WATER SUPPLY DEMAND STRATEGY

Transcription

1 WATER SUPPLY DEMAND STRATEGY Daylesford Water Supply System Strategic Plan

2 TABLE OF CONTENTS 1. INTRODUCTION CURRENT WATER RESOURCE REVIEW WATER DEMAND FORECASTING FUTURE WATER CHALLENGE DEMAND REDUCTION STRATEGIES SUPPLY ENHANCEMENT OPTIONS ALTERNATIVE WATER ATLAS WATER SECURITY OUTLOOK DEVELOPMENT OF PLANS MANAGEMENT OF RISK AND UNCERTAINTY STAKEHOLDER CONSULTATION GLOSSARY OF TERMS REFERENCES & RELEVANT INFORMATION Document Control Revision Document Approval Signed Date Draft Strategy V1 Written by M Jayasooriya (Planning Engineer) 16 Dec 2011 Draft Strategy V1 Endorsed by the Internal Review Panel 22 Dec 2011 Draft Strategy V1 Submitted to the Dept. of Sustainability & Environment 22 Dec 2011 Final Strategy V2 Submitted to the Minister for Water 30 March 2012 Electronic Copies Location of Report Draft Strategy V1 Trim Reference :BI/11/73094 Final Strategy V2 Trim Reference : Hard Copies Final Strategy V2 Location of Report Water Supply Demand Strategy Daylesford System 2

3 List Of Figures Figure 1.1 Policy Framework for Sustainable Urban Water Management... 4 Figure 1.2 Water Supply-Demand Strategy Objectives... 5 Figure 1.3 Water Supply Planning Framework in Victoria... 5 Figure 1.4 Regional Maps... 6 Figure 2.1 Schematic of Daylesford Water Supply System... 8 Figure 2.2 Daylesford Water Supply Catchment... 9 Figure 2.3 Wombat Creek and Kangaroo Creek... 9 Figure 2.4 Historical Daylesford Catchment Rainfall Figure 2.5 Recent Trends at Bullarto and Wombat Reservoirs Figure 2.6 Daylesford Recent Water Restriction History Figure 2.7 Summary of Security of Supply and System Yield Figure 2.8 Daylesford System Storage and Entitlement Figure 2.9 Minimum Passing Flow Requirements Below Water Diversions Figure 2.10 Daylesford Groundwater Licence Figure 2.11 Consumption by User Group 2010/ Figure 2.12 Water Demand Trends Figure 2.13 Summary of proposed actions for the short term as set out in the Daylesford WSDS Figure 2.14 Non-Revenue Water in the Daylesford Water Supply System Figure Current Demand Management Initiatives Figure 2.16 Future Demand Management Initiatives under Consideration in Figure 2.17 Daylesford 2006 Drought Response Plan Potential Supply Options Figure 3.1 Factors Influencing Water Demand Figure 3.2 Daylesford Projected Population and Connection Growth Rates Figure 3.3 Daylesford Current Water Demand Assumptions Figure 3.4 Daylesford Projected Bulk Water Demand Figure 4.1 Projected Demand and Current System Yield Gradual Climate Change Figure 4.2 Water Requirement Projections Gradual Climate Change Figure 4.3 Projected Demand and Current System Yield Return to Dry Climate Change Scenario Figure 4.4 Water Requirement Projections Step Climate Change Figure 5.1 Proposed Water Consumption Targets Figure 5.2 Summary of Daylesford Non-revenue Water Performance and Targets Figure 6.1 Future Water Supply Augmentation Options Figure 6.2 Excluded Water Supply Options Figure 7.1 Estimated Household Water Use Figure 7.2 Potential Water Savings from Potable Substitution Figure 7.3 Forecasted Potential Water Savings from Potable Substitution Figure 8.1 Forward Storage Projections Figure 9.1 Summary of Actions for Short, Medium and Long Term Planning Figure 12.1 Glossary Central Highlands Region Water Authority 7 Learmonth Road Wendouree VIC 3353 Australia Telephone: Facsimile: Water Supply Demand Strategy Daylesford System 3

4 1. INTRODUCTION Background information The Victorian Government has outlined a sustainable vision for Victoria s future water supplies. Part of this vision is to establish Victoria as a world leader in integrated urban water management so that our cities become more sustainable and liveable. The purpose of Water Supply-Demand Strategies is to identify the best mix of measures to maintain a balance between the demand for water and available supply in urban supply systems now and into the future.. Figure 1.1 Policy Framework for Sustainable Urban Water Management Balancing Water Supply & Demand Recycling & alternative water use Water Supply- Demand Strategy Reducing Water Demand Securing our urban water supplies The development of this Water Supply Demand Strategy (WSDS) details the commitment of Central Highlands Water (CHW) towards supporting efficient integrated urban water use and identifying supply options to maintain an appropriate balance between urban water supply and demand over the next 50 years. This long-term strategy is a component of CHW s overall planning processes, which includes planning for drought response, financial expenditure, asset management, water quality and wastewater reuse. Short-term actions presented in this strategy will inform the development of the Corporate Water Plan ( ). This strategy follows on from the initial WSDS for this system, completed in This WSDS is to be reviewed every five years to take into account changes to the availability of water supplies and changes in consumer demand, as a requirement under the Statements of Obligations (SoO) issued to all water corporations by the Minister for Water under sections 4I and 8(1)(a) of the Water Industry Act Considering the effects of conditions faced and actions taken in the period of , this update outlines the integrated urban water use and identifying supply options to maintain an appropriate balance between urban water supply and demand over the next 50 years. Key objectives The objective of WSDS is to facilitate efficient and effective urban water management in the medium and long term by adopting a range of measures that focuses on reducing water demand, securing water supplies, recycling and using alternative supplies, and balancing water supply and demand. Refer to Figure 1.2 for the key objectives. Water Supply Demand Strategy Daylesford System 4

