Serving Sunnyvale
Groundwater & Basement Water Intrusion in Sunnyvale, CA
Basement seepage, failed sumps, and hydrostatic pressure against the foundation are extracted and dried, and the path from the ground is identified so the loss does not repeat. Groundwater and basement seepage are extracted and dried only after the path from the soil is identified — a wall, a slab, a drain, or a failed sump. Drying the interior without stopping that path returns the same water to the same floor.
Frequently asked questions
The yard has drained fine for twenty years and now it does not.
On ground this flat the drainage depends on a path staying open, and paths close gradually. A swale planted over, a patio raised, or an inlet silted during the dry season removes the only route a lot has, and the arrangement keeps working until a storm needs the missing capacity. Walking the property during rain, rather than after it, shows where the water stops moving.
We are near the bay margin. What is different up there?
The water table, mainly. Ground at the northern edge is close to tidal water and the table sits near the surface, so water can arrive from below rather than across the ground, and the channels serving that area discharge into tidal levels. Grading achieves less there than it does further inland, and relief drainage achieves more. The two halves of the city need different thinking.
How would a slab leak show itself in a house like this?
Usually as a number rather than a puddle. A warm patch on the floor, a water heater cycling more than it should, or an unexplained rise in usage are the practical signals, because the water goes into the subgrade and may not surface for a long time. A meter test with everything off takes minutes and is worth doing annually on housing of this vintage.
The Sunnyvale overview carries this FAQ with the city research.