Optimisation for Sustainable
Water Resources Management
Case Study: Gediz River, TURKEY
The Gediz River Basin, neighbouring the city of Izmir and discharging into the outer bay,
is characterized by water shortage and competition for water among mainly irrigation with a
total command area of 110,000 ha versus the domestic and fast growing industrial demand
in the coastal zone, and environmental pollution as well as recurrent droughts.
Overall supply of water for various uses is currently approximately equal to the overall demand.
Thus, water allocation for growing demands has to be optimized among various competing water uses
under environmental as well as institutional, legal, social, and economic constraints.
Izmir is the third largest city in the country and an important harbour along the Aegean.
The Izmir metropolitan area, continuously growing, consumes a significant portion of the
groundwater resources of the Gediz Basin.
The seaward fringe of the Gediz Delta is an important nature reserve and has recently been designated
as a Ramsar site to protect rare bird species.
Due to irrigation demands, the reserve suffers from water shortages.
A second component of environmental demand is the water needed for waste conveyance to the sea,
requiring some minimum flow.
There is a good number of creeks that discharge directly into the inner Bay,
causing significant pollution problems and flooding due to recent land use changes
(primarily urbanization), which exerts considerable pressure on the water resource system in general.
The primary issues in the case study are water shortage, competing use, and high levels
of pollution that are typical for the coastal zone and its rapid economic development.
The linkage between the physical constraints and the institutional
and policy shortcoming are among the the main topics.
An optimization approach is required to solve problems of water shortage and
competing uses of natural resources under physical, institutional,
legal, social, and economic constraints.
The end user group includes the State Hydraulic Works (DSI),
Ministry of Environment (MoE), Metropolitan Municipality
of Izmir (MMI), other local governments in the Gediz River Basin,
General Directorate of Rural Services (GDRS), irrigation associations (IAs),
other irrigators, industries, Bank of Provinces (IB), and NGOs.