Downspout erosion at foundation
easy 1–3 h
Tools: spade, rake, hand tamper, level, hacksaw, screwdriver or drill · Materials: downspout extension (rigid) or a buried 10 cm (4-inch) drain pipe with a pop-up emitter, splash block, clay-rich fill soil, river rock and landscape fabric, grass seed or ground cover
Steps
- Fill the eroded trench with clay-rich soil, tamping it in layers, and grade it so the ground drops at least 15 cm over the first 3 m (6 inches over 10 feet) away from the wall.
- Fit a rigid extension to the downspout that carries the water 1.5–2 m (5–6 feet) from the foundation onto a splash block or a rock bed; the flip-up kind that lifts for mowing works well.
- Where an extension would cross a path, bury a 10 cm (4-inch) drain pipe from the downspout to a pop-up emitter in the lawn, sloping 1 cm per metre.
- Lay landscape fabric and river rock over the splash zone so the flow cannot carve a new channel.
- Seed or plant the regraded strip and water it in; bare soil erodes until roots hold it.
- Check after the next storm that water leaves the emitter or splash block and does not pool by the wall.
Stop and call a pro if
- the foundation or footing is exposed or cracked where the soil washed away
- water is already in the basement or crawl space after rain
- the ground around the house cannot be graded away because a patio, driveway or the neighbour's lot sits higher
Rules in the Netherlands: Check het afkoppelbeleid van je gemeente: regenwater van het dak mag vaak niet meer op het riool en infiltreren op eigen terrein wordt vaak gesubsidieerd.
What a pro does that you can't
A landscaper regrades the perimeter, installs buried drains to daylight or a dry well, and a foundation contractor repairs a footing that has been undermined.
DIY cost: $20–60 for an extension and rock; $80–200 for a buried drain