All construction projects in California are required to adhere to erosion control standards as set out by state and federal regulations. The goal of hydroseeding and erosion control is to minimize or eliminate the environmental impact of run-off, which can have a wide range of negative consequences for wildlife, plants, and waterways.
Hydroseeding is often a regulatory requirement for erosion control that designers, planners, engineers, and architects must include in construction specifications. Using a slurry mixture of nutrients, mulch, and seeds, it is applied with a pressure sprayer from a high-volume tank. Because the mixture holds in moisture, the process both reduces soil erosion and promotes faster seed germination.
To further enhance germination, slurry mixtures often contain fertilizer, green dye, tackifying agents, and other additives.
Hydroseeding is often used for highway construction projects and starting lawns in large areas such as a golf course or athletic field.
Preparation and Application
The following steps should be taken before hydroseeding for erosion control:
- Prior to hydroseeding, the area should be roughened in a manner that creates furrows along contours.
- The seed used in the mixture need to conform to the California State Seed Law of the Department of Agriculture.
- The seed bags should arrive on the site in sealed bags with labels indicating the species, test dates, germination percentage, purity, and suppliers guarantee along with clear identification of the amount of Pure Live Seed (PLS).
- The fertilizer needs to conform to the California Food and Agricultural Code and must be in either pellet or granular form.
- Straw mulch may be applied to help regulate soil moisture and temperature until germination.
- Follow-up applications may be required to negate weak areas and maintain erosion control.
- Necessary steps should be taken to avoid inadvertently spraying existing vegetation, sidewalks, roads, drainage ditches, and other adjacent areas.
Resources:
California State Document – Hydroseeding, http://www.ci.concord.ca.us/pdf/living/recycle/brochures/hydroseeding.pdf (accessed May 12, 2014)
California Dept. of Transportation – Key Concepts Of Sustainable
Erosion Control
Technical Guide, http://dot.ca.gov/hq/LandArch/ec/Erosion_Control_Technical_Guide_v2.pdf (accessed May 12, 2014)
California Dept. of Transportation – Erosion Control Toolbox, http://dot.ca.gov/hq/LandArch/ec/index.htm (accessed May 12, 2014)
California Dept. of Transportation – Hydroseeding, http://www.dot.ca.gov/hq/LandArch/ec/hydroseed/hydroseed.htm (accessed May 12, 2014)