Backyard Flooding Solution: Retaining Wall and Drainage Considerations

Missouri homeowner experienced flash flooding from a sloped backyard. FEMA assisted. Considering a retaining wall with drainage behind it to divert water around the house. Concerned about water displacement causing new problems.

Critical Principle: Water Must Go Somewhere

Diverting water without a safe, legal discharge point often shifts flooding downstream—to neighbors, streets, or other parts of the property. Any solution must include:

• Engineered grading and swales.
• Properly sized French drains or perforated pipe.
• A discharge point: storm sewer, daylight to a lower area, or dry well—verified to handle peak flow.
• Compliance with local drainage ordinances.

Professional Consultation Required

This exceeds typical irrigation advice. Engage a civil engineer, landscape architect, or drainage contractor. FEMA mitigation grants may cover professional design. DIY retaining walls on slopes often fail without geotechnical input.