Elmore System. Water Supply Demand Strategy. Final Report March to 2060

Transcription

1 Elmore System Water Supply Demand Strategy 2011 to 2060 Final Report March 2012

2 TABLE OF CONTENTS Executive Summary 4 1. Introduction 7 2. Overview Key Features How Water is Delivered to Elmore Customer Profile 8 3. Recent Experience Water Supply Raw Water Demand Water Quality Waterplan 2055 Review Levels of Service Climate Change / Variability Scenarios Demand Forecast Current System Demand - Baseline Demand Future System Demand Population and Demand Growth Residential Population Growth Non- Residential Demand Growth Total Growth in Residential and Non-residential Demand Environmental Demand Climate Change Impact on Demand Behaviour Change and Bounce-back Improved Water Quality Summary of System Demand Impacts Supply Forecast System Performance Evaluation Demand Reduction Measures Permanent Water Saving Rules (PWSR) Reduction of Operational Water Water Saving Incentives and Community Education Pricing Incentives 22 Page 2

3 10. Additional Supply Measures Permanent Water Market Temporary Water Market Additional Water Private Rain Water Tanks Alternative Water Sources Water Quality Measures Options Analysis Demand Reduction Additional Water Options Summary Management of Risk and Uncertainty General Murray Darling Basin Plan Proposed Actions Short-term Actions Long-term Actions Community & Stakeholder Engagement 29 APPENDICES Appendix 1: Appendix 2: Alternative Water Atlas Long List of Supply Options Page 3

4 Executive Summary Introduction Coliban Region Water Corporation is a state owned water authority that provides water and wastewater services to a region with a population of 140,000 people, across 16,550 square kilometres of Central and Northern Victoria. The service area covers 49 towns in nine separate supply systems of which Elmore Groundwater system is one. The Water Supply Demand Strategy (WSDS) identifies the best mix of measures to maintain a balance between the demand for water and the available supply in urban supply systems, now and 50 years into the future. Coliban Water is required to consider the social, environmental and economic costs and benefits and the actions needed to address population growth, nonresidential demand for water and potential climate variability. The Elmore Groundwater System The Elmore Groundwater system supplies an estimated residential population of 704 with 429 customer connections; 84% are residential and 16% are non-residential. Groundwater is drawn directly from the Lower Campaspe Valley Water Supply Protection Area (LCV WSPA) under a 284 ML groundwater extraction licence that accounts for approximately 0.5% of the water entitlements supplied from the LCV WSPA. There are no major on-site storages at Elmore and the system relies on water being available at all times from the groundwater bores. The groundwater is treated at the Elmore Treatment Plant and the treated water complies with the water quality standards specified in the Safe Drinking Water Act Recent Experience The dry weather conditions of the last 10 years resulted in Elmore receiving allocations of less than 100% for five years from 2006/07 to 2010/11 inclusive. The lowest allocation of 65% (185 ML) being received in 2008/09 and 2009/10. Water restrictions, involving Stage 1 and 2, were in force for more than seven years from November 2002 to July 2006 and from December 2006 to October 2010 when Permanent Water Saving Rules (PWSR) came into place. Annual water demand ranged from a maximum of 258 ML in 2006/07 to a minimum of 98 ML in 2010/11. Water restrictions had no obvious impact on Elmore s water demand. In 2006/07, at the height of water shortages throughout Central Victoria, there was a significant draw on the Elmore Standpipe by users from outside the Elmore Township utilising water carters. The low demand of 2010/11 was due to extremely high rainfall. The current estimated PWSR annual raw water demand is 172 ML. The average annual residential consumption for the four years from 2007 to 2011 was 204 kl per property or 33% greater than the regional average of 153 kl per property. The average annual non-residential consumption for the last four years was 828 kl per property that is similar to the regional average of 855 kl per non-residential property. A review five years on of Coliban Water s last Water Supply Demand Strategy, Waterplan 2055, is available from Coliban Water s website. Page 4

5 Level of Service The Water Supply-Demand Strategy is developed to achieve both: A PWSR supply reliability of 95% (where PWSR demand would be supplied in 95 out of 100 years and water restrictions would not be expected in more than 5 years in 100; and A desired restriction level of no worse than Stage 1. More severe restrictions, such as Stage 3, would only be expected if severe or unexpected water shortages occur. Supply and Demand Balance The available supply to the Elmore Groundwater system is currently estimated at 280 ML per year and is sufficient to meet the current PWSR raw water demand of 172 ML. The PWSR annual demand for water is estimated to increase to 209 ML by year The increasing demand is due to the growth in population, forecast at 0.5% per annum, and the potentially hotter and drier climate that is estimated to increase demand by another 4% over the next 50 years. However, offsetting these two factors is the continuation of changes in customer consumption behaviour supported by community education and technology improvements. Customers have made a remarkable contribution to reducing water consumption across our region and trends indicate that customers continue to be very aware of their water consumption with an estimated reduction in household consumption of 12% over the next 50 years. The current available supply of 280 ML per year is estimated to decline to 200 ML by year 2060 due to the potential hotter and drier climate. The increasing demand and the declining supply will lead to a potential shortfall in supply from about the year 2050 with an estimated maximum shortfall of 10 ML in year Elmore System Forecast System Supply and Demand Supply megalitres per year FORECAST DEMAND FORECAST AVAILABLE SUPPLY RANGE Meeting Supply-Demand Shortfall Supply reliability for the Elmore system is estimated to remain above the 95% target level over the next 20 years with the need for water restrictions in fewer than 5 years in 100 years. Water restrictions are likely to be Stage 1 or Stage 2. Supply reliability is estimated to drop below the 95% target level in the period beyond the next 20 years. It is proposed to purchase the small amount of water needed on the temporary water market in those instances where it is necessary to avoid harsh water restrictions and to ensure water restrictions are not enforced for more than 5 years in 100 years. Page 5