5 Figure 1.2 Water Supply-Demand Strategy Objectives Key Objectives: 1. Ensure safe, secure, reliable and affordable water supplies that meet society s needs; 2. Enable customers to have access to desired water products and services, and to choose to use water for activities they value highly; 3. Encourage all water resources including rainwater, stormwater and recycled water to be utilized in ways that are efficient and fit-for-purpose, whilst ensuring that public and environmental health are protected wherever possible; 4. Encourage water projects to also enhance the liveability, productivity, prosperity and environment of our cities and towns wherever possible; 5. Ensure that water needs of environmental assets are transparently considered and delivered; and 6. Ensure that water planning is subject to a transparent and rigorous decision-making process, with clear roles and responsibilities and accountabilities, which can adapt to the changing environment. Source: Guidelines for the Development of a Water Supply-Demand Strategy (Version 2) The WSDS is a key component of the framework of plans and processes that governs the management of water for urban consumption in the state of Victoria. Figure 1.3 depicts the Victorian water supply planning framework and highlights the importance of the WSDS in developing strategies to achieve sustainable management of water resources to ensure that they meet the current and future water needs of the community. Figure 1.3 Water Supply Planning Framework in Victoria Source: Guidelines for the Development of a Water Supply-Demand Strategy (Version 2) Previous long-term planning Long-term water supply planning is an ongoing process that requires regular review. As part of this process, Water Supply-Demand Strategies shall be reviewed every five years. Some of the previous long-term planning studies undertaken by CHW include: Daylesford Long-Term Water Resource Management Plan, 2003 Daylesford Water Supply System: Assessment of System Augmentation Options, October 2003 Daylesford Drought Response Plan Review and Investigation of System Augmentation Options, July 2003 Study of Daylesford Water Supply System Headworks, 1994 Water Supply Demand Strategy Daylesford 2006 Daylesford Water System Development Plan 2010 Water Supply Demand Strategy Daylesford System 5

6 Regulatory documents governing water management in the Daylesford system The Victorian Liberal Nationals Coalition Plan For Water Central Highlands Region Water Authority Water Plan Northern Region Sustainable Water Strategy 2010 Plan development CHW have developed this plan in accordance with the Guidelines for the Development of a Water Supply Demand Strategy (Version 2) prepared and issued in October 2011 by the Department of Sustainability and Environment (DSE), with the assistance of representatives of all metropolitan and urban water corporations and the Department of Treasury and Finance. Figure 1.4 Regional Maps Source: National Water Planning Report Card 2011 Water Supply Demand Strategy Daylesford System 6

7 Source: CHW GIS System Water Supply Demand Strategy Daylesford System 7

8 2. CURRENT WATER RESOURCE REVIEW Distribution network Daylesford and Hepburn Springs are located approximately 50 kilometres north-east of Ballarat. The water supply system provides potable water to 2782 water connections and serves a population of 4020 permanent residents and many temporary residents, as at 30 June The local area contains a large number of holiday resorts and water demand can increase substantially during holiday periods. The following localities are serviced by the Daylesford water supply system: Daylesford Hepburn Springs Musk Sailor s Hill Shepherds Flat Raw Water supply system The Daylesford system relies on the supply of water from Wombat Reservoir and Bullarto Reservoir. Hepburn Reservoir and Wallaby Creek on-stream diversion weir are utilised as secondary water supply sources, particularly during dry summer periods. The Coomoora bore was recently developed to augment surface water supplies as required. The schematic diagram of the Daylesford water supply system is displayed in Figure 2.1. Figure 2.1 Schematic of Daylesford Water Supply System Water supply catchments The Daylesford system lies within the Upper Loddon catchment on the tributaries above Cairn Curran Reservoir. The majority of the water supply catchment areas are proclaimed Water Supply Protection Areas, which are predominantly managed through planning controls. However, they are mostly open catchments that contain a wide variety of land uses. Water Supply Demand Strategy Daylesford System 8

