Report to/Rapport au :


Planning and Environment Committee

Comité de l'urbanisme et de l'environnement


and Council / et au Conseil


6 May 2009 / le 6 mai 2009


Submitted by/Soumis par : Nancy Schepers,

Deputy City Manager/Directrice municipale adjointe,

Infrastructure Services and Community Sustainability/

Services d’infrastructure et Viabilité des collectivités 


Contact Person/Personne ressource : Dixon Weir, General Manager / Directeur Général

Environmental Services Department / Services environnementaux

(613) 580-2424 x22002,


City Wide/à l'échelle de la Ville

Ref N°: ACS2009-ICS-WWS-0012













That the Planning and Environment Committee and Council receive this report for information.




Que le Comité de l’urbanisme et de l’environnement et Conseil prennent connaissance du présent rapport à titre d’information.





The Drinking Water Operations Branch is responsible for the treatment and delivery of the City’s drinking water.  In 2008, the City of Ottawa delivered an average of 297 ML of drinking water from two treatment plants to 815,000 customers on a daily basis.  This report highlights the recent activities of the Water Loss Control program and provides updated performance measures.


The City’s Infrastructure Leakage Index (ILI), a key performance measure of the Water Loss Control effectiveness has been reduced from 4.8 (2007) to 3.7 (2008).  The decrease in ILI is partly attributed to the repair of water distribution components (watermains, services, valves and hydrants) that eliminated approximately 2,500 ML of water losses, resulting in an estimated savings of $155,000.  Another factor attributed to the decrease is the reallocation of apparent losses to authorized consumption from the Water Meter Change-out program resulting in additional revenues of about $88,150.


The report will also highlight the current status of supply side initiatives including apparent and real loss control planned for 2009 for the consideration of the Planning and Environment Committee and Council.





La Division des services de gestion de l’eau potable est responsable du traitement et de la distribution de l’eau potable de la Ville. En 2008, la Ville d’Ottawa a distribué chaque jour une moyenne de 297 millions de litres d’eau potable, en provenance de deux stations d’épuration, à quelque 815 000 clients. Le présent rapport souligne les récentes activités entreprises dans le cadre de la Stratégie de contrôle des pertes en eau et fournit des mesures de rendement à jour.


L’indice des fuites de l’infrastructure (IFI) de la Ville, une mesure de rendement clé de l’efficacité de la Stratégie de contrôle des pertes en eau de notre Ville, est passé de 4,8 (en 2007) à 3,7 (en 2008). Cette diminution de l’IFI est en partie attribuable à la réduction de 10 p 100 des pertes réelles en 2008 comparativement à 2007, ce qui représente des économies évaluées à 155 000 $. On doit aussi cette diminution à la réattribution des pertes apparentes à la consommation autorisée consécutive au programme de remplacement des compteurs d’eau, ce qui a engendré des revenus supplémentaires d’environ 88 150 $.


Le rapport fait également ressortir l’état actuel des initiatives ayant trait à l’offre, notamment le contrôle des pertes apparentes et réelles, prévues pour 2009, aux fins d’examen par le Conseil et le Comité de l’urbanisme et de l’environnement.





The City of Ottawa has been providing drinking water services to residents of the City for over 125 years, and over this time the demand for drinking water has grown with the City’s increasing population.  The drinking water infrastructure required to provide this service has also expanded in order to meet the water demand.  High quality drinking water continues to be provided through an extensive network of infrastructure including water purification plants, booster pumping stations, reservoirs and tanks, watermains, hydrants and service connections.


The relationship between population, water produced and billed consumption from 1980 to 2008 is shown on Figure 1.

The original growth development strategy for the water infrastructure was to expand the system to ensure that adequate capacity (volume and pressure) was available to meet customer demand.  However, it is also recognized that the existing infrastructure must be utilized efficiently and effectively in order to minimize the financial pressures and defer the need of costly plant expansions and the installation of large diameter transmission watermains.