6 The potential impacts of the Murray Darling Basin Plan will become clearer over the next two to five years. The Plan will guide the management of water resources and aims to balance the water needs of the environment and other uses across the Basin s four states and one territory. The draft Plan identifies 12 GL to be recovered for the Campaspe River system and possibly more to contribute to the needs of the River Murray. Most aspects of the Plan will take effect in Victoria in Coliban Water s Elmore groundwater licence is only a small fraction, approximately 0.5%, of the water entitlements supplied from the Lower Campaspe Valley Water Supply Protection Area (LCV WSPA) and we are therefore likely to continue to have access to the water market in all but the very worst scenarios. Water Supply Demand Strategies are next due for renewal in 2017 which will be the appropriate time to incorporate any required changes. Further information regarding other possible alternative water supply considerations is available on Coliban Water s website. Extracts from the Alternative Water Atlas relating to the Elmore system are contained as Appendix. Proposed Actions Elmore System The proposed strategy for the Elmore system over the next 50 years: Continue with the main replacement and leakage detection programs to minimise nonrevenue water; Use the temporary groundwater market to address possible water shortfalls, and Use the groundwater market to acquire additional groundwater entitlement. Page 6

7 1. Introduction Coliban Region Water Corporation is a state owned water authority that provides water and wastewater services to a region with a population of 140,000 people, across 16,550 square kilometres of Central and Northern Victoria. The service area covers 49 towns in nine separate supply systems of which the Elmore Groundwater system is one. The Water Supply Demand Strategy (WSDS) identifies the best mix of measures to maintain a balance between the demand for water and the available supply in urban supply systems, now and 50 years into the future. Coliban Water is required to consider the social, environmental and economic costs and benefits and the actions needed to address population growth, nonresidential demand for water and potential climate variability. The development of Water Supply Demand Strategies is a requirement of water corporation s Statement of Obligations and are developed with close reference to the 2011 Guidelines for the Development of a Water Supply Demand Strategy (Version 2) issued by the Department of Sustainability and Environment. The supply-demand balance is tracked and reported on annually against the WSDSs and the WSDSs are thoroughly reviewed redone every five years. The development of WSDSs relies on many assumptions and estimates (including water availability weather, climate change, customer demands and growth) and the resultant recommendations are thus a guide to probable future needs, projects, capital investment and timing. It is therefore important to continually track and review performance on a regular basis and to also implement more serious drought response measures if and when required. Page 7

8 2. Overview 2.1. Key Features Towns Supplied The Elmore groundwater system supplies the town of Elmore. Customers 429 customer connections and an estimated residential population of 704, which is 0.6% of all regional connections and 0.5% of total estimated residential population. Source of Water Groundwater is drawn directly from the Lower Campaspe Valley Water Supply Protection Area (LCV WSPA) under a 284 ML groundwater extraction licence. An interim Groundwater Management Plan is presently in place. The licence is 0.5% of the water entitlements supplied from the LCV WSPA. Goulburn-Murray Water is the Groundwater Manager for the LCV WSPA. Coliban Water has a role to play as a referral authority in the proper and orderly implementation of Victoria Planning Provisions through Municipal Planning Schemes. Water Treatment Plants Elmore receives treated water from the water treatment plant in Elmore How Water is Delivered to Elmore Raw water is pumped from two ground water bores, each 75 metres deep. The water is then treated at the Elmore Ultra Violet Sterilization (UV) disinfection plant (capacity 3.6 ML/day) and then supplied via pipelines and tanks to the township of Elmore Customer Profile Of the 429 customer connections 84% are residential and 16% are non-residential. The average annual residential consumption for the four years of was 204 kl per property. This is one of the higher consumption rates of the region s water supply systems and 33% greater than the regional average of 153 kl per property. The average annual non-residential consumption for the four years of was 828 kl per property which is similar to the regional average of 856 kl per non-residential property. The four largest non-residential customers use between 5 and 12 ML per year and comprise two water standpipes, a sporting club and a recreation reserve. Table 1 shows the residential population and number of water connections in Elmore. Table 1: Elmore system Population and Service Connections Service Connections 2011 Groundwater Water Residential Supply System Population 2011 Total Connections Residential Connections Non residential Connections Elmore Page 8

