Water-Resources Investigations Report 03-4221
U.S. Geological Survey Water-Resources Investigations Report 03-4221, 44 pages (Published 2003)
By Anne Marie Matherne and Nathan C. Myers
Prepared in Cooperation with the NEW MEXICO DEPARTMENT OF TRANSPORTATION
This report is available online as a citation and a group of images at the USGS Publications Warehouse.
Following a 500-year flood in June 1965, New Mexico Highway 555 was constructed in its present (2000) configuration through the Canadian River Valley. During road construction, the river was channelized over several reaches. A 20-year recurrence- interval flood in 1999 damaged several sections of roadway. This study examines how changes in channel morphology associated with channelization may have contributed to damage caused by the 1999 floods by examining how different cross-sectional channel morphologies contribute to the effects of small- (bankfull and flood-prone) and larger (20-year recurrence-interval) magnitude discharges. The results indicate that in channelized reaches, channels that may effectively accommodate small-magnitude floods may be ineffective at containing larger magnitude floods. In addition, the 1999 stream channel overall had deepened since 1965. This deepening was most pronounced upstream from the most flow restrictive of the channelized reaches.
Geomorphologic and hydraulic data were derived from level-survey measurements at 10 channel cross sections and 10 channel slopes on the Canadian River and from digital elevation models developed from aerial photographs taken June 23, 1965, and June 1, 1999. A comparison of data derived from the 1965 and 1999 aerial photographs indicates that the Canadian River channel in the study area was shorter, deeper, steeper, and less sinuous in 1999 than in 1965. Prior to construction of New Mexico Highway 555, the zone of active-channel migration encompassed the entire width of the Canadian River Valley in the upper part of the study area. Streamflow-control structures designed to protect the road from erosion and deep, narrow stream channels built during construction of New Mexico Highway 555 now constrain the channel and have reduced the amplitude and frequency of channel meanders. Major channel modifications include channel straightening and elimination of meanders at cross sections CR4B and CR6B, gabion construction at cross sections CR3 and CR7, and construction of a bridge at cross section CR5.
The Coal Canyon debris-fan deposit, adjacent to the Canadian River channel where it parallels New Mexico Highway 555 downstream from cross section CR7, appears to effectively channelize the Canadian River along this reach, much like the artificially confined channel at cross section CR4. The deposit also causes consequences similar to the channelized reach at cross section CR4 in terms of increased potentia] sediment-transport capacity at large discharges.
Abstract
Introduction
Purpose and scope
Description of study area
Methods of study
Previous studies
Acknow ledgments
Precipitation, streamflow, and relation to aerial photography
Effects of channel changes on geomorphic and hydraulic characteristics
Geomorphic and hydraulic characteristics of the channel in 2000
Comparison of geomorphic and hydraulic characteristics of the channel in 1965 and 1999
Natural channelization
Summary and conclusions
Selected references
Glossary
This report is available online as a citation and a group of images at the USGS Publications Warehouse.
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