French Drains and Drainage Solutions in Portland, Oregon
Portland gets over 40 inches of rain a year. If your property doesn't have proper drainage, that water is going somewhere you don't want it — your crawlspace, your basement, your foundation, or your yard. A&N Construction and Excavation installs French drains and drainage systems that solve water problems permanently.
What Is a French Drain?
A French drain is a gravel-filled trench with a perforated pipe that collects and redirects groundwater and surface water away from problem areas. The pipe sits at the bottom of the trench, surrounded by gravel and wrapped in filter fabric to prevent clogging. Water flows into the gravel, enters the perforated pipe, and is carried by gravity to a discharge point — a dry well, storm drain, or lower area of the property. French drains are the most effective solution for persistent water problems around foundations, in yards, and beneath crawlspaces.
Our Drainage Services
Exterior French Drains
Installed around the perimeter of your foundation to intercept groundwater before it reaches your foundation walls or crawlspace.
Interior French Drains
Installed inside the crawlspace or basement perimeter to collect water that enters through the foundation and route it to a sump pump.
Yard French Drains
Installed across low areas of your yard to collect surface water and eliminate standing water and soggy spots.
Curtain Drains
Installed uphill from your home to intercept subsurface water flowing downhill toward your foundation.
Channel Drains
Surface drains installed across driveways, patios, and walkways to capture sheet flow.
Downspout Drain Lines
Underground pipes that carry roof runoff from downspouts away from your foundation to a discharge point.
Our French Drain Installation Process
- 1
Site Assessment
We evaluate your drainage problem, identify where water is coming from and where it's going, and determine the best solution.
- 2
System Design
We design the drain layout — trench location, pipe size, slope, gravel spec, and discharge point.
- 3
Excavation
We dig the trench to the required depth and slope, typically 18-24 inches deep for yard drains and 3-4 feet for foundation drains.
- 4
Installation
We lay filter fabric, install the perforated pipe with proper slope (minimum 1% grade), surround it with washed drain rock, and wrap the fabric over the top.
- 5
Backfill
We backfill above the drain with topsoil or gravel depending on the surface finish desired.
- 6
Testing
We test the system with water to verify proper flow and discharge before completing the backfill.
When You Need Drainage Solutions
Water pools in your yard after rain and takes days to drain. Your crawlspace has standing water or is consistently damp. You see water stains, efflorescence, or mold on your foundation walls. Your basement floods or leaks during heavy rain. Your downspouts dump water right next to your foundation. Your yard slopes toward your house instead of away from it.
French Drain Cost in Portland
French drain costs in Portland typically run $25-50 per linear foot installed, depending on depth, soil conditions, and discharge method. A standard exterior foundation drain (50-80 linear feet) typically costs $3,000 to $6,000. A yard French drain is usually $2,000 to $5,000. Interior crawlspace drains with a sump pump are $3,000 to $8,000. We provide detailed estimates based on your specific drainage problem.
Why Choose A&N for Drainage
Drainage systems are only as good as their installation. Improper slope, wrong pipe size, missing filter fabric, or inadequate gravel will cause a French drain to fail within a few years. We install drainage systems that work for decades — proper materials, correct slope, and solid construction.
Drainage Solutions Service Areas
We serve the entire Portland, Oregon metro area.
Frequently Asked Questions
How long does a French drain last?
Can you install a French drain in winter?
Do I need a sump pump with my French drain?
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A&N Construction and Excavation · CCB #268549