9 3. Recent Experience 3.1. Water Supply The Elmore extraction licence of 284 ML has historically received 100% allocations. However, in the last five years allocations have been less than 100% with the lowest allocation of 65% received in 2008/09 and 2009/10 as shown in Figure 1. An allocation of 65% is just sufficient to meet the estimated Permanent Water Saving Rules demand. In 2008/09, 50 ML of temporary water was purchased to supplement the allocation and to ensure sufficient supply. 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Elmore Allocation Figure 1: Elmore Annual Allocations There is no large on-site service basin and Elmore relies on access to groundwater at all times. Carryover is currently not available. A process is presently underway to develop a new Lower Campaspe Valley Water Supply Protection Area Groundwater Management Plan. This process commenced in November 2010 following the appointment of a Consultative Committee in accordance with the Water Act The Consultative Committee, which includes a representative of Coliban Water, has developed a draft plan following extensive discussions, consideration of technical work and public consultation. This plan will likely be finalised in the first half of 2012 and includes consideration of such matters as carryover Raw Water Demand The Elmore system demand is the total amount of water extracted from the Elmore Groundwater Bores to meet customer consumption and operational water needs. The total system demand and water restriction levels over the last 11 years are shown in Figure 2. Page 9

10 Annual Raw Water Demand megaliters Elmore System Annual System Demand Restriction Level Raw Water Demand Restriction Level Figure 2: Elmore Annual Demand and Water Restriction Levels Water restrictions were in force for more than seven years from January 2002 to July 2006 and from December 2006 to October Stage 1 water restrictions were in force except for a six month period in 2003 when Stage 2 water restrictions applied. Annual water demands have ranged from a maximum of 258 ML in 2006/07 (PWSR & Stage 1) to a minimum of 98 ML in 2010/11 (PWSR year). The low demand of 2010/11 was due to extremely high rainfall. The Stage 1 water restrictions had no obvious impact on water demand. The demand for raw water was influenced by other factors rather than by water restrictions. In 2006/07, at the height of water shortages throughout Central Victoria, there was a significant draw on the Elmore Standpipe by users from outside the Elmore Township utilising water carters that resulted in high non-residential demand. Table 2 shows the components of the system over the last 10 years. Table 2: Components of Elmore system Demand Component Percentage (%) Residential consumption 52% Non-residential consumption 34% Operational water 14% TOTAL 100% The water required for operational needs and water lost is known as operational water. Operational water includes the water required to backwash and to clean the treatment plant filters, losses incurred through leakage and pipeline bursts or from the use of fire hydrants and the flushing of mains to maintain general pipeline health. The amount of operational water is relatively constant at between 10 and 15% of the annual system demand making Elmore system one of the more efficient systems in the Coliban Region Water Quality The treated water complies with the water quality standards specified in the Safe Drinking Water Act Page 10

11 3.4. Waterplan 2055 Review A review five years on of Coliban Water s last Water Supply Demand Strategy, Waterplan 2055, is available from Coliban Water s website. It outlines our progress against the measures which were detailed in the Waterplan 2055 to ensure long-term water security for our region. In the context of the long-term climate variability challenge, the review summaries our progress with each of the Waterplan 2055 initiatives under the following categories: Urban Savings Rural Savings Recycled Water use Sourcing Additional supply Other Projects Page 11

12 4. Levels of Service Coliban Water is committed to providing the systems and infrastructure to support residential, business and industry needs throughout our region. With the major investments made in supply infrastructure in central Victoria through the recent Millennium Drought of 2002 to 2010, significant additional works are not anticipated to be required in the Coliban Water region over the next 5-10 years to maintain the objective for water security levels of service. However growth combined with weather variability and the potential for changes to our future climate may result in water shortages or drought and therefore the need for water restrictions. The Level of Service we aim to provide to customers has two components: 1. Reliability of Supply Coliban Water s objective is to provide sufficient water to meet customer demands of Permanent Water Saving Rules (PWSR) at 95% supply reliability. This means that PWSR would be in place 95 years out of every 100 years and water restrictions should not occur more often than the remaining 5 years out of every 100 years. 2. Maximum Restriction level (minimum water provision) Coliban Water s objective is that in those years where restrictions are necessary we would try to keep restrictions to no worse than Stage 1. However in the event of severe or unexpected water shortages, restrictions may need to be more severe, such as Stage 3. Under the Victorian Government s 2011 Model Water Restriction Review, Stage 1 restrictions is, in the language of the review document, intended to provide an alert of an impending possible shortage and Stage 3 Restrictions would mean that just enough water is provided for use. Stage 3 restrictions includes no watering of lawn areas however garden areas may be watered within restricted hours on alternate days. Full details are available from the website. For the purposes of this analysis and reporting, the additional water needs (or supply shortfall) generally relates the additional water required to either achieve the target reliability of supply at PWSR and/or to enable restriction levels to be no worse than Stage 3. Even then these restrictions levels would only be expected a few years out of every hundred years. Under particularly severe or highly unexpected water shortage conditions, the Drought Response Plan would be triggered which could include emergency water supply measures and harsher restrictions. Occasionally, restrictions may also be required as a short-term management measure to deal with operational emergencies and incidents. Page 12

