Putting Historical Water Structures into Operation, Comparing with New Water Structures Establishment Similar to “AHP Method”

Long engineering background of water structures in Iran can also increase the potential and the quantity of their relevant researches, but they have always been facing with lack or not having useful and useable resources for conservation, rehabilitation and fortification of historical and contemporary water structures and always this question “How Can We Conserve and Rehabilitate a Historical Water Structure?” lairs on our consideration in case of coming in contact with, which shows well enough the necessary deliberation from different points of view such as : architecture, rehabilitation, structure, hydraulics, archaeology, geology, hydrology, meteorology, eco-tourism, cultural, social and … about these kind of remains. This research has been done on 170 structures including bridges, weirs, water delivery canals in Iran. The measures of appraisals for decision making on necessary time and cost, social, cultural, cultural heritage, environmental, discussions, existing native technology for construction, rehabilitation and materials, geology, technical and structural discussions have been done during different expert sessions with the authorities and then the importance coefficient of each measure has been calculated by using Double Matrix Method. The weight of each measure has been taken from the expert inquiries. Finally the score of each option from the total points find by multiplying the weight of measure by the importance coefficient. The result of investigations show from the total of 45 investigated structures there are 9 cases where the new structural establishments have higher score where the rehabilitation of historical structures take priority in the other cases. It is necessary to mention, there are several reasons for less score for repairing of those 9 structures. First of all, maybe the changes in climate and decrease of rainfall cause the existence of a structure becomes pale in a certain place, so either to establish a new structure or repairing one shouldn’t be wise. This problem comes back to the wrong site selection of those 45 structures during early studying phases, which have been done by different experts with different viewpoints. The second reason, the lack of economical justification for rehabilitation of those historical structures with extreme destruction which made practically impossible to discuss about renovation and rehabilitation. The point should pay more attention in the following table No.7 is the higher score of rehabilitation of historical structures than establishing new ones. According to the analytical hierarchy process it has been cleared the rehabilitation of Korit & Torogh Dams are in priority from the technical, structural, cultural heritage, social, economical and … points of view. But unfortunately, according to the wrong decision which made in passed a new dam has been constructed near Historical Korit Dam with very high cost and longer time, but the results show the establishment of this new structure has been a great mistake. But the rehabilitation and renovation of Golestan Mashad & Abassabad Behshahr which have been made according to a proper and suitable decision based on a line of complete studies which have been approved. The results show the parameters such as native materials and technics for construction and cultural heritage have least effect on decision making for establishing a new structure.