Serving Hilo
Groundwater & Basement Water Intrusion in Hilo, HI
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
A hundred and twenty inches a year is hard to picture.
It is several times what most of the mainland receives, and it means the ground here is rarely dry rather than occasionally wet. Construction and drainage practice both reflect that, which is why post-and-pier is common and why buildings are designed to shed and dry rather than to keep water out entirely. Assumptions imported from drier places do not transfer.
The ground drains instantly in some places and not at all in others.
That is the volcanic geology. Younger lava is fractured and porous and takes water astonishingly fast; older flows and weathered ash layers are close to impermeable. Two parcels a short distance apart can behave completely differently, and the surface gives little indication of which is which.
The stream came up with no rain falling here.
These streams respond to rainfall high on the mountain, where the totals are far greater than in town. A storm sitting over the upper slopes puts a great deal of water into a channel with a short steep route to the bay, and it arrives quickly. Watching the sky overhead is a poor guide to what the stream is about to do.
This FAQ belongs to the Hilo page; it is repeated here.