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There are actually three separate systems involved. One is required before every single dig. One may or may not apply to your yard project. And one is almost certainly not your concern. Here is how to tell the difference.
Most homeowners in Washington County ask one question when they want to dig or regrade their yard: "Do I need a permit?" The real answer is that there are three separate things people regularly confuse, and they have nothing to do with each other. One is legally required before any digging, full stop, and it is not a permit at all. One is a local review process that may or may not apply depending on what you are doing and where. The third is a state-level stormwater permit that almost never applies to a single residential lot. Understanding which is which saves you time, money, and the genuine pain of a stop-work order.
This article lays out the three systems as clearly as we can. We are not a permitting authority, and thresholds, fees, and procedures change — sometimes without much notice. Treat what follows as a starting point for a conversation with Washington County's Land Use and Transportation department, not as a substitute for it. The county is the authority. Confirm with them before you break ground.
If you end up needing professional help with the ground work itself, Beaverton Excavation Co. handles grading, utility work, and land preparation throughout Washington County and can walk you through what we have seen on similar projects.
Before we talk about permits at all, this has to come first. Oregon law requires you to call 811 — or submit a request online — before any digging. No exceptions. This is true whether you are a homeowner doing it yourself, a landscape contractor, or an excavation company. The call is free. The service sends locators from the public utilities — gas, electric, cable, water, sewer — to mark their lines in your yard with colored flags and paint.
What 811 does NOT cover: private lines. If you have a line running from your house to a detached garage, a drip irrigation system, an old fuel oil tank, a secondary electrical panel in a shed, or a line from a previous owner's pool, none of those will be marked. You are responsible for knowing where they are. On older Washington County properties especially, there are frequently unmarked private lines that the current owner has no record of.
The practical takeaway: call 811 a few business days before any planned digging, even if you are pretty sure there is nothing there. It is not paperwork, it is not a government approval, and it does not cost anything. It is simply what you do before you dig. Skipping it exposes you to liability if you cut a line, and you can be billed for the full repair cost of any utility you damage.
The second thing is a genuine permit question, and this is the one most relevant to homeowners planning yard regrading, drainage work, or site preparation. Washington County regulates grading activity, and the question of whether your project requires a review or permit depends on several variables: how much material you are moving, the slope of the property, proximity to a waterway or wetland, and whether you are in a floodplain or special overlay zone.
We are not going to state a specific cubic-yard threshold here, because we cannot verify that figure and it is not ours to state. Thresholds also change as the county updates its code. What we can tell you is that residential grading work is commonly reviewed when it involves meaningful changes to drainage patterns, significant volumes of cut or fill, or sites near streams or wetland buffers. Projects that are clearly small — leveling a few inches in a level backyard far from any waterway — are less likely to trigger review than projects that move a lot of material or redirect runoff.
Slope matters independently. Washington County has heightened scrutiny for work on steeper grades, because regrading a slope can destabilize it, shift runoff onto neighboring properties, or accelerate erosion into a waterway. If your project involves any meaningful slope, treat that as a reason to call the county before you call anyone else.
The starting point is Washington County's Land Use and Transportation department. They can tell you whether your specific project — by address, by scope, by what you are trying to accomplish — requires a grading permit, a land use review, or neither. That call costs nothing and can save you from a stop-work order that does. Confirm with Washington County before you start any significant ground disturbance.
Professional grading and leveling contractors familiar with Washington County work will typically flag when a project looks like it needs county review. That is part of scoping the job correctly, not just showing up and moving dirt.
The 1200-C is a state-level permit administered by the Oregon Department of Environmental Quality. It is triggered at one acre of total ground disturbance for a construction activity. That is a significant threshold — one acre is about 43,560 square feet, roughly the size of a city block. The vast majority of residential yard regrading projects never come anywhere near this scale.
The 1200-C matters if you are doing a major site development — a new subdivision, a large commercial development, or any project that disturbs more than an acre of soil in the course of construction. For typical residential work in Washington County, it is unlikely to apply. But if you are doing something large — clearing and regrading multiple lots, for example — it becomes relevant, and ignoring it has serious consequences.
When the 1200-C does apply, it requires a stormwater pollution prevention plan (SWPPP), specific erosion control measures, and ongoing inspection and documentation. The permit is not a one-time filing; it requires active compliance throughout the project.
