G Gading Nias Residences Block A (Alamanda) is one of the subsidized apartment which is located in Pegangsaan Dua KM 3,3, Kelapa Gading North Jakarta and will be build on 8067 m2 area, consists 24 floor, height 65,4 m with total unit 1645 room. This apartment will use roof tank system, with the force of gravity, so it can flow the water from upper floor to the bottom easily. PDAM (Municipal Water Supply Enterprise) will supply 27,4166 m3/hour of clean water for 24 hour into two ground reservoir filled to capacity 108 m3, through 75 mm diameter sevice pipe, and will be pumped for 10 hour with transfer pipe passing through 2 galvanize riser pipe with 65 mm in diameter, so it can fill two roof tank with water. Using gravity force, the 20th floor till ground floor clean water distribution will be using 3 PVC riser pipe with 200 mm in diameter and Pressure Reducing Valve (PRV) will be added, which is located on the 8th floor. While the 24th till 21st floor water supply will be full-filled with the help from booster pump, because this four floor loss its 8,011 m head pressure. Clean water fluctuation measurement for Block A will focus on resident used water flow assumption methods, between Water Supply Fixture Units (UBAP) with the types and total amount of plumbing fixtures, so we can get the roof tank full capacity that needed, which is 85 m3. Block A will be using mixed system with gravity flow on waste water pipe, in which grey water and black water are mixed into one and flow through 77 riser pipe with 75 and 100 mm in diameter, in every unit shaft, so it can gives comfort to the resident and an easy access for fixing the pipe. This waste water will be flushed into two main grease trap compartment with capacity 22 m3/day, and will be process with gravity force to the nearest Sewage Treatment Plant (STP), 2,48 m beneath the ground. Waste water pipe diameter measurement will be based on building’s weight cumulative. Block A vent system consists of riser pipe vent, branch vent, and release vent. Vent pipe will discharge only on public rest room 3 and 4 because it exceeds the 3 m maximum prereqruitment between riser pipe vent with plumbing fixtures (SNI Plumbing, 2000). 100 mm diameter release vent will be put on the 10th and 20th floor to flattening the pressure within the pipe. Rainfall pipe size will be based on maximum weight for 200 mm rainfall and building width that’ve been poured.The rainfall from the roof and balcony will be distribute through 77 rainfall riser pipe into three infiltration well with capacity 115,64 m3, while the water from the ground and wall will flow into infiltration pond with capacity 360 m3.