Yard Drainage & French Drains in Bellevue, WA

Meaningfully, yes, and it is worth establishing whether your lot is in that basin before any design work. Down there the water table sits close to the surface, so there is less depth available before a trench reaches saturated ground, and there is less fall to route collected water along. Peat and organic soils are present in places too, which behave differently under load than the till elsewhere in the city. The consequence is that the discharge point has to be established first — on this ground it is the constraint, not a detail — and occasionally the honest answer is that surface regrading is a better investment than a drain.

Because developer grading is done to shed water off the building quickly, not to make the garden work. The finished levels are set for the house, and the ground left behind is frequently a thin skim of topsoil over subgrade that heavy plant has driven across for months, which is about as compacted as ground gets. Water reaching that layer stops. The garden then holds it for the whole wet season. Fixing it usually means a combination of decompaction where planting is going, a regrade so the ground falls somewhere useful, and a drain if there is no natural route out.

Sometimes, and it depends on the connection available and what the City of Bellevue permits for your property — which is a question we establish rather than assume, because rules differ from Seattle's and from the county's. On a sloped Bellevue lot there is frequently a better option anyway: daylight at a lower point on your own ground, which needs no connection and cannot be affected by anyone else's system. What we will not do is design a system that solves your garden by pushing the water onto a neighbouring property, which is how a drainage project becomes a boundary dispute.

Before, always, and on a Bellevue-sized project the saving is substantial. Drainage is buried work — trench, pipe, rock, geotextile — and while the ground is open and a machine is on site it costs a fraction of what the same run costs once there is a finished patio, a turf lawn and mature planting above it. This is the single most common regret we hear on large Eastside gardens: a beautiful landscape installed two years ago that now needs a trench cut across it because nobody asked where the water went.