13 5. Climate Change / Variability Scenarios Central Victoria has a highly variable climate and there is no 'most likely' or 'most probable' future climate scenario. CSIRO modelling indicates that the extent and nature of climate change is unknown, so our water resource planning is built around a range of potential climate changes and potential water supply and demand futures. Based on DSE Guidelines and using CSIRO modelling, the WSDS considers five potential climate futures each with varying changes to temperature, rainfall and inflow to rivers and catchment storages and recharge of groundwater aquifers. The five climate scenarios are: Scenario 1: Baseline climate. This scenario is based on a continuation of the historical climate, including rainfall and inflows, of the past 120 years from 1891 to Scenarios 2, 3 & 4: Change in future climate. This scenario set is based on a gradual increase in temperature of one degree (+1 o C) by approximately 2030 and two degree (+2 o C) by approximately The three scenarios under this set consider declining rainfall and groundwater recharge as a consequence of the increasing temperature being: Scenario 2: Wet (mild decline in rainfall and recharge); Scenario 3: Median (moderate decline in rainfall and recharge) and, Scenario 4: Dry (larger decline in rainfall and recharge). Scenario 5: Return to dry weather. This scenario is based on a return of the dry weather of 1997 to This scenario results in a greater and immediate reduction to available supply as well as an immediate increase in the demand for water. The changes to rainfall and groundwater recharge brought about by potential climate change and variability are shown in Table 3. Table 3: Climate Change Scenarios Scenario Change in Rainfall Change in Recharge Year 2030 Year 2060 Year 2030 Year 2060 S1 - Baseline climate 0% 0% 0% 0% S2 - Wet climate change -3% -5% -6% -4% S3 - Median climate change -7% -14% -16% -24% S4 - Dry climate change -7% -14% -16% -36% S5 - Return to dry weather -20% -20% -50% -50% Page 13

14 6. Demand Forecast 6.1. Current System Demand - Baseline Demand The baseline Elmore system demand for each level of water restriction is based on a detailed analysis of the last 12 years of raw water use (as extracted from the groundwater bores) and customer consumption. The current baseline demand for PWSR is 172 ML per year. The impact of water restrictions is shown in Figure 3. Elmore System Baseline Annual Demand Annual Demand Megalitres PWSR Stage 1 Stage 2 Stage 3 Stage 4 Figure 3: Elmore system annual system baseline demand. Table 4 shows the forecast water savings with water restrictions. Table 4: Water Savings with Restrictions in the Elmore System Restriction Level Approximate Saving (%) PWSR 0% Stage 1 4% Stage 2 30% Stage 3 40% Stage 4 49% 6.2. Future System Demand Future system demand had been determined by adjusting the baseline demand for population growth, future climate change and customer usage behaviour Population and Demand Growth Population growth has been determined based on reference to growth in connection numbers, the Victoria in Future (2008), census data and Local Government sources The impact of growth on residential population and non-residential demand is considered separately as follows Residential Population Growth Residential population is forecast to grow at 0.5% per annum. Page 14

15 Non- Residential Demand Growth In the last four years the non-residential consumption accounted for 43% of the total water consumption and is therefore a significant demand. All non-residential users are commercial with a forecast non-residential demand growth rate of 0.5% per annum Total Growth in Residential and Non-residential Demand The growth in residential population combined with the growth in non-residential demand is forecast to increase the demand for raw water by 0.5% per annum. This will mean a 10% increase in demand by 2030 and a 28% increase by Table 5 shows the projected growth rates for the various customer sectors and the overall growth in demand over the next 50 years. Table 5: Elmore forecast growth Adopted Growth Rate (% p.a.) Growth in Demand Elmore GroundWater Supply System Residential Agriculture, Forestry, Fishing & Mining Manufacturing Commercial Total Growth Rate (% p.a.) Environmental Demand 0.5% 0% 0.5% 0.5% 10% 28% There are no environmental water obligations with Coliban Water's Elmore bore water licence Climate Change Impact on Demand The analysis of the last 12 years of raw water data showed that demand increased with drier weather. Demands at year 2030 are forecast to increase with the reduced rainfall associated with climate change as shown in Table 6 Table 6: Impact of Climate Change on Rainfall and PWSR Demands Scenario Rainfall Decrease PWSR Demand Increase S3 - Median climate change -7% 4% S4 - Dry climate change -14% 8% S5 - Return to Dry -20% 10% The following Table 7 shows how the baseline demand of 172 ML is projected to increase over the next years to a maximum of 189 ML at year Table 7: Climate Change Demand Climate Scenario Year (ML) S1 - Baseline climate demand S2 - Wet climate change demand (3% and 5% less rainfall by 2030 & 2060 respectively) S3 - Median climate change demand (7% and 14% less rainfall by 2030 & 2060 respectively) S4 - Dry climate change demand (7% and 14% less rainfall by 2030 & 2060 respectively) S5 - Return to dry weather demand (immediate 20% reduction in rainfall) 172 (+0%) % % 189 (+10%) 174 (+1%) 178 (+4%) 178 (+4%) 189 (+10%) 176 (+2%) 185 (+8%) 185 (+8%) 189 (+10%) Page 15

