Hardscaping in Oregon Within the Runoff Rules

What we build across Oregon

Paver patios and retaining walls carry most of the work in Oregon. Patios need to handle rain and grading. Retaining walls hold back saturated soil on sloped lots from Portland to Medford.

• Paver patios built to shed water and sit level on compacted 3/4 minus.
• Retaining walls tied back into the slope with drainage behind the face.
• Walkways and steps that follow the grade without ponding.
• Grading and drainage to move water away from the house and out to the street or rain garden.
• Permeable driveways that let water soak through the surface.
• Gravel driveways on a packed base that holds up to traffic.
• Outdoor kitchens and fire pits placed on a stable, drained pad.

How an Oregon job goes

You get a written price before anyone digs. The price covers the base, the surface, and the drainage work specific to your lot. You approve it, then the crew sets a start date.

You need to be present at the start to confirm property lines and access points. You do not need to be there for the daily work. The crew handles the dig, the base, and the surface install. You see the finished job and walk it with the lead before the final cleanup. The process page lays out each step. The cost guide explains what drives the number on your written price.

The rules on runoff in Oregon

Oregon caps how much of a lot can shed water. That cap pushes patios and driveways toward permeable systems. An impervious surface, one that sheds all rain, counts against that limit. A permeable driveway or patio lets water soak through, so it does not add to the runoff.

In Portland and the Willamette Valley, clay and silt soil drains slowly. Water that cannot soak in has to go somewhere, often onto a neighbor or into a street drain. In Bend and central Oregon, volcanic soil drains faster, but the cap still applies. On the Oregon coast, sand drains well, yet the rules still measure what you pave.

So the question is not whether you want a drainage plan. It is whether the surface you choose works within the runoff rules for your lot. A permeable paver patio on an open-graded base meets that need. A standard patio on 3/4 minus may not, depending on the lot size and the soil.

What a permeable system is made of

A permeable system starts with an open-graded base. That base has larger stone and fewer fines, so water moves through it fast. Permeable pavers sit on top with gaps that let rain pass. Below that, the base stores water and lets it soak into the soil slowly.

Standard work uses 3/4 minus, the local name for aggregate base specified by ODOT gradation. That base compacts tight and carries weight well. It suits patios, walkways, and driveways where runoff is not the main issue. Permeable systems trade some load capacity for drainage, which is why they fit patios and light-duty driveways better than heavy traffic areas.

Water that does not soak in moves to a rain garden or a drain. Grading sends it there, not toward the house. The season window matters too. Year round work happens in the valley with a slow stretch in the wettest winter weeks. East of the Cascades, the season runs roughly April to November, so the base work happens when the ground is dry enough to compact right.

The dig, the base and the season

Portland stormwater rules put permeable systems and drainage detail into the price. That means more base material and more careful grading than a simple patio. On the east side, basalt close to the surface in the dig adds machine time. Breaking rock takes longer than moving clay.

Both factors show up in the written price before the dig starts. The base depth follows the frost line, about 12 to 18 inches in the valley and more east of the Cascades. The crew builds the base to that depth, not to a thinner guess.