In order to effectively and efficiently utilize existing water infrastructure, the City has developed programs to address both the supply and demand side of the overall water demand equation.  The supply side program update will be addressed in this report.  An update on the status of the demand side program is subject of report ACS-2009-ICS-WWS-0011 that addresses the progress of the water conservation efforts.





The purpose of this report is to present the activities undertaken in 2008 and outline those initiatives that are planned for 2009.  The following is a list of some of the initiatives currently in place or planned for:



§         Regular maintenance of production and distribution water meters;

§         Calibration and monitoring of existing water meters for service water required for treatment;

§         Chemical usage analysis to verify production input volumes;

§         Enhancement to flow reports utilized to monitor water usage in closed pressure zones and communal well systems.



§         Review watermain break repair response procedure;

§         Review the Preventative Maintenance program;

§         Prioritize watermain rehabilitation and replacement needs;

§         Conduct leak detection surveys on local distribution and transmission watermains;

§         Account for all metered and unmetered water usage;

§         Verify the large meter changeout procedure to ensure appropriate priority/use of existing resources;

§         Utilize district metering areas to identify leakage.



§         Report on the recent pilot for the repair of leaks on private property.


Water Balance Summary Report


In 2005, the City adopted the Standard Water Balance as an accounting mechanism to determine the volume of non-revenue water.  The Standard Water Balance Summary Report for 2008 is presented in Figure 2.  Staff continue to account for all water usage from the time the water is treated to the point of consumption.


Figure 2: Standard Water Balance Summary Report



Water Production Volume dropped by 1.8% from 2007 to 2008.  The Revenue Water Volume dropped by approximately 4% during the same period even though there was an increase in serviced population and installation of new watermains of about 1.3%.  The drop in Revenue Water may be attributed to water efficiency strategies, behaviour changes related to outdoor water usage or the increase in the water rate. 


The accounting of the various volumes that are used to determine the Standard Water Balance is improving.  From 2007 to 2008, there has been an increase in the volume of Unbilled Authorized Consumption due in part to a greater awareness and reporting of these unbilled uses.  This component includes the water used for operation and maintenance activities (flushing and commissioning of watermains and hydrant flow testing), temporary service water use and water quality within the distribution system (flushing and blow-offs), fire fighting and water service for City facilities.


When annual System Input Volume figures are compared against Authorized Consumption figures, there was a gap of about 13% in 2008, which is identified in the Water Balance Report as Water Losses.  In comparison, the gap in 2007 was 14.5%, which also indicates that the trend is improving.


The real loss component of the water losses is valued at about $784,300 per year using the marginal cost of water of $0.062/m3.  If it were possible to capture all of the Apparent Losses and reduce this component of the Standard Water Balance to zero, the additional revenue would be approximately $1,972,000[1] per year using the weighted water rate of $1.062/m3 for 2008[2].  It is important to note that a reduction in apparent losses may not lead to real financial savings, since in some cases, the reduction may only be a better accounting and reallocation of volumes within the Water Balance.


However, there are some saving opportunities by identifying unmetered properties and staff will continue to monitor the property tax and water billing databases to identify and rectify any unmetered, unauthorized or illegal water use.  Staff will also continue with such efforts as the Large Meter Change-out program to reallocate water volumes from apparent losses to billed authorized consumption and revenue for the City.


Figure 3 illustrates the trend in average day production by month for the last 3 years.

As shown in Figures 1 and 3, the overall water production has been decreasing in each and every month in spite of a growing population.  While many factors undoubtedly contribute to these reductions, part of the reduction in water production is attributable to the reduction in real losses through the replacement of aging infrastructure and the repair of leaks from the Active Leak Detection program. 


This reduction has been occurring since 2003 with a cumulative drop in the average daily water production of 70 ML since 2003.  All pressure zones have experienced a drop in consumption since 2003 with the exception of growth areas.  The following table (Table 1) illustrates the change by pressure zone. 


