To find the water level of the river at the end of summer, you need to add the two depths below sea level.
- Initial water level: 112 meters below sea level
- Drop during summer: 213 meters below sea level
To find the total, you add these two values:
\[ 112 , \text{meters below sea level} + 213 , \text{meters below sea level} = 325 , \text{meters below sea level} \]
Therefore, the total water level at the end of summer is 325 meters below sea level.
Answer: The water level is 325 meters below sea level.