Abstract
Gas supersaturation occurs when the amount of dissolved gas in water exceeds the
solubility for the given local pressure. Such conditions may happen in natural watercourses,
but more observations are associated with hydropower installations in rivers. The main
anthropogenic sources either originate from water spilled over dams into deep pools or
from air entrained through tunnel systems in hydropower plants. Supersaturated water in
rivers have significant ecological consequences to aquatic biota. This report provides a
literature review of the available reports and publications regarding supersaturation from
hydropower installations. The main focus is on high-head HPPs with secondary intakes,
which is the most common source of supersaturation in Norway. This report provides an
overview of the physical processes, main sources of supersaturation associated with in
hydropower installations and mitigation measure.
solubility for the given local pressure. Such conditions may happen in natural watercourses,
but more observations are associated with hydropower installations in rivers. The main
anthropogenic sources either originate from water spilled over dams into deep pools or
from air entrained through tunnel systems in hydropower plants. Supersaturated water in
rivers have significant ecological consequences to aquatic biota. This report provides a
literature review of the available reports and publications regarding supersaturation from
hydropower installations. The main focus is on high-head HPPs with secondary intakes,
which is the most common source of supersaturation in Norway. This report provides an
overview of the physical processes, main sources of supersaturation associated with in
hydropower installations and mitigation measure.