Performance Evaluation is routine work for IAM. Related to this, the Performance Indicator and Performance Factor need to be well understood. This paper presents the result of a preliminary reflection on infrastructure performance, performance indicators, and performance factors. Basic Quality of infrastructure is measure by its Performance to execute its Function. Performance Factor is something that can influence the performance. Performance may consist of several components. Each Performance components indicate different qualities. Each performance component may have different importance levels and different values. The factor may consist of several factors. Each factor has its nature as supporting or resisting performance. Each factor has its strength of influence, its easiness to be manipulated, and its value.

River infrastructures can be defined as facilities and structures that support all activities related to river. Many infrastructures that exist along river stream but few of them are listed and recognized as an important part in the river system. The condition of assets that support the river function should be considered since it determines the sustainability of water supply system for many areas. Starting from upstream, there were dam and reservoir that constructed to reserve the water. Moreover, the water can be distributed to the downstream area for many requirements, such as irrigation system, hydro power, industrial process, etc. In the other hand, dam and reservoir also functioned as flood control that protect the downstream area from flood and inundation. In alluvial river, there were erosions that occurs as river flow velocity could transported soft soil numerously. Hence, the river bank protections were built in order to protect the nearby river infrastructures. Therefore, the infrastructures recognition as preliminary assessment to the river asset management need to be done in order to maintain the river system.

The stability of infrastructure along river channel, such as bridges and embankments, is paramount to continuing service and public safety, and therefore, is essential consideration in the design, construction and maintenance. During the design process, infrastructure stability is often assumed to be static, and considered by implementing a safety factor which is produced by an analysis of extreme condition. However, this has failed to consider the variability of natural factors and importantly, the escalating threat of extreme environmental condition, induced by global climate change. This assumption should, therefore, be revisited for developing a more resilient design and maintenance regime. To demonstrate the changing infrastructure stability, an assessment of safety factor of river embankment and bridge foundation as nearby infrastructures along Bengawan Solo River's channel and estuary is presented. This was undertaken to determine the impact of water level fluctuation during two extreme conditions during dry and rainy seasons in several critical locations. The river characteristics (i.e. morphology, water fluctuations, velocity, and sub-soil characteristics), embankment conditions and bridge pile foundation were investigated in-situ to assess the change of safety factor. The laboratory investigation focused on river and embankment characteristics including the analysis of the drying-wetting conditions. In-situ and laboratory investigations found an extreme condition which the infrastructures are subjected into, where the water level and flow velocity were 3 m and 0.04 -0.27 m/s during dry season; and 10 m and 0.46 -0.84 m/s during rainy season. Furthermore, from the analysis, it can be concluded that certain areas in the river do not meet the minimum requirements for bridge foundation and embankment stability.

This study attempts to recognize the fundamental issues in river morphology by examining suspended sediment concentration (SSC) and flow velocity at the curved channel in an alluvial river. To capture the entire set of the afore mentioned conditions, a field investigation was conducted at the inner and outer banks of the flow path of a curved channel, which is considered as the critical section in river change development. The field observations were conducted over a 1-year period, from January to December 2014, in which both dry and rainy seasons occurred. Because the curved channel is subject to severe erosion, especially around the outer bank, lateral migration of the channel might regularly occur. The field investigation showed that the outer side of the curved section migrated approximately 0.0625 m/month during the study period. The SSC, which peaked at 25% and 43% of the maximal flow velocity in the upstream and downstream sections, respectively, showed the rapid erosion of the curved section leading to lateral channel shifting. A channel resistance evaluation confirmed the potential capability of the riverbed material at the curved section was 20% lower than that in the upstream and downstream sections. According to the SSC and flow features, a new understanding of changing river morphology with respect to a curved channel of the Bengawan Solo River was developed.

Sediment transport is the natural phenomenon which is occurred along river stream. Many factors are influencing on this process, but the main parameters are current velocity and flow discharge. The velocity and flow discharge are two river components which intercorrelated each other. Current velocity may cause scouring at the river stream continuously. The materials from scouring process would be become the primary sources of sediment load. There are two sediment load types, suspended load and bed load. The quantity of sediment load that expressed by sediment concentration plays an important part in river morphology changing. This study is focused to assess the sediment concentration affected by current velocity. The sediment samples were taken from Kanor village-Bengawan Solo River during the dry and monsoon seasons. Suspended load samples were taken by suspended trap equipment. River water current was measured by current meter magnetic. This paper is mainly investigated the differences between the quantity of sediment concentration affected by river water current during the dry and monsoon seasons. The investigation results were sediment concentration in milligram per liter (mg/L) and river water current. Based on the data analysis result, the sediment concentrations and current velocities shows the linear correlation. During dry season the sediment concentration and current velocity are lower than in the monsoon season. The highest sediment concentrations were at 0.8 of water depth. This phenomenon is thought be due the effect of particle settling process, so the sediment concentrations are accumulate at the lower point of water column.