What condition does a braided stream usually indicate about its sediment load?

A braided stream typically forms when the sediment load is greater than the stream's capacity to transport it. In this context, a braided stream is characterized by multiple interweaving channels that split and rejoin, which occurs as sediment accumulates in bars and islands between the channel flow. This situation arises when a river carries an abundant supply of sediment, unable to transport it all effectively during periods of lower water flow.

When the sediment supply exceeds the ability of the stream to carry it away, the excess material builds up and alters the flow path of the river, resulting in the braiding effect. This is often a response to rapid, variable discharge situations, such as glacial melt or heavy rainfall, which further enhances the sediment transport capacity. Hence, the correct answer reflects the understanding of how braided streams are indicative of a situation where the sediment supply is not just ample but exceeds what can be carried in a single, stable flow channel.