Improving international management of leakage the hidden water resource

Transcription

1 4 th BHS International Conference Cranfield University, 30 Aug to 1 Sep 2016 Improving international management of leakage the hidden water resource Allan Lambert Past President, BHS IWA Water Loss Specialist Group Presentation 2016L

2 Presentation Overview How, and why did a Hydrologist get involved in international leakage control? How you can assess the technical leakage management performance of a water Utility Where to get free information, on the web Myths, legends and misinformation

3 A life in water resources 1962 to 1990: Natural water management Hydrologist, Water Resources Engineer, Water Manager in UK River/Water Authorities Hydrometry, multipurpose river regulation, reservoir control rules, groundwater, conjunctive use, operational yield, flood forecasting models (UK and international for WMO) Since 1990: NRW/leakage management Technical Secretary. UK Leakage Control Initiative House of Commons Environment.Committee, drought Chair, IWA Water Loss Task Force Fellow, IWA Water Loss Specialist Group Leakage consultancy projects in 30 countries LeaksSuite free to all website as legacy project 15,000 users

4 1 st IWA Water Loss Task Force Representatives: UK, USA, Japan, Germany Objectives: recommend a standard international water balance terminology review performance indicators for international comparisons of losses in water supply systems concentrate on Real (Physical) losses comparisons based on traditional PIs (%, per km, per property) shown to have serious limitations develop a PI for international performance comparisons Conclusions published in AQUA Dec

5 International Tools for Practical Leakage Management Key to colours Development and testing Implementation Concepts UK Leakage Control Initiative IWA 1st Water Loss Task Force IWA 2nd Water Loss Task Force IWA Water Loss Specialist Group Component analysis of Real Losses (Bursts and Background Estimates, BABE) Economic Leakage Levels using minimum total cost approach without pressure management) Pressure: leak flow rate relationships: Fixed and Variable Area Discharges, FAVAD Developed by John May Night flow component analysis using BABE & FAVAD concepts IWA Best Practice International Water Balance and Terminology IWA recommended Key Performance Indicators (KPIs) for Non Revenue Water and Real Losses How low could you go? System-specific equations for Unavoidable Annual Real Losses UARL, and Infrstructure Leakage Index ILI Economic Intervention Policy for Active Leakage Control based on rate of Rise of Unreported Leakage Use of Confidence Limits in Water Balance and Night Flow calculations World Bank Institute Banding System for assessment of Real Loss Technical Management Performance and appropriate actions for improvement Economic Leakage Levels with and without pressure management Pressure: burst frequency relationships Quick predictions for systems with high initial burst frequency A more generally applicable 2-part equation with a non-pressure-dependent component Influence of reduced burst frequency on annual repair costs, extension of residual infrastructure life and economics of pressure management

6 IWA WATER LOSS SPECIALIST GROUP CONFERENCE STATISTICS

7 Presentation Overview How and why did a Hydrologist get involved in international leakage control? How you can assess the technical leakage management performance of a water Utility Where to get free information, on the web Myths, legends and misinformation

8 The 5 blind men and the Elephant It s A Hill It s A Snake It s A Tree It s A Wall It s A Donkey

9 The Performance Indicators Elephant M3/km of mains % (of what?) Litres/ property Litres/ connection UARL and ILI A spin-doctors dream!

10 3 ways to assess Water Losses Catchment Area Evaporative Losses Annual water balance Precipitation minus streamflow Field measurements Lysimeters Component Analysis Penman and similar formulas using key parameters (1946 on) Leakage in Distribution Systems Annual water balance Distribution Input minus consumption Field measurements Minimum night flows Component Analysis Background & Bursts Estimates concept (1994)

11 Component Analysis for Etp, and Leakage Type of Land Surface Trees Grassland Open Water Sum Evapo-transpiration Transpiration Interception Direct evaporation Sum T1 T2 T3 T1 + T2 +T3 G1 G2 G3 G1 + G2 + G3 UW1 0W2 OW3 OW1+OW2+OW3 T1 + G1 + UW1 T2 + G2 + OW2 T3 + G3 + OW3 Total Etp PENMAN Can specify calculation parameters but difficult to influence Infrastructure Component Service conns, main to meter Mains Utility Customer Sum Undetectable Background Leaks Length, rate per km/hr Number, flow rate per hour Number, flow rate per hour Components at a specified standard pressure (50 metres) Reported bursts and leaks Frequency, run time, flow rate Frequency, run time, flow rate Frequency, run time, flow rate Unreported bursts and leaks Frequency, run time, flow rate Frequency, run time, flow rate Frequency, run time, flow rate M1 + SU1 + SC2 M2 + SU2 + SC2 M3 + SU3 + SC3 Compare with Assessment from Water Balance Sum M1 + M2 + M3 SU1 + SU2 + SU3 SC1+SC2+SC3 Sum of Real Loss Components Real Losses from Water Balance LEAKAGE Can record calculation parameters + influence pressure, run times and frequencies

12 Most people think mains bursts are the largest source of Real Losses. Is this true? Reported mains bursts are usually less than 15% of annual real losses volume!

