Fixing a Flooded Backyard: Buried Stream, High Water Table, or Spring?

A backyard becomes a spring mudpit. Neighbor lore says a buried stream was filled with tree debris during construction. Water runs between properties. Need to diagnose and fix.

Diagnose the Source

1. Surface runoff: Check uphill grading, downspouts, neighbor drainage. Divert with swales/berms.
2. High water table: Dig a 3-ft test hole in the wet zone. If water rises without rain, it's groundwater.
3. Spring/seep: Constant flow from a point source, even in dry weather.
4. Buried organic layer: Decomposing fill creates a sponge. Probe with a soil auger—look for dark, woody layers.

Solutions by Source

Source	Fix
Surface runoff	Regrade, swales, downspout extensions, French drain to daylight
High water table	Perimeter drain tile + sump pump, or deep French drain to lower outlet
Spring/seep	Intercept with curtain drain upslope, pipe to daylight
Buried organics	Excavate and replace with granular fill, or install drainage grid above

Retention/Infiltration Options

• Rain garden (bowl-shaped, amended soil, wet-tolerant plants).
• Dry well (perforated tank in gravel) for point discharge.
• Permeable pavement if area is trafficked.

Permit Check

Any regrading >5 cu yd or discharge to a watercourse may need a municipal permit. Call the building department before digging.

Start with a test hole and a level. The fix follows the diagnosis.