Modelling water allocation increases using climate predictions

Verrall, Daniel Graham (2016) Modelling water allocation increases using climate predictions. [USQ Project]

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Water allocations in Australia often commence at the start of the year with less than 100% supply and rely on seasonal streamflows into dams throughout the year to meet demand. Therefore more than ever, water allocation models are used with forward planning in order to effectively manage water supply. This dissertation focuses on developing a water allocation model incorporating climate forecasts for Cressbrook Dam, a major water supplier for the regional town of Toowoomba.

After determining the best climate index of ENSO, the methodology focussed on identifying a relationship between streamflow and SOI on a monthly and seasonal scale and the creation of the water balance model. To apply the findings of these results, the use of three water management scenarios were then run through the water balance model using an extended streamflow sequence.

This analysis indicated that there was a significant correlation in the months of December to March which was further strengthened when looking at a seasonal scale. A consistently positive SOI observed in November suggested that there was a 100% chance that the dam level will substantially increase and this to develop alternative water management scenarios that raised restrictions when this SOI phase was observed.

By raising restrictions early, these management scenarios achieved a reduction of around 280 days from level 5 water restrictions which would have relieved the residents of Toowoomba during a major drought period. However, the raising of restrictions also resulted in lowering the dam level to a critical low volume.

This unexpected response in dam level storage was identified due to a short streamflow record available. The development of the water management scenarios were based off a limited range of historical climate variability, therefore recognising that a large streamflow record is crucial to developing water management strategies which incorporate decisions based off climate events on the past.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours) Major Civil Engineering project
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Baillie, Justine
Date Deposited: 24 Jul 2017 02:03
Last Modified: 24 Jul 2017 02:03
Uncontrolled Keywords: modelling; water allocation increases; climate predictions; Cressbrook dam; streamflow record
Fields of Research (2008): 09 Engineering > 0905 Civil Engineering > 090509 Water Resources Engineering
Fields of Research (2020): 40 ENGINEERING > 4005 Civil engineering > 400513 Water resources engineering

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