The purpose of this study was to assess the irrigation water requirements for rice farming and the associated Low Lift Pumps (LLP) of the Punarbhaba River Rubber Dam Subproject found in Biral Upazila within Dinajpur District, Bangladesh. A participatory approach, field observation, and hydrologic analysis were employed to collect local stakeholders’ reports of rainfall, and local river discharge, along with their crop water requirements, as well as the data obtained from national agencies. A survey was conducted in the study area, which covers a total area of 757 ha, with 454 ha designated as the command area. The purpose of the survey was to evaluate the effect of a dam on the availability of water. For the demand, evapotranspiration was calculated by the Penman–Monteith method along with crop coefficients for rice. Rubber dams help preserve water effectively, which guarantees a proper supply during the dry season, as indicated by the outcomes. The approximate IWR for Boro rice is 1.221065 L/second/ha. At this level of IWR, around 0.554 m3/s is drawn off from the river for irrigation. This has helped the dam to increase the rice yield and reduce the demand for fertilizers, thereby increasing agricultural productivity. However, it is important to emphasize the need for improved management of water practices and further infrastructure development so that optimal water use and environmental impacts are minimized. The dam's positive benefits should be enhanced, and ongoing monitoring should continue regarding environmental concerns.