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I I I I I I I I I I I I I I I I I I I N N ~ l'0 units is between 5 and 10 degrees to the north with the drainages incised and flowing to the south and southeast. In the upper reaches of the watershed are resistant sandstone and siltstone rock units that have deeply incised canyons cut into them. These canyon drainages exit steep rock face areas known as the Roan Cliffs and Book Cliffs. The drainages continue downstream through the Mancos Shale badland zone at the base of the cliffs. The drainages then flow through an broad, slightly dissected, alluviated pediment composed of Mancos Shale with eolian and coarse alluvium terraces. The pediment area includes a low gradient floodplain area known as Sagers Flat. The drainages merge in the lower downstream area of the Mancos Shale pediment and flow into the colorado River. There is an area in the southeastern portion of the watershed called The Highlands. This area consists of shales and sandstones in a low-lying, well dissected, generally east dipping structural bench. This structure forms the extreme eastern limb of the Salt Valley Anticline, a salt dome. The streams draining this area flow generally to the east into Sagers Wash. HYDROLOGY: The watershed consists of three subwatersheds that join in the lower portion of the drainage area. Each subwatershed has a distinct hydrologic character that affects the sediment and salt delivery process. Appendix I, Hydrologic and Drainage Area Data, contains the results of storm flow modeling and the drainage area measurements by geomorphic units and subwatersheds. Sagers Wash: Sagers Wash is located in the western portion of the watershed. It drains directly out of the Book Cliffs. There is significant sediment and salt yield occurring from the badland area adjacent to the Book Cliffs. The sediment and salt yielded from this area are subject to deposition and storage in the floodplain developed in Sagers Flat. Sagers Flat acts as a water spreading zone and traps significant amounts of sediment. It is estimated that up to 50% of the sediment load from upper Sagers Wash is deposited over Sagers Flat. Therefore, the estimated sediment delivery ratio for this drainage is 50%. The estimated salt delivery ratio is 50%. The drainages within Sagers Flat are approximately 10 feet deep and 20 feet wide. The water carrying capacity of the drainages is approximately 200 cfs. This results in significant out of bank flow in relatively frequent storm events (5- and 10-year events). Sagers Wash is not an efficient sediment delivery system. pinto Wash: Pinto Wash is a drainage that developed in the lower slopes of the Book Cliffs in the central portion of the watershed. Pinto Wash has approximately 500 feet less elevation drop than does Sagers Wash. This makes Pinto Wash a slightly 5