16 Behaviour Change and Bounce-back There are a number of factors that will potentially change the way people use water over the next 50 years. These include Permanent Water Saving Rules, water pricing, grey-water reuse, changes to garden and lawn areas, education, and continuing technological and efficiency improvements in household appliances such as dishwashers and washing machines. The adoption of PWSR is forecast to reduce water demand by 15% to 20% compared to the unrestricted supply years of the late 1990s and early 2000s. This reduction has been factored into the forecast of the current baseline demand of 172 ML. In 2009/10 the Elmore system demand was less than expected and about 24% less than forecast of 172 ML. This is illustrated in Figure 2 and the lower than expected demand could be partly due to a change in customer consumption behaviour. For WSDS planning purposes it is assumed that there has been an immediate 5% step-reduction in the Elmore system demand due to customer consumption behaviour. Customers have made a remarkable contribution to reducing water consumption across our region over the last 10 years and trends indicate that customers continue to be very aware of their water consumption. The full extent of further reductions in demand due to greater voluntary conservation measures within the community is unknown. However, communities are generally much more careful in the way they use water and it has been assumed that household demand will decline from the current estimated usage levels by a further 7% over the next 50 years with continuing behavioural change, education and technological improvements. These assumed reductions in demand are due to permanent change to the way customers use water, resulting in a permanent reduction in water use that will most likely not bounce back. The eight years of water restrictions and the extremely wet year of 2010/11 reduced the raw water demand by more than 50%. This prolonged period of low water use is likely to see a continuation of suppressed demand for a number of years below the forecast system demands Improved Water Quality Any future improvement in treated water quality is forecast not to increase demand for water Summary of System Demand Impacts There are a number of influences that include population growth, climate change, behavioural change and water quality improvements that are forecast to either increase or decrease the demand for raw water over the next 20 to 50 years. These impacts are summarised as follows: 0.5% per annum growth in population and non-residential demand; 8% increase with a Median climate change; 10% immediate increase with a return to dry weather conditions; 5% immediate reduction due to recent customer consumption behaviour; and 7% reduction in demand due to behavioural change, education and technology improvements. The overall impact of these influences is that by year 2030 the PWSR demand is forecast to be between a minimum of 175 ML to a maximum of 190 ML as shown in Table 8. Table 8: Forecast Future System Demand Climate Scenario Year (ML) S1 - Baseline climate S2 - Wet climate change demand S3 - Median climate change demand S4 - Dry climate change demand S5 Return to dry weather The forecast PWSR demand are forecast to increase gradually over the next 50 years as shown in Figure 4. Page 16

17 Annual System Demand megalitres per year Elmore System Forecast System Demand Return to Dry Demand Median Climate Change Demand Baseline Demand Figure 4: Forecast future system demands in the Elmore system Page 17

18 7. Supply Forecast The forecast supply is the average annual available supply (or amount of water) that sustainably available each and every year whilst meeting target levels of service. The Elmore groundwater extraction licence is 284 ML. It has been assumed that the future availability of groundwater extraction will align with the forecast future availability of surface water in the Campaspe River basin. The estimates of future rainfall, as projected by the CSIRO, have been used to assess the impact of a range of possible climate futures on recharge. For unconfined aquifers in the Campaspe River basin, the median climate change is predicted to result in a decline in groundwater recharge of 23% by 2030 and a decline of 34% by This is similar to the predicted decline in surface run-off in the Campaspe River basin. Computer modelling has been used to forecast the future available supply. Modelling, undertaken by the CSIRO and provided as part of the DSE WSDS Guidelines, forecasts the impact of the various potential climate scenarios on the Campaspe River basin catchment run-off and the inflow to storages. The forecast impacts on inflow are shown in Table 3. Declining inflows reduce the water available to water entitlement holders. REALM modelling, undertaken by DSE, has forecast how declining inflows impact on water availability in the Campaspe River basin, in terms of monthly water allocations, and these are assumed to reflect the future supply availability in the Elmore groundwater system. In-house modelling has then been used to analyse the forecast monthly allocations and to determine how they specifically meet the current and forecast system water demands. The analysis determines for each climate scenario the: Supply Reliability Frequency of water restrictions Severity of water restrictions; and Additional water needs to meet the target Levels of Service (both additional temporary water and permanent water needs) Modelling also allows for the analysis of the sensitivity of a number of variables to determine what factors have the greatest impacts the supply-demand balance. Variables and their current values (shown in brackets) include: Maximum allocation (100% or 284 ML) Minimum allocation (0% or nil ML) Carryover limits (0% or nil ML) System Demand (163 ML increasing to 212 ML at year 2060) Growth (0.5% per annum) Behavioural change in consumption patterns (5% immediate reduction in demand and a further 7% reduction over 50 years) Level of Service (95% supply reliability with water restrictions no more severe than Stage 3) Page 18