13 A Simple New Zealand Example of a Component Analysis of Annual Real Losses BABECalculationof Real Losses Background Reported Unreported Leakage Bursts Bursts Total m 3 x10 3 /yr m 3 x10 3 /yr m 3 x10 3 /yr m 3 x10 3 /yr Mains ServiceConns Totals Estimatefrom'Benchloss' Annual WaterBalance= 1596 Each component is separately assessed based on Utility-specific data and policies

14 Unavoidable Real Losses equations concepts and parameters Approach used identify how low could you go? for well maintained infrastructure in good condition Foundation concepts used were first developed in 1994: Component analysis using Background and Bursts Estimates pressure:leak flow rate relationships using FAVAD (Fixed and Variable Area Discharges) 15 auditable parameters used unavoidable background leakage, reported and unreported burst frequencies, typical flow rates of bursts and leaks at 50 metres pressure, average run times with perceived good management 4 key parameters identified number of service connections, location of meter average pressure, mains length

15 Parameters used for calculating Unavoidable Leakage at 50m pressure Table 1 of paper: same data as 1999 AQUA paper but with improved format Infrastructure Component Unavoidable Background Leakage Detectable Reported Leaks and Bursts Detectable Unreported Leaks and Bursts 12.4 bursts/100 km/yr. 0.6 bursts/100 km/yr. On Mains 20 litres/km/hr at 12 m 3 /hr for 3 days at 6 m3/hr for 50 days = 864 m 3 /burst = 7200 m 3 /burst On Service Connections, Main to Property Line 1.25 litres/conn/hr 2.25/ 1000 conns/yr. at 1.6 m 3 /hr for 8 days = 307 m 3 /burst 0.75/1000 conns/yr. at 1.6 m 3 /hr for 100 days = 3840 m 3 /burst On Service Conns from Property Line to meter, if customer meter is not located at the property line 0.50 litres/conn/hr* 1.5/ 1000 conns/yr.* at 1.6 m 3 /hr for 9 days = 346 m 3 /burst 0.50/1000 conns/yr*. at 1.6 m 3 /hr for 101 days= 3878 m 3 /burst * For average length of 15 metres

16 Influence of pressure on leakage Fixed & Variable Area discharges (FAVAD, 1994) Leak flow rate varies with pressure to the power N1 N1 = 0.5 for leaks with fixed area, N1 = 1.5 for leaks where area varies with pressure Use N1 = 1.0 (linear) as average for most systems Burst frequency BF on mains and services (2011) has small pressure-independent component pressure-dependent component varies with Pmax 3 separate calculations for mains and services essential with pressure, every metre counts!

17 How Low Could Your Leakage Go? UARL formula using Lc (main to meter) Unavoidable Annual Real Losses in m 3 /yr UARL (m 3 /year) = (6.57 x Lm x Nc x Lc ) x P Main length Lm km Number of conns Nc Average Pressure (metres) Length of underground connections main to meter Lc km

18 UARL in m 3 /year is easy to calculate Enter mains length Lm km, Number of service connections Nc, length of services main to meter Lc, average pressure P metres UARL m 3 /year = (6.57 x Lm x Nc x Lc) x P Distribution System Service Connections, Average Unavoidable Annual Real Losses Mains Conns main to meter pressure UARL per km Lm Nc Length Lc P m 3 x10 3 m 3 /km of litres/ service of mains km Number m/conn km metres per year mains/day conn/day A B C D But UARL in m 3 /km mains/day or litres/conn/day varies quite widely If you can reduce excess pressure P you can reduce UARL UARL may be lower if Nc < 3000, or if flexible pipes and P < 35m

19 Simplified IWA Water Balance showing Water Exported

20 UARL calculation based on mains length, number of services, customer meter location and average pressure Pressure Management Management ILI = CARL/UARL Speed Active and Quality Leakage of Repairs Control Unavoidable Annual Real Losses UARL Speed Active and quality Leakage of repairs Control Current Annual Real Losses CARL calculated from annual water balance Pipeline and PipeAssets Materials Management: Management: selection, Selection, installation, maintenance, Installation, Maintenance, renewal, replacement Renewal, Replacement