9 Figure 2.2 Daylesford Water Supply Catchment Reservoir Catchment Area Land Use Bullarto Reservoir (CHW) Wombat Reservoir (CHW) Hepburn Reservoir (CHW) Wallaby Creek Diversion Weir 680 ha 916 ha 218 ha 185 ha Almost half of the catchment area contains native forest, with the remainder being cleared land predominantly used for agriculture Almost 70% of the catchment area contains native forest, with the remainder being cleared land predominantly used for agriculture Predominantly cleared land used for grazing with some native forest Predominantly cleared land used for grazing and intensive horticulture with some native forest and scattered rural housing and lifestyle properties CHW is actively involved in catchment management activities to protect source water quality and maximise the harvest of water resources. Some of the most important activities include catchment inspections, river health works, creating buffer zones around streams, biodiversity management, fire prevention, property management, and the ability to respond emergency incidents. River health The official manager of the broader Loddon River Catchment is the North Central Catchment Management Authority (NCCMA). The NCCMA develops key strategies to maintain and restore river health and environmental values. Overall, the tributaries of the Upper Loddon catchment above Cairn Curran Reservoir are classified as poor, moderate, and good using the Index of Stream Condition (ISC) assessment obtained from the Victorian Water Resources Data Warehouse. Importantly, the Daylesford water supply system is situated on the upper tributaries of Jim Crow Creek and the Loddon River which are classified as being in good condition and contain ecologically healthy and representative streams. The upper tributaries of Jim Crow Creek and the Loddon River contain many important environmental assets including species of native fish, significant flora and fauna, aquatic invertebrate communities and areas of wetland rarity. High value is placed on the social value of the area, which is commonly used for fishing, swimming, bushwalking, camping, and passive recreation. These upper reaches also have economic importance as they contribute to local tourism; provide urban water for Daylesford, rural water for stock and domestic purposes, irrigated crops and lifestyle properties. Figure 2.3 Wombat Creek and Kangaroo Creek CHW will continue to undertake catchment protection activities within the water supply catchment area. It will also work with the NCCMA to identify opportunities and implement programs to maintain environmental values and improve river health, while securing the water future of Daylesford. Water Supply Demand Strategy Daylesford System 9

10 CHW is committed to maintaining compliance with current and future environmental water obligations as reflected in the Environmental Water Reserve and in the regional Sustainable Water Strategy. Recent water supply trends The Daylesford system is generally characterised by seasonal inflows that fill the reservoirs during winter and spring. The current system has a total storage capacity of 819 ML and annual demand of approximately 553 ML. Historical experience revealed that the system was vulnerable to the occurrence of dry winters, if the reservoirs do not recover to full capacity by the end of spring. The Daylesford system has experienced such conditions during the recent millennium drought. Recently, the reservoirs have failed to reach full capacity during the 2002/03 season and again during the 2006/07 season. As a result, CHW was compelled to impose water restrictions within the Daylesford system. CHW has also reinstated Hepburn Reservoir as a permanent supply source and has secured a ground water licence for Coomoora bore. Water treatment Water treatment occurs through a Dissolved Air Flotation and Filtration (DAFF) plant with disinfection by chlorine. Powder activated carbon can be added to remove taste and odour, while Potassium Permanganate can be added to remove Manganese and Iron, if required. The plant was built to facilitate chloramination (mix chlorine and aqueous ammonia) should disinfection by-products become an issue. The plant has the capacity to treat 8 ML/day and a clearwater storage of 7.9 ML that is sufficient for more than 20-year design loads. Drought conditions The extensive drought during the past decade has placed significant stress on water supply systems across the region. Figure 2.4 displays the below average Daylesford rainfall over the period. Water Supply Demand Strategy Daylesford System 10

11 Figure 2.4 Historical Daylesford Catchment Rainfall 1 Annual Rainfall Totals Rainfall (mm) Annual Rainfall (mm) Average Rainfall (mm) Source: Data obtained from the Bureau of Meteorology website, In recent times, the Daylesford system has displayed its vulnerability to dry winter/spring periods, particularly during 2002/03 and 2006/07. Figure 2.5 displays the impact of the dry conditions on storage levels. Figure 2.5 Recent Trends at Bullarto and Wombat Reservoirs Daylesford System - Water Storage 100% % Full Capacity 80% 60% 40% 20% 0% Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10 Jan-11 Water restrictions have frequently been required during the past 10 years in the Daylesford water supply system. 1 Incomplete rainfall data for available from the BoM for the Daylesford raingauge site Water Supply Demand Strategy Daylesford System 11

12 See Figure 2.6 for details on recent restriction levels. Figure 2.6 Daylesford Recent Water Restriction History Period January November 2002 December 2002 January 2003 Stage 2 February August 2003 Stage 4 September November 2003 Stage 2 December January 2006 Stage 1 February October 2006 November 2006 November 2006 Stage 2 December 2006 November 2007 Stage 3 December 2007 July 2011 Stage 2 July 2011 to present Water Restriction Level Nil Permanent Water Saving Rules (were introduced) PWSR As of August 2011, Permanent Water Saving Rules (PWSR) were in force and the volume of surface water available for the Daylesford water supply system was approaching 100% of total capacity. In addition, CHW has access to a further 273 ML/year from the Coomoora bore. Despite a full recovery of water supplies in the Daylesford system, CHW remain focused on implementing water saving and leakage detection initiatives to help conserve existing water supplies. Water resource modelling The assessment of current surface water supplies and the investigation of the Daylesford system s ability to cope with different supply and demand scenarios were performed using the Resource Allocation Model (REALM) software package. Detail information regarding the modelling process and underlying assumptions are given in appendix 1. Assessment of water resources was performed using four different scenarios, as outlined in the Guidelines for the Development of a Water Supply Demand Strategy (Version 2) prepared by DSE. In the first instance, a continuation of the low inflow period experienced during the past decade was adopted, where the impact of climate change is effective immediately. The other three scenarios adopted were based on long-term historical inflows, which decline gradually in the future due to wet, dry, and medium climate change. Standard of service CHW has adopted supply reliability as its level of service (LOS) measure. The measures include both the frequency of key restriction levels and the frequency of reaching critical storage levels. CHW s adopted standard of service for the Daylesford water supply system is to achieve supply outcomes such that water restrictions are not expected to occur more often than one year in every ten on average (i.e. 90% standard of service). In addition, the system must have the capacity to provide a base level of supply during the worst drought years. This approach provides a statistically sound and repeatable basis for identifying the timing for an upgrade of assets. It also allows a number of criteria to be applied in a system and the critical criteria for the system to be determined, providing a planning focus on the weakest point of the system. Water Supply Demand Strategy Daylesford System 12

