Grading & Drainage: Redmond vs Seattle
How do grading & drainage rules compare between Redmond, WA and Seattle, WA?
Redmond has fewer restrictions than Seattle.
Redmond, WA
King County
Redmond requires a grading permit for earthwork over 50 cubic yards or grading in critical areas under RMC Title 15, with drainage review by Public Works based on the DOE Stormwater Manual.
View full Redmond rules →Seattle, WA
King County
Seattle regulates all grading and drainage activities under SMC Title 22 Subtitle VIII, requiring permits for excavation, fill, and changes to site drainage patterns to protect slopes, waterways, and neighboring properties.
View full Seattle rules →Key Facts Comparison
| Fact | Redmond | Seattle |
|---|---|---|
| Permit trigger | 50 cubic yards cut or fill | - |
| Critical area | Any grading needs review | - |
| Wall engineering | Over 4 ft exposed | - |
| Drainage | DOE manual standards | - |
| Permit Trigger | - | Cuts or fills exceeding 4 feet depth or 50 cubic yards |
| Drainage Standard | - | Must maintain predevelopment hydrology to maximum extent feasible |
| Critical Areas | - | Additional review for steep slopes, wetlands, riparian corridors |
| Oversight | - | SDCI reviews grading permits and inspects work |
Highlighted rows indicate differences between cities.
Redmond FAQ
Do I need a permit to regrade my Redmond yard?
Yes if cut or fill exceeds 50 cubic yards, if it is on a steep slope, or if it is inside a critical area like a stream buffer.
Can I divert drainage onto my neighbor's lot?
No, Redmond requires grading designs that keep runoff on the originating property or into an approved drainage system.
Seattle FAQ
Do I need a permit to regrade my yard in Seattle?
A grading permit is required if the work involves cuts or fills deeper than 4 feet, more than 50 cubic yards of material, or if the site includes Environmentally Critical Areas such as steep slopes. Smaller projects may still need drainage control review as part of other permits.
Can I redirect drainage on my property?
Changes to site drainage must not adversely affect neighboring properties. The Stormwater Code requires that drainage from your property be managed on-site or directed to an approved discharge point. Redirecting drainage onto neighboring properties or into unauthorized locations is a code violation.
Compare other topics
See how Redmond and Seattle compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool