The Code River is one of the pathways from the cold lava flood of Mount Merapi that crosses the center of Yogyakarta City. The eruption material from Mount Merapi was carried by cold lava floods affected the sedimentation process. Along the watershed of the Code River, buildings are dominated by commercial buildings and densely populated areas. Water quality in the Code River is caused by buildings along the watershed that throw waste directly into the river, therefore it is necessary to know the status of water quality on the Code River. This research was conducted to find out how the water quality in the Code River, and the amount of sediment transport and its impact on the upstream area of the Code River. Methods used in determination of water quality is pollutant index and NSFWQI method, while the determination of sediment transport, the method used is the Frijlink method, Meyer Petter Muller and Einstein. The result of water quality research on the upstream Code River, according to the pollutant index method, the value obtained is 5-16, with the status of water quality is medium polluted and heavily polluted. Whereas according to NSF WQI, the value is at the range of 48- 56 with the status of water quality is medium to bad. The results of sediment transport research, according to the Frijlink method the sediment transport occurred is 19.79 – 85.43 m³/day, and the MPM method is 15.06 - 77.23 m³/day, whereas Einstein's method is 8.89 – 70.36 m³/day.