Cost Efficiency in Implementation of Pipe Siphons and Concrete Siphons Construction on the Rababaka Interbasin Channel of Dompu Regency Complex

Implementation of a project is often found the result is not suitable for the conditions at the time of implementation. To overcome this, it is necessary to do design adjustments aimed at adjusting the plan of execution with circumstances when the work is implemented. This design adjustment is based on data retrieval directly from existing field conditions by conducting surveys and field engineering. The result of this field engineering will be the basis of calculations for proposed changes in work added/less, volume switching and adding new work items. The minimum Diameter of the Sypon is 0.60 m because it will be used for cleaning and inspection and the maintenance door (gate valve) or main hole. To prevent sedimentation on the base of the Syphon, the water flow velocity in the Sypon should be high. However, high speeds cause increased energy loss. Therefore, the balance between high speed and high loss of energy that is kept must be maintained. The velocity of water flow in the Sypon should be twice higher than the normal speed of the flow in the conduit and should not be less than 1 m/dt, and not more than 1.5 m/dt. Maximum speed should not exceed 3 m/s. Construction of reinforced concrete and pipe Steel Carbon ASTM A 252 Grade 2, two types of construction can be applied on the 1. S RBK siphon, but in terms of ease of implementation as well as the ease of supervision, Steel Carbon ASTM A252 Grade 2 pipe construction is more profitable. Calculation result of work implementation of concrete reinforced Syphon is expensive when compared with the work of Syphon by using Steel Carbon ASTM A 252 Grade 2, with efficiency value of 5.14%.