Serving Rapid City
Groundwater & Basement Water Intrusion in Rapid City, SD
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
Why is there a park where the houses used to be?
Because the buildings were removed after the flood rather than rebuilt, and the ground was kept open deliberately. That corridor is floodplain doing what floodplain does, and its openness is the single largest reason the city is safer now than it was. Water in it is the arrangement working rather than a problem, which is worth understanding before reporting it.
The annual figure is modest and the flood record is not.
The average describes an ordinary year and says nothing about the exception. A storm that parks against the hills can put down a large multiple of a monthly total in a night onto short steep catchments that deliver it within the hour. That is why the flood history of this place looks so unlike its rainfall figure, and why the annual number is the wrong thing to plan from.
How fast do the creeks come up?
Within the hour, because the catchments above are short and steep and the ground sheds rather than absorbs. A channel that is a trickle becomes a torrent and returns to a trickle the same day. Any plan for a property near one has to be already in place; there is no useful amount of time in which to make one during the event.
This FAQ belongs to the Rapid City page; it is repeated here.