Window Well Flooding During Front Range Thunderstorms

Short, intense storms are the usual culprit

Aurora's summer weather often brings brief, heavy thunderstorms, sometimes with hail, that drop a lot of water in a short time. Basement window wells sit below grade, so they collect everything that falls into them plus runoff from nearby lawn, a downspout or a sloped patio. Hail is a particular problem: stones pile up in the well, block the drain at the bottom and then melt slowly, holding water against the window.

Basement windows are not designed to hold back standing water. Once the level reaches the sill, water seeps around the frame and then pours in, usually down the wall and into carpet. In homes with finished basements, the first sign may be a soaked bedroom under a window in an egress well.

During and right after the storm

Stay out of lightning.Do not go outside to bail a well while thunder is close. Move valuables away from the window and wait for the storm to pass.
Lower the water outside first.Once it is safe, bail or pump the well and clear hail and debris from the drain so water stops entering.
Protect the inside.Lift furniture off wet carpet, move boxes and electronics, and take photos of the water path and the full well.
Extract quickly.Runoff that came through a window is generally treated as contaminated because it crossed soil. Extraction and evaluation of carpet and pad follow.
Check the wall.Drywall below the window, and insulation behind it, may be wet even if the surface looks fine; a meter will show it.

Window well maintenance list

Clear leaves, hail and debris from the bottom of each well in spring and after storms
Find out whether each well has a drain and pour a bucket of water in to confirm it flows
Check that downspouts discharge well away from window wells
Look at the grading around each well; soil should slope away, not toward it
Consider clear well covers rated for the location; egress wells must still open from inside
Look at the window frame and sealant for gaps where water could get in

Why a well floods, and the matching fix

Cause	What you might see	Typical fix to discuss with a contractor
Clogged drain	Water sits in the well for hours after rain	Clear the gravel and drain; add a cover
No drain at all	Water only leaves by soaking into soil	Ask whether a drain to the perimeter system is feasible
Downspout nearby	Well fills fastest during heavy rain	Extend or reroute the downspout
Poor grading	Lawn runoff flows into the well	Regrade soil to slope away from the house
Leaking window frame	Water inside even when the well is not full	Reseal or replace the window

General information for Aurora, not a quote or professional advice. In an emergency, call 911.