In all prospect likely probable maximum precipitation (PMP) is the significant thing parameter used to assess the probable maximum flood (PMF), the two of which may be basic for dam assurance and structural building capacities. The World Meteorological Organization (WMO) characterizes PMP in light of the fact that the best power of precipitation for a given span this is meteorologically feasible for a watershed or a spot at a chose time of a year, and not utilizing a recompense made for long term climatic patterns. Together with auxiliary assurance, the hydrologic wellbeing of water frameworks is presently, subsequently increasing more noteworthy enthusiasm, because of the way that overtopping or dike disappointment could bring calamitous human and cultural misfortune There are exhaustively used procedures for surveying PMP, to be explicit hydrometeorological and real philosophies that are feature of the deterministic and probabilistic systems independently. The deterministic PMP improvement using the storm-based methodology proposed by using Colorado Water Resources Department and Applied Water Associate is gotten for PMP estimation in this examination. The assessment work contains five head portions, particularly storm choice, storm precipitation evaluation, estimation of storm adjustment segments, PMP estimation and PMF estimation. Such a methodology lets in to talk about the altering and surveying PMP values for the picked TNB dam, the assessments among the outcomes got from the proposed procedure and the results wrapped up from going before research to get section to its presentation.