Greater Sydney Water Quality Modelling Integrated Water quantity and quality modelling for Sydney Supply System (CARM – Greater Sydney) CARM – Greater Sydney Vision “To have a decision-making support system to manage the Greater Sydney Drinking Water catchments and supply for our customers based on best available science, forecast and planning models.” WaterNSW eWater Conference 1-2 December 2020 Why we are doing this? • Creating a complete set of linked quantity and quality models for: – Catchment – Reservoir – Supply • Quantitative comparison and justification of interventions • Ability to conduct Economic assessments • More robust, efficient operations 3 WaterNSW eWater Conference 1-2 December 2020 Where? • Warragamba catchment • Upper Nepean catchment • Shoalhaven catchment • Blue Mountains catchment • Prospect 4 WaterNSW eWater Conference 1-2 December 2020 What parameters? • 3 models – Catchment model – Lake model – Supply model • Contaminants: – Physical – Nutrient – Pathogens – Algae 5 WaterNSW eWater Conference 1-2 December 2020 How do we manage the project? 6 WaterNSW eWater Conference 1-2 December 2020 Modelling framework & data connection eWater Source Models External advice Hydrological/river Ops Model Research projects WaterNSW databases Water Quality Model Subject matter experts Hydstra/DRS/SCARMS GIS databases WQDB DHI Workbench Workflow Hydrohub Lake Models management 2D Data Process/Profiles Data Storage visualisation Inflow tracking Data postprocessing External agencies BoM Wathnet Models Climate/weather data Long term storage/inflow WWTP data Arc Dashboard models Data visualisation Programs Decision Support Planning Output Output Output Scenario assessment Source selection Catchment storage planning for Program evaluation Offtake level selection quality Input: Catchment Input: Risk assessment conditions and change Pre-event Catchment Input: conditions Catchment conditions and change 7 WaterNSW eWater Conference 1-2 December 2020 Climate conditions Three models interlinked • Catchment models for declared areas - in Source 5 • Sydney Water WWTP plugin Catchment Model • CSIRO SedNET Plugin • Use outputs from Source catchment models as input • Lake models for 7 key supply dams Lake Model • A supply system model - in Source 5. • model will use the outflow settings from the lake model Supply Model • route flows through upper canal/pipeline/riverine network 8 WaterNSW eWater Conference 1-2 December 2020 Catchment modelling • Points of interest (POI) – POI maps each catchment model – Each POI – output from the model • Modelled Parameters – Discharge – Turbidity, TSS, temp, DO, Example conductivity POI Maps – NO3, NOx, NH4, TN, TP, FRP – E. coli, FC – Silicate, metals (AL, Fe, Mn) 9 WaterNSW eWater Conference 1-2 December 2020 Catchment modelling Catchment models • Developed in Source 5 • WWTP plugin from Sydney Water • Sediment modelling (CSIRO SedNET) Calibration • Calibration/verification periods for inflow points into lakes – gauged flow data – 80-20 split of flow 10 WaterNSW eWater Conference 1-2 December 2020 Catchment modelling Fire modelling • Calibration periods – excluding periods of bushfire (base case) 2019/20 20 • catchment area u/s of gauges developed • cut-off 10% of area affected by fire • Post fire periods – analysed to quantify 2001/20 02 resulting impact 11 WaterNSW eWater Conference 1-2 December 2020 Catchment modelling: WWTP Plug-in • WWTP plug-in - by Sydney Water • A “Sewage Treatment Plant” node in Source – For each WWTP • Parameterize WWTP nodes using best available data • Data Source: from Councils, WaterNSW archives etc. 12 WaterNSW eWater Conference 1-2 December 2020 Catchment modelling: SedNET plug-in • The CSIRO SedNET plug-in will be used • Based on assessing the soil loss using RUSLE equation • Mean Annual Soil Loss (tonnes/ha/yr)= R K L S C P – R = Rainfall erosivity factor – K = soil erodibility factor (spatially variable) – L = Hillslope length – S = Hillslope gradient factor – C = ground cover factor – P = Supporting practise factor (=1)* • *P=1 as the C value is covering the soil coverage 13 WaterNSW eWater Conference 1-2 December 2020 Reservoir modelling • ELCOM-CAEDYM Existing reservoir model bathymetry developed by CWR, University of Western Lake Burragorang Australia would be used • Update existing lake models – Lake Burragorang – Prospect Reservoir – Fitzroy Falls – Wingecarribee – Yarrunga • Develop new lake models • Modelling conducted by Hydronumerics. Prospect Reservoir 14 WaterNSW eWater Conference 1-2 December 2020 Reservoir modelling Example 2D plot • Modelled Parameters: – Reservoir dynamics (e.g., level/outflow) – Turbidity, TSS, Temp, DO, Conductivity, pH – NO3, NOx, NH4, TN, TP, FRP – E. coli, FC, Cyanobacteria, Diatoms – Silicate, metals (AL, Fe, Mn) – DOC, POC, DIC – DOP, POP, PIP – DON, DOP, DIN 15 WaterNSW eWater Conference 1-2 December 2020 Supply system modelling • Outflow selection from Dams – Measured – Modelled • Routing through supply system to Water Filtration Plants • Mixing of water supplies through the system – Parameters of concern identified 16 WaterNSW eWater Conference 1-2 December 2020 Supply system modelling • Discharges from the dams – Operators decide flow settings from lake model. – Inflows into the supply system set through Mike Operations – Connect to the Source model 17 WaterNSW eWater Conference 1-2 December 2020 Supply system modelling • Calibration & Validation – Data collection points in: • River • Upper Canal • Pipeline – Parameters: • Flow • Level • TSS / Turbidity • Temperature • Conductivity • Nitrogen • Phosphorus 18 WaterNSW eWater Conference 1-2 December 2020 Supply system modelling • Water Filtration Plants – Demand on the system – Identify quality provided – Forecasted quality to be delivered to our clients – Calibration against measured data 19 WaterNSW eWater Conference 1-2 December 2020 Dashboarding and information sharing • Mike Operations 2020 platform - DHI – Workflow management – Input data preparation and processing – Data storages 20 WaterNSW eWater Conference 1-2 December 2020 Dashboarding and information sharing • Development of CARM GS Spatial Portal – ArcInsight – Data visualisation – Viewing results – Reporting and publications 21 WaterNSW eWater Conference 1-2 December 2020 Challenges… • Dashboarding/interfaces/ICT issues: intrinsically complex product/service • Data limitations: – Availability of historical data for calibration – GIS data status (availability of updated data prior to model build) • Colour modelling – How to model colour? Research programs in place. • Heavy metal modelling – Research to develop empirical models • Onsite wastewater modelling – part of land-use definitions or not? • WWTP modelling – data provision and collaboration with externals • Mining impact modelling – research on mining impacts on Water Quality (ARC DARE program) – Data provision and collaboration with mining companies and EPA • Swamp modelling – currently excluded. Will this impact the modelling? • COVID 19 – Applying agile has allowed us to stay closely connected 22 WaterNSW eWater Conference 1-2 December 2020 Thank You! Marlène van der Sterren Rizwana Rumman 23.