Final LDC WQ Report | Page 41

Table 6 . Modelled fine sediment reductions at the scale of the Burdekin basin for projects completed through to June 2020 from all investment schemes . Note that there was no model run in 2017 , resulting in a combined 2017 and 2018 Report Card released in 2019 .
LDC Project Year
1
Data / Report Card Year ( RC #)
2017 & 2018 ( 9 )
Anthropogenic Load
% Cumulative Reduction
% Reduction
Regional Target
% Cumulative Reduction
% Reduction
Reduction ( t / y )
LDC project effort
19.7 0.7 65.5 2.2 18,500 No LDC completions ( Start ) 2 2019 ( 10 ) 19.8 0.1 65.9 0.3 2,700 Some LDC completions 3 2020 ( 11 ) 20.1 0.3 66.8 1 8,100 High LDC completions 4 2021 ( 12 ) In Preparation Extra LDC completions
To assess the fine sediment reduction at the BBB catchment scale as per the Burdekin basin estimate , the calculation was made with the investment data to June 2020 . The cumulative fine sediment load reduction from the BBB catchment between 2017 and 2020 was estimated to be 6,855 tonnes , the PP reduction was 8.4 tonnes and the PN reduction was 13.3 tonnes ( Table 7 ).
The relative contribution of the BBB Catchment ( all investments , not just LDC ) to the Burdekin basin fine sediment reductions was estimated to range between 3 % in Year 1 ( no LDC Project completions ) to 68 % in Year 3 ( high LDC Project completions ) ( Table 7 ). For PP , the relative contribution ranged from 4 % in Year 1 to 62 % in Year 3 , and for PN the relative contribution ranged from 5 % in Year 1 to 54 % in Year 3 .
Table 7 . Bowen-Broken-Bogie regional contribution to the Burdekin catchment ( end of valley ) fine sediment , particulate nitrogen and phosphorus load reductions ( tonnes / year of load reduction ), from all BBB investment stream projects completed through to June 2020 . * Burdekin fine sediment load reductions are shown in Table 6 .
Year
LDC Project year
Data / Report Card Year
Fine sediment Particulate Phosphorus Particulate Nitrogen
Reduction ( t / yr )
% of total reduction *
Reduction ( t / yr )
% of total reduction
Reduction ( t / yr )
% of total reduction
2019
Year 1
2017 & 2018
630
3 %
0.5
3.8 %
1
5 %
2020
Year 2
2019
737
27 %
1.8
32 %
4.7
44 %
2021
Year 3
2020
5,488
68 %
6.1
62 %
7.6
54 %
2022
Year 4
2021
In preparation
Cumulative total
6,855
8.4
13.3
Annual average loads were calculated using the 2019 and 2020 Burdekin basin results , and the 2017 to 2021 LDC Project results . The Source Catchments model assessment of the annual average relative contribution of only the LDC Project reductions to the annual average Burdekin basin reductions , found that :
• The annual average modelled fine sediment reduction for the LDC Project is estimated at 2,410 tonnes per year . On average the LDC Project contributed 44 % of the Burdekin basin fine sediment load reductions .
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