The estimation of Suspended Sediment Load (SSL) is challenging due to its complex nature within the field of hydrology. The selection and reduction of input feature dimensions, along with the non-uniformity of the sediment and estimation accuracy, pose challenges when estimating suspended sediment load. By combining support vector regression models with MOGWO, MOPSO, and MOOTLBO, this study aimed to predict suspended sediment load. Hybrid models are constructed with three key objectives: enhancing accuracy, minimizing feature count, and optimizing sediment classification. In order to accomplish this, two scenarios have been formulated. The first scenario prioritizes performance accuracy, whereas the second scenario assigns equal importance to three objectives. The study focuses on the Kosar Dam watershed in southwest Iran. The CHIRPS precipitation product and the GLDAS soil moisture product are considered to be predictors. The extraction of input features is carried out utilizing Principal Component Analysis (PCA). The results from both scenarios indicated that the optimal sediment classification consists of 10 categories, demonstrating superior performance across all three integrated models. Incorporating feature selection enhances the model's performance and decreases the number of features. In the first scenario, 10 features are selected from a set of 30 input feature vectors, while in the second scenario, 14 features are chosen. Consequently, hybrid models prove to be effective in reducing input features, optimizing classification of SSL, and enhancing prediction accuracy. In general, the SVR-MOOTLBO model exhibits superior performance when compared to other models. The performance indices (R, RMSE, MAE, PBIAS, and MD) exhibit variations ranging from 0.02% to 0.75% between the first and second scenarios in SVR-MOOTLBO, while the RPIQ index shows a relatively modest difference of 6.2%. In both scenarios, the SVR parameters are well-tuned, and the search agents of the MOOTLBO algorithm exhibit effective functionality.