1. Introduction About this Document Context Drought Response Plan Scope Drought Response Plan Purpose...

Transcription

1 Drought Response Plan Western Water August 2012

2 Contents 1. Introduction About this Document Context Drought Response Plan Scope Drought Response Plan Purpose Objectives of Drought Response Plan Structure of Drought Response Plan System Context System Description Past Drought Experience Legal and Institutional Context Water Entitlements Permanent Water Savings Rules Water Restriction By-Laws Drought Response Options Introduction Demand Reduction during Drought Supply Augmentation During Drought Drought Response Action Plan Introduction Normal Operation Drought Response: Stage 1 Stage 4 Drought Response Actions Updating Actions During Drought Lifting of Restrictions and Restriction Levels Pre and Post Drought Evaluation Preparing for Drought Post Drought Phase Evaluation and Revision Updating of the Drought Response Plan Knowledge Gaps References Ref: WATER-PLAN-DROUGHT RESPONSE Page 2 of 55 Uncontrolled when Printed

3 Table Index Table 1 Planning and Operational Objectives 7 Table 2 Rosslynne System Bulk Entitlements 24 Table 3 Romsey Bulk Entitlement Summary 25 Table 4 Lancefield Bulk Entitlement and Groundwater Licence Summary 25 Table 5 Woodend Bulk Entitlement Summary 26 Table 6 Werribee Bulk Entitlement Summary 27 Table 7 Myrniong Bulk Entitlement Summary 28 Table 8 Permanent Water Savings Rules Summary (Source: Western Water, 2012b) 29 Table 9 Demand Reduction Options During Drought 30 Table 10 Water Restriction Demand Reduction Estimate 31 Table 11 Options for Augmenting Supply 33 Table 12 Summary of Storage Capacities 34 Table 13 Supplementary Supply Sources 43 Figure Index Figure 1 Western Water's water supply system 5 Figure 2 Merrimu Reservoir at 9.7% (Western Water, 2009) 6 Figure 3 Rosslynne Water Supply System 10 Figure 4 Gisborne Alternative Water Supply System 10 Figure 5 Romsey Water Supply System 11 Figure 6 Lancefield Water Supply System 12 Figure 7 Woodend Water Supply System 13 Figure 8 Macedon and Mt Macedon Water Supply System 14 Figure 9 Werribee and Myrniong Water Supply Systems 15 Figure 10 Regional Rainfall (Source: Melbourne Water) 16 Figure 11 Western Water Demand and Restriction Level History 17 Figure 12 Estimated Rosslynne System Inflows 18 Figure 13 Rosslynne Reservoir at 3% Capacity 19 Figure 14 Campaspe Reservoir, Woodend 20 Figure 15 Estimated Werribee System Inflows 21 Appendices A Water Security Outlook B Water Restriction By-Law 11/11 Ref: WATER-PLAN-DROUGHT RESPONSE Page 3 of 55 Uncontrolled when Printed

4 1. Introduction 1.1 About this Document This is the 2012 update of Western Water s Drought Response Plan. Western Water s previous DRP was developed in 2005 (Western Water, 2005). The 2012 DRP has adopted the same objectives as the previous DRP, as well as any actions that are still relevant to the current Western Water supply systems. 1.2 Context Established under the Water Act 1989, Western Region Water Corporation (trading as Western Water) is one of Victoria s thirteen regional urban water corporations. Western Water provides water, sewerage and recycled water services to over 56,000 properties across an area of 3,000 square kilometres. The region serviced by Western Water is located to the west of Melbourne, extending from Rockbank in the south to Lancefield in the north, as shown in Figure 1. Western Water has access to a diversified water supply, including water harvested from local catchments, groundwater, recycled water, and water from the Melbourne supply system. The region s population has grown by 3.9% in the past year to exceed 150,000 and is forecast to surpass 275,000 by During 2010/11, 10,251 ML of drinking water was consumed in the region. Treatment plants received 8,442 ML of sewage and produced 7,992 ML of recycled water, of which 51% was reused. Western Water operates under the Statement of Obligations issued under Section 4i of the Water Industry Act The purpose of the Statement of Obligations is to clarify the obligations of Western Water, including the requirement in Item 18 (Responding to Drought): To develop and implement a drought response plan for each water supply system operated; Make its drought response plans available to the public; and Review and if necessary amend the drought response plans at an interval of no more than 5 years or within 12 months of lifting water restrictions or any major change to water supply arrangements. 1.3 Drought Response Plan Scope This Drought Response Plan (DRP) will be used by Western Water to guide the organisation in making decisions about appropriate actions to manage potential water shortages. As all water shortage situations are different this DRP should be used as a guide only, and adjustments should be made based on the specifics of each water shortage event. The DRP has been developed based on the current Western Water supply systems using the information available at the time of its development. This DRP should be reviewed and updated following any significant changes to the Western Water supply system or demand and supply information. Ref: WATER-PLAN-DROUGHT RESPONSE Page 4 of 55 Uncontrolled when Printed

5 Figure 1 Western Water's Water Supply System (Western Water, 2011) Ref: WATER-PLAN-DROUGHT RESPONSE Page 5 of 55 Uncontrolled when Printed

6 1.4 Drought Response Plan Purpose There are two main components involved in planning water supply systems for periods of water shortage, these are: the provision of a supply system that satisfies current and future demands, ensuring that potential future shortfalls are minimised; and ensuring that when shortfalls in supply are possible, a range of appropriate response mechanisms are available. The first of these components represents the long term planning actions that determine the level of infrastructure development required to provide an adequate supply. This long term planning is outlined in Western Water s Water Supply Demand Strategy (Western Water, 2012). The second component relates to short term management actions that are available to Western Water to manage through periods of water shortage. This short term planning is the focus of this DRP. A DRP is designed for use by water resource managers and provides a mechanism by which drought may be responded to systematically and rationally thereby minimising the social, economic and environmental impacts of drought. A Drought Response Plan considers all aspects of drought response planning including pre and post drought actions, identification of supply augmentation, demand reduction options and a sequential action plan to be followed during periods of drought. This Drought Response Plan (DRP) for Western Water has been designed to comply with the principles of DRPs, as set out by the Department of Sustainability and Environment (DSE). Figure 2 Merrimu Reservoir at 9.7% (Western Water, 2009) Ref: WATER-PLAN-DROUGHT RESPONSE Page 6 of 55 Uncontrolled when Printed

7 1.5 Objectives of Drought Response Plan The major objective of this DRP is to: Provide for efficient and effective management of water supply to Western Water s customers during times of water shortage. This strategic objective will be met whilst also meeting specific planning and operational objectives, as detailed in Table 1. Table 1 Planning and Operational Objectives Planning Objectives Identify key actions that should be taken to effectively manage Western Water s water resources during various stages of drought, including clear triggers that instigate these actions Create a framework for regular review, as the supply system alters or as more information becomes available, both prior to and following a drought event. Establish methods for reviewing the plan both during and following the implementation of drought response plan actions, and making adjustments where required. Operational Objectives Ensure that drought response actions, including water restrictions, are aligned with those for the Melbourne water supply system. Ensure that back up drought response actions (not aligned to the Melbourne system) are available for each system to maintain minimum storage reserves under emergency conditions. Provide clear indicators to ensure a reliable assessment of drought status can be made by Western Water. Ensure minimum flows are maintained to meet any downstream operational commitments or environmental requirements. 1.6 Structure of Drought Response Plan This DRP includes: A summary of each system, including a physical description, the current security of supply and the historic drought experience of each township (Section 2); The legal and institution context for drought response (Section 3); A review of the options for augmenting supply in each system during drought (Section 4); A sequential plan of action for responding to drought (Section 5); and Pre and post drought actions to ensure preparedness for drought (Section 6). Ref: WATER-PLAN-DROUGHT RESPONSE Page 7 of 55 Uncontrolled when Printed

8 2. System Context 2.1 System Description This Drought Response Plan for Western Water covers six main systems as follows: Rosslynne System The Rosslynne system comprises all the Western Water urban water supply systems in the Maribyrnong Basin supplied primarily from Rosslynne Reservoir and the Melbourne Headworks system (Melbourne system). The townships included in the Rosslynne system are Sunbury, Diggers Rest, Bulla, Gisborne, Riddells Creek, Macedon and Mt Macedon. Sunbury was connected to the Melbourne system in March 2000, with Gisborne, Riddells Creek, Macedon and Mt Macedon connected in May Romsey System The Romsey system is located in the Maribyrnong Basin, and receives most of its supply from Bolinda Creek (Kerrie Reservoir) and Main Creek (Forster and Wright Reservoirs). Romsey can also receive a supplementary supply from Rosslynne Reservoir and the Melbourne system via Wright Reservoir. Lancefield System The Lancefield system is located within the Maribyrnong Basin, and receives supply from Garden Hut Reservoir and groundwater. Unlike other Western Water systems in the Maribyrnong Basin, Lancefield has no supplementary supply from Rosslynne Reservoir or the Melbourne system. Woodend System The Woodend system is located in the Campaspe Basin, and is supplied predominantly from Campaspe Reservoir and Reservoirs B and C on the north side of Mount Macedon. Woodend also receives a supplementary supply from transfers from the Macedon and Mt Macedon system (part of the Rosslynne system). Werribee System The Werribee system comprises all the Western Water urban water supply systems in the Werribee Basin supplied from Merrimu and Djerriwarrh Reservoirs and the Melbourne system. The townships included in the Werribee system are Melton, Bacchus Marsh, Rockbank and Toolern Vale. Melton and Bacchus Marsh were connected to the Melbourne system in April Myrniong System The Myrniong system is supplied from Pykes Creek Reservoir, located on Pykes Creek in the Werribee catchment. Water is supplied to Myrniong from a pumping station at Pykes Creek Reservoir. System descriptions for each of the supply systems are presented in the following sections. Ref: WATER-PLAN-DROUGHT RESPONSE Page 8 of 55 Uncontrolled when Printed