Table 1:  Cumulative change in consumption by pressure zone[3] from 2003 to 2008


Pressure zone


Water consumption change


Core – 7,12,14,15,17

-43 ML


West – 3,4,7,8,9,14,15,17

-6 ML


East – 1,2,10,111,12,13,17,18

-9 ML


East – 10,16,17,18,22

-8 ML


East – 1,2,19

No change (growth area)


South – 10,16,19,20

No change (growth area)


West – 4

+1 ML (growth area)


Central – 8,9,16

-2 ML


East – 11,13

-1 ML


South – 3,21,22

No change (growth area)



No change


West – 4,6,28

-2 ML


The top 4 pressure zones listed above with the greatest reduction in consumption account for 83% of the watermain breaks repaired in 2008. 


Staff will also continue to improve the level of confidence of the estimates found in the Water Balance.  The Water Balance is based on some assumptions and staff employs a continuous improvement strategy to increase the level of certainty in the data.  An economic analysis will be performed to optimize our efforts and to help target the level of investment required and determine the next ILI target.


Apparent Losses


Apparent Losses represent a far smaller portion of the water “lost” within the system, but it represents a larger revenue opportunity to the City, depending upon the actual source of those losses.





The Water Loss Control Strategies initiatives that will continue in this area are as follows:


1.      Reduction of Unauthorized Water Usage

The City has assigned some of its resources to closely monitor the use of flusher hydrants by contractors and to ensure the City is properly compensated for the water taken.  Through the course of our normal service delivery, field staff will note and report instances of unauthorized water consumption such as open water meter bypass valves and unauthorized water connections.


The number of infractions subject to enforcement under the water use provisions of the water by-law increased in 2008 over the previous year; hydrant related offenses increased from 12 to 34 and water meter related offenses increased from 17 to 21.


2.      Reduction of Water Meter Under-registration

The Large Water Meter Change-out program in 2008 resulted in additional water revenues due to improved accuracy.  Since it was not possible to determine whether the additional revenue was due to the Meter Change-out program or simply a change in behavioural pattern, the reported efficiency due to the Change-out program has been estimated as being half of the maximum revenue of $176,300 for 2008, which amounts to $88,150.


In 2009, staff will continue to verify that the large meters are sized appropriately for application and recommended replacement as well as confirm the large meter selection procedure to maximize the cost savings from the meter change-out.  As of January 2009, the average age of the compound and turbine meters has been reduced.  The range in age for the compound meters in 2003 was 5 to 8.5 years and it is now 2 to 5 years.  The turbine meter average age has gone from 3 to 8 years to 1 to 5 years.   By routinely performing the large water meter change-out, the accuracy of the large meter population should increase or at the very least, come closer to recording the actual consumption.


3.      Expand the Advanced Meter Infrastructure (AMI) Project

The City plans to award a contract for the supply and installation of a City-wide AMI project in 2009.  The implementation period will take place over two to four years.  The AMI system will replace obsolete meter reading technology and thereby eliminate estimated meter reading values, ensuring that accurate consumption figures are available both for billing and for water balance purposes.


While the main business drivers for the AMI project were improved customer service, financial management and cost effectiveness, a pilot 2007 project proved that advanced metering technology can be used to calculate the amount of distribution system leakage with greater accuracy.  The availability of higher resolution water meter registers and the resultant hourly consumption data will allow the City to leverage the data for a variety of applications, such as: validation of hydraulic models used to project future water system growth, identification of peak water use patterns, monitor the effects of targeted water conservation measures and provide a greater variety of customer service applications.



4.      Reduction of Unmetered Properties

The review of water billing accounts in 2006 and 2007 against the property tax database identified a small number of properties that have been investigated. This is an ongoing exercise to reconcile these data sets to further reduce the potential of unmetered properties.  Other studies have identified potential data gaps.  These records will be brought forward to Billing for further investigation. 


