Following a sharp reduction in output from the Zayandeh Rud Dam and the sudden cutoff of water flow to downstream reaches, thousands of fish and aquatic organisms died in remaining shallow pools and dried riverbed pockets.
After 94 days of continuous flow, the river stopped flowing in downstream areas on the morning of September 6 as dam releases were throttled. The sudden stoppage trapped large numbers of mature fish and fingerlings in shallow, remaining pools exposed to intense heat and sun.
Hossein Akbari, Deputy for Natural Environment and Biodiversity at the Isfahan Department of Environment, identified the intermittent turning on and off of the river’s flow as a primary cause of biodiversity destruction along the Zayandeh Rud.
Akbari explained that fish move downstream with the flowing water, but when releases are abruptly cut off during warm weather, they become trapped in isolated pools where significant die-offs occur.
The environmental official placed responsibility for these ecological consequences on the Isfahan Regional Water Company, demanding a minimum, continuous baseline flow for the Zayandeh Rud.