9 2.1.1 Rosslynne System The Rosslynne system supplies the townships of Sunbury (including Diggers Rest and Bulla), Gisborne, Macedon, Mt Macedon, Riddells Creek, as well as providing supplementary supply to the township of Romsey. The system services a population of approximately 60,200 people, with an estimated current average annual demand of around 4,420 ML/year. The Rosslynne system receives supply from Rosslynne Reservoir and the Melbourne system. Rosslynne Reservoir, located on Jackson Creek in the Maribyrnong catchment, is operated by Southern Rural Water under the constraints of the Bulk Entitlement (Maribyrnong system Western Water) Conversion Order. The reservoir has a capacity of around 25,000 ML, of which Western Water has an 86% storage share (the remaining storage shares are held by Southern Rural Water and Melbourne Water). Passing flow from Rosslynne Reservoir is shared according to the capacity share arrangements. Water is released from Rosslynne Reservoir to meet passing flow obligations at the following locations: Jacksons Creek at Gisborne, Jacksons Creek at Sunbury, and Maribyrnong River at Keilor. The passing flow requirement at Sunbury is 1ML/day, which requires releases of up to 6ML/day from Rosslynne Reservoir. Inflows to Western Water s share of Rosslynne are supplemented by transfers from the Melbourne system and the Macedon and Mt Macedon system (refer Section 0). Water supplied from Rosslynne Reservoir is treated in the Rosslynne Water Filtration Plant (WFP), with supply limited to a capacity of around 35 ML/d. Treated water from the Rosslynne WFP can be supplied to Sunbury (including Diggers Rest and Bulla), Gisborne, Macedon, Mt Macedon and Riddells Creek. Sunbury was connected to the Melbourne system in March 2000, with Gisborne, Riddells Creek, Macedon and Mt Macedon connected in May Romsey has since been connected to the Rosslynne system, via Wright Reservoir. The pipeline from the Melbourne system has the capacity to supply at a rate of up to 35 ML/day, although this can be limited when demands on the Melbourne system are high. The Riddells Road pump station delivers Melbourne system water from Sunbury to Gisborne, Riddells Creek, Macedon, Mt Macedon and Gisborne, and has a normal operating capacity of up to 9 ML/d (or 13 ML/d if required). Macedon and Mt Macedon have access to alternative untreated supplies from the Macedon and Mt Macedon for short term emergency use in the event of a supply system failure from the Rosslynne system. Gisborne also has access to alternative untreated supplies from the Barringo Creek system, for emergency use. Figure 3 shows a schematic of the Rosslynne system Gisborne Emergency Supply While Gisborne now receives all its supply from Rosslynne Reservoir and the Melbourne system, it has access to an alternative untreated supply from the Barringo Creek system, for emergency use. The Barringo Creek system formerly supplied the township of Gisborne, under the Bulk Entitlement (Gisborne Barringo Creek) Conversion Order While water from the Barringo system can no longer be treated, raw water is taken under the Bulk Entitlement for fire fighting purposes. A schematic of the Barringo Creek system is shown in Figure 4. Ref: WATER-PLAN-DROUGHT RESPONSE Page 9 of 55 Uncontrolled when Printed

10 Figure 3 Rosslynne Water Supply System Figure 4 Gisborne Alternative Water Supply System Ref: WATER-PLAN-DROUGHT RESPONSE Page 10 of 55 Uncontrolled when Printed

11 2.1.3 Romsey System Romsey is a township of approximately 4,600 people, with an estimated current average annual demand of around 330 ML/year. Romsey receives most of its supply from Bolinda Creek (Kerrie Reservoir) and Main Creek (Forster and Wright Reservoirs). Water supplied to Romsey (including supply from Rosslynne Reservoir and the Melbourne system) is treated in the Romsey WFP. While Romsey can now receive a supplementary supply from Rosslynne Reservoir and the Melbourne system (via Wright Reservoir), a large part of its supply continues to be sourced from small local storages, including Kerrie, Wright and Forster Reservoirs. Supply to Romsey has historically been from Kerrie Reservoir, an off-stream storage that stores inflow diverted from a weir on the upper reaches of Bolinda Creek. Kerrie Reservoir was enlarged in 1983/84 to its current capacity of 295 ML. Water from Kerrie Reservoir is transferred by gravity to the Glenfern Service Basin, a balancing storage basin of 45 ML capacity. Romsey has a high level supply zone, which is served by a pump station and a 0.45ML tank. The rest of the town is supplied by gravity. The Romsey water supply system has been disinfected and treated since mid More recently, Romsey has also received supply from the former Riddells Creek system, with water transferred to Kerrie Reservoir from Wright Reservoir. Under this arrangement, flow is diverted from Main Creek and stored in Forster Reservoir (18 ML capacity) and Wright Reservoir (55 ML capacity), before being pumped to Kerrie Reservoir. A schematic of the Romsey system is shown in Figure 5. Figure 5 Romsey Water Supply System Ref: WATER-PLAN-DROUGHT RESPONSE Page 11 of 55 Uncontrolled when Printed

12 2.1.4 Lancefield System Lancefield is a township of approximately 2,100 with an estimated current average annual demand of around 230 ML. Water for the system is currently sourced from groundwater bores in conjunction with surface water diversions from Garden Hut Reservoir (45 ML capacity), on Garden Hut Creek, and a diversion weir on Monument Creek (although this diversion has not been used for many years). From Garden Hut Reservoir, water is transferred to Lancefield Basin (55 ML capacity), with a maximum transfer rate of 0.7 ML/d. From Lancefield Basin, water is treated at the Lancefield WFP, with a capacity of 2.5 ML/d, before being supplied to customers. Groundwater supply to Lancefield is from two bores (Bores No. 2 and No. 3), located near the township. Bore No. 2 is located within the Lancefield Groundwater Management Area. Bore No. 3 was completed in February 2000 and replaced the now decommissioned Bore No. 1, which previously provided supply to Lancefield. Bore No. 2 was upgraded in 2002 to improve its construction and yield. The bores are between 42 and 60 meters deep and penetrate the local fractured basalt aquifer. These supply sources are managed within the limits described in the existing groundwater extraction licences and the Bulk Entitlement (Lancefield) Conversion Order In recent years, low summer flows combined with insufficient storage capacity have resulted in the increased utilisation and reliance on groundwater. Use of the groundwater is constrained by its quality, requiring blending with surface water supplies from Garden Hut Reservoir. Figure 6 shows a schematic of the Lancefield system. Figure 6 Lancefield Water Supply System Ref: WATER-PLAN-DROUGHT RESPONSE Page 12 of 55 Uncontrolled when Printed

13 2.1.5 Woodend The Woodend water supply system supports a population of approximately 5,400 people, with an estimated current average annual demand of around 410 ML/year. The Woodend system receives supply from Campaspe Reservoir, on the Campaspe River, some local creeks and springs, and the Macedon and Mt Macedon system. Schematics of the Woodend system and the Macedon and Mt Macedon system are presented in Figure 7 and Figure 8 respectively. Campaspe Reservoir is operated by Western Water under the Bulk Entitlement (Woodend) Conversion Order 2004, and has a capacity of around 245 ML. Typically the Campaspe Reservoir is used to supply winter and part of summer demand to Woodend. Water from Campaspe Reservoir is treated at the Marriages Basin WFP and stored in the Marriages Basin (5 ML capacity), before being supplied to Woodend. Supply from the Marriages Basin WFP is limited to a capacity of around 3.5 ML/d. Woodend also receives supply from a diversion weir on Falls Creek and from Kavanagh and Barbour Springs. Water from these sources is transferred to Reservoir B (26 ML capacity) and Reservoir C (75 ML capacity). Reservoirs B and C are typically used to supplement the Campaspe Reservoir supply to Woodend during summer. Under its Bulk Entitlement, Western Water also has access to diversions from Smokers Creek, although such diversions are not possible with the current supply infrastructure. A groundwater bore at Straws Lane is no longer operated, but may be available for emergency use. Woodend also receives a supplementary supply from the former Macedon and Mt Macedon supply system. This system comprises the Orde Hill Reservoir (250 ML capacity), located on Willimigongon Creek. As well as storing Willimigongon Creek inflows, Orde Hill Reservoir can receive diversions from Andersons Reservoir (3.8 ML capacity) and McDonalds Reservoirs (87 ML capacity), on Turritable Creek. Water from Orde Hill is transferred downstream to Willimigongon Reservoir (15 ML capacity), to which water can also be diverted from Gillespies Weir, on Turitable Creek. Water from Willimigongon Reservoir can be diverted via the Link Main into Reservoir B. Water from Kitty English and Frank Mann Reservoirs can be pumped to Woodend. Figure 7 Woodend Water Supply System Ref: WATER-PLAN-DROUGHT RESPONSE Page 13 of 55 Uncontrolled when Printed