For 2009, staff within the Water Loss Control group will work with Billing to investigate the water use of some of the larger accounts in order to identify water use trends for all customer groups to explain the reduction in Revenue Water.


Real Losses


It is recognized that all real losses cannot be completely eliminated from the distribution system as it would not be cost effective to do so.  The IWA (International Water Association) and the AWWA (American Water Works Association) have developed standard performance indicators based on a water system’s specific characteristics to identify the most achievable level of water loss for that system.  The 2008 performance indicators presented herein confirm that the City is headed towards achieving its water loss objectives, and has in fact achieved its Infrastructure Leakage Index target.


Infrastructure Leakage Index


The Infrastructure Leakage Index (ILI) is defined as the ratio of Current Annual Real Losses (CARL) to the Unavoidable Annual Real Losses (UARL).  It is a ratio comparing current utility performance to its own theoretical lowest level of leakage performance.  It can be used as a comparable performance indicator between water utilities regardless of their size or geographical location. 


The CARL for the City is estimated at 16.3 x 106 m3 for 2008, which reflects the “highest estimated” value, based on current levels of data confidence limits.  The UARL based upon the City’s infrastructure, is calculated as 4.4 x 106 m3 for 2008.


Using the CARL and UARL values noted above, the City’s ILI for 2007 is 3.7 compared to 4.8 in 2007.  In other words, the real losses in Ottawa are 3.7 times more than the lowest technically achievable level of real losses.  The IWA and AWWA guidelines suggest that for service providers that have a water source that is sufficient to meet the long-term needs of the community and have implemented good water control practices and effective maintenance programs, that an appropriate ILI is no greater than 4.0.  The City has met and surpassed that target; which means that the City’s Water Loss Control program is considered to be in the performance status condition known as “Good”.  As mentioned earlier, a strategic review will be undertaken in 2009 to re-evaluate the cost effectiveness of further reducing the ILI target.  This analysis will ensure that future objectives are feasible and cost effective.


In 2007, the Ontario Municipal Benchmarking Initiative started to report ILI values from cities in Ontario.  Out of the 15 surveyed, 9 municipalities reported values in 2007; and the reported average ILI was 3.38. 


Other Operational Performance Indicators


For 2008, with an ILI of 3.7, the volume of real losses is 318 L/service connection/day or 13 m3/km of watermain/day. 


Real Loss Control Initiatives


The four leakage management activities are shown on Figure 5.


Figure 5:  Real Loss Control Initiatives


The City will continue to focus on the four different aspects of leakage management activities:


§                     Active Leak Control (which includes District Metered Areas);

§                     Pressure Management;

§                     Speed and Quality of Repairs; and

§                     Pipeline Asset Management.


Active Leak Control


The City currently investigates a leak either reactively (reported leaks) or proactively (unreported leaks).  The Active Leak Control program is intended to locate leaks before they surface and to initiate repairs in a timely manner.  The Active Leak Control survey of the central water distribution system (metallic watermains) and metallic communal well systems was completed in 2008.  The survey identified leaks on watermains, service connections and other appurtenances within the water distribution system.  Once these identified leaks were repaired, it resulted in an estimated operational savings of about $155,000 in 2008.  The program will continue to survey metallic watermains throughout the system in 2009.


Leaks on Private Property


During the course of the leak survey activity, numerous leaks were identified on private property.  The City is not authorized or responsible for fixing leaks on private property.  When such a leak is identified, the property owner is given a letter from the City stating that a leak was found on their property and that they are responsible for the repair.  For those property owners who do not perform the repairs required, they run the risk of damage to the home or adjacent property.  It should also be noted that these leaks on private property contribute to the City’s real losses and associated ILI. 


In 2008, staff implemented a pilot as part of a future Water Loss Policy for Leaks on Private Property that requires property owners to make the necessary repairs within a 3-month time frame.  A notification process is instituted whereby the owners are reminded every 30 days, that if the repair is not completed within the 3-month timeframe, the water supply will be turned off, and will remain off until the leak has been repaired.  The pilot program made allowances for extensions in time to be granted to those property owners that demonstrated extenuating circumstances.  In these cases, an extension in repair time would be granted and the property owner would agree to repair their water service within the agreed upon time frame.


