Optimising The River Karun System, Iran

The River Karun is Iran's longest and largest river system with a total catchment area of over 67,000 km2 and a main river stream length of over 800 km. The catchment is located in the south west of Iran. The river system rises in the Zagros mountains in the north and flows into the Euphrates prior to discharging into the Persian Gulf. Mean annual river flows are around 575 m3/s. The catchment has unique conditions which feature: annual average rainfall of 250mm, summer temperatures in excess of 50°C, a series of cascade hydroschemes, major flooding in downstream areas, significant irrigation of agriculture extending to over 280,000 ha, with a further 100,000 ha under development. The river system has two existing 1,000 MW and 520 MW hydro-schemes respectively at Karun and Dez Dams which were constructed over twenty years ago. Two 1,000 MW schemes at Godar-e-Landar and Karun-l Dam are currently being impounded. Over eight large hydro-schemes are under various stages of preliminary design and are due to be completed in the next twenty years. Khuzestan Water and Power Authority (KWPA) is responsible for the planning, operation and co-ordination of the various hydro-schemes, river water control, power generation and energy distribution. The paper explores historic catchment developments with respect to river management and describes the current system characterisation. The philosophy of a staged approach to improvements is then explained.