14 Figure 8 Macedon and Mt Macedon Water Supply System Werribee System The Werribee system supplies the townships of Melton, Bacchus Marsh, Rockbank, and Toolern Vale. The system services a population of approximately 78,000 people, with an estimated current average annual demand of around 6,150 ML/year. The Werribee system receives supply from Merrimu Reservoir, Djerriwarrh Reservoir and the Melbourne system. Merrimu Reservoir, located on Pyrites Creek in the Werribee catchment, is operated by Southern Rural Water under the constraints of the Bulk Entitlement (Werribee System Western Water) Conversion Order. In addition to supplying Western Water urban demands, Merrimu Reservoir supplies irrigation water to the Werribee Irrigation District. The reservoir has a capacity of around 32,000 ML, of which Western Water has a 60% storage share (the remaining storage shares are held by Southern Rural Water and the environment (Melbourne Water), or are unallocated). The primary supply for the system is Merrimu Reservoir, with supplementary supply from Djerriwarrh Reservoir under some circumstances. Water use from Djerriwarrh Reservoir is constrained by quality, requiring blending with water from Merrimu Reservoir. Water supplied from Merrimu and Djerriwarrh Reservoirs is treated in the Merrimu WFP. Treated water from the Merrimu WFP can be supplied to Melton, Bacchus Marsh, Rockbank and Toolern Vale. The Werribee system was connected to the Melbourne system in April The pipeline from the Melbourne system has the capacity to supply at a rate of up to 38 ML/day, although this can be limited when demands on the Melbourne system are high. Figure 9 shows a schematic of the Werribee system. Ref: WATER-PLAN-DROUGHT RESPONSE Page 14 of 55 Uncontrolled when Printed

15 Figure 9 Werribee and Myrniong Water Supply Systems Myrniong System Myrniong is a township of approximately 300 people, with an estimated current average annual demand of around 25 ML/year. The Myrniong system is supplied from Pykes Creek Reservoir, located on Pykes Creek in the Werribee catchment, and operated by Southern Rural Water. Water is supplied to Myrniong from a pumping station immediately downstream of Pykes Creek Reservoir, with water pumped to a small service reservoir. Water is treated at the Myrniong WFP, before being supplied to customers. A schematic of the Myrniong system is shown in Figure Past Drought Experience Documenting the history of drought in the Western Water systems is important in ensuring that the experience of drought is progressively incorporated into future drought planning. In general, drought has been shown to have some of the following impacts on local communities: Loss of amenity for the community due to the deterioration of plants, gardens and sporting facilities; Financial loss to the community, incurred whilst restoring services to pre-drought conditions; Inconvenience to the community caused by forcing users to alter their water use practices; Financial loss to local businesses and agriculture; Stress on in-stream flora and fauna; Ref: WATER-PLAN-DROUGHT RESPONSE Page 15 of 55 Uncontrolled when Printed

16 Reductions in revenue for water authorities caused by restrictions on consumption; and Increased expenses for water authorities incurred in promoting and enforcing restrictions, additional system management and administration and providing emergency supplies Western Water Region The region serviced by Western Water is situated to the west of Melbourne. Average rainfall in the Western Water region is less than half that in Melbourne s water supply catchments to the east and north of Melbourne. This is illustrated in Figure 10, which shows mean annual rainfall in the Melbourne region. The dry climate to the west of Melbourne, represented as orange and red areas, includes the region serviced by Western Water. The Western Water region has a long history of drought. The lack of reliable inflows and the drought of 1967/68 led to the construction of the Rosslynne and Merrimu storages in the late 1960s and early 1970s, in order to improve the reliability of supply from the Maribyrnong and Werribee catchments. Dry conditions over the past ten years have resulted in significantly reduced inflows to Western Water s supply systems, to the extent where local water supplies were unable to meet demand from Western Water customers. The recent extended dry period led to the connection of Western Water s supply systems to the Melbourne system, with Sunbury connected in March 2000, Bacchus Marsh and Melton in April 2004, and Gisborne, Riddells Creek and Macedon and Mt Macedon in May A history of recent demand and predominant restriction levels for the Western Water region is presented in Figure 11. Figure 10 Regional Rainfall (Source: Melbourne Water) Ref: WATER-PLAN-DROUGHT RESPONSE Page 16 of 55 Uncontrolled when Printed

17 Figure 11 Western Water Demand and Restriction Level History Rosslynne System The Maribyrnong Basin has historically had highly variable rainfall and streamflow. This high variability has led to severe droughts on a number of occasions over the past 100 years, as shown in the estimated annual inflows to the Rosslynne system presented in Figure 12 (which includes the period prior to the completion of Rosslynne Reservoir in 1971). Within the last 50 years, notable droughts have included the droughts of 1967/68, 1981/82, 1994/95 and the Millennium Drought ( ). The 1967/68 drought saw relief bores sunk in the Shire of Romsey at Riddells Creek and at Monegeetta. Although these bores have since been abandoned, a number of new bores currently exist in the area, including those that supply Lancefield and the test bore at Romsey. The drought of 1967/68 also brought hardship to the Sunbury and Gisborne areas and the Trusts of the time sank bores to try to boost their dwindling supplies. Two of these bores are still visible from the Kilmore-Gisborne Road, but they have not operated for more than 20 years and there is scant information available about them. The drought of 1967/68 served as a trigger for the construction of the Rosslynne Storage. In more recent times, consumers supplied from this source have been on low level restrictions through some summers. Drought again began to impact on the Maribyrnong system in the summer of Sunbury, Gisborne and Riddells Creek experienced stage 3 restrictions (of the then 8 stage policy) from October 1998 to November Macedon and Mt Macedon were not subjected to restrictions at the time as they were still utilising the independent Macedon storages system as a main supply source (for untreated water). A water conservation campaign aimed at raising community awareness of water use and at encouraging responsible water use was implemented in the summer of The mascot used for this campaign was Sammy the Snake. Ref: WATER-PLAN-DROUGHT RESPONSE Page 17 of 55 Uncontrolled when Printed

18 The Millennium Drought which commenced in 1998 and broke in 2010 was the most severe on record, certainly in terms of duration. Average inflows to the Rosslynne system during this period were significantly below average, as shown in Figure 12. This drought caused a number of measures to be introduced including: Water restrictions to Stage 4a (modified Stage 4) in most towns in the Rosslynne system; Construction of the supplementary supply from the Melbourne system to Sunbury, which was commissioned in March 2000; Construction of a pipeline between Macedon and Rosslynne, completed in June 2001; Commissioning of the pump station (May 2004) to deliver water sourced from the Melbourne system, surplus to Sunbury s demands, to Gisborne, Riddells Creek, Macedon and Mt. Macedon. The delivery capacity exceeds 4ML/day. Intensification of the community water conservation campaign; Acceleration of the program for substitution of recycled water; Air scouring of water mains was temporarily discontinued; and Temporary amendments were obtained to relax some of the passing flow requirements stipulated in the Bulk Entitlements. Although Macedon and Mt Macedon are now supplied from Rosslynne Reservoir, the operational commissioning of the pipeline connecting Sunbury to Melbourne Water's supply system in March 2000 has since eased the demand on the Rosslynne system. In addition, surplus water from the Macedon storages (Orde Hill, Willimigongon, McDonalds, Andersons, Kitty English and Frank Mann Reservoirs) can now be transferred via the Link Main (between March and November, and based on certain flow and storage conditions) to supplement inflows to Rosslynne Reservoir. Figure 12 Estimated Rosslynne System Inflows Ref: WATER-PLAN-DROUGHT RESPONSE Page 18 of 55 Uncontrolled when Printed

19 Figure 13 Rosslynne Reservoir at 3% Capacity (Western Water, 2009) Romsey System Restrictions in Romsey were applied in 1982/83 due to drought and in 1983/84 during the re-construction of Kerrie Reservoir. Stage 3 restrictions (of the then 8 stage policy) were applied again from April 1998 to October In March 1991 the (then) Romsey-Lancefield Water Board saw the need to introduce Stage 3 restrictions for the Township of Lancefield. This was due to the drawdown on its surface water storages (Lancefield and Garden Hut Reservoirs) and to problems with one of its groundwater bores. On the whole, restrictions were accepted favourably, perhaps due to the prior history of water shortage in the district. Further restrictions for Lancefield were implemented in March 1992 (Stage 2) and in December 1994 (Stage 3). Bore No 2 was upgraded in Ref: WATER-PLAN-DROUGHT RESPONSE Page 19 of 55 Uncontrolled when Printed

