Monitoring ring-tanks dynamics

The aim of this project was to assess the feasibility of monitoring irrigation large on-farm storages in the northern Murray-Darling Basin by using satellite altimetry and optical remote sensing. The northern MDB is characterised by variable streamflow and large in-stream losses. Limited reservoir regulation capacity has resulted in water harvesting from floodplains during high flows into large private on-farm storages called ‘ring-tanks’. The on-farm storages are wide-spread and important, yet relatively unknown, component of the regional water system. For example, on the Lower Balonne there is about 595 GL of ring-tank storage, larger than Sydney harbour. Recent fish kills and algal blooms due to low inflows, an uncertain regulatory framework on floodplain harvesting, and the lack of monitoring all contribute to poor environmental and social outcomes. No assessment has been conducted on the feasibility of monitoring floodplain harvesting in large ring-tanks using multi-mission satellite altimetry to estimate stored water volumes, which is essential to understand the fate of large volumes of water during high flows, particularly on drier-than-average years. 

The main goals of this project were to provide:

1. location and surface area of ring-tanks across an area of the northern basin’s catchment which rely on water harvesting for irrigation (the Barwon-Darling region);
2. ring-tank information (e.g., year of construction, area, open water frequency and actual evapotranspiration);
3. an assessment of the feasibility of monitoring surface water height of ring tanks from multi-mission satellite altimetry products and optical remote sensing and
4. proof of concept showcasing monitoring of water levels and open water presence in a ring tank and relation to irrigated agriculture actual evapotranspiration. 

Results

Cross-section and volume estimations.

For more information, please contact jorge.penaarancibia@csiro.au.