Redmond · King County
Grading & Drainage in Redmond, WA
Grading, French drains, retaining walls and RV and equipment pads across Redmond, from Education Hill to Overlake. Built so water moves away from the house instead of toward it.
Why drainage matters on Redmond properties
Soft valley alluvium with high groundwater along the river, glacial till on the hills. That is the root of most wet-yard, wet-crawlspace and failing-patio problems we see. Water that cannot soak in runs along the surface or perches on the hard layer until it finds the lowest point.
The flat Sammamish valley through downtown and Marymoor Park, with hills rising east to Education Hill and west to Overlake. Slopes push water downhill onto the next lot, and flat ground leaves it nowhere to go. Getting the grade right is cheaper than fixing what water does to a foundation.
The Sammamish River, Bear Creek and Evans Creek are salmon streams with wide buffers. The valley floor has floodplain and wetland areas. Where drainage can legally discharge depends on these features, so we plan the outlet first and the trench second.
Common grading projects in Redmond
Wet yards and crawlspaces
Regrading and French or curtain drains for Redmond yards that stay soggy all winter because water perches on the hard till below.
Grading away from the foundation
Reshaping the ground around Redmond homes in Downtown Redmond and Education Hill so it falls away from the house, the cheapest fix for water at the foundation.
Ditches and culverts
Cleaning and regrading drainage ditches, and setting culverts under driveways, on the low, wet ground around Redmond.
Downspout tightlines
Connecting downspouts to solid pipe that carries roof water to an approved outlet instead of dumping it next to a Redmond foundation.
What our grading work in Redmond covers
- Retaining Walls
- French Drains & Footing Drains
- Rough & Finish Grading
- RV & Equipment Pads
- Yard Drainage Correction
- Erosion Control
Permits & Rules
Grading and retaining wall permits in Redmond
Inside city limits, the City of Redmond handles grading permits; outside them, the King County Department of Local Services. Small regrading and yard drains usually do not need one, but larger volumes of cut or fill, work in a critical area, or changes to how water leaves the property often do.
Retaining walls taller than about four feet, or walls holding back a driveway or slope, typically need engineering and a permit. We build to the approved plan and can tell you on the site walk when a wall is likely to need one.
Cost & Timing
What affects the cost of grading in Redmond
We do not publish flat prices because no two Redmond sites are the same. These are the things that move the number most here.
Tight lots
Narrow side yards and alley access in Redmond mean compact equipment and shorter truck loads. We plan it so it costs less than it could.
Soft ground
Where Redmond soils are soft or wet, over-excavation, fabric and imported rock are often part of the job, and we price that in up front.
Buffers and permits
Work near Redmond's rivers, creeks, lakes or shoreline can need permits and limits on where machines go. That affects scope and schedule more than price.
Haul-off and disposal
How much material leaves the site, and what it is, drives cost. Our own trucks keep that predictable on Redmond jobs.
When to schedule grading in Redmond
Grading in Redmond goes best in the drier months, when soil compacts properly and trenches stay open. Wet-season work is doable with erosion control and the right material, and we plan for it in the quote.
Redmond's till soils hold water through the winter, which is when drainage problems show up. That is a good time to see where water goes, and the dry season is the time to fix it.
On Redmond's floodplain ground, the river sets the calendar. Low-lying work is planned for the dry season, after high water has dropped.
Where We Work
Grading and drainage across Redmond
Redmond runs from the Sammamish River valley and downtown up onto Education Hill, Grass Lawn and the Overlake tech campuses. It mixes established neighborhoods with a lot of new construction.
We regrade yards, install French drains and curtain drains, build block and rock retaining walls, and set gravel RV and equipment pads across Downtown Redmond, Education Hill, Overlake, Grass Lawn, Bear Creek, Avondale and Idylwood.
Mid-century and 1970s to 90s homes on Education Hill and Grass Lawn, new townhomes and apartments downtown and in Overlake. Older lots often have no real drainage at all, while newer ones sometimes have drains that were never connected. We find out which before we dig.
We also do grading nearby in Kirkland, Sammamish, Bellevue and Woodinville. See everything we do in Redmond, read our full guide to grading, or browse all service areas.
Why DirtRaptor
Why Redmond owners call us for grading
Owner on the machine
On Redmond jobs you talk to the person who walks the site, writes the quote and runs the equipment.
Trees and dirt, one crew
If trees are in the way of your Redmond project, we take them down ourselves instead of waiting on a separate tree service.
Our own trucks
Haul-off and deliveries run on our schedule along SR 520 and SR 202, not a subcontractor's.
Permit-aware
We know Redmond has rules on trees and critical areas, and we flag what applies before any work.
How a grading job runs
- 01
Site Assessment & Water Tracing
- 02
Design & Elevations
- 03
Excavation & Base Preparation
- 04
Build, Drainage & Backfill
Real Jobs
Recent DirtRaptor work near Redmond
Demolition · Edmonds, WA
Driveway Removal & Concrete Prep
Tearing out an old blacktop driveway and prepping the ground for a new concrete pour — broken material hauled off, base left clean and ready.
Demolition · Everett, WA
Condemned 100-Year-Old Shed Teardown
A 100-year-old shed, condemned and unsafe, brought down and hauled off — the site left graded flat and clean.
Questions
Grading & Drainage in Redmond: FAQs
Why does water collect around homes in Redmond?
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Soft valley alluvium with high groundwater along the river, glacial till on the hills. When water cannot soak in, it follows the surface toward the house. Regrading so the ground falls away from the foundation, plus a drain where needed, usually solves it.
Do retaining walls need a permit in Redmond?
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Walls over about four feet, or walls supporting a driveway, building or slope, usually need engineering and a permit from the City of Redmond (or the King County Department of Local Services outside city limits). Shorter landscape walls often do not. We confirm before building.
Where can drainage water go on my Redmond property?
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It has to go somewhere approved: an existing storm system, a dispersion area or an infiltration trench where the soil allows. The Sammamish River, Bear Creek and Evans Creek are salmon streams with wide buffers. The valley floor has floodplain and wetland areas. We plan the outlet before we trench.
How much does grading cost in Redmond?
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It depends on the site, so we quote after a free site walk rather than guessing on the phone. The biggest drivers in Redmond are usually tight lots, soft ground, buffers and permits. You get a written number with inclusions and exclusions spelled out.
When is the best time to schedule grading in Redmond?
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Grading in Redmond goes best in the drier months, when soil compacts properly and trenches stay open. Wet-season work is doable with erosion control and the right material, and we plan for it in the quote.
What counts as a landmark tree in Redmond?
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Redmond gives very large trees extra protection, and removing one usually needs city approval and replacement. We measure and identify the tree on the site walk and tell you what applies.
Can you fix drainage on my Education Hill property?
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Yes. Most Education Hill drainage problems come from water perching on glacial till. Regrading and properly placed drains carry it away from the house.
How much does a retaining wall cost per foot?
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Face square foot is the usual unit, but cost per foot rises steeply with height because the work behind the wall grows faster than the wall itself. A two-foot garden wall and a five-foot structural wall are different trades. Site access and drainage requirements move it further.
Ready for a real number in Redmond?
Send the address and a few photos. We walk the site for free and come back with a written quote.