20 The Millennium drought, from 1998 to 2010, lead to a number of measures to be introduced in the Romsey system including: The emergency bore in Romsey was brought into operation from December 2002; and The pipeline from Wrights Reservoir to Kerrie Reservoir was commissioned in February Woodend System One of the worst affected supply systems in the 1982/83 drought was Woodend. In July 1982 there was only 20 ML of water in storage in the system (about 4 weeks supply). Substantial effort was spent in searching for alternative supplies; bores were drilled, water was carted from local dams and extensive carting from outside the district was considered. At the end of November 1982 the (then) Trust asked for Governor in Council approval to restrict domestic supplies to 40 L per person per day with discretion to reduce this to 20 L per person per day if the situation failed to improve. The occurrence of rain deferred this decision, but later in the season the Trust was again forced to cart water to maintain supply for its customers. Records show that a total of 9,255 KL of water were carted during February and March of The Millennium drought, from 1998 to 2010, led to the construction of a pipeline from the Macedon and Mt Macedon system to provide supplementary supply to Woodend. With Macedon and Mt Macedon demands now supplied from Rosslynne Reservoir, surplus water in the Macedon storages can also be transferred to supplement Reservoir C in the Woodend system. Water from Kitty English and Frank Mann Reservoirs can also be pumped into Reservoir C. Figure 14 Campaspe Reservoir, Woodend (Western Water 2009) Ref: WATER-PLAN-DROUGHT RESPONSE Page 20 of 55 Uncontrolled when Printed

21 2.2.5 Werribee System The Werribee system has a long history of drought. Growing demand for agriculture and urban water supplies, combined with a dry period immediately post 1960, led to the construction of Merrimu Reservoir in 1969 to secure water supplies. The high variability of streamflow in the Werribee Basin is illustrated in Figure 15, which presents estimated annual inflows to the Werribee system (which includes the period prior to the construction of Merrimu Reservoir in 1969). Notable droughts within the past 50 years have included the droughts of 1967/68, 1981/82, 1994/95 and the Millennium Drought ( ). The Township of Melton experienced Stage 4 and 5 restrictions (8 stage policy) between September 1982 and September These restrictions were necessary due to a reduction in allocation of supply from Merrimu Reservoir by the (then) Rural Water Commission to 75% of the previous year s consumption. Djerriwarrh Reservoir, which had been used in the previous winter, was empty during the period of restrictions. The application of restrictions during 1982/83 appears to have worked well, with good co-operation from consumers. The progress of the drought and details of restrictions and demand targets were well advertised in local newspapers at the time. Only a few complaints were recorded on file. Figure 15 Estimated Werribee System (Merrimu Reservoir) Inflows The Millennium drought which commenced in 1998 caused water restrictions up to modified stage 4 to be applied in the Werribee system. In addition to implementation of the water conservation campaign, a number of other drought management options were considered. The following actions were implemented: Following negotiation with Southern Rural Water and the Department of Natural Resources and Environment, the entire volume of unallocated water (4,900 ML) in Lake Merrimu was made available to Western Water as a temporary transfer. A total volume of 985 ML of water was purchased in 1999/2000 through a temporary transfer of water right from rural irrigators being supplied from Lake Merrimu. Ref: WATER-PLAN-DROUGHT RESPONSE Page 21 of 55 Uncontrolled when Printed

22 Supply to the system was further supplemented with water from Djerriwarrh Reservoir, with approximately 400 ML/annum being used. This water was mixed with water from Lake Merrimu prior to being passed through the treatment plant. The pipeline connection to the Melbourne Supply system at Sydenham as a means of supplementing the Merrimu Reservoir supply to Melton and Bacchus Marsh was also implemented by April Supplies of up to 41 ML/day are drawn from this source. The possibility of transferring water from alternative storages (including Newlyn, Colebrook and Lal Lal Reservoirs) was also investigated, but found not to be feasible and the Melbourne to Melton pipeline that was implemented does not make provision for this option. If implemented, water was to have been delivered to Ballan via existing pipelines, transferred into the Werribee River at Ballan and finally stored at Pykes Creek Reservoir. A transfer of water right involving Southern Rural Water between the Merrimu and Pykes Creek storages would then have resulted in an increase in Western Water s capacity share of storage at Lake Merrimu. A primary difficulty with this alternative as a drought response measure was the lack of available water at Lake Merrimu to affect the water right transfer from Pykes Creek Reservoir. Difficulties associated with arranging the physical link between the alternative storages and Pykes Creek Reservoir were also identified. The unallocated entitlement volume in Lake Merrimu was purchased on a temporary basis. However the absence of any significant inflow meant that Western Water s share of storage in Merrimu (including the unallocated share) continued to draw down and had reached approximately 1,500 ML by the end of April By this time however Bacchus Marsh and Melton were able to draw their whole supply from the Melbourne system as a new connection had been commissioned. The system operates under gravity and can be boosted by pumping. The gravity supply was operational from late January 2004 and the pump station was commissioned during April Ref: WATER-PLAN-DROUGHT RESPONSE Page 22 of 55 Uncontrolled when Printed

23 3. Legal and Institutional Context 3.1 Water Entitlements Western Water supplies water from its various sources under the provisions of the Water Act The quantity of water harvested, and the rate at which it may be taken, are governed by: Bulk entitlements governing surface water resources; and Groundwater licences governing groundwater resources. The details of the bulk entitlements and groundwater licences held by Western Water are presented below Rosslynne System Water supplied from Rosslynne Reservoir is taken under the Bulk Entitlement (Maribyrnong Western Water) Conversion Order 2000, while water supplied from the Melbourne system is taken under the Bulk Entitlement (Melbourne Headworks System Western Water) Conversion Order Water transferred to Rosslynne Reservoir from the Macedon and Mt Macedon system is taken under the Bulk Entitlement (Macedon and Mount Macedon) Conversion Order Water is taken from the Barringo Creek system under the Bulk Entitlement (Gisborne Barringo Creek) Conversion Order Summaries of the Maribyrnong, Melbourne Headworks, Macedon and Mount Macedon, and Gisborne Bulk Entitlements are presented in Table 2. Ref: WATER-PLAN-DROUGHT RESPONSE Page 23 of 55 Uncontrolled when Printed

24 Table 2 Rosslynne System Bulk Entitlements Bulk Entitlement Bulk Entitlement (Maribyrnong Western Water) Conversion Order 2000 Bulk Entitlement (Maribyrnong Western Water) Conversion Amendment Order 2006 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Share of Storage Capacity Share of Flow Bulk Entitlement Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Slatey Creek, Jacksons Creek, Salty Creek, Gisborne Creek; Rosslynne Reservoir 6,100 ML on average, over consecutive five year period 69 ML/d 86% of Rosslynne Capacity (24,670 ML at Full Supply Level) 86%, after meeting passing flow requirements at Jackson Creek gauging stations (Gisborne and Sunbury) Bulk Entitlement (Melbourne Headworks System Western Water) Conversion Order 2010 Various catchments and the Victorian Desalination Plant, via Melbourne Water s supply system 18,250 ML, based on imposing at least the same level of restrictions as the Melbourne retail authorities None specified Bulk Entitlement Bulk Entitlement (Macedon and Mt Macedon) Conversion Order 2004 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Railway Creek, Turitable Creek, Willimigongon Creek; Willimigongon Reservoir, Orde Hill Reservoir, Andersons Reservoir, McDonalds Reservoir, Kitty English Reservoir, Frank Mann Reservoir 873 ML in any one year and 3,225 ML in any consecutive five year period 1.7 ML/d from Andersons Reservoir and McDonalds Reservoir 2.0 ML/d from Orde Hill Reservoir and Willimigongon Reservoir 2.0 ML/d from Kitty English Reservoir and Frank Mann Reservoir 0.8 ML/d from Gillespies Weir (Turritable Creek) May to November inclusive: 5.0 ML/d from all waterways to Rosslynne Reservoir via Slatey Creek Bulk Entitlement Bulk Entitlement (Gisborne Barringo Creek) Conversion Order 2004 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Barringo Creek; Pierce Reservoir 585 ML in any one year and 1,600 ML in any consecutive five year period June to October: Max. 4 ML/d for Barringo Creek flow > 6.4 ML/d November to May: 0 ML/d Romsey System Water supplied to Romsey from Kerrie Reservoir and Wright Reservoir is taken under the Romsey Bulk Entitlement Conversion Order 2001 and Riddells Creek Bulk Entitlement Conversion Order Summaries of the Romsey and Riddells Creek Bulk Entitlements are presented in Table 3. Ref: WATER-PLAN-DROUGHT RESPONSE Page 24 of 55 Uncontrolled when Printed

