2020 Software Conference

Recent advances in eWater Source modelling in WaterNSW

WaterNSW Acknowledgements

Mole Dam modelling – Ashok Raut Dungowan Dams modelling – Tahir Hameed Wyangala Dam raising modelling – Gurmeet Singh Upper Hunter – Allen Lal Greater Sydney – Golam Kibria / Ashok Raut Barwon-Darling model development- Hemantha Perera & Gurmeet Singh

eWater Staff

2 WaterNSW eWater Source Modelling Program

• Models developed for the purpose of Infrastructure planning and Operations • Models underpinned 20 Year Infrastructure Options Study • Model currently used for New dam proposals • Barwon/Darling model linked to all the valley models • Barwon/Darling model used for Western weirs project • Models operationalaised within CARM system • Greater Sydney Catchment models used for Climate Change Impact assessment using NARCLiM1.5

WaterNSW Significant features

• Rainfall-Runoff models developed using Met Bureau AWAP Gridded rainfall/Evaporation datasets • River reach calibrations done using latest DEM data and abstraction data • Recent models used crop data derived from remote sensing • Flood/Hydraulic models provided hydraulic ratings • All models incorporate current Water Sharing Plan rules • System Operational knowledge captured in discussion with operational staff

4 WaterNSW Border River Valley 12 Gauged Tributary Inflows Source 6 Major Town Water Supplies Multiple owners system (NSW/QLD) 3 Water Resources Assessment Systems (2 continuous accounting and 1 Models continuous sharing) 4 Major Dam Storages 2 shared resources Gwydir About 10 regulating weirs 1 Major Storage, OFS appr. 600 GL 11 Gauged Catchments and 34 Ungauged Catchments 15 HS, Stock & Domestic User Nodes 3 Water Utility Users 20 General Security User Nodes 2 Environmental User Nodes 5 anabranch systems Namoi-Peel 26 Tributary Inflows 24 Residual and Ungauged Catchments 26 Irrigation Nodes (High and GS) 3 Town Water Supply Nodes 3 Stock and domestic users 4 Storages (4 Dams) 2 Resource Assessments Macquarie 15 Tributary Inflows 15 Residual and Ungauged Catchments 25 Irrigation Nodes (High and General security) 5 Town Water Supply Nodes 10 Stock and domestic users 2 Storages (2Dams) 1 Resource Assessments 4 Planned and Held Environment

LACHLAN 15 Tributary Inflows 44 Residual and Ungauged Catchments 39 Irrigation Nodes (High and General security) 8 Town Water Supply Nodes 20 Stock and domestic users 4 Storages (including 2 Dams) 14 weirs, 8 anabranches, 4 lagoons, 5 wetlands Murrumbidgge 27 Gauged Tributary Inflows 18 Residual and Ungauged Catchments 10 Town Water Supply Nodes 24 Water User Nodes ( includes 2 Irrigation districts (MIA, CIA) 5 2 Dam Storages, 8 Weirs, 8 Wetland Nodes with connectors), 4 Floodplain Storages, 2 Environmental User Nodes. Border Rivers Overview

Border Rivers and Mole River Dam Hydrological Modelling

6 WaterNSW Border Rivers Overview

• Pindari Dam, 312 GL (NSW 100%) • Glenlyon Dam, 254 GL( NSW 57%, QLD 43%) • Boggabilla Weir, 5.8 GL (regulating weir) • Coolmunda Dam, 69 GL (QLD 100%) • Complex water sharing and allocation rules detailed in: – NSW Water Sharing Plan – QLD Resource Operation Plan – Inter-governmental Agreement – Standard Operating Procedures • Mole River Dam proposed to augment the supply option in the valley under Federal and NSW government Water Security Improvement initiative • Complex Source model and used for different dam size options (50-300 GL) • A typical results given for 50-200 GL options

7 WaterNSW Mole River Dam Model Effective Allocation

8 WaterNSW New Dungowan Dam in Peel Valley Dam Size vs Yield •Existing Dungowan Dam of about 5 GL storage unable to meet Town demands 20.0 18.0 •A new Dam is proposed at a downstream site of the 16.0 existing Dungowan Dam 14.0 •Peel River eWater Source model used for this analysis 12.0 and more than 40 scenarios modelled exploring: 10.0 • different dam sizes Yield 8.0 • 3) Dungowan to Tamworth pipeline sizes 6.0 • variations of current Water Sharing Plan (WSP) Transparent 4.0 Flow and Environmental Contingency Allowance (ECA) flow 2.0 rules 0.0 • reduction of consumptive usages 0.0 20.0 40.0 60.0 80.0 • transitional system operation Dam Size • storage operation, etc. 71 Pipe 45 Pipe 22 Pipe •The Transparent and ECA increased proportional to increased total storage may be feasible. This increased environmental allocation reduced yield. •Full yield utilisation will not happen immediately. During Issues to be Resolved this transitional period, GS reliability will increase • Environmental Rules significantly. • MDBA Sustainable Diversion Limit (SDL) • Distribution of transitional Benefits • Optimal Storage Operation

