French Drains & Drainage Systems in Parkland, WA

Drainage & French drains in Parkland: what to know

Pierce County’s 2026 stormwater manual took effect in July 2026, and its August 13, 2026 errata moved the materials line for the Full Engineered tier to 250 cubic yards, down from 500. The Simple tier now covers more than 50 and fewer than 250 cubic yards of materials moved. Because those figures count materials moved, we total the cubic yards each trench will move before choosing a tier.

Outlets are the other half of a yard drain. Water has to reach ground the lot can hold or a point the county accepts, and it should never be aimed at a neighbor’s lot. Pierce County’s development code applies its stormwater manual to grading and home construction in unincorporated areas, so a drain that changes the lot’s grading is read against that manual.

Permits and rules in Parkland

We check each run’s cubic-yard total against the tier figures, and we confirm the outlet route with Planning and Public Works before the trench opens. We verify whether any line reaches county right-of-way, since that work needs the county’s approval, and we keep that answer on the job file.

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

How we approach it

Total the cubic yards each trench will move before layout
Trace where water enters the lot before picking a line
Choose an outlet the lot can hold or the county accepts
Settle right-of-way questions before the first cut

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

Questions from Parkland homeowners

Which review tier does a Parkland French drain fall under?

That depends on how many cubic yards of materials the trench moves, measured against the tier figures in the August 13, 2026 errata. We total the excavation and confirm the tier with the county before digging.

Where can a Parkland yard drain discharge its water?

To an outlet the lot can absorb, or to a point the county accepts in writing. Water should not be aimed at a neighbor’s lot. We choose the outlet on the site plan and note its location before any trench is cut.

Does a Parkland drain that reaches the road need county approval?

Yes if it sits inside the county right-of-way, since any work there needs Planning and Public Works approval. We route the line on the site plan and send the outlet question to the county before excavation starts.