Window Well Covers and Drainage in Billings

Window well covers keep snow, leaves, and animals out of the well and light coming in; drainage keeps the well from turning into a bathtub. In Billings, covers run $150 to $600 installed and drainage repair $300 to $1,000. Of the two, drainage is the one that saves your basement. A cover is the one that saves you from fishing a cat out of a five-foot pit in February.

If your well fills with water, skip to drainage. If it fills with cottonwood leaves and snow, skip to covers. If both, read the whole page.

Why Billings wells flood

Start with the ground. The USDA soil survey for Yellowstone County maps the broadest terraces in the county, between Billings and Laurel, as deep silty clay loams and silty clays underlain by stratified clay. It also counts roughly 82,000 acres of saline, saline-sodic, or sodic soils, and it explains what sodium does to clay: the particles disperse, permeability to water and air goes slow, and shrink-swell potential goes high. Water moving through that soil moves slowly, and water that lands in a pit dug into it stays there.

Now add the weather. NOAA normals give Billings about 57 inches of snow a year, with April alone averaging 7.5 inches on top of a spring thaw, and May and June are the wettest months. The Yellowstone hit its record 16.2 feet at Billings on June 15, 2022. Most homes are far above the river, but the same runoff pattern shows up in every unfinished corner of the valley: saturated ground in April and May, a thunderstorm in June, and a window well that fills faster than the clay beneath it can drain.

Then the house. A downspout that empties beside a well. A grade that slopes toward the foundation after 30 years of settling. An original 1980s well set straight on clay with a few inches of gravel that silted shut by 1995. The footing drain around a 1960s South Side ranch that was clay tile and quit working before you were born. Any one of these puts water in the well; most flooded wells have two.

Drainage: how we build it

Dig out. The well comes out or gets dug around, and the silt and old gravel get removed to a foot or more below the planned bottom.

Find the outlet. We look for a footing drain: the perforated pipe at the base of the foundation that carries water to a sump or daylight. Homes from the 1970s on usually have one. If it exists and flows, that is the best outlet there is.

Build the bed. Washed gravel, not pit run, from below the 36-inch frost line to the bottom of the well, wrapped in geotextile fabric so the surrounding clay cannot migrate in and choke it. This is what fails in bargain installs: unwrapped gravel in Yellowstone valley clay silts shut in a few seasons.

Tie in or dry well. Where a footing drain exists, a perforated riser connects the gravel bed to it. Where it does not, we dig a gravel dry well large enough to hold a real storm and let it soak away over hours rather than minutes. Sodic clay soaks slowly, so the dry well in Billings is sized bigger than a national rule of thumb.

Downspouts and grade. Downspout extensions carry roof water at least several feet past the well. Grade gets pulled back to slope away from the house. Cheap fixes, frequently skipped, frequently the whole problem.

Reset the well. Anchored to the foundation on the new bed, plumb, with a ladder if deeper than 44 inches. Full detail on window well installation.

A drainage rebuild in an existing well runs $300 to $1,000. On a full egress install, all of this is built into the same excavation as the cut and is included in the job price.

Covers: what code allows and what works

IRC R310, adopted in Montana’s 2021 residential code, is specific: bars, grilles, covers, screens, or similar devices are allowed over egress openings and wells only if the opening still meets the minimum net clear size and the device releases or opens from inside without keys, tools, special knowledge, or more force than the window needs. The City of Billings inspects to that, and so does every home inspector.

What that means in practice:

• Clear polycarbonate covers are the standard. They shed snow, let light in, keep leaves and animals out, and lift from below. Basic units for standard corrugated wells run toward $150 to $250.
• Custom-fit covers for oversized composite wells, stone-look terraced wells, or wells with odd projections run $350 to $600. Worth it on a well that is visible from the street or catches roof snow.
• Grates are fine for wells that are not egress, and a poor choice for egress wells because they do nothing about snow and leaves.
• Locks that engage from inside only, or latches that resist wind and raccoons but lift with a push from below, are fine. Anything that has to be unscrewed or unlocked from outside is not.

Snow load matters here. A cover that collapses under 30 inches of March snow is a cover that blocks the exit exactly when it is hardest to dig out. We size covers for Billings snow, not for Phoenix.

The order of operations

If the well floods, drainage first. A cover over a well with no outlet just means the water comes from below instead of above, and the basement gets wet a little slower. If the well is dry and full of leaves, a cover alone is the fix. If you are not sure, the free measure tells you: we look at the well after a rain, at the downspouts, at the grade, and at whether the house has a footing drain, and we tell you which problem you actually have.

Price and where we work

Full breakdown on the pricing page. Covers install year-round; drainage is dig work and follows the March through November season. Same crews and prices in Billings, Laurel, Lockwood, Shepherd, Huntley, and Columbus. Send us a photo of the well and where the downspout lands, and we will tell you what we think before we even drive out.