Mogawak Shrine can be found within Zora's Domain, in the Lanayru Great Spring region.
Shrine Location
Mogawak Shrine is located in Zora's Domain, at 3299, 0424, 0112.
The Power of Water
From the entrance, go to the right and use Ultrahand to take the treasure chest out of the water. It contains a Magic Scepter.
In the same area, there is a Hydrant pouring water downward. Use Ultrahand to take the stone slab that is floating in the water, and attach it to the top of the round item that has a slab on the bottom, so that the two slabs are on the opposite sides. Then use Ultrahand to pull the upper slab under the water. The water will make the slabs spin, powering the electrical wire.
Go to the central area and pick up the object on the floor. This is a battery that you can set on the terminal at the end of the wire that you powered. Wait for this battery to fill up, then use Ultrahand to take it to the opposite side of the area and place it on the round terminal. This will electrify the metal sphere in the water. Use Ultrahand to pull the two underwater metal spheres closer to each other so that the electricity will reach the other side. This opens the bars. Go through (don't swim close to the electricity) and open the chest to get an opal.
Move the metal spheres away from each other (if the battery hasn't run out of power yet), then go across and take the battery. Take it back to the electrified node to charge it back up. Then take it to the platform that has a fan underneath. Go up the stairs and step on the platform, then use Ultrahand to put the battery onto the terminal, or just set the battery in the middle of the platform to power the fan. This will take you up to the end of the shrine, where you will get a Light of Blessing.