19 Forecast supply for the Elmore system is shown in Table 9 below. Table 9: Forecast Future Supply Climate Scenario Year (ML) S1 - Baseline climate S2 - Wet climate change S3 - Median climate change S4 - Dry climate change S5 - Return to dry weather Figure 5 shows the variation in forecast supply over next 50 year 300 Elmore System Forecast System Supply Available Supply megalitres per year FORECAST AVAILABLE SUPPLY RANGE Climate Change Supply Baseline Climate Change Supply Dry Climate Change Supply Return to Dry Supply Page 19

20 8. System Performance Evaluation The performance of the Elmore system is measured on its ability to supply future demand and the target levels of service. The performance measures that are evaluated are: supply reliability with a target of at least 95% whereby the likelihood of water restrictions is no more than 5 years in 100 years; and water restriction levels with a target of no worse than Stage 3. By comparing the forecast supply and demand it is possible to estimate the shortfall in available supply and when this may occur. The forecast supply and demand for Elmore is shown in Figure 6; it is forecast that supply will exceed demand in the next 30 to 50 years. 300 Elmore System Forecast System Supply and Demand 250 Supply megalitres per year FORECAST DEMAND FORECAST AVAILABLE SUPPLY RANGE RETURN TO DRY SUPPLY (YIELD) Climate Change Supply Supply with Median Climate Change Return to Dry Supply Demand with Median Climate Change Figure 6: Forecast Supply and Demand Elmore Figure 7 shows that the forecast demand increases gradually from the current 163 ML to exceed the forecast median climate supply from about the year Additional supply is required beyond the year 2055 to a maximum of 9 ML by year 2060 to meet expected demand and levels of service. Figure 7 also shows that a return to dry conditions would result in a shortfall in supply from about 2040 that increases to approximately 25 ML by year The shortfall in available supply over the next 50 years and the forecast supply reliability are shown in Table 10. Table 10: Shortfall in the Supply-Demand Balance and Supply Reliability Year 2011 Year 2030 Year 2060 Climate Scenario Shortfall (ML) Supply Reliability Shortfall (ML) Supply Reliability Shortfall (ML) Supply Reliability S1 - Baseline climate Nil 100% Nil 100% Nil 100% S3 - Median climate change Nil 100% Nil 100% 10 94% S5 - Return to dry weather Nil 100% Nil 97% 20 72% Table 12 shows that a continuation of the baseline climate conditions would result in high supply reliability with no requirement for additional supplies over the next 50 years. Page 20

21 With regard to the median climate change scenario, the supply reliability is estimated to be 94% with probability of water restrictions occurring six years in 100 years by the year The return to dry scenario has poor supply reliability at 2060 of 71% which would result in the probability of water restrictions occurring on average three year in every ten years. Figure 7 shows the supply reliability over the next 50 years for the median climate change scenario together with water supply shortfalls. Elmore System Reliability (Median Climate Change) Reliability of PWSR 100% 99% 98% 97% 96% 95% 94% 93% 92% 91% 90% 95% Target Reliability Forecast Reliability median climate change Target Reliability Median Climate Change Scenario Year 2011 Year 2030 Year 2060 Reliability of PWSR Supply 100% 100% 94% Frequency of Water Restrictions Nil Nil 6 years in 100 Reliability meets Target Level of Service (LOS) Yes Yes No Levels of Water Restrictions Nil Nil Stage 2 Minimum Supply meets Target Level of Service (LOS) Shortfall in Available Supply in Restriction Years Permanent Water Needed to meet Level of Service (LOS) Temporary Water Needed in Restriction Years to meet LOS Figure 7: Forecast Supply Reliability Yes Yes Yes Nil Nil 9 ML Nil Nil 18 ML Nil Nil 9 ML (6 years in 100) Page 21

22 9. Demand Reduction Measures Coliban Water will continue to work with the community and pursue efficiency measures within the Elmore system to achieve demand reduction which can be permanent or temporary in nature. Demand reduction measures that provide on-going and continuous improvement to water reliability are described below. These demand reduction measures have been considered in the development of the WSDS and formulation of system demands Permanent Water Saving Rules (PWSR) PWSR were introduced by the Victorian Government in March 2005 and came into force in the Loddon system in January 2011 following the lifting of water restrictions. The rules are designed to have customers permanently conserve water by requiring them to adopt some basic common sense water conservation measures. These rules were revised by the Victorian Government in December It is expected that PWSR will reduce 'unrestricted' demand, as experienced in the late 1990s, by 15% to 20%. An allowance of approximately 15% was factored into the assessment of the future Elmore system demand. The extent of actual water savings attributable to PWSR will be better understood with the evaluation of demand over the next four to five years Reduction of Operational Water Over the last four years, operational water accounted for 14% of the raw water extracted from Elmore groundwater system making Elmore system one of the more efficient in the Coliban Region. Coliban Water will continue its leakage reduction and water main replacement programs to replace old mains that are susceptible to bursts and leaks and adjusting pressures where this is appropriate and may assist. This program will ensure that operational water does not increase with the potential for marginal reductions in water losses Water Saving Incentives and Community Education A number of water saving incentives and education programs have been in place during the last five years to achieve permanent behavioural change in community water consumption. Incentives and scheme have included the fitting of efficient water fixtures, such as low-flow shower roses and taps, in new dwellings and the water-efficiency labelling of water using appliances such as washing machines. Other schemes have provided rebates for households and organisations involved in water smart programs such as the retro fitting of existing dwellings and the maintenance of efficient garden irrigation systems. These programs and other options such as grey-water re-use, installation of rain water tanks, continued improvement in the efficiency of appliances and fixtures are expected to continue to change the behaviour and volumes of community water consumption. A 7% reduction in demand spread over the next 50 years has been assumed in the water demand projections for these continued water efficiency savings Pricing Incentives Increases in the customer's water price can have an influence on reducing consumption. Price increases implemented over the last ten years may have influenced customer behaviour and thereby reduced overall demand. Similarly, any future price increases could be expected to further reduce demand. Any demand reductions that do occur are considered to be included as part of the 7% reduction in demand as outlined in the above Water Saving Incentives and Community Education programs. Page 22

