To find the water level at the end of summer, we need to add the two elevations below sea level together.
- The initial water level is 112 meters below sea level.
- During summer, it drops another 213 meters below sea level.
To find the total water level below sea level, we add the absolute values of the two depths:
\[ 112 \text{ m} + 213 \text{ m} = 325 \text{ m} \]
So, at the end of summer, the water level is 325 meters below sea level.