PART II : Synthesis of the current understanding of water quality outcomes from irrigation management in sugarcane in the Lower Burdekin
3 Water quality issues in the Lower Burdekin sugarcane area
3.1 Description of the area
The area of sugarcane in the region is approximately 91,000 hectares ( 91 square kilometres ), with approximately 80,000 hectares under production ( NQ Dry Tropics , 2016 ). Most of the region ’ s sugarcane is located in the Lower Burdekin catchment , with small areas in the Don and Black catchments . The most practical boundaries for this document and future planning discussion are the Burdekin River Irrigation Area ( BRIA ) and the Delta sugarcane growing area ( Figure 3.1 ). These two areas combined are referred to as the Lower Burdekin sugarcane area throughout this document .
Figure 3.1 . Map of the two-distinctive sugarcane growing regions in the Lower Burdekin catchment , the BRIA and the Delta .
The characteristics of the BRIA and Delta areas are quite distinct and are shown in Table 3.1 , highlighting the following key points :
� Analysis of paddock scale monitoring and modelling data indicates that a larger proportion of DIN loss occurs via surface runoff in the BRIA area than in the Delta .
� Much of the runoff from the BRIA is directly discharged to Barratta Creek , compared to the Delta where the waterways are typically used as water transfer channels ( Davis et al . 2012 ). Recycle pits are also used in the BRIA to capture and recycle irrigation tailwater .
� The soils in the Delta are also more permeable than in the BRIA , making them less suitable for achieving efficient furrow irrigation techniques .
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