25 Table 3 Romsey Bulk Entitlement Summary Bulk Entitlement Bulk Entitlement (Romsey) Conversion Order 2001 Water Sources and Storages Bolinda Creek; Kerrie Reservoir Annual Entitlement Volume 460 ML ML drought reserve (1) Daily Diversion Limit Max. 32 ML/d for Bolinda Creek flow > 35.8 ML/d Bulk Entitlement Bulk Entitlement (Riddells Creek) Conversion Order 2001 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Main Creek; Forster and Wright Reservoirs 300 ML April to January: Max. 1 ML/d for Main Creek flow > 1 ML/d February and March: 0 ML/d Note (1): drought reserve based on unused entitlement in previous year Lancefield System Water supplied from Garden Hut Reservoir and Monument Creek weir is taken under the Bulk Entitlement (Lancefield) Conversion Order 2001, with Bore No. 2 and Bore No. 3 each managed under groundwater licences from Southern Rural Water. Summaries of the Lancefield Bulk Entitlement and groundwater licences are presented in Table 4. Table 4 Lancefield Bulk Entitlement and Groundwater Licence Summary Bulk Entitlement Bulk Entitlement (Lancefield) Conversion Order 2001 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Licence Garden Hut Creek, Monument Creek; Garden Hut Reservoir 315 ML (299 ML from Garden Hut Reservoir; 195 ML from Monument Creek diversion weir) 1.1 ML/d from Garden Hut Reservoir 0.85 ML/d from Monument Creek diversion weir Lancefield Groundwater Licences Water Sources and Storages Bore No. 2 and Bore No. 3 Annual Licence Volume Daily Diversion Limit Bore No. 2: ML Bore No. 3: ML Bore No. 2: 0.8 ML/d Bore No. 3: 0.8 ML/d Ref: WATER-PLAN-DROUGHT RESPONSE Page 25 of 55 Uncontrolled when Printed

26 3.1.4 Woodend System Water supplied from Campaspe Reservoir, Falls and Smokers Creeks and Kavanagh and Barbour Springs is taken under the Bulk Entitlement (Woodend) Conversion Order Water transferred to Woodend from the Macedon and Mt Macedon system is taken under the Bulk Entitlement (Macedon and Mount Macedon) Conversion Order Summaries of the Woodend and Macedon and Mount Macedon Bulk Entitlements are presented in Table 5. Table 5 Woodend Bulk Entitlement Summary Bulk Entitlement Bulk Entitlement (Woodend) Conversion Order 2004 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Campaspe River, Falls Creek, Smokers Creek, Barbour Spring, Kavanagh Spring; Campaspe Reservoir, Reservoir B, Reservoir C 470 ML (332 ML in total from Falls Creek, Smokers Creek, Barbour Spring and Kavanagh Spring) 3.5 ML/d from Campaspe Reservoir 1.2 ML/d from Falls Creek Weir 1.2 ML/d from Smokers Creek Weir Bulk Entitlement Bulk Entitlement (Macedon and Mt Macedon) Conversion Order 2004 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Railway Creek, Turitable Creek, Willimigongon Creek; Willimigongon Reservoir, Orde Hill Reservoir, Andersons Reservoir, McDonalds Reservoir, Kitty English Reservoir, Frank Mann Reservoir 873 ML in any one year and 3,225 ML in any consecutive five year period 1.7 ML/d from Andersons Reservoir and McDonalds Reservoir 2.0 ML/d from Orde Hill Reservoir and Willimigongon Reservoir 2.0 ML/d from Kitty English Reservoir and Frank Mann Reservoir 0.8 ML/d from Gillespies Weir (Turritable Creek) May to November inclusive: 5.0 ML/d from all waterways to Rosslynne Reservoir via Slatey Creek Werribee System Water supplied from Merrimu and Djerriwarrh Reservoirs is taken under the Bulk Entitlement (Werribee System Western Water) Conversion Order 2004, while water supplied from the Melbourne system is taken under the Bulk Entitlement (Melbourne Headworks System Western Water) Conversion Order Summaries of the Werribee and Melbourne Headworks Bulk Entitlements are presented in Table 6. Ref: WATER-PLAN-DROUGHT RESPONSE Page 26 of 55 Uncontrolled when Printed

27 Table 6 Werribee Bulk Entitlement Summary Bulk Entitlement Bulk Entitlement (Werribee System Western Water) Conversion Order 2004 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Share of Storage Capacity Share of Flow Bulk Entitlement Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Pyrites Creek, Lerderderg River, Goodmans Creek, Coimadai Creek, Djerriwarrh Creek; Merrimu Reservoir and Djerriwarrh Reservoir Merrimu Reservoir: 8,500 ML Djerriwarrh Reservoir: 1,486 ML Merrimu Reservoir: 83.5 ML/d Djerriwarrh Reservoir: 19 ML/d 60% of Merrimu Reservoir storage capacity 100% of Djerriwarrh Reservoir storage capacity 70% of Merrimu Reservoir, after meeting passing flow requirements 100% of Djerriwarrh Reservoir, after meeting passing flow requirements Bulk Entitlement (Melbourne Headworks System Western Water) Conversion Order 2010 Various catchments and the Victorian Desalination Plant, via Melbourne Water s supply system 18,250 ML, based on imposing at least the same level of restrictions as the Melbourne retail corporations None specified Ref: WATER-PLAN-DROUGHT RESPONSE Page 27 of 55 Uncontrolled when Printed

28 3.1.6 Myrniong System Water supplied to Myrniong from Pykes Creek Reservoir is taken under the Bulk Entitlement (Myrniong) Conversion Order 2004, summarised in Table 7. Table 7 Myrniong Bulk Entitlement Summary Bulk Entitlement Bulk Entitlement (Myrniong) Conversion Order 2004 Water Sources and Storages Annual Entitlement Volume Daily Diversion Limit Pykes Creek; Pykes Creek Reservoir 58 ML (may be restricted by the Werribee Entitlement Holder (Southern Rural Water) under specified conditions 0.47 ML/d 3.2 Permanent Water Savings Rules Western Water introduced new Permanent Water Savings Rules in its Permanent Water Savings Plan in December Permanent Water Savings Rules were legislated under the Water Act The revised Permanent Water Savings Rules consist of five simple rules, which will guide the efficient use of water on a permanent, ongoing basis. A summary of the revised Permanent Water Savings Rules is presented in Table 8. As Permanent Water Savings Rules have already been implemented by Western Water, they are not an option for further demand management during periods of drought. 3.3 Water Restriction By-Laws Mandatory water restrictions are an effective tool to manage water demand during periods of water shortages. Western Water currently has a four stage water restriction policy that is designed to restrict non-essential water uses such as garden watering and car washing. This policy is given legal effect under Water Restriction By-Law 11/11 under the Water Act 1989 (December, 2011). This By-Law is contained in 9. Under each stage of water restrictions, various non-essential uses of water are restricted or banned. As the water restrictions levels increases so do the limits on non-essential water use. The limitations that Western Water may implement under each stage of water restrictions are detailed in Water Restriction By-Law No. 11/11. The Melbourne Headworks Bulk Entitlement provides Western Water the option of aligning restrictions with Melbourne or accepting a restricted supply in some years. Western Water has made a decision to align its water restrictions with those for the Melbourne system, because Western Water s reliability of supply is integrally linked to the Melbourne System and it is easier to communicate and implement restriction levels that align with Melbourne. Western Water s standard of service for each of its water supply systems is aligned with the service levels proposed in Melbourne s WSDS: Restrictions will only be implemented in Western Water systems: - once in 20 years - for a maximum of 12 months duration - at a maximum level of Stage 2 - except in extreme circumstances Ref: WATER-PLAN-DROUGHT RESPONSE Page 28 of 55 Uncontrolled when Printed

29 Table 8 Permanent Water Savings Rules Summary (Source: Western Water, 2012b) Residential and commercial lawns Manual watering with a bucket or hand-held hose fitted with a trigger nozzle is permitted at any time Watering systems may be used between 6pm and 10am Residential and commercial gardens Manual watering with a bucket or hand-held hose fitted with a trigger nozzle is permitted at any time Watering systems may be used between 6pm and 10am Public gardens and lawns Manual watering with a bucket or hand-held hose fitted with a trigger nozzle is permitted at any time Watering systems may be used between 6pm and 10am but must be fitted with a rain or soil moisture sensor Hard surfaces A high pressure cleaning device, a bucket or hand-held hose fitted with a trigger nozzle may be used: in response to an accident, fire, health hazard, safety hazard or other emergency to clean staining on a surface no more than once per season (summer, autumn, winter and spring), or in the course of construction or renovations Vehicles Washing with a bucket or hand-held hose fitted with a trigger nozzle is permitted at any time Fountains and water features Must recirculate water Ref: WATER-PLAN-DROUGHT RESPONSE Page 29 of 55 Uncontrolled when Printed

