Rust stains run down the foundation below every window well, and the window wells have no drains. Reported together, these indicate:

A window well is a small pit against the foundation, and without a drain it becomes a container. Rain and roof runoff collect in it and stand against the wall and the window assembly, which is the one place the foundation is interrupted by an opening. Two consequences follow, and the question presents evidence of both. The rust stains running down the foundation record water repeatedly standing in a steel well and carrying its corrosion products down the wall — a durable record of water level over time. And water standing against a below-grade window is directly above the sill, so it finds any gap in the window's perimeter. The absence of drains explains the mechanism, the stains document that it has been happening, and together they justify recommending drains, covers, or both.

Undrained wells collect water that stands against the foundation and the window assembly, and the rust running down the wall records that this has happened repeatedly. The two observations together identify the mechanism and confirm it is active.

Below-grade window wells require drainage — typically a gravel-filled drain connected to the footing drain — and often covers, to prevent water accumulating against the foundation and the window. Standing water in wells is a common source of basement leakage at window openings.

A Well Without a Drain Is a Bucket held against your foundation, right where a window interrupts the wall.

Look inside at the same location. Staining on the interior below the window confirms the water has already found its way through.

• •Attributing the staining to the liner's own weathering
• •Reporting the missing drains without noting the evidence of standing water
• •Failing to check the interior at the same window locations