French Drains & Drainage Systems in Redmond, WA

Drainage & French drains in Redmond: what to know

A curtain drain laid along the low edge of a side yard catches runoff from the adjoining lot before it saturates the lawn or reaches the house. The trench follows the grade and keeps clear of any fence footing, so the cut does not undermine the fence. Water moves to an outlet on the parcel without disturbing the neighbor’s ground, and the line is recorded on the site plan.

Tightlines gather roof water from each downspout and carry it through solid pipe to a single outlet, kept apart from the perforated run. The outlet governs the whole scheme. Water must leave onto ground that can absorb it or into a storm connection the city accepts, and it stays off the street and the neighboring parcel. Any drain that touches the right-of-way is reviewed separately, because the right-of-way page requires a permit for work that modifies infrastructure within the right-of-way.

Permits and rules in Redmond

We confirm whether the drain reaches the right-of-way or runs along a fence line, and we confirm whether any city system connection needs approval before the trench is cut. The adopted manual carries successor wording, so we confirm the edition in force for your parcel before sizing the outlet. Each open review is listed on the estimate with its status.

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

How we approach it

Trace the runoff that crosses onto the side yard
Lay the curtain drain along the low edge, clear of fences
Run each downspout in solid pipe apart from the perforated line
Settle the outlet and any right-of-way review before digging

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

Questions from Redmond homeowners

Where may a Redmond French drain release its water?

Ground on your lot that can take the water is the first choice, with a storm connection the city accepts as the fallback. We do not route water onto the street or a neighbor’s parcel, so the outlet is settled before the trench is dug.

Is a permit needed for a French drain in Redmond?

It turns on the outlet and on whether the drain reaches the right-of-way or runs along a fence line. We confirm the track with the city before work begins, and the reply goes into the job file.

My Redmond side yard floods from next door. Can a drain help?

It can, when runoff from the neighboring lot keeps the yard wet. We map the flow, check the grade, and propose a line only where the water has a route off the parcel, and the reason is written into the estimate.