There was some flow recorded at the control site , however , there were issues with the velocity readings , appearing to relate to high flow turbulence which resulted in no useful data . The sensors were rotated in 2021 to face upstream ( away from the turbulent area ) to improve their performance . The sediment and nutrient loads for the control site were calculated using the recorded depth during events across the 2020- 21 wet season . The flow characteristics of the Mt Wickham control site which has a similar profile and channel morphology , were applied at this site . This is a reasonable approach given we are not comparing between control and treatment sites for this year . However , no runoff data or samples were collected from the treatment site due to shallow flow depths .
( A )
Figure
23 . ( A ) TSS concentration and ( B ) TN concentrations at Glen Bowen for the 2019 / 20 wet season . No samples were collected the treatment site in 2019-20 or 2020-21 .
The limited particle size data ( Figure 18 ) collected to date indicates that the sediment in runoff is very fine , around 10 µ M , making it a high priority for management .
In summary , following the second wet season since treatment , the amount of vegetation cover and biomass on the treatment gully has significantly improved . It is difficult to compare between treatment and control without any water quality data from the treatment sites , , but the absence of any runoff data at the treatment site suggests that the treatments have managed to capture most of the rain that fell on the treatment area and virtually no water or soil left the treatment gully during either wet season . There has also been very little runoff at the control gully , therefore , additional years of data under ( hopefully ) average or above average rainfall conditions will further test the effectiveness of the treatment at this site .
( B )
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