23 10. Additional Supply Measures Permanent Water Market The water market can be used to purchase permanent water entitlement to meet supply shortfall. Permanent water entitlement is subject to annual allocation and is therefore not guaranteed to be fully available every year. The volume of permanent water entitlement to be purchased approximates to be about twice the volume of the supply shortfall in order to ensure that there is sufficient available water in most years. Table 11 shows the amount of permanent water required to ensure the target levels of service of 95% supply reliability and a minimum level of service of Stage 3 water restrictions are achieved. Table 11: Permanent Water needs to achieve Target Levels of Service Climate Scenario Year 2011 Year 2030 Year 2060 S1 - Baseline climate Nil Nil Nil S3 - Median climate change Nil Nil 18 ML S5 - Return to dry weather Nil Nil 30 ML The supply reliability is forecast to remain above the 95% target level for the next 30 to 40 years which would mean that it is unnecessary to purchase permanent water in that period Temporary Water Market The purchase of temporary water is an appropriate response if water shortages are likely to be infrequent. The Elmore system has supply reliability for the next 20 to 30 years of close to 100% with water restrictions required only very infrequently. Even in circumstances where water shortages do occur, the purchase of a relatively small volume of temporary water would only be required to avoid water restrictions that are worse than Stage 3. The major drawback is the potential lack of availability of temporary water in times of severe water shortages. Table 12 shows the amount of temporary water required to ensure the target levels of service of 95% supply reliability and a minimum level of service of Stage 3 water restrictions are achieved. Table 12: Temporary Water needs to achieve Target Levels of Service Climate Scenario Year 2011 Year 2030 Year 2060 S1 - Baseline climate Nil Nil Nil S3 - Median climate change Nil Nil 9 ML S5 - Return to dry weather Nil 0 ML 21 ML The purchase of temporary water is likely to be required infrequently making this option a cost effective means to meet target levels of service Additional Water Private Rain Water Tanks At present, recommendations from the Department of Health is that water for potable purposes should come from a reticulated potable supply where one is available rather than from rainwater tanks. Many households in the Elmore system most likely use rain-water tanks for non-potable purposes which effectively reduce the demand on the potable system. A restriction relating to rain water tanks is that they are reliant on local rainfall and shortages of tank water associated with low rainfall are highly likely to coincide with any shortage that may occur in the Elmore groundwatersystem. To be effective in significantly reducing potable demand, rainwater tanks have to be of a larger size and appropriately used. Tanks and plumbing associated with such systems are also expensive. Page 23

24 10.4. Alternative Water Sources An Alternative Water Atlas is being compiled that will identify and communicate potential sources of alternative water that may form part of the future supply-demand balance. The objectives of the Alternative Water Atlas from the Water Supply Demand Strategy Guidelines (DSE, 2011) are to: Identify the volumes of stormwater, recycled water and other alternative water sources available within the works of the Corporation (including wetlands and retardation basins) and/or local council; and Help to inform future opportunities for the use of treated stormwater, recycled water and other alternative water sources in the control of either a water corporation or local council. Some of the alternative sources identified through the development of the Alternative Water Atlas are included in the assessment of options where a supply-demand shortfall exists. Page 24

25 11. Water Quality Measures The Elmore water treatment plant is generally able to meet required customer water quality standards even when the source water is of poorer quality such as through the recent dry period. The Department of Health is also increasing the standards it expects for treated water quality including meeting a TDS (salinity) level of no more than 500 mg/l by The Elmore system WTP will not require upgrades to achieve required water quality standards into the future. Page 25

26 12. Options Analysis Demand Reduction Demand reduction measures as listed in section 9 are in progress and have been taken into account in the forecast future demands. These include an estimated 12% reduction in household consumption over the next 50 years due to permanent changes in customer consumption behaviour and the implementation of future technologies Additional Water No additional water is required in the next 10 to 20 years. The water market can be used to purchase temporary water allocation to meet any supply shortfall should one arise Options Summary The long list of options to address future water needs is attached as Appendix 1. Table 13 details those options that have been short-listed as the preferred options to meet future shortfall in demand over the next 50 years based on a consideration of the social, environmental and economic costs and benefits. Table 13: Water Supply Strategy Elmore system Elmore System Short List Options Strategy Source of Additional Water Item Project Reduce Nonrevenue water Median Climate Change (ML) Implemented and Committed Projects Shortfall at Year 2060 Return to Dry (ML) Additional Supply Demand Balance Benefit to 2 ML by year 2030 Project Summary Already Implemented Already Committed Project Status Ongoing; to maintain and improve system efficiency Additional Water sub total Other Projects if Required 10.3 Purchase Temporary Water 2 2 Cost Benefit/ Cost (ML/$1m) Project Status to 25 ML < $ Purchased as and when required to avoid harsh restrictions 10.2 Puchase Permanent Entitlements Total Additional Water 9 25 < $2, Not expected to be necessary in next 30 years Based on the above, the priorities for future additional supply, if required would be; 1. Purchase Temporary Water 2. Purchase Permanent Entitlements Page 26

