French Drains & Drainage Systems in Fircrest, WA

Drainage & French drains in Fircrest: what to know

Fircrest’s wetland chapter sets buffer widths by category and habitat score, using the Washington State wetland rating system for western Washington. The chapter’s example is a Category I wetland scoring 32 points for habitat function, which would need a 225-foot buffer made of a 75-foot base plus 150 feet. Under buffer averaging, the narrowest point is never less than 75 percent of the standard width, or 75 feet for Categories I and II, whichever is greater. Stormwater management facilities are not allowed in buffers of Category I or II wetlands.

A drain that stays on the lot still needs a check against those buffers when a regulated wetland sits nearby. A drain tied to a street, ditch, or stormwater system needs an answer from Public Works first, since the city’s stormwater page gives no threshold for changed drainage. The soil matters too. If your lot sits on Alderwood soil, the series description notes a dense layer 50 to 100 centimeters down, so the drain depth and outlet are set after the probe, not before.

Permits and rules in Fircrest

The city’s stormwater page gives no threshold for changed drainage, so we confirm with Public Works whether a drain or outlet needs a stormwater review before we dig. A drain in or near a regulated wetland or its buffer also falls under the wetland chapter, which regulates excavation, grading, dumping, fill, and drainage changes there. We confirm the path for each outlet before the trench is laid out.

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

How we approach it

Map any regulated wetland and its buffer on or beside the lot before choosing an outlet
Probe the soil for a dense layer and standing water before the trench is cut
Keep discharge out of regulated wetland buffers, where stormwater facilities are not allowed in Category I and II
Confirm the outlet with Public Works before any tie-in to a street, ditch, or storm system

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

Questions from Fircrest homeowners

Can a French drain in Fircrest discharge toward a wetland?

Only after checking the buffer. The wetland chapter regulates dumping, discharging, or filling in a regulated wetland or its buffer, and it regulates draining or disturbing the water level or water table. It also bars stormwater management facilities in Category I and II buffers, so we confirm the wetland category before we choose an outlet.

Does a yard drain near my Fircrest home need a city permit?

It depends on the outlet and the site. The city’s stormwater page gives no threshold for changed drainage, so we confirm with Public Works before the trench is cut. A drain near a regulated wetland or its buffer also falls under the wetland chapter.

Where can a Fircrest downspout drain go?

Onto the lot, to an outlet the city accepts. We confirm the outlet with Public Works before any downspout line ties into a street, ditch, or city stormwater system, and we check any regulated wetland buffer that could be affected.