water level
Refers to the height of a water surface, especially in rivers, lakes, reservoirs, or tanks. Common in weather reports, flood warnings, and engineering contexts.
The river's water level rose rapidly due to heavy rain.
The water level of the dam has been dropping.
The river's water level is rising due to heavy rain.
The dam's water level has been dropping.
They measure the lake's water level every day.
The water level reached three meters, and an evacuation advisory was issued.
水面 refers to the water's surface itself, while 水位 refers to the measured height of that surface.
水量 means the total volume or amount of water, whereas 水位 refers to how high the water surface is, not how much water there is.
水位 refers to the height of the water surface (water level), whereas 水深 refers to the distance from the surface down to the bottom.
Compound of 水 (water) and 位 (rank, level). The meaning is transparent from its components.