How to Install Farm Drainage Tiles

Healthy plants need the right amount of water.

Wet spots in agricultural fields can be more than a maintenance issue. Besides the problems of ruts caused by stuck equipment and soil compaction caused by heavy tillage equipment, wet soils can adversely affect field productivity. Soils that are too wet will leach nutrients and stress plant root zones, resulting in unhealthy plants and reduced profits. Field tile drains can lower the water table in soils, thereby reducing the stress on plants.

Things You'll Need

• Excavator
• Heavy duty corrugated polyethylene drainage tubing (ASTM F 405), minimum 4-inch diameter
• Well graded course sand/gravel mixture, maximum size 0.5 inches
• 10 foot length of solid outlet pipe of PVC schedule 40 the same diameter as the tile line
• Rodent guard

Instructions

1. Calculate the number of lines of tile and length needed for your field. The tile should drain through the middle of wet areas and drain with the slope of the land to a stable outlet area. The tile can be formed in random, herringbone or straight line patterns to drain multiple wet areas.

2. Excavate the trench to a minimum of 3 feet in depth and a minimum width of a foot. The trench should have positive drainage toward outlet area with no low spots in which water would pool.

3. Lay a minimum of 3 inches of the well graded course sand/gravel mixture in the bottom of the trench.

4. Install the tile over the granular fill. Carefully add sand/gravel mixture over the tile until a minimum cover of three inches is over the pipe.

5. Fill the remainder of the trench with excavated soil. Place extra soil over the trench so that it is higher than surrounding ground. This will allow for settlement of the soil.

6. Install solid PVC pipe to end of the tile so that a foot of solid PVC will extend from the ground at the outlet area.

7. Build a rock head wall around the solid PVC outlet. It should be a minimum of 18 inches deep and contain a small plunge pool below the pipe.

8. Install a rodent guard in the end of the solid PVC.

Tips & Warnings

• Start at end of tile and work uphill to prevent water from backing up into the unfinished trench and tile.

• Be careful not to crush the pipe when placing granular. Maintain at least a 2-foot cover over corrugated tile to prevent potentially crushing.

• Solid PVC at the end will protect corrugated tile from being crushed as the ground level drops. If the outlet is near the surface, use a longer solid PVC until the tile has a minimum cover of 2 feet.

References

• U.S. Environmental Protection Agency: Drainage
• "Engineering and Design -- Handbook for the Preparation of Storm Water Pollution Prevention Plans for Construction Activities"; USDA-NRCS; 1997