Southern California Erosion Control & Revegetation

This is a great article by Janis Keating, regarding Erosion Control and Revegetation.

Erosion Control, the official journal of the International Erosion Control Association

Planting for erosion control isn’t like tending a garden. The scale of such projects often covering acres or miles makes it impossible to give each site the “tender loving care” one might lavish on a favorite flowerbed. Yet the required tasks are somewhat the same; one chooses the right seeds for the site and climate, uses mulch to keep the soil moist and combat weeds, and enriches the soil to make sure it provides the best growing medium.

Erosion and Aesthetics

When the Talley family decided to develop property adjacent to its Arroyo Grande, CA, ranch into a prestige development named Las Ventanas, combating erosion wasn’t the only concern. “Preserving the heritage and beauty of this amazing land is of utmost importance to my family,” says Brian Talley. “Long-term sustainability and a commitment to quality are hallmarks of our four-generation history in the Arroyo Grande Valley. Las Ventanas is the ultimate expression of these beliefs.”
Of course, building homes required a lot of construction. “First, new roads had to be built,” Talley explains, “requiring substantial grading and earthmoving. All areas had to be hydroseeded, per San Luis Obispo County’s guidelines. It also stipulated using a seed type specific to this area.” Talley purchased his seed from S&S Seeds in Carpinteria, CA; the mixture included native wildflowers: goldfields, tidy tips, lupine, and poppy.

The project began in April 2007. The roadsides were hydroseeded that August and required irrigation. “This is a very moderate climate, with about 20 inches of rain per year, and very little frost,” Talley says. “The rains come between November and May; between June and October, it’s almost completely dry. But, thankfully, it’s cooler here than in southern California, because of ocean currents. Since we have a farming operation, we know how to grow things. To get the wildflowers growing, we used standard irrigation piping, a Rainbird-type system, and also water trucks as needed.”

Stan Shahan, the manager of construction services for RRM Design Group, worked on the Las Ventanas project. “Las Ventanas consists of 55 residential lots, situated on approximately 3,800 acres in what’s known locally as cluster housing. The lots range from one-and-a-half to two acres each, with the remainder of the property dedicated to open space,” he explains. “The Arroyo Grande Creek runs adjacent to the property and was a major concern during the project’s construction phase with respect to erosion control and runoff.

RRM Design Group provided oversight and project construction assistance to the owner during the construction phase. “The designers decided to use Profile Products’ Flexterra Flexible Growth Medium-hydraulically applied blankets, as opposed to rolled blankets,” says Shahan. “A native-seed-mix design, approved by the county and supplied by S&S Seeds, was chosen for the hydroseeding. The plants sown will reseed themselves each year, providing beautiful spring blooms.”

Roadways were a particular problem. “One of the challenges was approximately five miles of residential roadways carved from the project’s scenic hillsides. This resulted in miles of cut-and-or-fill slopes-some 30 acres and the existing soils varied extensively, from clays to sandy soils. Flexterra helped hold moisture and expedited the hydroseed mix’s germination. Talley Farms also helped by using sprinklers and other types of irrigation to hasten the establishment of vegetation.”

Overall, the revegetation went well. “The project was adequately stabilized to file for the Notice of Completion with the regional water board,” Shahan says. “During construction, the project required over five miles of silt fencing, thousands of feet of fiber rolls, hundreds of gravel bags, and other extensive measures to help in the control of erosion and runoff. Given the close proximity of the Arroyo Grande Creek and the natural topography that drained toward it, it was a challenge to keep sediments from entering the creek. Credit should be given to the Talleys for their commitment to spare no expense to meet this challenge and maintain the clear-water integrity of the Arroyo Grande Creek.”

Click here for full article. Or Call Canyon Hydroseeding for more erosion control options and guidance at (951) 680-1949.  We service residential and commercial customers in California.