French Drain vs Swale vs Catch Basin: Oregon Guide

Picking the Right Drainage System for Your Oregon Property

When water won't leave your yard, the hard part isn't deciding to fix it — it's choosing which system to install. French drain, swale, catch basin, area drain, dry well: they all move water, but they solve different problems. Install the wrong one and you spend money without solving anything.

This guide compares the main drainage systems used across Oregon and gives you a decision framework for matching the system to the symptom. It's a companion to our complete Oregon drainage guide, which covers the underlying concepts in more depth.

Start With the Question: Surface or Subsurface?

Before comparing systems, identify where your water is. Surface water runs across the ground after rain. Subsurface water sits saturated in the soil. The systems below split neatly along that line, and getting this right is half the battle.

The Decision Matrix

French Drains: Pulling Water Out of the Ground

A French drain is a gravel-filled trench with a perforated pipe at the bottom, wrapped in filter fabric. Water in the surrounding soil seeps into the gravel, drops into the pipe, and flows to an outfall. It shines when you have saturated ground or water seeping downhill into a low area.

The catch in Oregon: in dense clay, water can't migrate fast enough to reach the drain, so a deep French drain may sit dry while the surface stays wet. On clay, pair it with surface grading or choose a surface system instead. For pricing, see our French drain cost in Oregon guide.

Swales: The Underrated Workhorse

A swale is a shallow, gently sloped channel — often grassed — that carries surface water from one place to another. It's one of the most cost-effective drainage tools when you have room for it, because it moves a lot of water with minimal materials. Swales steer runoff around buildings, across yards, and toward a safe discharge point. Our guide on swale excavation in Oregon covers how they're built and graded.

The trade-off is footprint. Swales need width and a continuous downhill path, so they don't fit every tight urban lot.

Catch Basins: Capturing Water at the Low Point

A catch basin is a box set into the ground with a grate on top. Surface water collects at the low spot, drops into the basin, and exits through a pipe to your outfall. Basins shine where water consistently pools in one place — the corner of a lawn, a sag in a driveway, a low spot in a parking lot. They also trap sediment, which means they need occasional cleaning. See catch basin installation cost for budgeting.

A basin is only as good as the pipe leaving it. Without enough slope to a real outfall, it just fills and overflows.

Area Drains and Dry Wells

Area drains are small point drains — a grate over a sump that ties into a drain line. They're ideal for hardscape: patios, walkways, sunken entries, and driveway low spots where a full catch basin would be overkill.

Dry wells are buried chambers or gravel pits that store collected water and let it soak into deeper, more permeable soil. They're a solution for sites with no daylight outfall, but they only work where the deeper soil actually percolates — something a perc test confirms before you commit.

How to Combine Systems

Real properties rarely use just one system. A common Oregon setup catches roof water at downspouts on solid pipe, collects yard ponding in a catch basin or area drain, intercepts subsurface seepage with a French drain, and routes everything to a single daylighted outfall. The art is keeping clean roof water on solid pipe separate from the soil water a French drain collects, so neither overwhelms the other. Our yard drainage cost guide shows how combined systems affect budget.

Matching System to Symptom

• Lawn ponds in one spot → catch basin or area drain
• Whole yard stays soggy → surface regrading plus a swale; French drain only if soil cooperates
• Water seeps in from a hillside → curtain or French drain across the slope
• Patio or driveway puddles → area drain with a grate
• No low outfall available → dry well, if soil percolates

The right answer depends on slope, soil, and where water can exit — which is exactly what a site assessment determines.