30 4. Drought Response Options 4.1 Introduction Options for responding to drought can be classified into two broad categories: Demand reduction reducing the volume of water consumed; and Supply enhancement increasing the volume of water available for consumption. For the purposes of a DRP, reducing demand and enhancing supply are only related to changes achievable in the short term. For example installation or reinstatement of groundwater bores or the introduction of water restrictions are short term options that are feasible within the timeframe of a drought. The raising of storages or systemic changes in consumer patterns of consumption would not be feasible within a limited time frame and are therefore more appropriately considered as part of Western Water s Water Supply Demand Strategy. In this section of the DRP, potential short term demand management and supply enhancement options for Western Water are identified and evaluated. 4.2 Demand Reduction during Drought These are summarised in Table 1-5, which also includes an indication of their relative merit for Western Water systems. Each option is discussed further in the following sections. Table 9 Demand Reduction Options During Drought Demand Reduction Option Potential for Western Water Systems Restrictions Community awareness campaigns Changed tariffs in drought ß Restrictions The use of restrictions is an accepted and effective option for reducing demand during drought. The main purpose of a restriction policy is to ensure the community does not run out of water and to conserve dwindling supplies during drought periods. Restriction policies should be based on achieving a balance between the need to reduce water consumption to protect available supplies during drought and community expectations of acceptable maximum restrictions, the frequency at which they occur and the amount the community is prepared to pay to avoid them. These expectations can be established by extensive community consultation. Water restrictions are designed to predominantly impact on non-essential water uses (for example garden watering and the filling of pools) and minimise the impact on the use of water for commercial services, public health and essential residential use. Demand can be thought of as comprising two components: a component that can be restricted (termed the restrictable demand); and a component that cannot be restricted (termed the unrestrictable demand). Western Water may, through its By-Law No. 11/11 under the Water Act 1989, declare water restrictions where this is deemed necessary to reduce the consumption of water within its supply systems, in order Ref: WATER-PLAN-DROUGHT RESPONSE Page 30 of 55 Uncontrolled when Printed

31 to protect available supplies during periods of drought. This By-Law, which outlines a four stage restriction policy, with each successive stage specifying more severe water restrictions, is included in 9. This restriction policy is consistent with that applied to all regional Victorian and metropolitan supply systems. The Melbourne Headworks Bulk Entitlement provides Western Water the option of aligning restrictions with Melbourne or accepting a restricted supply in some years. Western Water has made a decision to align its water restrictions with those for the Melbourne system, because Western Water s reliability of supply is integrally linked to the Melbourne System and it is easier to communicate and implement restriction levels that align with Melbourne. Table 10 summarises the expected impacts of implementing each of the four stages of water restrictions outlined in the By-Law. The Stage 3 and Stage 4 demand reduction estimates in Table 10 are taken from the Review of Water Restrictions and PWSRs Position Paper (VicWater, 2011). Depending on the assumed level of unrestricted (PWSR) residential demand adopted, Melbourne s retailers have estimated a reduction in total Melbourne demand of between 6.6% and 14.1% under Stage 3 restrictions, and 13.5% and 20.4% under Stage 4 restrictions (VicWater, 2011). Western Water management believes that water efficiency behaviour has now become embedded into its customers normal water use and as such the reductions from water restrictions are likely to be at the lower end of the range estimated by the Melbourne retailers. No estimates were made by VicWater (2011) for demand reduction under Stage 1 and Stage 2 restrictions, and these have been interpolated from the PWSR and Stage 3 estimates. Table 10 Water Restriction Demand Reduction Estimate Level of Restriction Annual Demand Reduction Basis Stage 1 2% Interpolated between PWSR and Stage 3 Stage 2 4% Interpolated between PWSR and Stage 3 Stage 3 7% Melbourne (VicWater, 2011) Stage 4 14% Melbourne (VicWater, 2011) Community Awareness Campaigns It is important that the community is made aware of the need to conserve water, particularly during periods of drought. Recent education campaigns by Western Water, together with the promotion of Permanent Water Savings Rules, have substantially increased the level of water literacy among Western Water s customers. Customers are increasingly likely to implement water conservation measures voluntarily, if they are made aware of the possibility of drought before the need for restrictions. The following are ways Western Water will increase awareness in the community: Publication of storage volumes and/or recent rainfall data indicating water availability on the Western Water website, in local newspapers, council newsletters, radio or television programs. Delivering information on water conservation methods via leaflets in water accounts, directly to letterboxes or in prominent locations (such as the town hall, general store or post office); Use of slogans and mascots; Ref: WATER-PLAN-DROUGHT RESPONSE Page 31 of 55 Uncontrolled when Printed

32 School campaigns and competitions; Western Water has an ongoing communications strategy, which is measured by the Balance Scorecard and approved by the Board. An integral part of the communications strategy is Western Water s education campaign, which has been designed to: Promote water conservation messages; Change community attitudes to water usage habits; Raise awareness that we live in a drought continent; Increase appreciation that water is a precious resource; To promote water saving messages before during and after restrictions; To increase customers confidence that Western Water is a responsible manager of their water supplies. When restrictions are in place, Western Water aims to ensure that all customers are aware of their responsibilities during restrictions. A detailed restrictions communications strategy was developed and implemented to raise community awareness of restrictions and water conservation measures. As part of the strategy, in order to ensure all customers are fully informed about restrictions, Western Water has: Devised and implemented a direct mailing program to all Western Water customers regarding restrictions. Follow up promotions to individual residents occur when restrictions are escalated/deescalated or introduced in a newly affected area. Regular media updates to promote water conservation message and keep customers informed of current water levels, storage volumes. Developed a series of customer Q&A information sheets to specifically address the different restriction issues of individual townships. Developed a water restrictions hotline Devised Speakers Forum to present water wise message to local community groups, such as Rotary, Probus, and University of the Third Age, schools groups, etc. Developed a children s water wise club to promote water conservation to our younger customers Worked with Councils and Schools to assist them to reduce their water usage Ensured website was constantly updated with latest restriction information Developed a comprehensive media policy and advertising campaign Developed a community newsletter which is mail out to customers with their water account. Ref: WATER-PLAN-DROUGHT RESPONSE Page 32 of 55 Uncontrolled when Printed

33 4.3 Supply Augmentation During Drought In general, there is a range of options open to augment supply during drought. The feasibility of each option depends to a large extent on the size of the population, the physical characteristics of the local supply and, ultimately, on the severity of the drought. Table 11 indicates a range of augmentation options and the potential of each for the Western Water systems. As Table 11 indicates, although potentially important in the context of overall medium to long term water resource planning, options such as rainwater collection tanks, reducing network losses, water cartage and wastewater or stormwater use have all been considered as impractical short term drought response measures for most Western Water systems. These medium to long term actions are discussed in detail in the Western Water WSDS A detailed discussion of the options is presented below. Table 11 Options for Augmenting Supply during Drought Augmentation Option Rosslynne System Romsey System Lancefield System Woodend System Werribee System Myrniong System Groundwater ß ß ß Supplementary surface water Transfer of water right ß ß Rainwater tanks Loss reduction Water cartage Wastewater and/or stormwater Aquifer storage and recovery ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß Rosslynne System Under the Water Act, it is now possible to transfer water rights from Southern Rural Water (SRW) and Melbourne Water to Western Water. This could be negotiated either directly with Melbourne Water and SRW, or by approaching irrigators downstream of Rosslynne. It should be noted however that, due to the relative volumes of water held by SRW, Melbourne Water and Western Water (1,110 ML, 2,344 ML and 21,216 ML respectively at full supply level), the advantages of Western Water negotiating a temporary transfer of water right are minimal. An additional source of supply both for normal supply, but especially in drought, is from the Melbourne supply system (operated by Melbourne Water), to which Sunbury was connected in March The original agreement with Melbourne Water provided for lower cost water purchases between March and November, with the possibility of negotiating for additional supply through December to February (at a considerably increased cost). This agreement was renegotiated to provide a uniform water cost throughout the year, and effectively there is no ceiling on the annual volume which may be purchased. The supply link provides the possibility of buying additional water from Melbourne Water during periods of drought. Ref: WATER-PLAN-DROUGHT RESPONSE Page 33 of 55 Uncontrolled when Printed

34 It should be remembered that during drought, nearly all operators would be under pressure to deliver the maximum volume available to their consumers. It will therefore be difficult to buy (or transfer) large volumes of water right. Western Water experienced this problem during in the Melton system. The smaller townships of Macedon, Mt Macedon, Gisborne, and Riddells Creek have historically been supplied by their own small reservoirs and have only relatively recently been connected to Rosslynne Reservoir. With the increased security provided by the link from Melbourne to Sunbury, it is unlikely that the original supply sources of the smaller townships would be required during drought. However, in severe drought, these storages would potentially be available. It should be noted that for the Macedon storages, it is more likely that these would be needed to augment Woodend's supply or to be transferred to Rosslynne Reservoir. Table 12 summarises the storage capacities of the smaller, operational storages in the Rosslynne system that could potentially be used for short term drought supply augmentation. Table 12 Summary of Storage Capacities Storage Townships Supplied Capacity (ML) Pierce Reservoir Gisborne (emergency only) 18 (reduced capacity) Forster Reservoir Riddells Creek (emergency only) 21 Wright Reservoir Riddells Creek (emergency only) 55 Orde Hill Reservoir Willimigongon Reservoir Woodend via Reservoir C Macedon (emergency only) Woodend via Reservoir C Macedon (emergency only) Andersons Reservoir Macedon (emergency only) 3.8 McDonalds Reservoir Macedon (emergency only) 87 Frank Mann Reservoir Macedon (emergency only) 34 Kitty English Reservoir Macedon (emergency only) 85 TOTAL 569 It should be noted that many of these systems would have water quality problems requiring treatment at the outlet (expensive and unlikely) or boiling for consumption in the household and would require Department of Health approval. The following summarises the supply links from the smaller reservoirs to the townships they once supplied. Mt Macedon Township can be supplied by the Andersons and McDonalds Reservoirs. These storages have capacities of 3.8 ML and 87 ML respectively, with Andersons storage having the capacity to supply directly into the reticulation system or via McDonalds reservoir. This supply would be activated, for example if a fire fighting situation caused a large drop in reticulation system pressure, which would trigger automatic pressure valves and direct supply into the reticulation network zone above Douglas Road from Andersons Reservoir. A similar connection to Orde Hill Reservoir can feed the zone below Douglas Road. A diversion weir on Stoney Creek can also be Ref: WATER-PLAN-DROUGHT RESPONSE Page 34 of 55 Uncontrolled when Printed

