Peel Valley Works and Drought Update 5 th and 6 th August 2019 Dungowan and Tamworth \ Adrian Langdon Executive Manager, System Operations Ronan Magaharan Executive Manager - Assets
Discussion Agenda • Introduction from Tamworth Regional Council • Overview • Worst Drought Ever • Drought Outlook Impact on the Peel • Groundwater • Tributary Inflows Customer Impacts • Peel System Users • BLR • Environment • What is WaterNSW doing now? • How to keep updated • Next steps 2 • Questions and Answers
The Peel System 3
Worst Drought Ever 4
NSW rainfall 1 May 2017 – 30 April 2019 5
NSW rainfall 6
NSW rainfall 7
NSW rainfall 8
Temperature 9 Water NSW
Maximum temperature 1 May 2018 – 30 April 2019 10 Water NSW
Drought Stages 11
State Policy 12
Peel River Operations 13
Peel System Inflows 14
15
Peel Tributary Inflows 16
Chaffey Dam Levels WaterNSW May 2019 17
Chaffey Dam releases 16-17 INSERT GRAPH 19
Chaffey Dam releases 17-18 INSERT GRAPH 20
Chaffey 18-19 Releases Gap between black and red line highlights high losses in the system = 2 years Tamworth Supply demand WaterNSW 21
Groundwater Table Groundwater Depth (m) -11.5 -10.5 -9.5 -8.5 -11 -10 -9 -8 1/07/2010 1/10/2010 1/01/2011 1/04/2011 Depth to groundwater table below the measuring point. 1/07/2011 1/10/2011 1/01/2012 1/04/2012 1/07/2012 1/10/2012 1/01/2013 1/04/2013 1/07/2013 1/10/2013 1/01/2014 1/04/2014 1/07/2014 1/10/2014 1/01/2015 1/04/2015 1/07/2015 1/10/2015 1/01/2016 1/04/2016 1/07/2016 1/10/2016 1/01/2017 1/04/2017 1/07/2017 1/10/2017 1/01/2018 1/04/2018 1/07/2018 1/10/2018 22 1/01/2019 1/04/2019
Drought Outlook 23
Temperate Outlook 24
Rainfall Outlook 25
So… What does all this mean for the Peel Valley ? 26
Storage Forecast Chaffey Dam - forecast storage volume (chance of exceedance) 100 80 Storage capacity (GL) 60 40 20 0 May-18 Aug-18 Nov-18 Feb-19 May-19 Aug-19 Nov-19 Feb-20 May-20 Aug-20 Nov-20 Feb-21 Minimum 99% COE DRY 80% COE Median 50% COE WET 20% COE actual No Inflow 27
Block banks will extend water supply (Zero Inflow Model) 28
Block banks - Drought of Record Model 29
Peel River: Current State of Play Drought stage Stage 3 severe water shortage. • Chaffey Dam at 23% of active storage and currently releasing Storage Level 20ML/d. • No allocation for general security in 2019/20. • Last general security allocation made in October 2018. Allocations • Reduced allocations for high priority (town and domestic and stock) and for high security users, although supply below Dungowan will be restricted later in 2019 if dry conditions continue. • Work is underway for a series of temporary weirs in the Peel River to extend supply for Tamworth and reduce around 17,000 ML in Action transmission losses below Chaffey Dam. The Government has committed $3.4 million for these works and $2 million for further supply investigations. • Inflows into the dam and transmission losses below Chaffey Dam are at record high levels. Issues • Supply below Dungowan will be restricted and alternative supply may need to sought for downstream commercial users. • All efforts are being made to secure and extend Tamworth’s Outlook supply. 30
Mitigation Measures PEEL Secure Alternative Supply Future Water Supply Operational Savings Longer Medium 1. Assess 1. Accessing deep water storage for Now 1. Pipeline Chaffey to Late May 201 9 Chaffey (Peel) Tamworth Investigations Trigger : Last responsible moment Develop proposal to secure Bathymetry and water quality for necessary before water ceases to flow. supplies to Tamworth if inflows peel. Benefits : Benefits : Optimises water supply Possibility of supplying town water for continue to stay below the longer period when ground water and quality for towns and high drought of record source is used as an alternative security Industry 2. Groundwater storage and 2. Develop carting and distribution 2. Block Banks options usage Options June : Development of block bank Trigger : Stopping flow at Tamworth requirements with council Benefits : Extend high security water to Benefits : Supply Town water for a critical industries. longer period from Chaffey Dam. 3. Sinking Bores Trigger : Stopping flow at Tamworth 3. Block Banks Benefits : Water supply for towns and June : Water quality for fauna industries. assessment to be done for Northern Valleys 4. Aeration for deep/dead storage Benefits : Help protect and maintain Benefits : Extend town water supply ecosystem.
