1. Nonfarm Erosion Control
Chapter 7
Nonfarm Erosion Control

2. Introduction
Soil is also disturbed by home building, industrial expansion, urban construction, highway construction, and many other nonfarm activities
Daily, as many as 8,000 acres of U.S. farmland are converted to nonfarm use
Cont.

3. Introduction
Millions of acres of land are disturbed annually by strip mining for coal and other resources
As new highways are constructed and old ones are widened, moved, or repaired, millions of miles of road banks are subject to water-caused erosion

4. Controlling Nonfarm Erosion
CAUSES
Construction
Drainage ways drastically changed
Concrete or asphalt
Runoff problem severe
Sedimentation or gullying
Expensive control practices

5. Mechanical Erosion Controls
DIVERSION DITCHES OR BERMS
Collects the runoff
Typically earth structures
Runoff to an outlet
Ditch is dug out of the ground
Berm is mounded

6. Mechanical Erosion Controls
WATERWAYS
Collect excess soil water
Rock-lined or concrete-lined
Conducted away quickly
Slope is very steep
Steep diversion waterway
Water chute

7. Mechanical Erosion Controls
SEDIMENT BASIN
Like a small pond
Designed to be filled up
Catches excess runoff
Sediment settles
Temporary structures
Used during construction

8. Mechanical Erosion Controls
BANK PROTECTION
Extra efforts to stabilize banks
Seed, mulch or hydroseeding
Concrete or stone walls
Jute matting
Wooden strips placed across the slope
Chemical binding

9. Mechanical Erosion Controls
TERRACING
Solution on long, steep banks
Breaks into shorter slopes
Disposal areas
Grassed or lined waterway
Chute
Wooded area
Storm sewer

10. Mechanical Erosion Controls
DOWNSTREAM RUNOFF
Very large construction projects
Large factories
Normal stream flow may be greatly increased
Flooding
Measures may be needed downstream

11. Vegetative Erosion Controls
LAWN
Most common technique
Nonfarm sites
Seedbed
Sprigging
Plugging
Sodding

12. Vegetative Erosion Controls
SOD
Quick development
Heavy growth of grass
Squares or strips
Living layer
Produced on a sod farm
Soil must be well prepared

13. Vegetative Erosion Controls
MULCH
Holds grass seed in place
Maintains surface moisture
Protects from erosion
Silage-like slurry
Chemical bonding

14. Vegetative Erosion Controls
GROUND COVERS
Low-growing shrubs,
Vines, or other plants
Used much like grass
Combined with mulching
Increase protection

15. Vegetative Erosion Controls
TEMPORARY COVER CROPS
Construction sites
Protect an area temporarily
Construction delays
Many plants can only start at certain times

16. Highway Erosion Control
SPECIAL PROBLEMS
Highway surfaces
Practically waterproof
As level as practical
Exposed banks
Erosion damage
Sediment

17. Strip Mining Operations
PROBLEMS
Large increase
Appalachia
Very steep slopes
High-velocity water

18. Strip Mining Operations
VIRGINIA COAL MINES
Spoil
Drainage and erosion-control system
Two-year period
Land must be reclaimed
Bond is forfeited with noncompliance
Government regulations to be followed

19. Summary
The impact of falling raindrops must be absorbed by something other than the soil surface, and the speed of the runoff must be kept under control
Because almost all construction disturbs and reshapes the land, it exposes the soil to greatly accelerated erosion
Cont.

20. Summary
Mining operations and highway construction present the same or even more extreme problems of erosion
The best solution to the erosion problem is almost always a combination of both vegetative and mechanical measures