13 Security of supply The actual likelihood of water restrictions occurring is known as the security of supply. CHW have calculated the security of supply under two modelling scenarios. Using long term historical inflow averages, the current likelihood of water restrictions in the Daylesford system is above 90% security of supply. While using a continued low inflow scenario water restrictions are likely security of supply is also above 90%. System yield The system yield is a term used to describe the volume of water that can be harvested in order to achieve the adopted standard of service. System yield is always associated with a standard of service and reduces if the standard of service increases. In practical terms, this means that a water supply system may be acceptable to one community, which is willing to accept more frequent restrictions. However, the same system may be unacceptable for another community who are less tolerant of frequent restrictions. Using the 90% standard of service and long term inflow averages, the Daylesford water supply system has a system yield of approximately 1000 ML/year. However, under a continued low inflow scenario the system yield using the 90% standard of service is only 865 ML/year. Another important consideration is the risk of severe drought affecting water supply and assessing the likelihood of critical supply shortfalls during prolonged dry conditions. Figure 2.7 provides a summary of the current level of demand, adopted standard of service, security of supply and system yield for the Daylesford water supply system using the two modelling scenarios. Figure 2.7 Summary of Security of Supply and System Yield Item Scenario based on long Scenario based on a term average inflows continuation of low inflows Adopted standard of service (water restriction target) 1 in 10 years (90%) Current level of unrestricted demand 553 ML/year Current security of supply above 90% above 90% Current system yield 1000 ML/year 865 ML/year Current augmentation required to meet adopted standard of service Bulk Entitlement and Groundwater Licence CHW s entitlement to extract water from the system is specified in the Bulk Entitlement (Daylesford-Hepburn Springs) Conversion Order 2004 made under sections 43 and 47 of the Water Act Figure 2.8 Daylesford System Storage and Entitlement Source Storage Entitlement Total System 819 ML Up to 916 ML in any year Bullarto Reservoir 219 ML At a rate not exceeding 2 ML per day Wombat Reservoir 568 ML At a rate not exceeding 5 ML per day Hepburn Reservoir 35 ML At a rate not exceeding 0.5 ML per day Wallaby Creek Weir Inflow Only At a rate not exceeding 0.4 ML per day Nil Nil Water Supply Demand Strategy Daylesford System 13

14 Figure 2.9 Minimum Passing Flow Requirements Below Water Diversions Source Minimum Passing Flow Requirement Bullarto Reservoir Wombat Reservoir Hepburn Reservoir Wallaby Creek Weir 0.3 ML/day from July to November 0.1 ML/day from December to June No minimum passing flow requirement No minimum passing flow requirement When inflow is <0.2 ML/day - all flow shall pass When inflow is >0.2 ML/day and <1.0 ML/day, 0.2 ML/day shall pass, plus half of the remaining flow When inflow is >1.0 Ml/day all flow shall pass, less 0.4 ML/day CHW s licence to extract groundwater for the Daylesford system is specified in the Groundwater Licence No. WLE made under sections 51, 67 and 145 of the Water Act Refer to Figure 2.10 for details Figure 2.10 Daylesford Groundwater Licence Source Annual Volume Extraction Rate Daily Volume Coomoora Bore 273 ML/year Water demand trends At a rate not exceeding 0.75 ML per day Max volume extracted per day must not exceed 0.75 ML The 2010/11 bulk demand for the Daylesford water supply system was recorded as 553 ML. Figure 2.11 depicts the comparative usage of different consumer groups for the 2010/11 financial year. There has been a significant decline in per capita demands, as a result of restrictions, demand initiatives and other factors, from those experienced in the pre-restriction period as shown in Figure The current level of demand is approximately the estimated level of unrestrictable demand, indicating that further demand management initiatives are unlikely to provide significant further reductions in unit demands. Figure 2.11 Consumption by User Group 2010/11 Non-Revenue Water, 32% Residential, 49% Concessional, 3% Non-Residential, 16% The lifting of restrictions and the adoption of Permanent Water Saving Rules (PWSR) has not led to any significant rebound in demand to date. There has been a modest increase in demand in the 2010/11 demands over those of the previous year. Water Supply Demand Strategy Daylesford System 14

