Onsite vegetation , runoff and water quality data is collected by CSIRO , commencing in 2018 .
Indicators of success of treatments start with increased vegetation cover , followed by a ‘ reshaping ’ of the gully and terrain ( either naturally or through intervention ), then improved water quality and reduced sediment loads . Previously published research , mostly from overseas , suggests that water quality improvements start to occur between 3 and 20 years after works are complete , when and if dynamic equilibrium across the landscape is achieved . Early indications at Mt Wickham are still positive .
The water quality monitoring equipment was installed on 21 February 2018 , and the pre-treatment pasture and biomass surveys were initiated in August 2018 . The rehabilitation of the treatment site commenced on 22 October 2018 following the site plan completed by Verterra and Alluvium consulting services .
The location of the treatment and control sites is shown in Figure 12 . The area of the catchment above the monitoring station is 14.1 ha for the treatment site and 3.0 ha for the control site . Images of the control and treatment water quality monitoring equipment before , during and after events in the 2019-20 wet season are shown in Figure 13 .
The rainfall in the period July 2019 to March 2020 was around 390mm which is well below the annual average of 630mm . This contrasts with the previous year of 1,100mm , well above average . From a project perspective the heavy rainfall events at the beginning of the treatment were welcome . This allowed the site be ‘ tested ’ and learnings recorded .
Figure 12 . Location of the Mt Wickham Treatment and Control gullies . The location of the treatment structures and monitoring equipment / locations are shown . Source : Bartley et al . ( 2020 ).
53