35 used to supply consumers in the Mt Macedon system. In 1997/98 the Willimogongon Supply to lower Mt Macedon was partially decommissioned. Emergency supply to Macedon could come from the Kitty English Reservoir, Frank Mann storage and Orde Hill Reservoir. Under the terms of the Bulk Entitlement order for Macedon and Mt Macedon, diversions from the streams supplying the Macedon storages are limited by the capacity of the diversion and storage network. Emergency supply to Gisborne is available from Pierce Storage. This storage is filled from a gravity diversion on Barringo Creek. Riddells Creek was originally supplied from the Forster and Wright storages, which could again be utilised in times of drought. Diversion to the Forster and Wright Storages is from Main Creek and is subject to a maximum daily diversion rate of 1ML/day (with an annual maximum of 300ML). Under the Water Act 1989, scope exists for transfer of bulk entitlements, water allocation transfers (temporary) or water share transfers (permanent). In the Rosslynne system, potential exists for transfer between the users of Rosslynne Reservoir: Western Water (urban); SRW irrigators; and Melbourne Water (environment). The potential for use of the groundwater resource in the Rosslynne supply area is limited as groundwater salinity is generally above potable levels. At Mt Macedon, the salinity is at potable levels but bore yields are limited to 1-2L/sec Romsey The emergency bore in Romsey has been operational since December Western Water s Water Supply Demand Strategy has identified development of the Romsey borefield and connection to the Lancefield system as a priority supply augmentation action. The Romsey Bore licence has is capped at 300 ML/year and 2.1 ML/day. Supplying Riddells Creek with water from Rosslynne Reservoir has freed up the local supply from Main Creek and this supply now has been redirected and forms part of the supply to Romsey. Since the connection of the Rosslynne system to Wrights Reservoir, Romsey is now able to receive supply (at a limited capacity) from the Rosslynne and Melbourne system. In general, the other available surface water options, such as raising of Kerrie Reservoir, would not be suitable for implementation as short term responses to existing drought, due to the implementation times required. During times of severe drought, it may also be possible to negotiate a temporary qualification of rights for the Romsey system Bulk Entitlement, to allow additional harvesting from Bolinda Creek. It should be noted however that this option would be subject to intense scrutiny, and is considered an option of last resort. It would also depend on sufficient flow being available in Bolinda Creek, which would be unlikely during a period of severe drought. Ref: WATER-PLAN-DROUGHT RESPONSE Page 35 of 55 Uncontrolled when Printed

36 4.3.3 Lancefield The availability of both groundwater and surface water supply systems in Lancefield means that the security of supply to Lancefield is high, however there are currently issues with the groundwater quality that effectively limit the system yield. Western Water s Water Supply Demand Strategy has identified connection of the Lancefield and Romsey systems and upgraded treatment capacity in Romsey or Lancefield as a priority supply augmentation action. This action will address the current water quality constraints associated with the Lancefield system, and increase operating flexibility. Factors that could influence the security of the current Lancefield system include lack of normal seasonal recharge, over-use of the bores, over-use of adjacent bores (both options resulting in rapid depletion of the aquifer), failure of a bore and poor water quality. Records show that prolonged pumping during dry spells does cause the water table level to draw down. Bore 2 is located in the Lancefield Groundwater Management Area (GMA) and the second bore (Bore 3) is immediately to the north of the GMA. Prior to the construction of Bore 3, Bores 1 and 2 were being pumped to their full allocation of 208 ML/year with minimal or no interference with each other. Following the construction and testing of Bore 3 in 1999, excessive interference with (drawdown of) Bore 1 was observed. Since this time Bore 1 has been decommissioned and is no longer part of the town water supply network. Groundwater allocations in the GMA are at the level of estimated sustainable yield of the aquifer (referred to as the Permissible Annual Volume) and the area has been proclaimed a Water Supply Protection Area. DSE and SRW have embarked on a program of installing monitoring bores in the GMAs. Water level monitoring (and quality monitoring) will substantially improve the understanding of the groundwater resource, including supply security Woodend Woodend currently draws upon the resources of the Campaspe, B, C and the Macedon Reservoirs. Whilst Campaspe, B and C Reservoirs are allocated purely to the supply of Woodend, the Macedon Storages are shared with water transfers to Rosslynne Reservoir. Water from Kitty English and Frank Mann Reservoirs, part of the former supply to Macedon, can also be pumped to Reservoir B or C for supply to Woodend (although is generally transferred to Rosslynne Reservoir). With the connection of Macedon and Mt Macedon to the Rosslynne system, it is also possible, albeit unlikely, for water from Rosslynne Reservoir or Melbourne to be utilised to supply Woodend through the Link Main. Under its Bulk Entitlement, Western Water also has access to diversions from Smokers Creek, although such diversions are not possible with the current supply infrastructure. A groundwater bore at Straws Lane is no longer operated, but may be available for emergency use. The supply line that feeds Reservoir B from Straws Lane bore is currently being used as a potable water supply to a number of customers previously on raw water. This would need to be addressed prior to utilising Straws Lane bore. Additional emergency supply could potentially be obtained from the North Woodend Borefield. These bores were drilled at the end of the 1982/83 drought and are located in Boundary Road north of the Woodend/Lancefield Road. The bores have been tested and can supply up to 5 to 8L/sec each over short periods. The nearest bore is 1,750 metres via road from the nearest reticulation. Bore water would need treatment to remove suspended solids and iron but would be suitable for emergency purposes. There is no power near the bore site and there are currently no pumps or pipes connecting the bore to the reticulation system. Ref: WATER-PLAN-DROUGHT RESPONSE Page 36 of 55 Uncontrolled when Printed

37 4.3.5 Werribee System The three major storages in the Werribee system are Merrimu and Melton Reservoirs, both of which are managed by Southern Rural Water, and Djerriwarrh Reservoir, operated by Western Water. In addition to supplying Western Water urban demands, Merrimu Reservoir supplies irrigation water to the Werribee Irrigation District. Western Water has a 60% storage share, with the remaining storage shares held by Southern Rural Water and the environment (Melbourne Water), or unallocated. Melton Reservoir serves the Werribee irrigators. Water to these irrigators can be supplemented from Merrimu or Pykes Creek storage if required. As Melton Reservoir is downstream of all demand centres supplied by Western Water and there is no transfer infrastructure, it is not a feasible option for augmenting supply, particularly during drought. Djerriwarrh Reservoir is owned and operated by Western Water and was the first permanent water supply for Melton. Water quality is poor and is expensive to treat and the maximum rate of supply limited to 5-15 ML/d. For these reasons supply from the Djerriwarrh Reservoir is currently limited to approximately 400 ML/annum and is used in conjunction with water from Lake Merrimu. Djerriwarrh Reservoir can be used for emergency supply in the event that drought, water quality issues, or maintenance works prevented supply from Lake Merrimu. This option was utilised during the Millennium drought. Under the Water Act 1989, scope exists for transfer of bulk entitlements, water allocation transfers (temporary) or water share transfers (permanent). In the Werribbee system, potential exists for transfer between the users of Merrimu and Pykes Creeks Reservoirs: Western Water (urban); Southern Rural Water irrigators; and Merrimu Reservoir unallocated share (currently managed by DSE). In addition to direct negotiation with the water authorities, Western Water could purchase water allocations from irrigators in the Werribee and Bacchus Marsh Irrigation Districts. Western Water successfully purchased water from downstream irrigators and was granted the unallocated portion of Merrimu (as a temporary transfer) during the Millennium drought ( ). In 2003 it purchased the unallocated portion of Merrimu, as a temporary transfer. Securing part or all of the unallocated entitlement in Merrimu Reservoir has previously been identified by Western Water as a promising option to increase yield in the Werribee system. 10% of storage inflow and 20% of storage capacity are currently unallocated. DSE is currently in the process of determining the preferred method for allocating the unallocated entitlement in Merrimu Reservoir. At this stage, it appears that the preferred approach is to allocate Western Water 10% of the storage capacity, with the remaining entitlement (10% of storage capacity and 10% of inflows) to be offered to the market. Western Water would then have the opportunity to bid for some of the remaining entitlement. Western Water s Water Supply Demand Strategy has an action to maximise its capacity and inflow share of Merrimu Reservoir. An additional augmentation option for the Werribee system is the importing of water from either the Central Highlands Water system or from Newlyn Reservoir. The former option would require the water to be pumped along the existing link between Lal Lal or Colebrook Reservoirs to Ballan and then into the Werribee River at Ballan. It should be noted that, at present, there is no direct link to the Werribee River and therefore, if this option were to be implemented, some connection would need to be made. The water could then be transferred to Pykes Creek Reservoir. Once in Pykes Creek Reservoir, Western Water would need to negotiate a transfer of entitlement with Southern Rural Water from Pykes Creek to Ref: WATER-PLAN-DROUGHT RESPONSE Page 37 of 55 Uncontrolled when Printed

