How to Redirect Water to Keep a Yard from Flooding After Rain

Water runoff always finds the lowest elevation to gather and flow.

Rain runoff from the house roof and concrete driveway and walks leads to an increase flow of water drainage across the yard and garden. Water always flows downward, finding the path of least resistance, which means that any flower bed or patio in the way gets temporarily flooded. If the drainage issue after rain in your yard creates shallow ponds or soggy spots, correcting the problem is much simpler than if torrents of water gush. If water flows across your property because of a nearby ditch or neighbor's impermeable surfaces cause all localized water to flow onto your property, a professional landscape architect and surveyor must be consulted.

Things You'll Need

• Can of spray paint
• Wood stakes or old bricks
• Shovel
• Wheelbarrow
• Coarse gravel
• Flexible drainage roll-piping

Instructions

1. Mark off the areas on your property that suffer poor drainage. Wait until a rain event causes the problematic drainage and flooding issues in your yard. Using a can of brightly colored spray paint, make lines on the grass or mulch to reveal the extent of soggy or flooding conditions. If the conditions are too wet, drive wood stakes or rest bricks on the ground to delineate the edges of the extent of water flow across your yard.

2. Dig into the lowest elevations within soil area that naturally floods or is washed in runoff to create a swale or river basin-like bed to capture and redirect the water flow. Water always flows downhill in the path of least resistance, so a trench to capture and direct the water quickly across the property is needed. Place removed soil from the trench away from the area so it doesn't impede the natural downward flow of water. This extra soil can be made into a small berm to help block or channel water into the trench. Use a wheelbarrow to relocate excavated soil if needed.

3. Fill the drainage trench with coarse gravel, granite chips or sand. This essentially creates a modified french drain in which water flows into the trench that is supported and hidden by the gravel. Turf grass or other wet-soil tolerant plants can be planted to improve the aesthetics of the drainage trench, such as creating a dry stream bed with accents of shrubs. The plant materials or mulch must not restrict or block the natural flow of runoff across the property into the drainage trench.

Tips & Warnings

• Place a flexible length of PVC or sturdy polyurethane tubing into the trench for added drainage before backfilling with gravel. Often this tubing is sold as corrugated piping or drain piping. Tubing with holes on the upper half permits runoff to drip into the tubing and flow. Make sure the holes are smaller than the gravel aggregate used to backfill around it in the trench.

• Not all issues with water runoff on properties can easily fixed by a homeowner. Local landscape or building codes may dictate soil grading or any property modifications. Moreover, a licensed landscape architect and construction company with experience may prove worthwhile to handle extensive water runoff problems on your property.

References

• Buckeye Gardening: How to Improve Site Drainage
• Learn2Grow: Making Site Improvements: Drainage, Lighting and Irrigation

Resources

• Learn2Grow: Garden: Swamped (for Plants That Like It Wet)
• Canada Mortgage and Housing Corporation: Rain Gardens: Improve Stormwater Management in Your Yard