Question 455Navigation General

The correct answer is A) 74.0 feet (22.6 meters). Explanation: 1. The normal upper pool elevation is 420.0 feet (130.8 meters) MSL, and the vertical clearance at the Clark Memorial Highway bridge is 72.6 feet (22.1 meters) above normal pool. When the gage reads 10.6 feet (3.2 meters), the water level is 1.4 feet (0.4 meters) below normal pool. Therefore, the clearance at the bridge is 72.6 feet (22.1 meters) plus the 1.4 feet (0.4 meters) of lowered water level, which equals 74.0 feet (22.6 meters). 2. The reasoning is based on the relationship between the normal pool elevation, the vertical clearance at the bridge, and the current water level indicated by the gage reading. 3. The other options are incorrect because they do not accurately account for the lowered water level when the gage reads 10.6 feet (3.2 meters).