CSLB C-27 Landscaping ContractorSite Preparation and DrainageMedium
A C-27 contractor is preparing a site for a new planting area on a recently graded hillside. To stabilize the soil and prevent immediate erosion from rainfall before permanent vegetation is established, which temporary measure is most effective?
- AInstalling a subsurface drain system
- BCovering with erosion control blankets
- CApplying a layer of gravel
- DHydroseeding with a tackifier
Show answer & explanationAnswer & explanation
Correct answer: B. Covering with erosion control blankets
Erosion control blankets (or mats) are highly effective for immediate stabilization of graded slopes. They physically shield the soil from raindrop impact, slow down surface runoff, and provide a microclimate for seed germination while permanent vegetation establishes.
Why the other options are wrong
- A. Subsurface drains manage groundwater, not surface erosion from rainfall, and typically take longer to install.
- C. While gravel can reduce surface erosion, it's generally not practical or cost-effective for large planting areas and can alter soil composition.
- D. Hydroseeding is good for establishing vegetation, but without a tackifier or blanket, it doesn't provide immediate physical protection against heavy rainfall erosion.
Temporary Slope Erosion Control
Measures implemented to protect recently graded slopes from erosion by wind or water until permanent stabilization methods (like vegetation) are established.
- Prevents soil loss and sediment runoff.
- Protects nascent plant growth.
- Often biodegradable or removed after use.
Memory trick: Slopes need a shield, until seeds yield.