To find the water level at the end of summer, you need to add the additional drop in water level to the current water level.
- The current water level is 112 meters below sea level.
- During the summer, the river drops another 213 meters below sea level.
To find the total decrease, you add the two amounts:
\[ 112 + 213 = 325 \]
Thus, the water level at the end of summer is 325 meters below sea level.
The final answer is:
The water level is 325 meters below sea level.