Using Drones to Inspect Drainage Tile Systems in Iowa Fields

Iowa has some of the most extensively tiled agricultural land in the world. Millions of feet of drainage tile run beneath corn and soybean fields across the state — and when that tile fails, plugs, or collapses, the result is a saturated zone that costs yield year after year. Finding which tile run is the problem without aerial data means digging blind.

NDVI and near-infrared drone imagery changes that. Here's how we use aerial data to help Iowa farmers localize tile failures before they break out the backhoe.

Why NDVI Reveals Tile Problems

When a tile run fails or becomes blocked, water that should be removed from the root zone stays. The affected soil stays saturated longer after rain events, creating measurable differences in plant health that show up in NDVI data as linear or oval low-NDVI zones. These patterns are distinct from drought stress (which tends to be random or follow soil texture) or nitrogen deficiency (which follows field-wide application patterns).

The key diagnostic indicator is pattern linearity. Tile runs are installed in parallel lines or herringbone patterns. When you see a low-NDVI zone that traces a straight or gently curving line across a field, it almost always corresponds to a tile failure — either a broken pipe, a collapsed joint, or a plugged outlet.

Best Timing for Tile Detection Flights

Tile-related stress is most visible:

• Early season (V5–V8 corn, V3–V5 soybeans) — saturated zones from spring rains are still present, canopy is thin enough to reflect soil moisture effects
• 48–72 hours after a significant rain event — this is the sweet spot. Affected zones are still saturated while better-drained areas have dried. The contrast is maximum.
• Mid-summer during a dry period — paradoxically, tile problems can also appear as higher NDVI zones during dry weather if the failing tile is creating a perched water table that plants can access

What the Deliverable Looks Like

For a tile inspection flight, we deliver:

• Full-resolution NDVI orthomosaic of the field
• Annotated PDF map with flagged low-NDVI zones, color-coded by severity
• Overlay on your existing tile map (if you can provide as a shapefile or PDF)
• GPS coordinates of each flagged zone centroid — so you can navigate directly to each location for ground inspection

We do not diagnose the specific cause of failure — that requires a tile contractor with a camera. What we do is tell you exactly where to look, which converts a potentially multi-day random excavation into a targeted, efficient repair operation.

Subsurface Detection Services

For farms that have lost their original tile maps (common with older installations), we also offer Ground Penetrating Radar (GPR) survey services to locate existing tile runs before they fail. See our Subsurface Detection page for details on that workflow.

What This Costs

NDVI tile-inspection flights are priced the same as standard agricultural NDVI mapping — $9/acre with a $275 minimum — because the flight itself is identical. The tile-specific annotation and GPS coordinate export is included at no additional charge when you specify tile inspection as the primary use case at booking.

Ready to find your problem tiles before next planting season? Request a quote or call (712) 318-2470.