The response to the wet season at each of the two Strathmore work sites is clear to see.

Strathmore work responds well to wet season

Strathmore Station near the Bowen River rodeo grounds is LDC’s fourth large-scale gully. The remediated site has responded well following the wet season.

Gully works consist of two sites within the Strathmore Station boundary, and are referred to as the Northern zone (gully reshaping) and Southern zone (bund and chute). The gullies are on a small eastern tributary which joins Red Hill creek about 2km upstream from its confluence with the Bowen River.

The design was led by engineering firms Verterra and Alluvium Consulting. They managed the works which were carried out by local companies Pattle Contractors and Beauchamps Excavating.

This link provides an overview of the works carried out.

Active gully before treatment at Strathmore Station.

How the site held up after the wet in January 2021:

  • The rock chute and bund were completed, and hay and ameliorants were spread over the heavy scaled areas. The remediation site is responding well with vegetation germinating in scalded areas.
  • Minor maintenance was carried out in April including earthworks to rilling areas, and reseeding.
  • The site has been fenced and will not be grazed.
  • There was an historical dump site located to the west of the airstrip. Potholing was carried out to define the extent and soil samples were taken for contaminants. There was no contaminant of concern found however the extent of rubbish was larger than originally allowed for. A report of the finding has been provided to the local government authority, Whitsunday Regional Council (WRC), for their review. Work was carried out to the end of the airstrip.
  • It is expected final remediation works will occur when WRC decides how to deal with the historical waste site.

The gully has been stabilised and good grass is growing across the entire site.

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KEQ #1

Figure 1. Total fine sediment reduction by project type and erosion source. Inset shows the proportion of the total project area for each project type.

These estimates have been calculated using two methods: 

1) The pollutant reduction component of the Alluvium/Great Barrier Reef Foundation (GBRF) investment tool for hillslope and streambank erosion management projects; 

2) The Reef Trust Gully Toolbox method for gully erosion management projects. The LDC Water Quality Report 2020 (Waterhouse et al., 2020) highlights that a number of assumptions underlay these calculations, therefore these figures should be treated as the best available estimate of sediment reductions to date.

Preventing sediment from reaching the Great Barrier Reef

Each wet season sediment is washed into local waterways and out to the Great Barrier Reef (GBR). 

Most sediment is very fine, and can stay suspended for a long time and can travel great distances. Valuable topsoil is lost from production, and increased concentrations on the reef can be harmful to seagrasses and corals. 

Landholders in the BBB have completed 69 on-ground water quality practice changes, and it is estimated that these have contributed a fine sediment reduction of 6,154 tonnes per year from reaching the GBR. 

Of this, approximately half of the sediment savings are attributable to grazing land management changes on hillslopes and streambanks, and the other half as a result of gully remediation treatments across a broad range of scales, as shown in the graphs above. 

The table below also highlights the relatively small area of intervention in the gully management projects compared to the large sediment savings that these can achieve - 60 per cent of the sediment savings over only 4 per cent of the project area.

Table 1. Estimated sediment reductions (tonnes) from projects completed in the LDC Project to date.

KEQ #2

*GLMWW = Grazing Land Management Wire and Water

KEQ #3

*The Exploring New Incentives activity area has provided an opportunity for graziers to adopt improved land management practices through a range of activities. For some of these properties, it was the first time they signed contracts for on-ground works.

KEQ #4

The LDC project monitors four gully sites (represented in this table) with gold standard equipment and analysis, carried out by CSIRO.

Results have been compiled in a preliminary report from Bartley et al (2020), with the final report expected to be released by the end of 2020. The preliminary report shows all four sites have indicators of improvements, notably the Strathbogie and Mt Wickham sites.

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Reef regulations - grazing, standard conditions

  1. For land in good or fair condition (more than 50 per cent ground cover at 30 September), continue using measures to maintain land condition.
  2. For land in poor condition (less than 50 per cent ground cover at 30 September), steps must be taken to improve land condition.
  3. For land in degraded condition (less than 20 per cent ground cover at 30 September), steps must be taken to improve land condition OR prevent areas from further degrading or expanding.
  4. Keep records of measures taken and also of agricultural chemicals, fertiliser and mill mud or mill ash applied to land.
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