15 The lack of any significant rebound might be partly attributable to the relatively high rainfall occurring in the summer months. However, the significant uptake of rainwater tanks, greywater diversions, drip systems and other measures seems to have had a significant impact even on relatively warm and dry periods within those years. Indoor demand, which is far less sensitive to rainfall levels, has not significantly increased either. This is probably attributable to reductions in underlying demand caused by the adoption of water efficient devices within the home which was accelerated during the long restriction periods and is now expected for new houses and renovations. There has also been no significant rebound in non-residential and concessional demands. The results of a number of measures, including WaterMap Plans has seen reductions in potable water demand for major process water users, which constitute a large proportion of this demand. There is also a reduction in demands in smaller non-residential that parallels, with a slight lag, that of residential indoor demands. It should be noted that NRW shown in Figure 2.11 includes losses associated with raw water transfer and the treatment processes, as well as distribution system losses. This is known as Total Losses. Figure 2.12 Water Demand Trends 2 Daylesford Per Capita Usage 's Average /11 Recorded Demand Estimated Unrestricted Demand 2010/11 0 Total per capita usage (litres/head/day) Residential per capita usage (litres/head/day) The current total per capita water usage and current residential per capita water usage is significantly lower than 1990 water usage. This is due to the impact of long term water restrictions which have resulted in behavioural changes in water use by the wider community. Extensive customer awareness programs initiated by CHW also contributed to the reduction of per capita water usage. Review of previous WSDS Actions The previous WSDS for the Daylesford system was completed in Short-term actions recommended in that strategy are included in Figure Figure 2.13 Summary of proposed actions for the short term as set out in the Daylesford WSDS 2006 Timeframe Action required Status Short term (next 5 years) Secure groundwater licence and commission Coomoora bore Achieve 10% target for unaccounted water by 2013 Completed Not yet achieved, NRW policy to be reviewed 2 Note that total per capita usage is derived from bulk water usage, and will therefore include a non-revenue water component and also losses associated with the treatment process. Water Supply Demand Strategy Daylesford System 15

16 Timeframe Action required Status Continue to implement current demand management initiatives Ongoing In addition to the actions discussed in Figure 2.13, the following additional works has also been completed within the Daylesford catchments: Bushfire remediation works following the Wombat catchment bushfire. Assessment on potential water quality/yield reduction issues relating to the bushfire. Dam safety and outlet works completed at Bullarto Reservoir Spillway works at Hepburn Reservoir Non-Revenue Water CHW has had a strong focus on reducing non-revenue water throughout the region, setting a target of 10% non-revenue water by 2013, as an average across all systems. The performance of the Daylesford system is shown in Figure It should be noted that NRW shown in Figure 2.14 does not include losses associated with raw water transfer and the treatment processes. Associated NRW targets relate to Distribution Losses only. Figure 2.14 Non-Revenue Water in the Daylesford Water Supply System System Losses - Daylesford 1, % 1, % Volume (ML ) Oct-02 Feb-03 Jun-03 Oct-03 Feb-04 Jun-04 Oct-04 Feb-05 Jun-05 Oct-05 Feb-06 Jun-06 Oct-06 Feb-07 Jun-07 Oct-07 Feb-08 Jun-08 Oct-08 Feb-09 Jun-09 Oct-09 Feb-10 Jun-10 Oct-10 Feb-11 Jun-11 Oct-11 Feb-12 Jun-12 Oct-12 Feb-13 Jun-13 Volume Actual Proportion Tri-Cycle Targetending Rolling 12 Month Actual Proportion Since the release of the initial Daylesford WSDS in 2006, non-revenue water in the Daylesford water supply system has decreased by approximately ML/year. Leakage rates have decreased from a rate of 5.64 L/s in 2006, to a current leakage rate of 1.83 L/s. Work completed and ongoing in the Daylesford water supply system to minimise non-revenue water losses include the following: - Installation of a new flow meter at the Water Treatment Plant. - Monitoring bulk flows on a weekly basis. - Measuring unaccounted water at the end of each property meter tricycle (three times per year). - Quantify losses associated with scouring of mains for water quality purposes. - Prompt service response times to burst water mains. 20.0% 15.0% 10.0% 5.0% 0.0% Proportion Lost Water Supply Demand Strategy Daylesford System 16

17 - Measuring unaccounted water in all Daylesford zones. - Determine minimum nightly flow level - Viewing all remote pipeline alignments in Daylesford for visible signs of leakage, including leak detection on a yearly basis. - Relocation of all private service meters closer to the water main - Maintaining bulk meter accuracy through regular verification. Demand Management Demand for CHW supplied potable water has changed greatly over the last five years. The protracted dry climatic conditions and resulting shortages of surface water resources created a major change in attitudes and behaviours of CHW customers and CHW strategy and actions. CHW was prompted to accelerate demand management plans and develop new strategies for rapidly improving customer water efficiency and maintaining the improvements. Through CHW initiatives and the general severity of the supply situation, customer research indicates that customers developed an appreciation of how precious water resources are and now firmly believe that water is a precious resource that should be used sustainably. The research also indicates that the current attitudes and behaviours towards water conservation are strongly held and are unlikely to weaken significantly in the short term. Almost all of the Demand Management Initiatives, current and future considered, in the 2006 WSDS, have been successfully implemented already, with some still continuing. New initiatives not even considered at the time have also been implemented. The main initiative that was proposed, but did not proceed, was the Washing Machine Rebate Scheme. A washing machine rebate is however now available through the Victorian Government s new Living Victoria Rebate Program and is being promoted by CHW to its customers. With the combination of restrictions and a large variety of demand management activities it is challenging to separate out the impacts of individual initiatives. Estimated impacts of some major programs are given below and on-going end use analysis will allow the impact of device adoption and behaviour change (both temporary and in-grained) to become clearer as more detailed data collection and surveys are undertaken. Figures 2.15 and 2.16 show the initiatives listed in the 2006 WSDS. Figure Current Demand Management Initiatives Current Initiative Permanent Water Saving Rules Community Education program Supporting community events Media releases and advertising Customer newsletters Water saving information listed on the CHW website Retrofitting and rebates scheme National Water Week events and promotions Consumption reduction strategies for major consumers Large (non-residential) consumer efficiency program Five Star House Description Statewide regulations that conserve water usage Ongoing primary school education program CHW provide sponsorship and displays to promote water saving awareness Ongoing campaign to keep raise community awareness of water issues Household water saving information for customers Water saving information for household and commercial customers State Government s Water Smart Gardens and Homes Rebates Scheme to encourage installation of water efficient appliances Local events that raise awareness during National Water Week CHW liaise with the local shire, community groups, major customers and key stakeholders to explore demand reduction options and alternative water sources (such as wastewater reuse). Provision of assistance to large consumers to improve efficiency Energy and water efficiency legislation for new homes Water Supply Demand Strategy Daylesford System 17

