Hundreds of kilometres high in the sky, satellites are getting ready to replace probes and divers to help hydropower plant operators understand and manage their reservoirs more economically and more sustainably than ever. Their secret? HYPOS, an EU-funded project carried out by five organisations specialised in water management and the capture and analysis of satellite images of Earth. To date, the software has been tested on four sites, across Switzerland, Albania, and Georgia. The results have helped operators build a more accurate and comprehensive picture of their reservoir. Literally.

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The results from HYPOS appear at the click of a mouse. From the amount of sediment in the water to surface temperature and the distribution of markers for harmful algae, the software’s algorithm produces an instantaneous image of the reservoir at any given point, provided satellite data is available. Users have described the step up from usual practice as a ‘quantum leap’: to make decisions on essential water management activities such as flushing or dredging, or prevent damage from floods, reservoir owners used to rely on surveys carried out in person in selected areas.

With HYPOS, the wealth of information made available from a computer image can simplify many of the activities required from hydropower plant operators: identifying sediment baseline and seasonal trends, monitoring and reporting on sediment dynamics and other environmental impacts for planning purposes, visualising the evolution of algae bloom across the reservoir. When combined with a model developed by one of the partners on the project, HYPOS is also able to provide real-time estimates of flow and water quality, something particularly useful during flushing operations.

EOMAP, the Swedish Meteorological and Hydrological Institute, Stucky, the Norwegian University of Science and Technology and the Institute for Remote Sensing of Environment, all partners in the project, are enthusiastic about their collaboration and the future of HYPOS. The outcomes to date are promising for the water and energy sector: improving decision-making with better images and data is essential to reduce environmental impacts and for the power plant to continue to deliver water, energy and climate services.

Satellite-based water monitoring software solutions providing analytical information on:

• Turbidity in FTU/NTU
• Total Suspended Matter in mg/l (after calibration with turbidity)
• Chlorophyll-a in µg/l and qualitative harmful algae bloom indicator
• Sea Surface temperature in°C
• Secchi depth or visibility in meter

 Available spatial resolution

• Typically, 10-30m grids for water bodies with minimum 30m diameter
• Higher resolutions up to 2 m can be tasked for specific events

 Available temporal resolution

• Dating back to early 1980’s
• Typically between every 3 to 5 days for the 10-30m products, depending on overflight paths over the area of interest
• Daily coverage possible for larger water bodies with coarser resolution or by using commercial satellite data

 Main application

• Identification of sediment baseline and seasonal trends
• Monitoring of sediment dynamics
• Calculation of sedimentation rates and flows
• Environmental monitoring of algae bloom evolution in reservoirs
• Monitoring environmental impact changes useful for baseline analysis and planning purposes