Due to the need to know the availability of water resources, the construction of a curve whose purpose relates two hydrological variables such as level and flow and is known as the rating curve. The rating curve uses geometric data of the section of the channel and gauging campaigns in order to determine flow rates from the measured levels. Currently in Colombia, the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM) performs an average of three to four gauging per year, an interval which does not meet international standards that propose a minimum of ten gaugings, a situation that can potentially affect the accuracy of the curve. The method used by the IDEAM for the construction of this curve is to draw a smoothed line through a cloud of points whose values are taken from gauging campaigns (Salazar & Chaparro, 1999). Since this is a time-consuming method, it is necessary to evaluate more efficient methods in economic and temporal terms. To this end, a methodology is proposed in which it is possible to optimize the way in which flow versus level curves are constructed by adjusting them through mathematical equations. As a result, the most favorable equations for the data set of each station were the equations of degree two, which met the established selection criteria. In addition to this, there is a decrease in the errors of dispersion of the curve adjusted to mathematical equations with respect to current curves constructed by the IDEAM.