Impact of sampling frequency on mean concentrations and estimated loads of suspended sediment in a Norwegian river: Implications for water management

► We studied reliability of riverine suspended sediment concentration averages and load calculations. ► We produced six datasets with different sampling frequencies based on daily data. ► Reliability of mean concentrations increased with increasing sampling frequency. ► Rating curves based on fortnightly samples and additional flood samples gave the best load estimates. ► Managers must be aware of high uncertainty in pollutant concentration and load estimates in rivers.