Document - Effects of Streamflow on River Trips on the Colorado River in Grand Canyon, Arizona
AbstractEffects of flows on whitewater boating can be profound, but there is little evidence that shows impacts on specific trip attributes. A normative approach developed in other resource management applications is used to develop evaluative information about streamflows for whitewater trips in the Grand Canyon, below Glen Canyon Dam. A mailed survey was completed by 134 commercial river guides and 152 private trip leaders. Questions covered the effects of flows on trip quality and scheduling, quality and safety of rapids, camping, and visits to off-river attraction sites. For positive characteristics, such as the overall evaluation, ratings follow a bell-shaped curve, where flows below about 10,000 cubic feet per second (cfs) and above about 45,000 cfs are considered unsatisfactory, and 20,000-25,000 is the optimum. For negative characteristics, such as the likelihood of accidents, ratings follow a "U"-shaped curve. The study identifies the diversity of attributes affected by flows, evaluates specific effects of flows on those attributes, and presents methods for data collection, analysis, and interpretation. Such information is particularly helpful for developing flow requests, integrating recreation needs with the needs of other resources, and developing flow scenarios for dam operation. Changes in operating regimes for Glen Canyon Dam are being considered, based on this and other research conducted as part of the Glen Canyon Environmental Studies. (DBO)
DescriptionA normative approach was used to develop evaluative information about streamflows for whitewater trips in the Grand Canyon, below Glen Canyon Dam.
Filename - Effects of Streamflow on River Trips on the Colorado River in Grand Canyon, Arizona518.pdf
Size - 857.52KB