Most discharge records are developed using stage-discharge relations (ratings) to estimate the discharge based on measured water stages, permitting a fast and relatively inexpensive means to determine the discharge. However, for all but the simplest stage-discharge ratings, uncertainties in the resulting discharges have either been ignored or were based on a statistical estimate of the fit between the rating and calibration measurements. Recent research has demonstrated the feasibility of developing stage-discharge ratings theoretically, rather than empirically, providing unprecedented opportunity to examine the uncertainties in the rating and in discharges determined from the rating. Reliability-analysis methods, particularly, the point estimation method, can be applied to estimate the uncertainty in discharges determined from theoretically developed ratings and appropriately addresses complicating factors such as correlation among independent variables. This paper presents an overview of the application of reliability-analysis methods to determine the uncertainty in theoretical developed ratings. An example for an existing gauging station shows the uncertainties in discharges determined from the theoretical rating and the stage record from the site.