What are we doing Now? 32
Infrastructure Solutions Ronan Magaharan
Approach to extending Water Supply Context • Chaffey Dam supplies most of Tamworth Regional Council’s water • High transmission losses incurred through delivering water along the Peel River • Prolonging supply in Chaffey is the most effective way of servicing Tamworth’s water needs. • The sooner the rate of depletion level in the dam can be reduced and river transmission losses can be minimised, the longer we will be able to supply water to Tamworth. • Doing nothing is simply not an option. Proposed Solution WaterNSW has proposed a two-staged infrastructure solution supported by NSW Government • Stage 1: Installation of temporary weirs and pump station, extending supply for approximately four months • Stage 2: Construction of permanent infrastructure, pipeline for Chaffey Dam to existing Dungowan pipeline that would ensure Tamworth does not run out of town water supply (under drought-of-record conditions) if constructed early enough.
Stage 1 – Temporary Weirs Stage 1 – Install Temporary Weirs on the Peel River To reduce heavy transmission losses and extend water supply. WaterNSW is proposing to install temporary weirs on the Peel river at two locations: – Dungowan Village • Allows for pooling of water to be pumped into the existing TRC owned Dungowan pipeline for delivery to Tamworth • Water pumped via a temporary pump station with a temporary pipeline of approximately 700M in length from temporary weir to existing Dungowan Pipeline. – Jewry Street • to control flow downstream of Tamworth and provide further backup of town supply • Construction options being analysed (soil, gabion, sump), and will be removed when supply is secured (pipeline operation or significant inflows) • Weirs are expected to be 1.5 to 2m high, and store 22ML (capacity of Dungowan pipeline) • Tributary flows downstream of the dam will continue • Installation required by November 2019 to maximise available water supply • Funding commitment of $3.4M by Minister Pavey to complete the works 35
Stage 1 – Location of Infrastructure Proposed temporary weir location Option for temporary pipeline route Option for temporary pipeline route
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Stage 1 – Key Dates • Commencement of construction works at Dungowan is likely to be early October 2019 • Completion of construction works at Dungowan is early November 2019. • Pump Station Operational at Dungowan same time • Completion of Construction works a Jewry St to be confirmed after Dungowan project is completed. 38
Local Tributary inflows only below weir. 39
What about impacts on Fish and Wildlife? There is very likely to be if drought continues and inflows remain low… Critical human needs is now the top priority. Here is what we are doing • Working with DPI Fisheries around priority refuge water holes. • Monitor water quality and quantity • Tributary inflows will flow through the system • Community can report issues with fish / wildlife to DPI Fisheries on 1800 043 536 41
Stage 2 – Permanent Pipeline Stage 2 – Construction of a Permanent Pipeline • Pipeline (approx. 17-20km in length) from Chaffey Dam to Dungowan Town (and connecting to the existing pipeline owned by TRC), which would conserve Chaffey’s remaining storage by reducing transmission losses on the Peel River. • Critically, this project would provide long-term drought security for Tamworth, and would ensure the town does not run out of water supply (under drought-of-record conditions) provided it is installed early in 2020. • Funding of $1.9M announced my Minister Pavey to complete planning works. Funding for construction (~$38M) subject to further Govt approval. • Where possible construction to be within existing road easements or land within the Chaffey Dam property boundary. 42
Where could the pipeline run? Stage 2 Two routes are to be considered: Currently preferred route (~18.5 km) via Back-Woolomin Road (Red Line). Alternate route (~16.5 km) via Tamworth-Nundle Road (Yellow Line). A third “Yellow, Pink & Red Lines” connecting pipeline of about 490 m length along Westbank Road at Woolomin is also to be considered.
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