This study aims to identify the existing conditions (discharge, velocity, river dimensions and identification of vegetation), evaluate the river's capacity at the confluence and the application of eco-hydraulic in reducing flood potential. Based on the river classification based on width, the river is categorized as a small river with different flow characteristics, it is proven that the Kerekeh River flow rate is 3,278 m/second larger than the Semongkat river flow rate is 0.442 m³/second. The vegetation at the confluence of the river consists of bamboo, teak trees, jackfruit, sengon, bananas, coconuts, katang-katang plants and thistles and malacca trees. Based on the planned flood discharge for a 10 (ten) year return period, it is known that it is 79.483 m³/second. There are 5 (five) observation points made at the confluence of the Kerekeh River and Semokat River, only 4 (four) observation points that have the potential for flooding, namely the 2nd point with a channel capacity of 41.43m³/second, the 3rd point with a capacity of 41.43 m/sec. channel of 6.81 m³/second and the 4th point has a capacity of 31.63 m/second and the 5th point only has a capacity of 35.70 m³/second. The 4 (four) points have a channel capacity smaller than the planned flood discharge which is known to be 79.483 m³/second and has the potential for flooding. Only at the 1st observation point has a channel capacity of 150.31 m³/second, which is greater than the planned flood discharge, which is 79.483 m³/second and has no potential for flooding. the banks of the Kerekeh River, with a vegetation diameter of 4 cm can retain flood discharge to 39.453 m³/second from 79.483m³/second. Keywords: Drainage, Flood, Discharge, Ecohydraulic