38 Merrimu Reservoir. During discussions in January 2000, Southern Rural Water indicated that losses of 20% would need to be deducted from any transfer from CHW to Pykes Creek Reservoir. It is important to note that this option would need to be considered early in drought planning to ensure sufficient Southern Rural Water storage in Lake Merrimu for transfer (a problem which arose in the Millennium Drought ( ). Following the construction of the Melbourne to Melton pipeline this option has less current relevance. Supply from Newlyn Reservoir is similar to that from the Central Highlands system except supply to Ballan would be via the Wombat pipeline, constructed in This pipeline has only been used once since construction. Some doubt therefore exists as to the potential to use this as a ready supply source. A review of the system by Southern Rural Water (in the mid 1990s) found it to be in good condition, the primary obstacle being that the transformers had been removed from the pumping stations. Some resources would also need to be allocated for testing the pipeline. Southern Rural Water also indicated that they would anticipate losses of up to 50% of volumes leaving Newlyn Reservoir. A review of the Newlyn system by Southern Rural Water and Western Water in 1999 concluded that in addition to the condition of the infrastructure, this option would require the purchase of water right from existing entitlement holders in the Goulburn-Murray system. Given the small volume of water that was available, anticipated losses of up to 50%, the unknown condition of the infrastructure and the requirement to purchase water rights, this option was discarded. It should be noted that although Bacchus Marsh was originally supplied via the Bacchus Marsh irrigation channels, the pump station enabling this to occur was removed in Additionally, the treatment plant treating water at Bacchus Marsh has been decommissioned due to capacity, safety and public liability issues associated with this plant Myrniong System Myrniong is currently supplied from Pykes Creek Reservoir. Pykes Creek Reservoir is used primarily for irrigation in the Bacchus Marsh district. This storage can also supply the Werribee irrigation system but generally, it is kept as full as possible for the Bacchus Marsh irrigators. In extreme drought circumstances additional supply could be obtained by pumping the dead storage of Pykes Creek Reservoir. The current demand of Myrniong is about 25 ML/annum, so it is expected that the Pykes Creek dead storage volume (of approximately 1,005 ML) would be ample to supply urban demands in emergency situations. However, during the Millenium Drought the high turbidity of the water at very low storage levels rendered the water unfit for use and water has had to be trucked into Myrniong. Other options, including connections to Ballan or Bacchus Marsh have also been investigated. Generally in this system, groundwater offers poor potential for emergency supply as groundwater salinity is generally high and bore yields are low. Ref: WATER-PLAN-DROUGHT RESPONSE Page 38 of 55 Uncontrolled when Printed

39 4.3.7 Options Regarded as Having Less Potential Rainwater Tanks Rainwater tanks are generally used in isolated rural communities where no reticulated supply is available. In planning a reliable water supply, reliance cannot be placed on widespread use of tanks that are installed and operated at the discretion of householders. Rainwater tanks may, however, have some merit as a back-up supply in severe droughts. Although the installation of rainwater tanks as a drought response measure (as opposed to installation prior to the occurrence of drought) is likely to be of limited value in supplementing household supplies (the tanks would be expected to fill slowly if at all during drought), they would give owners the option of purchasing and storing carted water during very dry periods. Loss Reduction Metered water consumption across the whole water supply system accounts for around 90% of the total treated water entering the system. The 10% non-revenue demand comprises unmetered consumption, meter error, routine flushing of mains, bursts, firefighting, illegal connections and leakage. The individual percentages of the unmetered components cannot accurately be determined. Overall, it is expected that leakage from the system would be minor and perhaps constitute only 2% to 3% of total water consumption. The potential for loss reduction is therefore unlikely to be easily realised as an effective short term drought response action, but rather is a long term strategy. Water Cartage The viability of water cartage as a supply option is dependent upon the size of the town and the severity of the drought. Costs have previously been estimated at around $10-$25/KL. Clearly, on a purely economic basis, this type of action is an emergency measure only. Water cartage was used to supply parts of Woodend during the drought. Records show that a total of 9,255KL were carted during February and March of Water was carted to Myrniong during the Millennium Drought ( ) due to water quality problems in Pykes Creek Reservoir. Water was also carted to Romsey following technical problems at the water treatment plant. Water has also been carted to Lancefield, however this is problematic due to the difficulties encountered with access to the tanker filling positions. The use of water cartage to supplement water supply to even a portion of townships the size of Melton, Sunbury and Bacchus Marsh is not feasible. In addition to the requirements regarding water cartage set out in the By-Law (refer 9), the following provisions will also apply: Mobile tankers should not be filled in any supply zone, for the purpose of supplying water to customers in another supply zone where less stringent water restrictions are applicable; For filling of tankers in supply zones subject to stages 3 and 4 restrictions prior written approval for all tanker filling is required from Western Water who may prescribe the water source. Ref: WATER-PLAN-DROUGHT RESPONSE Page 39 of 55 Uncontrolled when Printed

40 5. Drought Response Action Plan 5.1 Introduction This section of the DRP outlines actions that Western Water will take to monitor and respond to water shortages. In most cases, drought response actions are guided by the prevailing level of water restrictions. Water restrictions in the Western Water region may be required to be implemented in townships for three reasons: 1. Melbourne Water - implements restrictions due to limited volume in storages. Under the Melbourne Headworks Bulk Entitlement, Western Water must apply at least the same level of restrictions as Melbourne Water to towns that are receiving any Melbourne Headworks supply 2. Event based - may require temporary local restrictions. Examples of events that may require restrictions are (but not limited to): o o o o o High demand on reticulation system during bushfire events Water supply Infrastructure failure A water quality incident Algae blooms in water storages Extreme weather and continual peak demands 3. Limited or reduction in local water resources Western Water has made a decision to align its water restrictions with those for the Melbourne system, however there may be times of severe water shortage when Western Water is required to impose higher level restrictions on some systems. It is therefore important that Western Water continues to monitor climatic and water supply indicators to detect the onset of drought and once this has occurred, the severity of the drought event. This drought response action plan is divided into the following operating modes: Normal Operation; and Drought Response (Stage 1 4 Drought Response). 5.2 Normal Operation Normal operation occurs when a drought event is not anticipated in the short term that will threaten the security of the region s water supply (which typically corresponds to periods under Permanent Water Savings Rules). Under normal operation, the focus of the action plan is on climatic and system monitoring, and water conservation. Ref: WATER-PLAN-DROUGHT RESPONSE Page 40 of 55 Uncontrolled when Printed

41 5.2.1 Normal Operation Actions The following actions should be undertaken during periods of normal operation: Normal Operation Actions Action A1 System Status Monitoring Monitor the following aspects of system security on a monthly basis: Climatic trends and seasonal outlooks published by the Bureau of Meteorology; Storage levels; System inflows; and Water consumption and trends in water consumption behaviour. Action A2 Promote Voluntary Water Conservation Measures Action A1: System Status Monitoring Monitor the following aspects of system security on a monthly basis: Climatic trends and seasonal outlooks published by the Bureau of Meteorology; Storage levels; System inflows; and Water consumption and trends in water consumption behaviour. Monitoring of the system will also occur on an annual basis (in December) using Western Water s Water Security Outlook (refer Appendix A). The Water Security Outlook comprises a short term forecast and monitoring of supply and demand measures to identify departures from longer term supply and demand forecasts included in the Corporation s Water Supply Demand Strategy. Antecedent rainfall is often used as a measure or warning of drought. A drought is assumed to occur when the total rainfall for a period of three months or more is in the first decile range (the lowest 10% of recorded rainfalls). The Bureau of Meteorology has used the following definitions for severe and serious droughts: a severe rainfall deficiency exists for the period in question when the rainfall is among the lowest five percent of the recorded rainfalls; a serious rainfall deficiency exists when the rainfall lies above the lowest five percent of recorded rainfalls for the period in question but is less than the first decile value. The Bureau of Meteorology provides information on its website ( which has the potential to assist in the preparation for drought. These include the following monthly reporting: Drought Statement ( - highlights areas of the continent experiencing significant rainfall deficiencies during the current month and extended periods. Ref: WATER-PLAN-DROUGHT RESPONSE Page 41 of 55 Uncontrolled when Printed

42 Seasonal Rainfall Outlook ( - provides three month forecasts of likely rainfall conditions expected over Australia; Monthly Weather Review ( - provides a detailed review of Victorian weather patterns for each month including departures of temperature and rainfall from "normal". More detailed information on rainfall is also available from Climate Data Online, on the Bureau s website (bom.gov.au/climate/data/). In addition to rainfall deficiencies, another early warning sign of drought is low streamflow. For streams that are gauged, low streamflow can be assessed by comparison with historical records (or through extension of the historical record using a rainfall/runoff model). For ungauged systems, anecdotal evidence and observation can be used to detect low streamflow. Ref: WATER-PLAN-DROUGHT RESPONSE Page 42 of 55 Uncontrolled when Printed