18 Figure 2.16 Future Demand Management Initiatives under Consideration in 2006 Future Initiative Washing machine rebate scheme Exchange/Giveaway program Description Review of Drought Response Plan Actions A rebate scheme for CHW customers who purchase water efficient washing machines Program where CHW customers could exchange old showerheads for new water efficient showerheads (free of charge) or receive a free do-ityourself water efficiency kit for home installation. The Daylesford Drought Response Plan (DRP) was first developed in 2006, and is currently undergoing a review. See Figure 2.17 for a list of potential actions specified in the Daylesford DRP. Figure 2.17 Daylesford 2006 Drought Response Plan Potential Supply Options Option Current Status Key considerations Lake Jubilee Opportunity may exist to pipe water a short distance into the Wombat Water entitlement would need to be arranged pipeline, which is within close Quality of water and community proximity to Lake Jubilee. issues may need investigation Private dam on Daylesford-Trentham Road No pipeline or arrangements are currently in place. Water could be piped into the Bullarto pipeline or Water would need to be piped further than the Lake Jubilee option directly to the WTP. Potential difficulty in obtaining a Use of dead storage at Wombat Res Water cartage Dead storage can be pumped into the pipeline if levels became critically low Water cartage could be used for short term relief in extreme circumstances water entitlement Dead storage volume of only 8 ML Pumping costs Highly impractical Low yield, high cost Of the potential supply augmentation options listed in the 2006 Daylesford Drought Response Plan, none were acted upon. Upon further investigation, CHW established that the following actions were more appropriate: Use of Wallaby creek diversions Use of Hepburn Reservoir Commissioned Coomoora bore Water Supply Demand Strategy Daylesford System 18

19 3. WATER DEMAND FORECASTING General Water demand forecasts are a key component of developing effective water supply-demand strategies as they drive the need to implement measures that moderate demand, or investigate the provision of alternative and additional water supplies. CHW recognise the difficulty in establishing statistically accurate projections beyond a five-year period due to the wide range of factors that influence water demand and have used rigorous analysis of historical trends and developed forecasts using local and regional information. Figure 3.1 Factors Influencing Water Demand Source: Guidelines for the Development of a Water Supply-Demand Strategy (Version 2) Methodology CHW have based the water demand forecast on a demand model incorporating end use analysis of key demand sectors. This has allowed the impacts of water device adoption rates and changes in customer water use behaviours to be tracked. The model incorporates a weather correction module to allow differentiation between the impacts of annual variation in demand due to changes in temperature and rainfall, and changes in underlying demand caused by device adoption and customer behaviour in reaction to restrictions, supply issues and other external factors. The model also incorporates impacts of pricing and economic conditions. The model forecasts have been based on forecast trends in the adoption rates and assessments of the possible range of customer behaviours in reaction to the climate scenarios. Water Supply Demand Strategy Daylesford System 19

20 It should be noted that, due to the permanent impacts of device adoption rates, the model has demonstrated that unit demand rates are likely to remain low even assuming a return to customer behaviours (e.g. shower times, garden watering times) from pre-restriction drought conditions. In particular, the advent of rainwater and greywater systems, the adoption of water efficient devices (such as drip systems), the conversion to drought tolerant gardens and the increasing stock of smaller house blocks with reduced garden space, has reduced the potential rebound in outdoor potable water reuse even if garden watering behaviours are relaxed. Due to the large uncertainties regarding demand factor trends beyond the next water plan period, unit demands have been held constant beyond 2017/18. The future climate trends and changes in water device technologies will have an unpredictable impact on demand. CHW will continue to monitor these trends and update forecasts. It is planned that, if any signs of a demand re-bound appear, CHW will continue to design focused demand management initiatives to encourage customer behaviours that promote efficient water usage. The model has been used to generate a range of scenarios providing reasonable upper and lower bounds to future demand. The end use modelling for this system has initially been based on that for Ballarat due to data limitations. A separate end use model will be developed for this system as more local data is collected. Adopted growth rates Through the release of Victoria In Future 2008 (VIF) statistics, the Department of Sustainability and Environment (DSE) developed population projections for Statistical Local Areas across Victoria. The Daylesford water supply system lies within the Statistical Local Area (SLA) of Hepburn (S) East. The SLA also incorporates the rural areas surrounding Daylesford, small rural communities and the township of Trentham. In developing forecasts for the Daylesford system, VIF growth statistics have been used as the baseline for CHW forecasts, along with sensitivity tests against historic CHW water data and other local information. The VIF projected statistics suggest that growth is likely to occur for the Hepburn East SLA. CHW have elected to adopt a growth rate consistent with those projected by the VIF statistics for the Daylesford and Hepburn townships. Figure 3.2 Daylesford Projected Population and Connection Growth Rates Period Victoria In Future Projections Adopted Population Growth Adopted Connection Growth Decade Hepburn (S) East Daylesford Residential Non- Residential Concessional % 0.99% 0.78% 1.10% 1.10% % 0.92% 0.71% 1.00% 1.00% % 0.90% 0.70% 1.00% 1.00% % 0.90% 0.70% 1.00% 1.00% % 0.90% 0.70% 1.00% 1.00% The projections shown in Figure 3.2 form the base demand figures for future water demand in the Daylesford system and provide the basis of CHW s short, medium and long term planning to achieve an appropriate balance between supply and demand. The base demand figures used for Daylesford s water demand projections also include water savings due to strategies that CHW already have in place. These savings include reductions due to existing demand management initiatives and the proposed non-revenue water strategy Water Supply Demand Strategy Daylesford System 20

