Basement Waterproofing in Fall City, WA

Basement waterproofing in Fall City: what to know

Exterior drains are laid at footing level on the uphill side and tied to an outlet on the same parcel. The county’s residential drainage guidance counts land disturbing activity, and 7,000 square feet or more of it is a drainage review line, so a long trench is totaled with the rest of the lot. An outlet that reaches the road shoulder or public land is a right-of-way question.

Where gravity cannot move the water, a sump sits at the low corner and a pump sends it to an outlet on the parcel. Interior channels run along the slab edge into a covered sump, and the lid is sealed and vented. A cut of 5 feet or more in any one location, or cumulative earth moved above 100 cubic yards, can need a clearing and grading permit before the digging starts.

Permits and rules in Fall City

We check each excavation depth and the total earth moved against the county’s clearing and grading lines, confirm that the drain outlet stays on the parcel, and look for any foundation work near a retaining element before the cut. Any change to a load-bearing element is put to King County in writing first, and the reply is kept with the scope.

Rules change and vary by parcel, so we confirm the current requirements with the city before we start.

How we approach it

Log where water appears through the wet months before any fix
Lay the exterior drain at footing level on the uphill side
Set a sump only where gravity cannot reach an outlet on the parcel
Check the cut depth and total earth moved against the county lines

For the full process, see our Basement Waterproofing page.

Our basement waterproofing work, serving Fall City

Examples of our work. We build basement waterproofing in Fall City and the cities around it. See all of our work

Questions from Fall City homeowners

Does a Fall City basement drain need a county permit?

It depends on how much ground the drain disturbs. The residential drainage guidance uses 7,000 square feet of land disturbing activity as its line, and the clearing and grading guidance uses a 5-foot cut in any one location and more than 100 cubic yards in total. We check both lines for the trench before digging.

Where can a Fall City sump discharge?

To an outlet on the same parcel, traced on the site plan. An outlet that reaches the road shoulder or public land is a right-of-way question, since private work in county right-of-way needs a right-of-way use permit, so we confirm the route with King County before the pump is connected.

Does a Fall City crawlspace need a pump?

Not always. When gravity carries the water past the footing to an outlet on the parcel, no pump is needed. A low corner below any usable outlet calls for a sump, and we measure that before choosing one.