New subsection is introduced after “10.6 Diversion Culvert Hydromechanical Equipment” as follows: 10.7 Dam Drainage System 10.7.1. General requirements The supply includes the following components: (1) Three (3) submersible pumps with associated control system including equipment in Damo Control Building. (2) Lifting equipment for pumps removal (3) Hand operated valves (4) Check valves (5) Discharge line to discharge outlet (6) Associated instrumentation for the complete system (7) A monorail beam including an electric hoist shall be provided on top of each pump sump for maintenance purposes (8) All necessary facilities, including slings, embedded metalwork, supports, masonry anchors, anchor bolts, studs, bolts, screws, nuts and washers shall be provided. (9) All accessories necessary for the equipment to be complete and ready for operation when installation is finalised. shall be furnished. The Contractor shall furnish all foundation material required to support the equipment i.e. pumps. piping etc. (10) Spare parts The main characteristics of the ecological flow: Pump type Submersible pump Number of pumps 3 Gross head (to be confirmed in Detail Design) 30 Estimated pump discharge min 15 l/s 10.7.2 Design requirements and operating condition The capacity of each pump shall be at least 1.5 times the normal seepage inflow, but not less than 15 l/s. Flow velocity in any pipe shall not exceed 3 m/s. The Contractor shall determine, in consultation with the employer, suitable operating levels for the various pump starts and stops. Pumps and motors shall be of the same type/duty and shall be identical and interchangeable to enable distribution of operating hours over time Outlet pipe shall be minimum 0.5m above the maximal flood level. 10.7.3 Structure and Material