21 (details of which are listed in Figure 3.3). The introduction of Permanent Water Saving Rules (PWSR) in 2006 was a significant factor in reducing demand, and in changing community behaviour in relation to responsible water usage. However, CHW believe that PWSR s have a negligible ongoing effect on actual water savings, and any savings will now be part of the existing baseline demand. Figure 3.3 Daylesford Current Water Demand Assumptions Water Demand Savings Item Permanent Water Saving Rules Proposed Demand Management Strategy Non-revenue Water Strategy Residential Bulk Water Demand Projections Non- Residential Concessional Comments 0% 0% 0% Now form part of baseline demand 0% 0% 0% 10% 10% 10% Figure 3.4 gives the forecast bulk water demands for the planning period. Figure 3.4 Daylesford Projected Bulk Water Demand Committed to maintaining current estimated per capita consumption over the next 50 years. 50 year target as per CHW s draft Nonrevenue Water Strategy for Daylesford October 2011 The demand forecast adopted is based on a conservative selection of a scenario near the upper limit, making some provision for the uncertainties involved in whether there will be a return to pre-restriction customer behaviours. This provides a bias towards an early date for reaching the system yield. Water Supply Demand Strategy Daylesford System 21

22 4. FUTURE WATER CHALLENGE Climate change Perhaps the greatest uncertainty in assessing the future water demand against water yield is the potential impact of climate change. Although uncertainty exists, CHW can still undertake effective planning by considering a range of plausible scenarios that may eventuate, and developing plans to take the most appropriate action to deal with these circumstances. Yield estimates for the Daylesford system have been made based on the DSE Guidelines. These figures show that Daylesford has sufficient yield to service demand for at least the next few decades, including under the Return to Dry (Millennium Drought) scenario. Figure 4.1 Projected Demand and Current System Yield Gradual Climate Change Daylesford Projected Demand and Yield Volume (ML) Anticipated Bulk Demand - Gradual Demand Increase Yield under wet climate change Yield under median climate change Yield under dry climate change Figure 4.2 Water Requirement Projections Gradual Climate Change Projected Demand Wet Climate Change Dry Climate Change Year Forecast Water Yield Shortfall Water Yield Shortfall ML 1000 ML Nil 1000 ML Nil ML 989 ML Nil 936 ML Nil ML 954 ML Nil 744 ML Nil ML 926 ML Nil 672 ML 126 Return to dry climate change Following the severity of the dry conditions experienced during the past decade the DSE subsequently made the decision to consider a step climate change scenario. This strategic government decision and the severity of the drought necessitated the development of plans for a resumption of low inflows in CHW s water supply demand strategies. Under this scenario, historical data sets were adjusted to mirror the low inflow trends of the past decade. The approach assumes that a sudden shift or downward step is effective immediately and is equivalent to a return to dry climate change scenario. Water Supply Demand Strategy Daylesford System 22

23 Figure 4.3 and 4.4 depict the water supply and demand situation under a return to dry climate change scenario. This scenario also depicts an adequate buffer between water yield and water demand for at least the next 50 years, so there is little need for short-term future options under this scenario. Figure 4.3 Projected Demand and Current System Yield Return to Dry Climate Change Scenario Daylesford Projected Demand and Yield Volume (ML) Predicted Demand Yield under return to dry Figure 4.4 Water Requirement Projections Step Climate Change Projected Demand Return to Dry (Step Climate Change) Year Forecast Water Yield Shortfall ML 865 Nil ML 865 Nil ML 865 Nil ML 865 Nil Planning approach Through the development of this water supply demand strategy, CHW has adopted the most appropriate course of action, timing of options, and contingency plans to deal with the uncertainty and risk associated with drought and climate change. Annual reviews of the water resource situation will be undertaken, as well as a five yearly comprehensive review of the strategy, and future options will be implemented earlier than anticipated, if necessary. Water Supply Demand Strategy Daylesford System 23

