Which of the following is a cause of flooding?

Flooding occurs when water inflow surpasses the capacity of a water channel, such as a river, stream, or creek. This can happen due to a variety of reasons, such as heavy rainfall, rapid snowmelt, or a combination of both that leads to an excessive buildup of water. When the volume of water exceeds what the channel can carry, it overflows its banks and causes flooding in the surrounding areas.

In this context, the factors that inhibit or manage water levels, like water conservation initiatives or increased vegetation along riverbanks, do not contribute directly to flooding. Instead, they can potentially help in managing and reducing runoff, which might mitigate flooding risks. Heavy snowfall can contribute to flooding if it melts rapidly, but it does not directly cause flooding on its own without an increase in water flow. Therefore, exceeding the channel's water capacity is the direct cause of flooding, making it the correct answer.