Excavation
Drainage Solutions for Standing Water, Ranked
Cojo
March 6, 2026
10 min read
If you have been watching water pool in your yard every winter, creep toward your foundation, or turn your lawn into a swamp, you are not alone. Oregon's wet climate and the clay-heavy soils of the Willamette Valley create drainage challenges for property owners across the state.
The good news: every drainage problem has a solution. The key is matching the right solution to your specific situation. Here are the most effective drainage methods, ranked by versatility and effectiveness for Oregon properties.
A French drain is a gravel-filled trench containing a perforated pipe that collects and redirects subsurface water. It is the most versatile and effective drainage solution for most Oregon residential properties.
How it works: Water seeps through the soil, enters the gravel bed, flows into the perforated pipe, and is carried by gravity to a discharge point (storm drain, dry well, or daylight outlet).
Best for:
Cost: $10-$25 per linear foot installed. A typical 100-foot run costs $1,500-$3,000. See our detailed French drain cost guide.
Installation: Requires trenching 18-36 inches deep, placing gravel and perforated pipe, and backfilling. Slope must maintain a minimum 1% grade (1/8 inch per foot) toward the discharge point.
Oregon considerations: French drains are ideal for the Willamette Valley's clay soils because they collect water below the surface where clay prevents natural drainage. Size the pipe (typically 4-inch diameter) and gravel bed for Oregon's high rainfall volumes.
Effectiveness rating: 9/10
Regrading reshapes the ground surface to direct water away from structures and low spots toward proper drainage points.
How it works: Soil is cut from high areas and filled in low areas to create positive drainage slopes. The Oregon building code requires a minimum 6-inch fall within 10 feet of any foundation.
Best for:
Cost: $1-$5 per square foot for the regraded area. A typical residential regrading project runs $2,000-$10,000. See our site grading cost guide.
Oregon considerations: Regrading in clay soil should be done during dry months (June-September). Clay soils compacted when wet may create a hardpan layer that worsens drainage.
Effectiveness rating: 8/10 (addresses surface water but not subsurface issues)
A catch basin is a surface inlet (grate) that collects water and routes it through underground pipes to a discharge point.
How it works: Water flows across the surface into a catch basin grate, drops into a sump, and exits through a solid (non-perforated) pipe to the storm drain, dry well, or daylight outlet.
Best for:
Cost: $200-$500 per catch basin installed, plus $5-$15 per linear foot for pipe. A typical two-basin residential system costs $1,500-$4,000.
Oregon considerations: Size catch basins for Oregon's peak rainfall intensity (approximately 2 inches per hour in the Willamette Valley during heavy storms). Undersized basins overflow during the storms when you need them most.
Effectiveness rating: 7/10 (excellent for surface water at specific points)
A dry well is an underground chamber that collects water and allows it to slowly percolate into the surrounding soil.
How it works: Water from downspouts, French drains, or catch basins flows into the dry well chamber. The water then seeps out through the chamber walls into the surrounding soil over time.
Best for:
Cost: $500-$2,000 per dry well installed, depending on size and excavation difficulty. Most residential applications need one to three dry wells.
Oregon considerations: Dry wells work best in sandy or gravelly soil where water percolates quickly. In clay-heavy Willamette Valley soils, dry wells may fill faster than they drain. Oversizing (using larger chambers or multiple wells) helps compensate. Some jurisdictions require a percolation test before permitting dry wells.
Effectiveness rating: 6/10 (limited by soil permeability)
A swale is a shallow, vegetated channel that collects and conveys surface water along a gentle slope.
How it works: Water flows across the lawn, collects in the low point of the swale, and follows the channel's slope to a discharge point. Vegetation in the swale slows the water and filters sediment.
Best for:
Cost: $3-$10 per linear foot for simple graded swales. Engineered bioswales with specific plantings and amended soil cost $15-$30 per linear foot.
Oregon considerations: Swales work well for surface water but do not address subsurface drainage in clay soils. They require ongoing maintenance (mowing, keeping clear of debris) and can become soggy areas themselves if the soil is impermeable.
Effectiveness rating: 5/10 (good for surface water management on large properties)
The simplest and cheapest fix for water pooling near foundations is redirecting roof runoff.
