Water can be supplied or retained in shafts and tunnels already in the catchment area, according to requirement and quality. Reservoir water can be take in at several horizontal levels so that an appropriate quality of water can be used. Deeper water rich in nutrients can be discharged through ground drains, blue green algae can be fed into the siphon pipe by draining surface water through the flood relief installation that supplies a lifting line. (Figure)
Drainage of deep
water rich in nutrients and aeration of deep water are usual methods in
reservoir operations in terms of improvement of water quality.