27 13. Management of Risk and Uncertainty General The use of the water market to supplement supply is considered the lowest risk and lowest cost option Murray Darling Basin Plan The Murray Darling Basin Authority has responsibility for developing the Murray Darling Basin Plan, which will guide the management of water resources across the Basin s four states and one territory. The Plan builds on and complements previous water reforms and contributes to the Authority s vision for a healthy working Basin. The Basin Plan aims to balance the water needs of the environment and other uses, through the establishment of new limits (known as sustainable diversion limits, or SDLs) on the volumes of water use in systems and regions. The draft Basin Plan identifies the following additional water needs to be recovered for southern catchments relevant to Coliban Water s systems: Wimmera-Avoca 23 GL Campaspe 12 GL Loddon 10 GL Murray 63 GL (This volume is expected to be met through NVIRP 2) Goulburn-Broken 99 GL (This volume is expected to be met through NVIRP 2) However, to meet the needs of the River Murray, a further 971 GL needs to be recovered. This volume would need to be recovered from somewhere within the southern Basin catchments that regularly flow into the Murray and there is flexibility as to where this water comes from. Coliban Water would likely only be affected by Basin Plan implications in the irregular times that it wishes to access the market to supplement low allocations or reservoir inflows. Due to the very small fraction of total system water that Coliban Water would be seeking, it is reasonable to assume that in all but the worst scenarios that there would be at least some water available. There is some risk relating to how much of the 971 GL may be sought from the smaller catchments upon which Coliban Water relies and what may happen if the proposed Murray- Darling Basin Authority voluntary buy-back process does not achieve the targeted volumes. From Coliban Water s perspective, the Campaspe and Loddon systems may be the catchments of greater concern to be more closely monitored into the future. Most of the aspects of the Basin Plan are presently not intended to take effect in Victoria until 2019 and as such there is time to monitor, contribute to and further assess the likely future impacts of the Basin Plan over the next couple of years. Water Supply Demand Strategies are next due for renewal in 2017 which will be the appropriate time to incorporate any required changes. Page 27

28 14. Proposed Actions The WSDS proposes the following actions for the Elmore system Short-term Actions The actions proposed for the period covered by WaterPlan 3 (2013 to 2018) and WaterPlan 4 (2018 to 2023): Continue with the main replacement and leakage detection programs to minimise nonrevenue water; and Use the temporary groundwater market to address possible water shortfalls Long-term Actions The actions proposed for the period to 2060: Continue with the main replacement and leakage detection programs to minimise nonrevenue water; Use the temporary groundwater market to address possible water shortfalls, and Use the groundwater market to acquire additional groundwater entitlement. Page 28

29 15. Community & Stakeholder Engagement The Water Supply Demand Strategies are key strategies for a water business that guide the level of service to our customers and drive augmentation works to enable us to have available required supplies to meet demands. We recognise the importance of implementing a community engagement program that: Inspires confidence in the process and our ability to manage water resources now and into the future; Promotes acceptance and understanding of our plans; and Provides information that supports communities understanding and ability to have informed input. Some of the methods that have been utilised in engagement around the development and finalisation of this WSDS, or have fed into the WSDS, were: 2009 region wide Understanding our residential customer research project. This included focus groups and mail survey with willingness to pay a key focus; 2011 surveys sent to all 66,000 residential customers and 5,000 non-residential customers; Attended and presented to community groups upon request; Held public meetings in the Loddon system which had been particularly heavily impacted through the drought; Meetings with individuals and groups who came forward offering suggestions and comments relating to particular systems and towns; Website posting of a five year progress review of WaterPlan 2055 (Coliban Water s 2005 WSDS); Website posting of draft strategies requesting comments and feedback; Direct mail to almost 100 key stakeholders directing them to the website and requesting comments and feedback; Sending out hardcopies of the WSDS draft reports upon request; Presentations to Coliban Water staff of draft strategies requesting comments and feedback; and Presentations and strategy sessions with the Coliban Water Board leading up to WSDS endorsement. The feedback received and conversations had have been useful in informing development and in finalisation of our WSDS. There have been no major issues or suggestions raised significantly affecting the outcomes and recommendations of the WSDS with feedback received suggesting a high level of support for the direction proposed by Coliban Water and articulated through the strategies. Page 29

30 APPENDIX 1 Alternative Water Atlas Elmore System Summary Page 30

31 Page 14