From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / Southwestern rivers are few in numbers and low in discharge. The physiographic and climatic reasons for this are discussed. To the east of the 100th meridian, rainfall is reliable and agriculture is stable; while to the west, there is a chronic deficit of water, droughts are frequent and lifestyles must be accordingly adjusted. Dam building results in greatly increased silting behind the dam in both the river and its tributaries and accelerated channel erosion below the dam. Total flow must also decrease due to withdrawals and increased evaporation from reservoirs. The correction of apparent errors in measuring the virgin flow of the Colorado River now indicates that this flow is about 15 maf/yr. Current legal allocations total 17.5 maf/yr of river water, including the central Arizona project (cap), which will withdraw 1.2 maf/yr. While the river is being dammed and overallocated beyond all reason, the water table is being mined at the alarming rate of 20 ft/yr. In central Arizona, it has dropped to about 250 ft below the surface, and even if all withdrawals ceased immediately, it would take many centuries of of desert rains before it would return to its former level of 50 ft. The cap water will cancel only about 1/2 of this overdraft annually. A glance at the phoenix area today shows that rain follows neither the farmers plow nor the subdividers bulldozer.

From the Proceedings of the 1972 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 5-6, 1972, Prescott, Arizona / Increased useer intensity of the Colorado River through Grand Canyon National Park and Monument required the national park service and the Colorado River outfitters association to adopt new policies to improve the quality of river trips and to protect the river. This study was undertaken to gain a greater awareness and understanding of visitor expectations, perceptions, interactions, satisfactions and dissatisfactions by analysis of response to a questionnaire mailed to a random sample of 2,622 past river runners from which a 65 percent return was received. Analysis of individual question tabulation and multivariate data-cluster analysis were performed. Users found crowding or user density to be at least tolerable. The largest group of runners were average in wilderness or other activities, and low relative to less strenuous activities. A large group of runners had relatively little experience in the wilderness. A large group of runners enjoyed the trip, desired more regulations, and were moderate about taking more trips. A large group rated the trip as a wilderness adventure which provided the opportunity to 'get away'. Cluster analysis is shown to be a useful tool of policy-making institutions.