Which of the following would not be an indicator of floodplain presence?

Clear water would not be an indicator of floodplain presence because floodplains are typically associated with water that is often murky or turbid due to the presence of sediments, organic material, and other pollutants that can be washed into the water body during floods. Floodplains are formed by the overflow of rivers during high-water events, leading to the deposition of sediment and nutrients in the area, which tends to cloud the water.

In contrast, a high sediment load, riparian vegetation, and organic drift lines are all characteristics commonly found in floodplains. High sediment loads indicate the transport of materials that can accumulate on floodplains. Riparian vegetation thrives in the moist conditions of floodplains, providing habitat and helping to stabilize the soil. Organic drift lines, which are accumulations of organic debris along the banks, often mark the high-water lines of previous floods, further signifying the presence of a floodplain. Therefore, clear water is not a typical indicator of floodplain areas.