Water in My Trunk Mazda 2003 Protege

I have been getting water in the small well on the driver’s side of my trunk (not in by the tire). The water is clear and I have gotten up to 4 cups of water in the well. The gaskets around the trunk all seem intact and sound. The carpet and the board that sits over the tire are not getting wet. Where could the water be coming from and how can I stop it?

I get water in the trunk of my 92 Mazda Protege, but it does soak the board and carpet.

my brothers '94 protege has water in the trunk too. it’s some strange thing that a lot of proteges have.

it could be coming up from below.

The obvious things to check would be the seals on the tail/brake/turn light and whether there is a missing plug for an unused wire pass-thru in side wall of that well. Any wires hoses, pipes in the well? Check the seals. My understanding is that the seal around the trunk is a common cause of problems like this – especially in climates where ice dams can form in the space between the trunk gasket and the car body that then route rain or ice-melt into the trunk.