بررسي پيامدهاي زيست محيطي سد شهر جاي اروميه بر محيط زيست طبيعي منطقه

Determination of the Environment Consequences of Shahr Chai Dam on Natural Environment of the Region

Shahr Chai Dam is being constructed on Shahr Chai River, 12 Kilometers south west of Orumieh City in West Azerbaijan Province. The Capacity of the Dam is about 215 million cubic meters and is designed to provide irrigation water to the 12,500 hectares of agricultural lands on the southern parts of Orumieh and industrial waters of Orumieh city. Prior to the construction of the Dam, no Environmental Impact Assessment was conducted. Thus, the present research carried out in order to determine the environmental consequences of the Dam on the natural surrounding. Although at the immediate vicinity of the Dam, none of the quadruplet regions protected by the Department of the environment or Natural Sensitive Areas are present, this region is at the periphery of the City and it is situated on the route used by the local people and their herds. Therefore, it is highly affected and much of its pastures and agricultural lands are either destroyed or their application has been altered. There is no sign of flora and fauna species in this region. However, Orumieh National Park Lake, located in the region, is directly affected by the construction of the Dam. This park has a unique ecosystem with global importance and the storage of water in the dam reservoir would reduce the incoming flow of water to the Park, which eventually would threaten its ecosystem. Fortunately, the construction of Shahr Chai Dam has little effect on Orumieh Lake, since only 3.3 % of its incoming water is provided by Shahr Chai River. The positive impacts of dam construction on the natural environment of the region are the activation of the river ecosystem from dam construction site to the estuary, increase in biodiversity of fauna, and enhancement of fisheries potential. In order to mitigate the negative consequences of Dam on Orumieh Lake and to increase the biological capacity of the river, it is recommended to discharge one cubic meter of the damʹs water reserves per second. This would increase the water supply of the minor branches of the river on the lower part of the dam and ultimately would discharge 40 million cubic meters of water into Orumieh Lake.