Straw wattles are a relatively new product for use in erosion control projects such as: storm water pollution control on construction projects, fire burn rehabilitation, revegetation projects, and anywhere erosion and sediment protection is required. Straw wattles that are manufactured by Loomis, California-based California Straw Works are tubes of rice straw that are typically eight to nine inches in diameter, approximately 25 feet long and weigh about 40 pounds. These products can be made with UV degradable plastic netting for longevity, or with 100 percent biodegradable burlap for sensitive sites. Wattles made with the plastic netting will last approximately three to five years, with the straw bio-degrading and the netting breaking down to small pieces from sunlight. The biodegradable wattles will last only a season to a year due to the fairly rapid breakdown of the burlap covering. Wattles manufacturer R.H. Dyck, Inc./Earth Savers of Winters, California has straw wattles available in 12-inch and 20-inch diameter, designed to replace traditional straw bale barriers. They are also available with biodegradable netting. According to the U.S. Department of the Interior, the effectiveness rating of straw wattles ranges from "excellent" to "fair," depending on the circumstances in which they were used and the quality of the installation. Comments within one Department of Interior region on straw wattle effectiveness ranged from being an "excellent" treatment at a reasonable cost and still functioning after two years, to that of exhibiting "pronounced undercutting immediately on the downhill side." The Interior Department's visual monitoring has noted that straw wattles usually remain in place and often fill with soil material on the uphill side, where that happens, good seed germination occurs. Straw wattles have been placed onto specific sites and randomly located on slopes. Some monitoring observations have noted that there does not appear to be a difference in overall vegetative recovery between contour felled log areas and straw wattle treatment areas. Overall effectiveness can be affected by breakdown of the wattles and release of built-up sediment onto the rest of the slope or into drainages. Correct installation of straw wattles is crucial to their effectiveness, according to Interior Department studies. Wattles are labor intensive because they need to have good ground contact and anchoring. Wattles can be anchored to the ground by trenching and backfilling or staking. An effective anchoring technique is to use "U" shaped 1/8-inch re-bar. Re-bar can hold wattles to the ground without trenching and is less likely to break than wood stakes in shallow soils. Straw wattles can work well on slopes greater than 40 percent but they are difficult to carry and hard to install on steep terrain. The Interior Department notes that spotting the wattles with helicopters can solve some of this problem. Straw wattles seem to be more popular in the western United States, primarily during the late summer/early fall. Bob Quenzel, vice president of the Environmental Services Division of Odyssey Landscape Co., Inc./Odyssey Environmental Services, Inc., in Stockton, Calif., said his company has several on-going projects utilizing straw wattles. He expects the straw wattle season to really take off by mid to late August. "It seems like developers panic later in the year because they don't have their erosion control in place," he said. "The increasing threat of bad weather and procrastination on the part of the developer seems to lead to more work for us." Quenzel said he believes California is leaning toward mandating developers to have erosion control in place on project sites early in the life of the project, which would end the late summer rush. Quenzel has used other materials for erosion control, such as hay bales and silt fencing, but he said straw wattles are a cost-effective solution for site development. "They create an avenue for developers who don't want to spend too much money on erosion control products such as silt fencing," he said. Straw wattles are also a popular item during forest fire season. After forest fires are extinguished, burned slopes are left bare and exposed to the elements, particularly rain and wind. Straw wattles help slow the velocity of the runoff from rain, helping to prevent the development of rills and gullies that erode the slope and render them unable to sustain plant life. Wattles stabilize bare slopes by trapping sediment and holding the soil in place so plants have a chance to become established and thrive. Straw wattles have been used to replace the labor intensive and dangerous job of contour tree felling for erosion control. Trees have branches at one end and roots at the other. This holds the body of the tree above the ground, so runoff and soil can wash underneath. Straw wattles are laid in trenches on slope contours, and secured with wood stakes to prevent undercut by runoff. The San Bernardino, Eldorado, Tahoe, Klamath, and Angeles National Forests in California, and the Boise National Forest in Idaho have used straw wattles manufactured by California Straw Works successfully for fire rehabilitation erosion control. Interior Department officials noted that getting straw wattles to mountainside sites is not difficult. A helicopter can sling them to the site, or they can trucked in if road access is available. If necessary, using a team of workers to carry them to the site is also an option. Interior Department studies found installation of the wattles to be basic. First, a shallow depression should be dug for the wattle. Second, drive a stake through the wattle and into the ground, so the stake is at least six inches in the ground and about two inches above the wattle. Five stakes per wattle is recommended. Manufacturers suggest that the wattles should be placed in a checkerboard pattern with a 15-foot horizontal spacing and a 30-foot vertical spacing. The Interior Department notes that considering how contour felled logs would be placed across the slope can alter these recommendations, then adding a few more wattles. In addition, there are few safety concerns with installing straw wattles. Quenzel echoes the Interior Department's findings, noting that installing wattles is not difficult, but labor intensive. "It takes a lot of manual labor to dig the trenches and to stake the wattles," he said. "Moving the material to the site is also cumbersome, especially when we're dealing with a hillside installation."