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i 1-5 Below this area, the channel is sorre\ovhat natural v,.'ith some intel~estin9 channel cross-sectional shapes. The stream appears to have cut to a boundary between the Piney Creek alluvium and a possible Denver forlna- tion claystone layer. The result is a vertical w2l1ed bank on -~:he south side and a moderate bank on the north side where the alluvium exists. Near Orion Street, the heavy cobbles and boulders are rlot present in the recent alluvial deposits, suggesting that the streamjed has flattened enough to create a somewhat 5 lower f lowing channel. 50i 1 samples taken near the stream at Orchard Street were moderately organic alluvial 5i lts and clays. Near South Golden Road recently deposited (this year), medium grain sized semel samples were taken. The enti re reach of Lena Gulch in Basin 3 has undersized culver-,:s a:1d a significant amount of plant overgrowth and cebris strewn area~). As the stream passes through Camp George vJest, it travels in a fai :~ly IrJell defined swale that has rock-lined banks. During a field trip on September I, 1973, the dumping of a chemical pollutant was noted comiog from a 24- inch reinforced concrete pipe near a truckyard of the camp. The Welch ditch crosses just below Camp George Wc"t in a ccncrete strLC. ture that has a 16-foot wide opening. Unfortunately, a great percentage of the opening is filled with trasr, debris, and sediment. As Lena Gulch passes through the remainder of Basin 3, it begin-; to cut a deeper channel, in some places cutting through the Piney Creek alluvium to a claystone-like layer beleM. Below Indiana Street, a large amount of concrete rubble has been dumped in the streambed to curtai 1 erosion. Near the culvert passin~J through 1-70, the channel is on the order of 15 feet deep, with more alluvial material at the bottom. Basin 4. Basin 4 is the porticm of South Table Mountain that drains to Lena Gulch above 1-70. South Table Mountain is principally a layered system of basalt on top, with slopes of the Denver formation claystone that lead into the Piney Creck allLviucl. Field tests in this region indicated an infi ltration rate of 0.8 inches per hour. Basin 4 sheds water into Lena Gulch into Basin 4 above Camp GeorSle West for the ent ire reach unt i I 1-70. It is not anticipated that a significant further urbanization of Camp George West wi 11 occur in the futL;re. The non-government areas l ho\.^/- ever, should be monitored carefully so that developments which would cause problems as a result of increases in runoff and erosion can be con t ro 11 ed.