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Its regulation is a fact. in the runoff characteristics the drainage. The San Miguel emerges from a well confined canyon just above the project area and flows across a large alluvial fans that has been deposited with cobble and boulder size material originating in the watershed. This feature hoe a slope of 4.7Z and is slightly convex in cross-section. As a result the channel that flows across the fen is a high energy system that tends to migrate back and forth across the fan over time. In contrast the South Fork emerges from a moderately confined glaciated valley with well developed floodplains and fluvial terraces. Both the valley and stream gradient are much flatter than the mainstem. The banks of the South Fork are well sorted cobbles and gravels that are very erodible and easily collapsed if oversteepened. The area is underlain by sedimentary rocks, conglomerate and younger volcanics. Surficial deposits include alluvium, colluvium, talus, glacial drift, and landslide deposits. Masts wasting processes are common where conglomerate ie underlain by weak sedimentary rocks of the Mancos Shale or Morrison Formation, particularly where the valley sideways have been oversteepened by glaciation. This continual supply of material to the channels, has resulted in the formation of fluval deposited fans, bars and floodplains and a very high bedload component which is transported during high flows. The majority of precipitation occurs as snow, with winters being long and cold. Spring runoff typically begins in mid to late May and ends in early July, but in unusual years may persist well into late July, such was the case in 1995. Snowmelt runoff is responsible for the annual peak discharge in the streams. Stream channels usually begin to ice up in December. Ice may persist until the 1st of May. Ice jams and flows are common and capable of both channel bed and bank scour. Average annual precipitation is elevation dependant and varies from about 18 to 35 inches. High intensity/short duration summer storm events are common. Climatic data maps list the 10 year - 6 hour storm event as 1.4 inches. Alternative 1. NO ACTION ALTERNATIVE. Under this alternative there would be no plane implemented to stabilize ar restore the channel. Over many years, the laws of physics will continue to dictate adjustment processes in the river channel until such time as natural stability is re-established and the river heals itself. The most significant and visible effects are likely to occur on the South Fork, where accelerated bank erosion will continue until a new flooplain is created at a lower elevation. The previous floodplain is now abandoned and has become a terrace. As a new floodplain is created and stabilized by invading vegetation a new, stable channel will evolve. Once a sufficiently wide and stable floodplain is created, energy from high water will be dissipated across the floodplain rather than directed against eroding banks. As the cycle of undercutting and collapsing banks is broken, they will gradually unravel to an angle of repose and revegetate. The adjustment of the channel gradient, in response to downstream gravel removal, will continue to move headword until this adjustment has occurred throughout the system or a geologically resistant feature is encountered that halts any further headword movement. 7