The Leak on Private Property pilot was initiated in August 2008.  Of the 56 leaks reported to the end of the year, 48 (86%) have been repaired.  Another 7% of the leaks are on services that are not being used at this time, as the properties are not occupied, and these services have been turned off to stop the loss of water.  Four services were not yet repaired at the time of preparing this report.  Only two services have been turned off during this pilot for failure to complete the repairs.  One remains turned off, as the property is unoccupied; and the other was turned back on as a result of a change in ownership and a request to extend the time period to repair the water service.


Leak Surveys on Large Diameter Watermains


The City operates and maintains about 200 km of large diameter watermains (610 mm and larger in diameter) within the central distribution system.  In 2007, a pilot project was initiated to perform leak surveys on large diameter watermains in order to evaluate the effectiveness of current and available technology.  The results from the pilot project indicate there are reliable cost-effective options to conduct leak surveys on large diameter watermains, which are critical components of the water infrastructure.  The implementation of an annual Large Diameter Leak Detection program will allow the City to proactively identify leaks and schedule repairs with minimal disruption to the customers’ service.  The City will continue to conduct leak surveys in 2009.  A leak survey will be conducted on transmission watermains (1220 mm in diameter) at two locations for about 5 km each.  The proposed locations include the watermain feeding Orleans between Blair Road and the Orleans Reservoir and the watermain that feeds Kanata and Stittsville located between Moodie Drive and Eagleson Road.


As a result of a large diameter watermain failure on Woodroffe Avenue in November 2007, a condition assessment was conducted on approximately 3 kilometres of that watermain in October 2008, between Hunt Club Road and Fallowfield Road.  A Remote Field Eddy Current/Transformer Coupling (RFEC/TC) investigation was conducted and the results of the inspection revealed that about 3% of the pipes within the inspection length had wire breaks and were under some distress.  This level of distress is consistent with observations made within similar pre-stressed concrete pressure pipelines across North America.  Additional review of these results will continue in 2009 to identify any required maintenance and/or potential replacement of the watermain.

District Metered Areas (DMAs)


Another method of Active Leak Control is the use of District Metered Areas. In 2008, six temporary DMAs were delineated and tested in the spring and fall – one in the 2E pressure zone (Ward 19), two in the 3W pressure zone (Wards 6 and 23), and three separate areas in the Barrhaven pressure zone (two in Ward 3, and one in Ward 22). 


The results from this program in 2008 showed that DMAs continue to be an effective tool for identifying leakage in areas with plastic infrastructure.  DMAs in areas of metallic infrastructure have been deferred, as the annual hydrant leak survey has been successful in keeping the water losses in these areas at a minimum. 


Two PVC DMAs targeted in the fall of 2007 were remonitored in the spring of 2008.  The follow-up monitoring in one area indicated that excess losses observed in the fall of 2007 had been reduced as a result of repairs to six service leaks.  The result for the second area indicated that losses were slightly higher than measured in the fall, but may have been influenced by early spring usages.  It should be noted that these losses were still within the expected normal range for night flows.  In 2009, PVC zones will be the focus for DMAs, and follow-up surveys will be conducted in those zones that were monitored in the fall of 2008 to evaluate the results. 


Staff has been monitoring the night flow in the communal well systems (Carp, Vars, Munster Hamlet and Richmond-Kings Park) and the three closed pressure zones (Morgan’s Grant, Meadowlands and Montreal Road) using the reports generated from the Water Production’s SCADA (Supervisory Control and Data Acquisition) system.  Night flow reports have been generated to illustrate the minimum flow between 2 am and 4 am.  These reports are reviewed on a regular basis and when the night flow exceeds certain criteria, leak detection staff are dispatched to the zone in order to identify these potential leaks, since the increase in the flow base level is likely due to watermain breaks that have not surfaced.  A series of watermain breaks were identified by monitoring the night flows in Munster Hamlet and led to the identification of 1.2% of the real losses identified in 2008.  The regular monitoring of night flows leads to a reduction in the leak run time, which leads to an overall reduction in real losses.


