Intensive landscape-scale remediation improves water quality of an alluvial gully located in a Great Barrier Reef catchment

Abstract. Gully erosion can be a major disruptor to global fluvial sediment budgets. in the catchments of Great Barrier Reef is attributed ?40 % fine suspended pollution freshwater and marine ecosystems downstream. Mitigating this source will have lasting positive impact on water quality connected rivers receiving environment. Here we conduct preliminary evaluation ability intensive landscape-scale gully remediation reduce associated nutrient export from catchment draining Reef. The method was first attempt, region, at investing high level financial (total cost AUD ?90 000) logistical effort (e.g. earthworks, including establishment an on-site quarry) develop long-lasting mitigation measures (i.e. regraded, compacted, battered walls, rock armouring banks channel, installation check dams). A novel monitoring network, comprised suite new established automated methods capable operating remote environments, used evaluate remediated gully, control their respective catchments. recently developed pumped active (PASS) sampler optimised sample ephemeral flows deployed outlets runoff flow paths. This study demonstrates how combination low- high-cost techniques configuration that ensures collection redundancy complementary data between methods. Monitoring conducted during two consecutive wet seasons and, thus, only provide information. over longer timescales 5–10 years) need carried out order validate findings discussed herein. Samples collected had significantly lower concentrations compared providing evidence works were successful stabilising within gully. Dissolved particulate also samples, consistent with decreased concentrations. measurements both channels overland surrounding suggests nutrients site are likely sourced processes occurring (at relatively low concentrations). In contrast, primary itself. potential as effective action for reducing alluvial gullies. It provides useful case required appropriately assess effectiveness type control.