Crawlspace water on Cavalero Hillwater that comes from uphill

Shine a flashlight across the crawlspace from the hatch, and note where the wet is. If the uphill end is damp and the downhill end is dry, that is a strong clue. Water moves through soil sideways when it meets a denser layer, and a foundation wall cut into a slope is an obvious place for it to collect. It may seep at the footing, come up through the soil just inside the wall or run along the base of the wall to the lowest point.

Compare this with a leak. A plumbing leak leaves a wet spot beneath a bathroom, kitchen or laundry, and it stays wet even in dry weather. Water that arrives only after a few days of rain and clears up within a week or two usually comes from the ground or from surface runoff. Keep notes through one winter to get a clearer pattern. Our main crawlspace water damage page explains the rest of the process.

Many houses have some sort of drain system around the footing, and newer homes generally have downspouts connected to buried tightlines. The city's comprehensive plan notes that large parts of Lake Stevens developed in the past several decades, so these systems may now be old enough to have clogged. Roots, silt and crushed pipe can stop them working. When they fail, the water they were carrying can end up right beside the foundation.

Here is a simple way to test it. On a dry day, run a hose into a downspout's underground connection and go to where it should discharge. If the water never comes out, or if it comes out slowly or at the wrong place, something is wrong. If you do not know where it discharges, check any plans you have or ask your association. A drainage contractor can run a camera through the line. It is worth doing that before spending much on other things, as a blocked line is often a simple fix. Keep the roof water separate from the footing drain, if at all possible, because a clogged roof line can flood the footing drain.

Summers here are dry. Published Everett normals show about an inch of precipitation in each of July and August, then roughly 5.8 inches by November. Modelled figures for the Lake Stevens location read higher, although they may run high. Soil on a slope takes a while to fill up, so the first storms of autumn may do nothing at all. Then, sometime around November, water starts turning up at the footing, usually after a run of wet days. If you only look under the house in summer, you may never see it.

A good habit is to look under the house in September, for a dry baseline, and once again in late November or December after a wet stretch. Keep the two sets of photos together. This gives you, and anyone you hire, a real record of what your particular hillside does.

Do not rush into encapsulating a crawlspace that is taking on ground water. Sealing it does not stop water coming in, and water under a sealed liner can be harder to see. Don't dig near the foundation without knowing where the utility lines and drains are. And do not build a retaining wall or a large drain without first checking on permits, especially on steeper ground. If you see signs of ground movement, get professional advice before doing anything else. The Lake Stevens permit center can tell you what requires review, and a typical home policy excludes flood, so ask your agent how ground water would be treated. ^[6]