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Brush matting (crimping) is essentially a mulch of hardwood brush crimped into erdsting drainage cuts. The technique is employed very effectively in stream channels and on stream banks to protect against accelerated erosion rates when a channel needs repair. Erosion control fabrics, mattings, fibers, strands and soil confinement systems are used effectively in reducing stream velocities and increasing sedimentation in reconstructed drainage channels. Various combinations of materials are used to solve erosion prob- lems on a site specific basis. Erosion control fabrics provide a ground armor that dissipates the energy generated by water movement from run-off or rainfall. Soil retention is a secondary function. Fabrics offering high strength and abrasion resistance are used under rip rap. Erosion control and revegetation matting protects newly-reseeded surfaces until perma- nentvegetation is established. The blankets reduce rainfall impact and run-off velocity, and also enhance plant growth by moderating soil temperatures and reducing evapora- tive moisture losses. Blankets are commonly made of coconut fiber and a synthetic netting material and are sewn together with nylon thread. The natural fibers degrade over tune, but non-degradable synthetic matting materials made of bonded, plastic fila- ments are used for mote permanent applications. Moldable erosion control fibers aze bundles of polypropylene fibers that can be stuffed into rills or gullies and anchored with stakes or staples. T'he bundle slows the velocity of run-off and causes upstream sedimentation, allowing the channel to heal itself and revegetate. • Erosion control strand (roving) is a relatively thick, spaghetti-like yarn that is blown onto an erosion trouble spot or newly-reseeded azea. The 5berglass or polypropylene yarn is tacked to the ground with an asphalt emulsion or similar substance. The mass of fibers slows run-off flow and catches sediment in the spaces between strands. Soil confinement systems generally consist of a series of honeycomb-like cells formed into a spreadable sheet or blanket. Sheets of the material aze anchored and filled with soil, creating a solid, pavement-like surface in areas of poor soil stability. 3.4 Improvements and Repairs Drainageway improvements and repairs were performed to provide benefits to all drainages treated in 1987-90, as well as portions of undisturbed drainage segments. Drainage improvements included the installation of several thousand shrub seedlings in 1987-89 treatment areas, the rock armoring of a few hay bale structures in 1987 treated drainageways, and dozer basin construction in newly stripped topsoil areas and on regraded spoils. Drainage repairs and enhancement were conducted in all previous reconstructed drainageways (87-89) with a minimum of effort required to complete this task. Essentially no downcutting in drainage bottoms occurred, therefore efforts were directed at reinforcing potential problem areas. Rock structures were installed at an average frequenry of 40-100' throughout the recon- structed Johnson Gulch tributary in 1990. .~