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I II. SOILS -- The S.C.S. has performed a detailed soils 'investigation of the Delta- Mont"ose area ("Soil Survey Delta-MontroSE! Arl:a, Colorado", S.C.S.; 1967). Four general soil associations predominate in the study '~atershed. In the lower basill, the Billings-Christianburg association is made up of deep, nearly level and ')ently sloping, fine to moderately fine textured sons on alluvial fans, fl 00<1 plains, and terraces. The Chi peta Persayo associ ati on is cons tituted of shallow, nearly level to hilly, fine to moderately finely textur,:d soils deri'led from shale or mudstone. The Bostwick..Cerro association is found 'in the uppe," basin areas. It is composed of deep, gently sloping, moderately fine textured soils on alluvial fans .and valley side slopes. The rock outcrop .. Travess'illa association is composed of bare rock outcrop and shallow, ro~ll ing to stE!ep moderat,:'ly coarse textl,,'ed soils found on hills, ridges, and sides of mesas (see Genet'al Soil Map, FigUl": 8). . An attempt was made to incorporate data derived in the "Geolog'jc Hazards, Subslll"face Soi I-Groundwater Investi ga ti on and General FOllnda tion De~;-j gn Criteri a Repol't". The data was generally consistent with the S.C.S. report, and, as such, was used as a source of additional infoY'lnation. However, due to the 1 imitE!d area covered by this report, and its focus on geologic hazards and genenll construction criteria, as opposed to hydrologic properties, the S.C.S. data lias primari ly reI i edupon in determi ni ng soil runoff properti es" Infiltration rates which would be maintained after a I-inch thllnderstonn are reeded for the S.C.S. runoff procedure as modified by the Bureau of Reclamation. The S.C.S. soil information canta'ins data on permeabil ity ranges 9