Pressure Management


The amount of leakage from any distribution system is directly related to the water pressure.  If it is possible to reduce the operating pressure in the distribution system with little or no change in service level, leakage from the system can be reduced.  Staff will be assessing pressure management area opportunities based on the review of the economic analysis that will be conducted in 2009 to determine future targets for the Water Loss program.  We anticipate that Montreal Road Pressure zone might be a good candidate for pressure management.  It is a closed pressure zone with capacity to reduce the pressure at night.  Furthermore, this pressure zone experienced a large number of watermain breaks in 2008 when compared to the other pressure zones. 


Speed and Quality of Repair


The speed and quality of repairs are centered around the reduction of the leakage run time which starts at the time when the City becomes aware of a leak until the time that leak is repaired.  The volume of water lost in any leak is calculated as the product of the flow rate of the leak multiplied by the leakage run time.  Shortening the leakage run time by earlier detection will reduce the volume of lost water.  Detecting leaks before they are visible at the ground surface is an important means of shortening leakage run time and lost water.  In 2008, about 15% of the repairs conducted on the central water distribution system were initiated from the Active Leak Survey program. 


Pipeline Asset Management


The City currently has a progressive watermain replacement capital program in place.  Funds are allocated annually to replace and rehabilitate watermains based on a priority matrix comprised of many factors such as age and watermain break history.  There are other capital programs that aim to improve pipe condition, such as the Structural Relining and Cathodic Protection programs.


The reduction in water production observed in the last 5 years can be attributed in part to the infrastructure rehabilitation and replacement program.  In particular, the pressure zone with the greater reduction in water consumption from 2003 to 2008 was 1W, where the majority of the Capital Rehabilitation program has been focused. 



All performance indicators associated with the Water Loss Control program confirm that the City is effectively reducing water losses through the combination of various operational management activities:

§          ILI has gone from 4.8 in 2007 to 3.7 in 2008;

§          Volume of water captured through repairs to the water distribution system resulted in  $155,000 in savings;

§          Volume of non-revenue water is 318 L/service connection/day;

§          Volume of real losses is 13 m3/km of watermain/day; and

§          Water Meter Change-out program resulted in $88,150 in additional revenues.


These positive improvements can be attributed to our customers and staff involvement in both the Water Conservation program and the Water Loss Control Strategy activities.  In 2008, $43,000 was spent for the district meter area night flow work and $254,000 for labour, equipment and material for conducting the active leak detection work.  For 2008, the program costs totaled $297,000 and program efficiency savings totaled $243,150.





Public consultation was not required for this update.





There are no adverse legal or risk management implications.





The estimated net savings and additional revenue of $155,000 associated with the reduction in real losses from the Active Leak Detection activities, and estimated increases of $88,150 in billed consumption from the Large Meter Change-out program will be reflected in the Department’s Efficiency Targets for 2009.




Document 1 – Map of the City of Ottawa Water Distribution Systems Facilities and Feedermains




The Environmental Services Department will continue to implement the Water Loss Control program in 2009.  Staff will prepare a summary report related to the program’s performance to Committee and Council on an annual basis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        


[1] Revenues were calculated for the water rate only.  The combined revenues, including the sewage rate is estimated to be $4,186,000 using a weighted rate of $2.2542 per m3.

[2] The 2008 Council approved water rate of $1.159 per m3 came into effect on May 1, 2008.  The calculated rate of $1.062 per m3 represents the weighted annual rate considering the approved water rate from January 1, 2008 to April 30, 2008 was $0.868 per m3.

[3] A map illustrating these pressure zones is included in Appendix A