24 5. DEMAND REDUCTION STRATEGIES CHW s current and future demand management strategies have and will continue to help to reduce the amount of additional water supplies that need to be used in the future. Demand reduction initiatives look towards improving water conservation through the achievement of greater efficiency, technological improvements and behavioural change. Current and future demand management initiatives The demand management initiatives outlined in Section 2 have achieved significant reductions in water demand for both residential and non-residential customers. Residential indoor demand has declined and is forecast to continue to decline as customers adopt, both consciously and through growth and natural replacement, water efficient devices. Residential outdoor demand has largely been supplied through alternative water sources (primarily rainwater tanks) and changes to community behaviours. Whilst there is expected to be some bounce-back in outdoor usage, it is expected that an increasing percentage of this will be serviced by alternative water. The non-residential and concessional demand is expected to remain low due to the impact of demand initiatives such as Water MAP which have reduced both process water demand, predominately through alternative water sources, and employee related demand. CHW will continue with a number of the current demand initiatives during the near future; however, given the very low demands currently being experienced, it is too early to identify new initiatives that may be able to have a significant impact. It is likely that there will be some increase in water usage if there is a return to dry hot summers and CHW will continue to monitor water demand patterns to identify any particular usages that are increasing and develop focused demand initiatives (or modify existing initiatives) to suit. The future savings that can be achieved will heavily depend on the balance between demand reductions with continued adoption rates and demand increases due to customer behavior bounce-back. Figure 5.1 Proposed Water Consumption Targets Water consumption Total water usage (per capita) Residential water usage (per capita) Daylesford System Litres/person/day Litres/person/day Current Unrestricted Demand and 2060 Target Demand Future water efficiency initiatives are expected to continue to focus on leading the community in water efficiency and sustainable use of our water resources, specifically aiming at maintaining customers good behaviours and high levels of water efficiency. CHW will continue to support Government initiatives such as rebates for water efficient devices and assistance to nonresidential customers with their water efficiency efforts. These targets and initiatives are driven by the community s intention of being water efficient and environmentally responsible, which CHW fully supports and encourages. There is no projected supply demand imbalance in the short to medium-term. In the short-term CHW will continue to support the current initiatives listed above. CHW will continue to monitor the situation and remain ready to respond to changes. The medium to longterm outlook will depend on a number of factors, especially the effects of climate variability and the availability of water supply, Government direction and community consultation. There is also an expectation that technology improvements over the next 50 years will create natural improvements in the efficiency of water-use applications. Water Supply Demand Strategy Daylesford System 24

25 Non-revenue water CHW is currently reviewing the non-revenue water strategy for all water supply systems and a key component of this review is likely to be the announcement of a 10% overall target for nonrevenue water by To achieve this, a target of 10% non-revenue water is likely to be set for the Daylesford system. See Figure 5.2 for details on non-revenue water targets and performance for Daylesford, note that all figures relate to Distribution Losses, which corresponds to information shown in Figure Figure 5.2 Summary of Daylesford Non-revenue Water Performance and Targets Daylesford NRW (FY2010/11) Daylesford Long-term Average NRW Proposed Daylesford System NRW Target Overall CHW NRW Target 14% 25% 10% 10% Future non-revenue water initiatives for Daylesford will not only include a renewed commitment to current initiatives, but will also include:. The replacement of existing Break Pressure Pits (BPP) with new Pressure Reduction Valves (PRV) and the installation of new flow meters and pressure sensors linked to CHW s SCADA system, to ensure an increased capability to promptly detect and locate bursts and leaks within the system. The creation of Pressure Management Areas (PMA) through the installation of additional PRVs to reduce pressure, and leakage rates within the Daylesford system. Water Supply Demand Strategy Daylesford System 25

26 6. SUPPLY ENHANCEMENT OPTIONS The Daylesford water supply system has sufficient capacity to service the forecast demand until at least 2040, as discussed in Section 4, based on conservative demand scenarios and adopting the worst cast Return to Dry scenario. CHW will continue to assess Daylesford s water demand growth and the effects of climate change to ensure that an appropriate balance between supply and demand is maintained. CHW is also reviewing opportunities to modify existing system strategies to address the reform principles provided in the Living Melbourne, Living Victoria Roadmap. Potable Water Initiatives The rate of population growth in the Daylesford area and the previous shortfalls between water yield and water demand identified the need for an additional water supply source. CHW has recently secured additional ground water supply from Coomoora bore, which is licensed for an annual volume of 273 ML/year. The water supply resources available at Daylesford appears to be adequate for at least the next 30 years, even with the anticipated population growth and any reductions in water yield due to climate change. A shortfall of 126 ML is predicted under the dry climate change scenario in CHW will establish comprehensive operating rules for the operation of Coomoora bore/hepburn Reservoir, as part of a broader plan to optimise the use of all available water sources for the Daylesford system. This will include a study into the treatment options for the Coomoora bore, as it could be utilised during dry seasons to conserve water storages in Bullarto Reservoir and Wombat Reservoir. CHW will conduct investigations to improve the delivery capacity of the Bullarto raw water main, as it is currently unable to deliver sufficient volume to supply Daylesford independently. Alternative Water Initiatives CHW is currently undertaking a review of its re-use strategy for wastewater to identify any further opportunities for re-use. Demand Initiatives Demand is currently at the estimated non-restrictable level of demand, limiting the options for new demand initiatives. Continual monitoring of demand levels will be undertaken to identify any signs of bounce-back. Current demand initiatives will be modified or new initiatives will be undertaken to provide a focused response to the identified nature of the bounce-back. Contingency options CHW have identified contingency options to establish additional water supply options if required due to unexpected circumstances. The two possible options are: Enlargement of Bullarto Reservoir or the construction of a new offstream raw water basin, and; Development of additional local groundwater sources. These options are unlikely to be required in the short term to medium term, but CHW have the capacity to introduce these options earlier than expected, if necessary. Water Supply Demand Strategy Daylesford System 26