French Drains & Drainage Systems in Lake Tapps, WA

Drainage & French drains in Lake Tapps: what to know

Rain on a lakeside slope runs downhill like rain anywhere, so the water in a yard is often headed for the reservoir. A French drain can intercept it uphill of a house or patio. The harder part is the end of the pipe. Cascade’s property policy lists any discharge onto its land as needing permission and new discharge onto its dikes as not allowed, so a pipe cannot simply run to the shore.

Away from the water, the usual outlets sit on your own lot: a dispersion trench that spreads the flow, or an infiltration trench where the soil takes water. USGS mapping puts many of the area’s small lakes in natural hollows and kettles, so some yards sit in natural low spots. Septic fields set limits on where a drain can go.

Permits and rules in Lake Tapps

Pierce County asks for a site development permit for work such as altering a stormwater system, creating impervious surface, moving 50 cubic yards or more, or grading within 25 feet of a ditch or drainage course. A cross culvert or a catch basin connection in the right-of-way needs county approval. Inside Bonney Lake, city rules apply, and shoreline review may reach within about 200 feet of the water. We check the current requirements for your parcel before we quote.

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

How we approach it

Trace where the water enters and where it can legally leave
Keep pipe outlets off Cascade land unless Cascade has approved the discharge
Call for utility locates and map the septic tank and field
Size dispersion or infiltration trenches to the hard surface they serve

For the full process, see our Drainage Systems & French Drains page.

Questions from Lake Tapps homeowners

Can I run a drain pipe down to Lake Tapps?

Not as a simple pipe to the shoreline. Cascade’s policy treats any discharge onto its property as needing permission, and the county asks where stormwater goes. A drain that disperses water on your own lot is the more common design.

Which drainage work in unincorporated Lake Tapps needs a county permit?

County site development rules reach work like altering a stormwater system, creating impervious surface, moving 50 cubic yards or more, or grading within 25 feet of a drainage course. Smaller jobs may fall below those lines; we confirm first.

How close can a French drain go to the septic field on a Lake Tapps lot?

We do not work from a single number. The health department approves septic systems, and a drain can never send water into the field. We locate the field first, then lay the drain out beside or uphill of it.