9 WaterNSW Raising Wyangala Dam

• Wyangala Dam, Rock and fill dam constructed in 1971, capacity 1200 GL- proposed upgrade raising dam wall, FSL 6 to 12m • eWater Source Model developed for Lachlan River Valley used to investigate options for raising the dam wall.

• The objectives of dam raising was to provide water security and reliability for irrigation, towns and other high security users. Also to provide flood mitigation for major towns including Cowra and Forbes.

WaterNSW Dam Raising- Analysis of Raised FSL Options

• Model runs were done for the assessment of number of options for dam raising, including operational scenarios, translucency rules and spillway options. • Hydrological metrics were developed to assess the impact of dam raising options based on

reliability, water security for HYDROLOGICAL METRICS Whole Record (1900/01-2015/16) existing users and Environmental BDL WyRaise12m WyRaise10m WyRaise_8m WyRaise_6m Percentage of time full entitlement is available as available 32% 42% 38% 34% 28% water (AW) at start of water year (at 1 July) Water Requirements (EWR Percentage of time full entitlement is available as available 40% 56% 56% 50% 42% water (AW) at 1st October Percentage of time full entitlement is available as available 51% 66% 65% 57% 53% metrics). water (AW) end of water year (30 June) Percentage of time full entitlement is available as effective 47% 70% 65% 63% 60% • Model was used for Bio-diversity available water (AEW) at start of water year (at 1 July) Percentage of time full entitlement is available as effective 58% 74% 70% 68% 66% available water (AEW) at 1st October) Percentage of time full entitlement is available as effective modelling to evaluate bio 66% 78% 75% 73% 70% available water (AEW) end of water year (30 June) Average available water (AW) on 1 July (GL/Yr) 165 428 396 370 341 offsets and u/s inundation Average available water (AW) on 1 Oct (GL/Yr) 427 522 512 485 451 Average available water (AW) on 30 June (GL/Yr) 512 587 577 551 526 • Model was used for Average Effective available water (AEW) on 1 July (GL/Yr) 501 798 763 725 690 Average Effective available water (AEW) on 1 Oct (GL/Yr) 763 892 879 841 800 Average Effective available water (AEW) on 30 June (GL/Yr) 848 957 944 906 875 construction risk modelling for 8 Percentage of time zero Effective available water (AEW) on 1 6% 7% 7% 7% 9% July (GL/Yr) Percentage of time zero Effective available water (AEW) on 1 3% 3% 2% 3% 3% and 10m dam raising. Oct Percentage of time zero Effective available water (AEW) on 30 3% 2% 2% 3% 3% WaterNSW June Number of months with zero effective available water (AEW) 39 28 27 38 41 BD/LD Source Model Development

Upper Darling Model Structure Inflows to the model Main river and tributary inflow – 20 inflow nodes Residual inflows to River reaches – 13 reaches Storages Weirs – 20 weirs, 5 on tributary Dams – 2 dams on Warrego river Reach Dead Storages Water Users Irrigation – 47 irrigation users with one or more access license classes (A,B,C) Town Water Supply – 11 TWS, 8 on main river and 3 on tributaries Stock and Domestic – Lumped into 13 reaches.

12 WaterNSW Relevance of Hydraulic model data for LD Source Model Development

Identification of breakouts and derivation of effluent relationships Hydraulic data needed for weirs and block bank setup (including dead storage volume) Travel time needed for setting routing (piece-wise routing) parameters in Weir node Initial losses Water levels at weirs River chainages Weir Ratings

WaterNSW Current Challenges • Operationalising Models (Hot start, automation) • Water Quality Modelling • Model refinements with improved modelling standards • Provenance (Version control) • Independent reviews

WaterNSW WNSW Contact details

Thank you Any Questions!

Call us on 1300 662 077 Visit us at waternsw.com.au

WaterNSW