21 ILIs for 71 Systems in 10 European High Income Countries (2014)

22 European ILIs data set (2014) 83 systems in 15 countries European country ILI data sets Denmark 36, Austria 25, Croatia 19, Portugal 9 Australasian ILIs: Australia 65, New Zealand 6 North American ILIs AWWA 26, Georgia 107, Canada 33 More country ILI data sets are being added every year

23 Which Leakage KPI should I use? Evidence-based conclusions from 16 EU Case Studies Good Practices on Leakage Management Case Study document._final.pdf OBJECTIVE SET TARGETS AND TRACK PERFORMANCE, FOR AN INDIVIDUAL SYSTEM TECHNICAL PERFORMANCE COMPARISONS OF DIFFERENT SYSTEMS DRAW GENERAL CONCLUSIONS FROM SINGLE OR MULTIPLE SYSTEMS GOOD PRACTICE PERFORMANCE INDICATOR FOR LEAKAGE, FIT FOR PURPOSE Volume per year YES, for large systems litres/ service connection YES* m 3 /km mains YES* litres/ billed property YES (UK) % of System Input Volume NO % of Water Supplied NO Infrastructure Leakage Index, with Pressure Only if all justifiable pressure management completed NO NO NO NO NO NO YES NO NO NO NO NO NO YES, together with other context factors * Choose services connection density > 20/km; if not, choose mains; or base choice on country custom and practice Each Leakage KPI (except % of System Input Volume or Water Supplied) is suitable for some purposes, but not other purposes

24 Summary: Performance Indicators for Leakage (Real Losses) Use litres/conn/day or m 3 /km/day for tracking performance of individual systems but not for comparisons of performance between systems and sub-systems with different characteristics Use ILI for comparisons of technical performance at current pressure between sub-systems within a larger system, or between Utilities and countries Reduce pressure transients and excess pressure as much as possible, and remember that every metre counts.

25 Presentation Overview How, and why did a Hydrologist get involved in international leakage control? How you can assess the technical leakage management performance of a water Utility Where to get free information, on the web Myths, legends and misinformation

26 Where to get more Information free, on the web HOME WHATS NEW ABOUT US CONCEPTS OUTREACH FREE SOFTWARE SPONSORS CONTACT US BLOGS Archive Activities Component Analysis Free Papers & PPTs 3 Global Support FAVAD and N AZP&NDFCalcs Allan Lambert IWA Water Balance ILMSS KPI WLR&A UARL and ILI Real Loss Overview Up to 2007 Economic Intervention Pressure and Bursts Economic Leakage 9 65 EurWB&PICalcs 5 18 < ---Recently created Info-Hubs on Specific Topics ---> INFLUENCES OF PRESSURE KPIs FIT FOR PURPOSE APPARENT LOSSES GLOBAL ILIs JO-APPS JO-APPS 1 Free Software 1 Free Software Outreach (App Loss) Australian 1 Blog 8 Blogs Europe + Austria, Croatia, Denmark, 1 Guideline Portugal 6 Case Studies 15 Papers/Articles 9 Global ILIs 18 Papers/Articles 23 Papers North America AWWA + Canada, Georgia 13 PPT Presentations 14 PPT Presentations 2 PPT Presentations IWA Water Balance Snapshot ILI Night Day Factor FAVAD N1 Test Night Flow Analysis 9 ILI data sets 3 Jo-Apps As at 24th Feb 2016

27 Thanks for your interest Questions? Myths, Legends and Misinformation next if time allows, or explore them yourself If you can t find what you want on the website, ILMSS@live.co.uk and ask If I have it, I ll tell you where it is If I don t, I may know where you can find it

28 Myths, legends and mis-information Does most leakage occurs on mains so small leaks on service pipes don t really matter? see Slides 12 and 13 Is 10% leakage 5 x worse than 2% leakage?: Slide 29 Is 8% leakage much better than 13% leakage: Slide 29 Can you track & compare leakage in % terms? Slide 30 Is there no convincing relationship between pressure and mains repair frequency? (UK 2003): Slides 31 to 35 Do rota cuts save water during droughts? Lemesos Case Study in ment%20-%20case%20study%20document._final.pdf

29 Percentages damage your perception Is 10% leakage 5 times worse than 2%? Tokyo has 2% leakage Yarra Valley Water (Melbourne) has 10% leakage but both have ILI ~ 1.0, excellent performance but Yarra Valley has much lower consumption and significantly higher pressure due to topography! Is 8% leakage much better than 13%? the two %s are same Utility (a European capital city) 8%: if system input volume includes water exported 13%: if system input volume excludes water exported which % do you think they do (or don t) like to quote? how would you know the difference?

