The water pump bolts to te timing cover and pushes water through outlets into the block on both sides. There are gasket between the WP and timing cover, and the timing cover and the block. Some of the bolts that secure the WP and timing cover go into the water passages in the block. The leak could be one of the gaskets, or around a bolt thread. Because it could save a lot of work, before you disassemble the entire front of the motor, try removing some of these attaching bolts and reseal with RTV. Of course, to do this you must first drain the coolant. Good luck.