The water pump is leaking. I had a new pump installed, and it's been leaking for about a year.
If you’re positive the water pump is the source of the leak, then the replacement pump was not properly installed. Either the seal is skewed or the pump is not tightened down correctly. I recommend that you have a cooling system pressure test performed to confirm the source of the leak. This test uses dedicated equipment to pressurize the cooling system to detect the location of the leak. A professional technician from YourMechanic can come to your home or office to perform this inspection and replace your water pump if needed.