Clean Water Services is the local water management agency for Washington County. Their jurisdiction is primarily around streams, wetlands, and drainage infrastructure — and they have their own set of requirements that operate separately from county grading permits and the state's 1200-C.
If your project is near a stream, creek, drainage swale, or any mapped water body, Clean Water Services may require erosion and sediment control measures regardless of whether the county grading review applies. Their concern is water quality: loose soil disturbed by grading or excavation can wash into streams and damage aquatic habitat. Even small residential projects near surface water can trigger their review process.
This is especially relevant in the Tualatin Valley, where there are many small tributaries, roadside ditches, and drainage features that connect ultimately to the Tualatin River. A project that looks well away from a waterway on a property map may still be within a protected buffer zone. Buffer distances vary by water body type and classification, and they are set by Clean Water Services, not by the county permit system.
If there is any drainage feature on or near your property, ask Clean Water Services specifically whether your project falls within their jurisdiction. Their pre-application review process is free and can clarify requirements before you start. Professional erosion control planning is often the deliverable that satisfies both the county and Clean Water Services requirements when a project is near the water.
Stop-work orders are issued by county inspectors when work is proceeding without required permits or in violation of conditions. The financial penalty itself can be significant — but for most homeowners, the schedule cost is actually worse.
When a stop-work order goes on a project, everything stops. The crew leaves. Equipment sits or is pulled off-site. You now have an open excavation, disturbed soil, and possibly a partially completed drainage system or foundation sitting exposed to rain. In the Oregon wet season — which runs roughly October through May — an exposed excavation can fill with water within days. Disturbed soil erodes. A partially graded site can develop drainage problems that did not exist before.
Then you have to resolve the permit issue, which requires submitting applications, waiting for review, potentially modifying the project design, and scheduling an inspection before work can resume. Depending on the county's workload and the complexity of the issue, that process can take weeks. By the time work resumes, you may be paying to redo stabilization work and re-mobilize equipment. The direct cost of "going first and asking later" regularly exceeds the cost of the permit itself by a wide margin.
The right sequence is: call 811, confirm permit requirements with Washington County, check with Clean Water Services if you are near any water feature, then start work. That sequence is slower by a few days at the front end. It is faster overall.
Again — we are not the permitting authority. Thresholds, fees, and processes change. The information above reflects our general understanding of how these systems work, not a legal or professional opinion on what applies to your specific project. Confirm with Washington County before you break ground. If you have questions about a specific project, our team is happy to share what we have seen on similar jobs in the county.
It depends on the scale and location of the work. Small projects — leveling a modest area away from waterways, on a level lot — may not require a county grading permit. Larger volumes of material, steep slopes, and proximity to streams or wetland buffers are the factors most likely to trigger review. The county is the authority on this. Call Washington County Land Use and Transportation before you start any significant regrading.
Calling 811 is legally required before any digging — that is not a permit but it is mandatory. Whether county approval is required depends on what you are doing and where. Shallow utility work, small drainage projects, and minor grading may not require a permit. Significant ground disturbance, work near waterways, or projects on steep ground are more likely to. Confirm with Washington County for your specific address and scope.
Oregon's building code has exemptions for certain structures — small detached accessory structures, fences under a certain height, and some agricultural buildings. The specific exemptions depend on the type of structure, its size, and local zoning. Washington County administers permits locally, and the county code may be more restrictive than the state baseline. Check with Washington County's Building Services before assuming a structure is exempt.
Building without a required permit can result in a stop-work order, fines, and a requirement to bring the structure into compliance or remove it. In some cases, unpermitted work surfaces when you sell the property — buyers, lenders, and title companies do check. The cost of retroactive permitting and required modifications is typically higher than the original permit cost would have been. When in doubt, ask first.
No. Calling 811 is a free utility locate service required before any digging. It marks public utility lines and has nothing to do with county grading permits, land use review, or DEQ permits. After you have called 811 and had lines marked, you still need to determine whether your project requires a county permit separately. The two processes are completely independent.
Clean Water Services manages water quality and drainage infrastructure in Washington County. If your project is near a stream, wetland, drainage swale, or any mapped water feature, CWS may have erosion control and buffer requirements that apply to your work. Their requirements are separate from the county's grading permit system. Contact Clean Water Services directly if there is any water feature on or adjacent to your property.
Most of these questions have a general answer and a site-specific answer, and the site-specific one is the one that decides the cost. If you want a real number for your property, call (458) 272-9359 or send the details and we will walk the ground with you.