The river's ability in flowing water has been there naturally. The benchmarks of river ability in carrying out the function are mentioned as the river performance; however, the benchmarks of river infrastructure ability in carrying out the function are mentioned as the river infrastructure performance. This study intends to review some aspects of the previous research related to river performance and infrastructure. The methodology consists of reviewing several acts and relevant previous research that some aspects have been proved to influence the river performance and infrastructure. The aspects are classified into two categories: 1) technical aspect that is directly affecting the river performance (come from the nature condition); and 2) non-technical aspect that is indirectly affecting the river performance (come from human intervention). The result shows that: 1) The technical aspects affecting the river performance and infrastructure are erosion, sedimentation, slope, infiltration, morphology, and vegetation surrounding the river; 2) The non-technical aspects that are affecting the river performance and infrastructure consists of land use, residential density, trash, operation and maintenance of river, human activity, and government policy.

The study of river performance and infrastructure is not only conducted qualitatively. An instrument is needed to examine the object being observed quantitatively (usually with a minimum and maximum number scale interpretation). The review of the physical condition assessment for the river performance index and river infrastructure has not been developed based on a study of the variables that influence it. Therefore, this study aims to develop a mathematical model of the index of river performance and infrastructure as a decision support system for the integration of programs and activities related to river management. The research location was chosen based on the consideration that there has been no preparation of a performance index model in the Babon River. In this study, the authors use the Smart-PLS (Partial Least Square) application to analyze and narrow the variables and then re-analyze them using the Generalized Reduced Gradient (GRG) method to calculate non-linear equations. There are four variables, eight dimensions, and 51 (indicators) used, with the types of technical, spatial, social, and regulatory variables. Based on the PLS-SEM analysis, the results were narrowed into 4 (four) variables, 8 (eight) dimensions, and 51 (fifty one) indicators that were interrelated with one another. The GRG (Generalized Reduced Gradient) analysis with the solver in Microsoft Excel showed the most influential weights consisting of: technical variables, namely rivers (0.475) and flood problems (0.582); spatial variables, namely land use (0.418) and land cover (% Urban) (0.498); social variables, namely community activities (0.454), settlement density and socio-cultural conditions (0.289), and community participation (0.257); and regulation variables, namely law enforcement efforts (1.000). This research can be used for other watersheds with conditions or characteristics relatively similar to the Babon River. However, research related to this formulation on other watershed conditions still needs to be done.