Monitoring keeps track of work and keeps the work on track

By MERI Officer
Marc McConnell

Monitoring project activities helps keep track of milestones and monitor progress towards pre-defined project outcomes.

It also determines which techniques succeed, which ones are cost effective, and allows successful projects to be replicated.

Flow event samples from the treated site at Glen Bowen (left) and the control, or untreated site. The efficacy of the remediation is clear.

MONITORING LARGE-SCALE GULLIES

 

Large gullies are a major contributor to land degradation and poor water quality in the BBB catchment. 

NQ Dry Tropics’ large-scale gully monitoring program is yielding results to assist land managers operating in the catchment to apply the most appropriate treatments to ensure successful gully repair.

Five large-scale remediated gully sites are monitored as part of our long-term gully monitoring, each with a different treatment or in a different geographic setting and each with an untreated control site nearby.

At each site, we measure:

  • Land condition: ground cover percentage and composition; gully floor walls and site.
  • Local rainfall.
  • Total suspended solids (TSS) SS and Total Nitrogen. Total suspended solids (TSS) refers to waterborne particles exceeding two microns. While some sediment will settle at the bottom of a water source, other TSS will float on the water surface or remain suspended somewhere in between. TSS affects water clarity, so the higher a water source’s TSS content, the less clear it will be. 
  • Total Nitrogen (TN) is the sum of all nitrogen forms.
  • Velocity.
  • Photos linked to sampling.

During the 2021-22 wet season, there were 29 flow events across the monitored gullies yielding hundreds of samples. The findings will be published later this year.

Gully remediation at Havilah and Gattonvale stations.

Before and after the work at Mt Wickham.

The result of the first of two large-scale gully remediation projects at Glen Bowen Station is a picture.

GLEN BOWEN

 

Three sites treated along the Bowen River

Three sites, covering an area of 10.2ha have been treated. They are part of an extensive gully system adjacent to the Bowen River.

Treatment included reshaping and battering the active gullies, installing rock chutes and bunds to control water movement and establishing vegetation.

The first automatic monitoring triggered by a rain event early in 2022 showed 52,800mg/L coming from the untreated site compared to 794mg/L at the treated site.  This demonstrates tremendous success of the treatment.

Total suspended solids transported from the Glen Bowen control gully peaked at just below 70,000 mg/L while the treated gully yielded less than 200mg/L. 

Overall the median values from the two sites were 794mg/L at the treatment site to 52,800mg/L at the control. For context, water transporting 10mg/L or more is sufficient to affect seagrass growth rate.

The median sediment size transported from this area is 7um (superfine). Grains this size are quick to be transported and once suspended remain in the water column for long periods of time. 

Long term monitoring of remediated gullies provides us with important information on treatment effectiveness. The sites monitored can give us a broad understanding of what the best, most cost effective way to bring gullied land back into production.

Why is it important?

Monitoring and evaluation is important because it:

  • provides the consolidated source of information, showcasing project progress;
  • allows stakeholders to learn from each other’s experiences, building on expertise and knowledge;
  • generates reports that contribute to transparency and accountability, and allows for lessons to be shared more easily;
  • offers paths for learning and improvements;
  • provides a basis for questioning and testing assumptions;
  • provides a means for agencies seeking to learn from their experiences and to incorporate them into policy and practice;
  • provides a way to assess the crucial link between implementers and beneficiaries on the ground and decision-makers;
  • adds to the retention and development of institutional memory; and
  • provides a more robust basis for raising funds and influencing policy.

The focus of this section has been on how the project monitors and evaluates large-scale gully remediation, but LDC also monitors small-scale gully works, rehydration works, and grazing land management practice changes. 

To measure the effectiveness of these activities, LDC has a suite of tools to suit each property project including looking at the general land condition and soil types, mapping, before and after photos, and water and soil sampling. 

This information helps LDC to provide graziers with the tools and resources to implement sustainable land management decisions on their properties.

 

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.
KEQ #8

KEQ #7
KEQ #6

KEQ #5

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.

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 #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

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