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To: Brumar89 who wrote (22214)	8/5/2012 12:49:16 PM
From: Wharf Rat	Read Replies (2) \| Respond to of 85487

Mitigation for the loss of native plant material was also an integral design pollution prevention component of the Rincon Creek restoration project, which included native oak, walnut, cottonwood, white alder, and sycamore trees. The design team used an innovative method of brushlayering/bioengineering at the ends of the bridge's rock slope protection (RSP) and at a narrow portion of the stream. Caltrans traditional approach to stream bank stabilization has been to use standard methods like rock slope protection. This is one of the first times a brush layering vegetative technique was incorporated into a Caltrans biddable contract. Before, State Route 150 was continuosly subjected to flooding, erosion and closures during storm events. Brush layering was approximately 196 feet in length and consisted of placing layers of locally harvested willow cuttings (Salix lasiolepis-Arroyo Willow) and soil wrap (100% spun coir fiber netting) during embankment construction. Local willow cuttings were harvested from an area within a 5-mile radius of the project site. Cuttings from healthy vigorous plants were taken with lengths ranging from 5-10 feet and diameters ranging from 7/8-2 inches at the base of each cutting. Cuttings were kept wet and shaded until installation. Soil wrap work consisted of placing and wrapping fill material with netting in approximately five, 30 inches layers on top of a keyed-rock slope protection installed from 10 to 20 degree angle. The leading edge of the netting was stapled in place using a minimum 11 gage steel wire u-shaped staples and allowed to lay over the embankment face while fill material (Imported topsoil) was placed on top of the netting. After placing the fill material, the netting was pulled-up and over the top of the fill and fastened in place with staples at about 2 feet intervals. Adjacent pieces of netting were overlapped a minimum of 6 inches and fastened with staples perpendicular to the slope. Prior to placing cutting, soil wrap was thoroughly moistened to a depth of 8 inches. Cuttings were placed in 4 inches thick layers with a minimum of about 30 cuttings per linear foot with minor criss-crossing. Butt ends of cuttings were placed in the embankment with the leafy ends protruding 6-12 inches from the embankment. The cuttings and soil wrap materials were placed in alternate layers and compacted with a minimum of 6 inches of fill, which remained between the equipment and the cutting for protection. Environmental guidelines and restrictions for the harvesting of cuttings were specified in the contract and monitored during construction. The design team used an innovative method of brushlayering/bioengineering along RinconCreek. The revegetation of the creek not only armored the stream bank, but it also shaded the south side of Rincon Creek and improved habitat for potential migrating steelhead by providing overhanging vegetation for cover and promoted oxygenated and cooler water temperatures. According to a letter provided by the US Department of the Interior, "the combined actions reduce or eliminate sloughing of bank material into Rincon Creek and improve fisheries habitat and water quality. Reduced sedimentation is particularly beneficial for anadromous steelhead, which require gravel to cobble substrate with little or no silt for spawning." In addition to the environmental requirements for wetland, riparian, and upland habitat mitigation, Caltrans hired an arborist to supervise the pruning of oak and other native trees, and was able to protect approximately 120 native acorn seedlings found on site. Caltrans also hired a bird monitor to avoid impacts to breeding/nesting birds within and adjacent to the project site during construction of the project. One year after completion, the restoration project contributes to the area's rural feel and is aesthetically pleasing. Due to the sensitive habitat status of the area and to further insure the success of the project, Caltrans will continue to maintain the woodland and wetland revegetation areas for a period of five years with an additional three years of monitoring performed. The design team from Caltrans included departments from Landscape Architecture, Environmental Planning, NPDES/Stormwater, Hydraulics, Engineering, and Construction. Partnering between Caltrans and the contractor was implemented and it was evident throughout the project that quality and reducing environmental impacts were key objectives. Despite the challenges of negotiating the use of this unusual mix of both RSP and planting techniques to protect Rincon Creek bank, as well as the use of non-standard details and specifications, the team succeeded in providing a successful solution to restoring this riparian area. Overall, the innovative design and engineering methods used in the Rincon Creek project have proven positive results environmentally, hydraulically and visually. Caltrans' commitment to the Rincon Creek Bridge replacement project is but one example of its dedication to serve the public and protect California's water quality and its natural resources. L&W Approximately 1 1/2 years after completion, the innovative brushlayering/bioengineeringdesign methods have proven positive results environmentally, hydraulically and visually. Caltrans is continuing to explore various options for providing vegetative enhancements and softer treatments for stream-bank stabilization. Until more extensive performance data is generated on the various techniques commonly used in stream restoration applications, Caltrans will continue to pilot a number of projects in varying hydraulic, climatic, and environmental conditions so that uniform standards can be adopted and published. Long-term evaluation of sites, such as Rincon Creek, will be instrumental in establishing the basis of these future standards that balance the environmental stewardship with protection of public safety and infrastructure. landandwater.com