RESUMEN
There is much discussion going on lately whether dam construction is economic or not in terms of social consequences. Accordingly, various techniques and software have been released to estimate the real social cost of dam construction among which, the Software SIMPACTS has been used extensively by researchers, worldwide. The present version of SIMPACTS software only focuses on adverse effects of hydropower dams regardless of their potential positive impacts. In order to fix the existing bugs, the software was modified by programming a new cost-benefit model in which the costs of power generation, irrigation and drainage, aquatics, and potable water as well as the benefits from electricity sales, elimination of pollutants, increased cultivated area, aquaculture practice and also prevention of flood in the area, were included. The obtained results revealed that the total costs of the Alborz Dam, including the costs added to the modified model, will raise from 164 US$/Mwh calculated by the original version of the software to US$ 1049 per MWh. Besides, total revenues resulting from the above mentioned variables added up to the model reaches US$ 1994 per MWh. Therefore, the cost over benefit ratio for construction of Alborz Dam is equal to 1.5. In other words, a sum of US$ 28 million would be expected as the annual net profit of the project which has totally been overlooked in the original model
RESUMEN
Despite the numerous advantages of large dams, there is still a deep suspicion about the real, long-term benefits and costs of their construction. Land use change on a vast scale, displacement of a large population of indigenous people, loss of biodiversity and production of greenhouse gas emissions, as well as environmental, socioeconomic and cultural consequences resulting therefrom, indicate clearly the need to reconsider the growing trend of dam construction in the world. The present study was conducted to calculate the real cost of generating electricity imposed on communities and environment in order to clarify the adverse socioeconomic impacts of large dams that are often ignored due to short-term, economic benefits. Accordingly, Alborz Dam, a large dam in northern Iran, was selected as a case study to run cost-benefit analysis by SIMPACTS Software. The obtained results revealed that the total external cost of electricity generation by the hydropower dam is about 0.16 US$/kWh. In other words, the annual cost of the electricity generation by Alborz Hydropower Plant is US$ 4.8 million/year. The highest share [163 US$/MWh] belongs to the loss of agricultural production while the lowest cost [0.10 US$/MWh] is associated with the loss of life. According to the estimated values, a total amount of 1074 tons of greenhouse gas emissions is expected to be released into the air by the hydropower dam operation. It should be stated that SIMPACTS Software only considers the adverse effects of hydropower dams and there is a need to improve the capability of the software by adding the positive impacts in to the overall computations, as well