 18 x Lm x Nc + 25 x Lp ) x P Length of mains Number of service connections Length of underground pipe:- not used in South African cases Average operating pressure 16

17 Households per connection Average system pressure (m) Length of mains (km) 29/08/2017 Infrastructure leakage index (ILI) ILI = CARL UARL CURRENT ANNUAL REAL LOSSES CARL = system input volume components of authorised consumption - apparent losses UNAVOIDABLE ANNUAL REAL LOSSES UARL = (18 x Lm x Nc + 25 x Lp) x P The ILI provides an indication of the actual physical leakage versus the expected minimum level of leakage For example, an ILI of 4 indicates that the physical leakage in the distribution network is 4 times higher than expected. Metro No Drop basic information Metered connections: Unmetered connections:

18 No Drop Score Real losses (m 3 / km mains /day) Infrastructure Leakage Index Real losses (m 3 /connection/day) Connections / km mains 29/08/2017 Metro No Drop Results 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Good Average performance 45% 42.3% 39.5% 40.9% 39.4% 83.5% 40% 37.8% 76.0% 75.0% 70.5% 67.6% 67.3% 35% 31.4% 56.7% 54.9% 30% 25% 21.1% 23.6% 20% 15% Average No Drop score = 69% 10% Average NRW = 34.3% 5% 0% CPT EKU ETH TSH NMB JHB MAN BUF Average l/c/d = Average ILI = Other Physical Water Loss Indicators

19 Infrastructure Leakage Index (ILI) Connection losses (m 3 /annum) 29/08/2017 Density of connections vs ILI ILI = Current Annual Real Losses ( 18 x Lm x Nc) x P Constants Length of mains = 1000 km Average pressure = 50 m CARL = m 3 /annum losses = 110 litres / connection / day connections Connections / km connections CONCLUSIONS 19

20 Misleading IWA Water Balance Authorised consumption Billed metered Billed unmetered Revenue water 50% 50% 50% System input Water loss Apparent loss 20% Real loss Non-revenue water 50% 50% 30% Informative IWA Water Balance Billed metered Billed unmetered Revenue water System input Authorised consumption 73% 50% 50% Water loss 27% Unbilled metered Unbilled unmetered 23% Apparent loss10% Real loss 17% Non-revenue water 50% 20

21 Conclusions Include all authorised connections supplied by the utility in the water balance connection = connection with no intension of disconnecting Losses before the user connections = physical or commercial losses Consumption and losses after the user connection = authorised consumption Review all KPIs to ensure key issues are identified and addressed THANK YOU 21