The answer to 'water line replacement overflowing' is that the most common cause is a problem with the new water line installation. This can happen if the water line was not properly connected or sealed, or if there is a leak in the new pipes. Symptoms include water pooling around the new water line, water pressure issues, and potentially water damage to the surrounding area.
In this situation, it's best to call a professional plumber to diagnose and fix the issue. Trying to DIY a water line replacement can be risky and may lead to further problems if not done correctly. A licensed plumber has the tools, expertise, and experience to properly install a new water line and ensure there are no leaks or other issues.