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Vegetation. e stakes driven into the brush at regular intervals to form a square grid. Brush mattresses are often used in conjunction with live fascines, which are long sausage-like structures of live vegetation (usually willows) brush tightly bound with wire or twine that are buried in trenches parallel to the bank slope and held in place by stakes. The brush mattress protects the surface of the bank from scour until the branches can root and grow and native vegetation can invade the site. This living system normally roots in the entire bank face and causes increased sediment deposition that encourages natural invasion. Woody vegetation used for brush mattress construction provides good riparian and aquatic habitat and a natura1look that is aesthetically superior to artificial materials. Brush mattressing has been used throughout the U.S. and Europe to control slope and streambank erosion caused by scour. Properly installed brush mattresses have performed well in most cases, especially on small streams. Most failures appear to result from improper installation, failure to confine construction to the dormant season, or construction in poor soils that were not properly treated or fertilized. In some cases the brush may deteriorate and cause settlement of the bank. Soil Stabilization - Vegetative treatments are often sufficient to protect the banks of streams that are composed of cohesive materials and are not subject to high flow velocities. However such streambanks sometimes contain lenses of highly erodible material, such as sand, that create localized erosion problems. These areas can be covered with clay blankets several inches thick, then planted to grass or woody vegetation. Another soil stabilization technique involves discing portland cement into the native soil, welling and compacting to form a hardened bank. Clay blankets have been used on the Little Blue River, Independence, MO, where they were used to protect high flow berms and side slopes, and on the White River in Arkansas. The technique is applicable to any area where vegetative cover can be expected to survive. Brush Mat Revetments . Protecting both upper and lower banks, brush mat revetment construction methods resembles that for tree revetments. Willow brush and other lumber (if desired) are woven together to form a mat 6 to 12 inches thick. The unit is then placed on the stream bank and secured with wire or rock. Vegetation is planted on the sloped bank after the mat has been secured. A typical brush mat revetment is illustrated in Figure 4 - 17. The mat provides mulching for the vegetation but requires hand labor (which can be expensive) is usually reqttired to plant the vegetation. This method is not practical for streams subject to high channel scour. e Cellular Blocks - Some of the manufactures listed in Appendix A marlcet cellular block products. Cellular blocks are designed to be placed on a prepared bank in a manner that leaves many openings. This method allows vegetation to grow from cavities in precast concrete blocks. Construction often involves the placement of a filter cloth between the soil and the cellular blocks if the soil is erodible. Specialized equipment can be used to install the blocks, but hand placement will be required when bank access is inadequate. Colorado Erosion Control Manual 49