Drainage & French Drains in Hillsboro, OR

Drainage work in Hillsboro is the difference between a dry, usable property and one that floods every winter. Hillsboro Excavation Co. designs and installs French drains, catch basins, swales, and downspout tie-ins that move water off your property before it damages a foundation, floods a crawl space, or turns your yard to mud. Around here, drainage isn't optional — it's the single most important thing excavation gets right or wrong.

The Willamette Valley is one of the wetter places to own property in the country, and Hillsboro sits on heavy silty clay that holds water instead of letting it soak away. From October through May the water table climbs and the rain barely stops, so any low spot, negative slope, or clogged drain shows up fast. We solve standing water, saturated yards, wet basements, and foundation seepage at the source — by giving the water a path out.

Our Hillsboro Drainage Services

Hillsboro Excavation Co. installs the full range of residential and commercial drainage solutions:

• French drains — perforated pipe in a rock-filled, fabric-wrapped trench that collects and carries groundwater away.
• Catch basins and area drains — grated inlets that capture surface water from low spots and hardscapes.
• Downspout and gutter tie-ins — piping roof water underground to a proper outfall instead of dumping it at the foundation.
• Swales and surface grading — shaping the ground to carry runoff where it should go.
• Foundation and footing drains — perimeter drainage to keep water out of crawl spaces and basements.
• Curtain drains and yard drainage — intercepting water before it reaches the wet part of your property.

Why Drainage Is the Job to Get Right in Hillsboro

Water is what wrecks foundations, and Hillsboro gives it plenty of chances. Clay soil around South Hillsboro, Witch Hazel, and the older neighborhoods near downtown holds water against foundations all winter, and a high seasonal water table pushes moisture up from below. We diagnose where your water is actually coming from — surface runoff, roof water, groundwater, or a high water table — and build the right system for it. A French drain fixes groundwater; a catch basin fixes a low spot; downspout tie-ins fix roof water. Putting in the wrong one wastes money and leaves you wet.

Built for clay and a high water table

Drainage in the Willamette Valley has to account for soil that won't absorb water and a water table that rises in winter. We bed French drains in clean drain rock, wrap them in filter fabric so the clay doesn't clog them, and run them to daylight or a drywell sized for our rainfall — not a token installation that silts up in two seasons. Done right, it's the kind of system you install once and forget about.

Hillsboro Rain Is a Number, Not a Guess

Hillsboro gets rain on about 161 days a year and roughly 36 inches of it, and it does not fall evenly — November and December each dump over five inches, and the wet stretch from November through March is when drainage problems surface. That is a marine west-coast climate parked on the flat floor of the Tualatin Valley, and it means any drainage system here has to move real, sustained volume, not a summer sprinkle. We size French drains, outfalls, and drywells for Hillsboro's actual rainfall, not a generic spec that silts up the first real winter.

Where your water ends up matters too. Hillsboro sits at only about 194 feet of elevation and is threaded with creeks — Rock Creek, McKay Creek, Dairy Creek, Dawson Creek — and the Tualatin River along the south edge, so the water table climbs in winter and low-lying areas around Reedville and Witch Hazel drain slowly. We plan an outfall that actually carries water away from your foundation, whether that's a creek, a ditch, or an approved storm tie-in, and we build it to handle a wet Willamette Valley winter that runs half the year.

How Much Does Drainage Installation Cost in Hillsboro, OR?

A residential drainage system in Hillsboro typically runs $1,800 to $5,500, and French drains are usually priced per linear foot at about $25 to $60 per foot installed, depending on depth, soil, and how far the water has to travel to an outfall. A simple downspout tie-in or a single catch basin can run a few hundred dollars; a full-property drainage system with multiple runs costs more. Below are typical ranges across Washington County so you can budget before we come out.

Permits, Outfalls, and Code

Drainage work in Hillsboro has to send water somewhere legal — you can't just pipe it onto a neighbor's lot or into the street without meeting the rules. Depending on the system, work may need a plumbing or site permit, and connections to public storm systems have Clean Water Services requirements. Hillsboro Excavation Co. plans a compliant outfall — daylight, drywell, or an approved storm connection — pulls any permit the job needs, and builds erosion control in so the fix doesn't create a new problem downstream.

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