Development of eWater Source ‐ Sacramento model for the Valley

eWater's 4th Source Workshop, 24–25 August 2016, Canberra. 1 Presentation outline

Information about the Namoi River Catchment • Peel River System – Chaffey • • Split Rock Dam • Topography and climate conditions eWater Source modelling • Sacramento model developmet • Catchment delineation • Model parameters • Channel routing • Calibration results

Future work • Planning model development Namoi River Catchment

The Namoi River is one of the Murray‐Darling Basin’s major NSW sub‐catchments.

It covers a total area of about 42,000 km2 from the Great Dividing Range near Tamworth to the Barwon River near Walgett.

The Peel River is a major regulated tributary to the Namoi with a catchment area of around 4,700 km2.

It contributes an average annual volume of approximately 280,000 ML to the Namoi River. Peel River Catchment

Chaffey Dam is situated on the Peel River, 43 kilometres south‐east of Tamworth in the New England region of NSW. The dam is about 400 kilometres north of . holds a maximum of 62,830 megalitres of water, or about 30,000 Olympic swimming pools.

The dam’s name pays tribute to former parliamentary members for Tamworth, Frank Chaffey who represented the district in the NSW Legislative Assembly for 27 years to 1940, and his son Bill who followed in his footsteps for 33 years until 1973. Keepit and Split Rock Dam

Keepit Dam is situated on the Namoi River about 40 kilometres upstream of Gunnedah on the of the NSW Northern Tablelands. The dam is about 400 kilometres north of Sydney. Topography and Climate Information

Elevations range from over 1,500m to the south and east to just 100m on the alluvial floodplain of the lower catchment west Narrabri.

Annual average rainfall varies from Max of 1,300mm over the ranges in the east to around 400mm near Walgett. Average Class A pan evaporation Varies from around 1,000mm per Year in the south‐east, to over 2,200mm per year in the north‐west. Overview of eWater Source eWater Source is a modelling framework which provides an interface for the input, modelling of rainfall run‐off & planning and output of flow and water resources related information

This is achieved through the creation of models and scenarios which can bring together catchment features and planning requirements. Sacramento rainfall run-off model For rainfall run‐off modelling the Sacramento model was selected form the suite of rainfall run‐off models available through eWater Source.

The Sacramento model requires catchment rainfall and potential evapotranspiration to simulate flows.

These data was derived from the BOM aerial rainfall and potential evaporation estimates. Catchment delineation Peel River

15 sub catchments 6 calibrated catchments Catchment delineation Namoi River

42 sub catchments 18 calibrated catchments

The whole Namoi River catchment contains 57 sub‐catchments and 24 sub‐catchments are calibrated Calibration strategy

• The challenge was that we couldn’t calibrate all the 57 sub‐catchments, because there are extractions

• 24 sub‐catchment can be calibrated

• Aim of manual calibration of the 24 sub‐catchment was to generate parameter sets that contains similar parameter values that could be transferred to other catchments Channel routing

In Source three Routing Type is available: • Straight Through Routing • Lagged Flow Routing • Storage Routing Model results Gauge 419051

CALIBRATION PERIOD 09/06/1972 – 31/12/2010 The flow data @ 419097 is available 2002 – 2015 (data quality is not good enough for calibration).

Parameters were used from the upstream catchment 419035. Challenges

One of the major challenge was to find a calibration strategy to calibrate the Sacramento models.

NEW Software Development of the Planning model

Development of the Planning model

is in working progress. Thank you for your attention