French Drains & Drainage Systems in Shoreline, WA

Drainage & French drains in Shoreline: what to know

A curtain line across the grade intercepts runoff above the lower yard and the foundation. Its trench holds a constant grade, and the stone is sized to carry water instead of storing it. Where a flat run collects overflow, a French drain carries it on to the outlet, and the layout is recorded on the site plan.

Roof water runs through solid pipe from each downspout to a discharge point of its own, so one roof never feeds another. The exit is picked from three options: soil that takes in the flow, a storm connection the city accepts, or a dip where nothing reaches adjoining parcels. Our layouts never treat the street or an adjoining lot as an outlet.

Permits and rules in Shoreline

Work in the public right-of-way or on a storm connection follows a separate review path. The permit table lists a Right-of-Way Use permit, and we confirm with city staff which office and conditions apply before any trench is cut. The drainage tier for the drain’s new surface is recorded on the quote, and we confirm that tier before quoting the layout.

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

How we approach it

Place the outlet before sizing the first trench
Intercept runoff above the lower yard and foundation
Run roof water through solid pipe to its own exit
Confirm right-of-way status before any excavation

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

Questions from Shoreline homeowners

Where can a Shoreline French drain discharge?

Into soil that takes the water, into a storm connection the city has approved, or to a dip where nothing reaches adjoining parcels. Each exit is checked against the survey, and an exit that depends on a storm connection is held until the city replies.

Is a permit needed to install a yard drain in Shoreline?

The cut depth, the route the water takes, and any public property the route crosses all feed the answer. City staff give the controlling reply, and we wait for it before starting. The reply date is written into the job record.

Would a drain fix a soggy side yard on a Shoreline lot?

Where runoff arrives from higher ground next door, a line can help. We survey the descent and recommend a line only where the flow can leave the site. A drain placed without a survey can send water to the wrong place, so we report what the survey shows before any trench is planned.