How it works: Extend downspouts to discharge water at least 6-10 feet from the foundation, or connect them to underground pipes that carry water to a catch basin, dry well, or storm drain.
Best for:
Cost: $10-$50 per downspout for above-ground extensions. $200-$500 per downspout for underground connections.
Oregon considerations: Above-ground extensions are a trip hazard and visual nuisance. Underground connections are preferred but require trenching. Ensure underground pipes have sufficient slope and capacity for Oregon's rainfall volumes.
Effectiveness rating: 4/10 (addresses one source of water but not the underlying drainage issue)
A sump pump actively removes water that collects in a low point (sump pit) and pumps it to a discharge location.
How it works: Water enters a sump pit through drain tiles, French drains, or gravity flow. When the water level reaches a set point, the pump activates and pushes water through a discharge pipe to an exterior location.
Best for:
Cost: $1,000-$3,000 for a complete sump pump installation (pit, pump, discharge pipe, check valve). Battery backup adds $500-$1,000.
Oregon considerations: Power outages during winter storms are common in Oregon. Battery backup is essential. Consider a water-powered backup pump for extended outages. Discharge water must be directed away from the foundation and not onto neighboring properties.
Effectiveness rating: 7/10 (highly effective but requires power and maintenance)
| Problem | Best Solution | Cost Range |
|---|---|---|
| Water pooling against foundation | French drain + regrading | $3,000 - $8,000 |
| Wet crawlspace | Interior French drain + sump pump | $3,000 - $6,000 |
| Soggy lawn (clay soil) | French drain + surface regrading | $2,500 - $7,000 |
| Driveway/patio puddles | Catch basin + pipe | $1,500 - $4,000 |
| Downspout flooding | Underground extensions + dry well | $1,000 - $3,000 |
| Hillside water flowing toward house | Curtain drain (interceptor French drain) | $2,000 - $5,000 |
| Standing water after rain (sandy soil) | Regrading + dry well | $1,500 - $4,000 |
Most properties benefit from multiple drainage solutions working together. A common residential approach in the Willamette Valley:
This layered approach handles surface water, subsurface water, and roof runoff with redundancy that protects your property even during Oregon's heaviest storms.
Drainage problems often have multiple causes. What looks like a simple grading issue may also involve subsurface clay layers, a high water table, or inadequate storm drain connections. A professional assessment identifies all contributing factors and designs a solution that addresses the root cause.
Cojo provides free drainage assessments for properties across Oregon. We evaluate your site conditions, identify the water sources, and recommend the most cost-effective solution for your specific situation.
Schedule your free drainage assessment or explore our excavation and drainage services. For detailed pricing on the most popular solution, see our French drain cost guide.
What causes standing water in my yard? Standing water is caused by one or more factors: compacted soil that prevents infiltration, low spots that trap water, clay soil with poor permeability, high water tables, improperly graded surfaces that direct water toward the house, clogged or absent gutters, and downspouts that discharge too close to the foundation. Oregon's heavy rainfall from October through May makes these issues more apparent.
Is standing water near my foundation dangerous? Yes. Standing water against a foundation causes hydrostatic pressure that can crack walls, promotes mold and mildew in crawlspaces, can undermine footings through soil erosion, and creates conditions for wood rot in structural members. Addressing foundation drainage is urgent and should not be delayed.
How much does a French drain cost in Oregon? French drains in Oregon cost $10 to $25 per linear foot installed, depending on depth, diameter, soil conditions, and accessibility. A typical 100-foot residential French drain runs $1,500 to $3,000. For detailed pricing, see our French drain cost guide.
Can I fix drainage problems myself? Simple solutions like extending downspouts, adding splash blocks, and improving surface grading in small areas are reasonable DIY projects. French drains, dry wells, catch basins, and any work involving trenching near utilities or foundations should be handled by a professional to ensure proper slope, materials, and code compliance.
What is the best drainage solution for clay soil? French drains are generally the most effective solution for clay soil because they intercept water below the surface where clay prevents natural drainage. Surface solutions like swales are less effective in clay because water infiltrates too slowly. Combining a French drain with surface regrading provides the most complete solution for clay-heavy properties common in the Willamette Valley.
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