30 I want to track and compare leakage in % terms, because everyone understands %s (!) Germany stopped using %s over 30 years ago, because of influence of changes in consumption see UK regulator (OFWAT) stopped in 1996, same reason, but from time to time others think they know better.. Leakage as a % of System Input Volume is a Zero-Sum Indicator: what does that mean? Should I be concerned? see where you can download Play the %s game software and see for yourself

31 Reduction of Excess Pressure: UK examples Effect on bursts was not noticed when pressure reduced in 2002; only identified in 2005 as part of IWA group study Source: David Pearson & Crowder & Co (Netbase)

32 Source: David Pearson & Crowder & Co (Netbase) Effect on bursts was not noticed when pressure was reduced in 2002; only identified in 2005 as part of IWA group study

33 Source: David Pearson & Crowder & Co (Netbase) Effect on bursts was not noticed when pressure reduced in 2002; only identified in 2005 as part of IWA group study

34 2004: Gold Coast, Burleigh Heads Pilot Scheme: Gravity System, 3300 services, Inlet pressure reduced by 30% (72 metres to 50 metres) Burleigh Waters - W DM Pilot Area Daily Minimum Night Flows Average MNF 6.20 l/sec Average MNF 4.13 l/sec Average MNF 3.77 l/sec Average MNF 3.44 l/sec Average MNF 3.25l/sec 7.00 Daily Minimum Flow (l/s Repairs Complete trendline Night flow reduced from 6 litres/sec to 3 litres/sec Fixed Outlet Pressure Control Commissioned 16/09/03 Flow Modulation Pressure Control Commissioned 01/12/03 Flow Modulation adjustment 08/01/04 Night time pressure outlet reduced to 32m during mimum night flows Flow Modulation second adjustment to controller 28/01/04 Best a chieve d MN F 2.20 litres/sec /08/ /08/2003 5/09/ /09/ /09/ /09/ /09/ /09/2003 5/10/ /10/ /10/ /10/ /10/ /10/2003 4/11/2003 9/11/ /11/ /11/ /11/ /11/2003 4/12/2003 9/12/ /12/ /12/ /12/ /12/2003 3/01/2004 8/01/ /01/ /01/ /01/ /01/2004 2/02/2004 7/02/ /02/ /02/2004 Days B u r le ig h D M A /P M A M a in t o M e t e r C o r r e c t iv e M a in t e n a n c e S e r v ic e B r e a k s M a in s B r e a k s R e d u c t io n in S e r v ic e B r e a k s 7 5 % R e d u c t io n in M a in s B r e a k s 7 1 % Mains repairs reduced by 71% Service pipe repairs reduced by 75% 0 Mar-99 Jun-99 Sep-99 Dec-99 Mar-00 Jun-00 Sep-00 Dec-00 Mar-01 Jun-01 Sep-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Mar-05 No. Breaks M o n t h

35 .. and the savings continue, 10 years to date

36 More slides that may interest you Key questions rarely asked Component Analysis: background leakage, reported leaks, unreported leaks Volume lost = flow rate x run time compare volume lost per burst for the examples N1 varies with pipe material and leak type LEAKSSuite website statistics to June 2016 Much more availabe at

37 Key questions rarely asked What s your Utility s average pressure? how did you calculate it? How many service connections? usually different to (less than) billed properties what s the total length and repair frequency? If leakage is quoted as a %: what s your consumption in litres/conn/day? does it include water exported? can I see your water balance?

38 Component Analysis: background leaks, reported leaks and unreported leaks Acknowledgement: Jairo Tardeli Filho, Sabesp, Brazil

39 Volume lost = flow rate x run time

40 N1 varies with pipe material and type of leak Fixed area leaks: N1 = 0.5 Ring cracks Longitudinal splits in rigid pipes. Variable area leaks: N1 = 1.5 Undetectable small background leaks at joints and fittings Splits in flexible pipe Acknowledgement: Ken Brothers, Canada Holes drilled in pipes (irrespective of material) Corrosion holes Acknowledgement: van Zyl, South Africa Acknowledgement: Tardelhi Filho - SABESP

41 Source: Updated every 3 months, in Blogs Section

42 Source: Updated every 3 months, in Blogs Section ANALYSIS OF LEAKSSUITE WEBSITE FROM 1st JAN 2013 TO 31st MAR 2016 ALL REGIONS USERS BY GOOGLE REGIONS EUROPE AMERICAS ASIA AFRICA OCEANIA TO 30 JUN 2016 USERS QUARTERLY INCREASE 20% 18% 23% 21% 27% 18% COUNTRIES AVERAGE USERS/COUNTRY