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<br />Impacts From Erosion
<br />The erosion of the South Platte River has consequences, Damages experienced
<br />
<br />include the following:
<br />
<br />V I II-9
<br />
<br />Exposed utility lines
<br />Br idge pi er scour
<br />Caving river banks
<br />Eroded trees and resulting debris
<br />Lost agricultural land
<br />Breached gravel pits
<br />Erosion downstream of dams and drop structures
<br />Head cutting on tributaries
<br />Lowered groundwater tables
<br />Increased channel capacities
<br />
<br />~~,_I.'.I.I:"I_(I.._f_1 ~k:..f.-1._II'" CV~~_[~~..
<br />
<br /> -
<br /> .. SAND CREEk AND
<br />. CLEAR CREEK
<br />w
<br />z
<br />~ ..
<br />.
<br />z
<br />w SAND CREEl< FIGuRE VIII-/
<br />u
<br />. ..
<br />w
<br />~
<br /> BED MATERIAL
<br /> ..
<br /> . SIZES
<br /> ..., 0.01 ... ,~ 'u ..
<br /> ....,,. Sllf
<br />
<br />
<br />REFERENCES - SECTION VIII
<br />
<br />Sediment Load
<br />The sediment load of the South Platte River in the 40 mile study reach,
<br />prior to construction of the Tri-Lakes (Chatfield, Bear Creek and Cherry
<br />Creek Reservoirs), is shown in Table VIII-3.
<br />
<br />Colorado Geologic Survey, "Sand, Gravel, and Quarry Aggregate Resources,
<br />Colorado Front Range Counties," Department of Natural Resources, 1974.
<br />
<br />Hunt, C.B., "Pleistocene and Recent Deposits of the Denver Area," U.S.
<br />Geological Survey Bulletin 996-C, 1954.
<br />
<br />TABLE VIII-3
<br />SEDIMENT YIELD - SOUTH PLATTE RIVER
<br />
<br />Annual
<br />
<br />Sed iment
<br />Tons
<br />330,000
<br />40,000
<br />300,000
<br />150,000
<br />100,000
<br />80,000
<br />
<br />1,000,000
<br />
<br />Load
<br />
<br />Hurr, R.T., Schneider, P,A., Jr., and Minges, D.R., "Hydrology of the South
<br />Platte River Valley, Northeastern Colorado," Colorado Water Resources
<br />Circular No. 28, prepared by USGS with CWCB and the Colorado Division of
<br />Water Resources, Office of the State Engineer, Denver, Colorado, 1975.
<br />
<br />River
<br />South Platte River
<br />Bear Creek
<br />Cherry Creek
<br />Sand Creek
<br />Cl ear Creek
<br />Other tributaries
<br />
<br />Locat i on
<br />Chatfield
<br />Mouth
<br />Mouth
<br />Mouth
<br />Mouth
<br />Mouth
<br />
<br />Stevens, M.A., "Final Report, Stream Stabil ity Investigation, South Pl atte
<br />River, Chatfield Dam to Baseline Road," November 1983.
<br />
<br />South Platte River
<br />
<br />Henderson
<br />
<br />Within Denver, the sediment load has been reduced 95 percent due to Tri-
<br />Lakes, At Henderson, the estimated sediment load has been reduced 8D per-
<br />cent, to 200,000 tons/years.
<br />
<br />Turner, A.K., "Surficial Geology Investigations and Evaluation of the Sand
<br />and Gravel Deposits, Brighton Quadrangle, Colorado," 1974.
<br />
<br />The size distribution of the sediment for five sampling points is shown on
<br />Figure VIII-I.
<br />
<br />U.S. Bureau of Reclamation, Project Files on Channelization of Middle Rio
<br />Grande, Flaming Gorge Dam, Sedimentation Section, Hydrology Office, Project
<br />Investigations, 1957 and 1958.
<br />
<br />Wright Water Engineers, Design Memorandum, 1984.
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