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Show CHAPTER V FACTORS DETERMINING THE RECREATIONAL BENEFITS OF RESERVOIRS LOCATION In the Colorado River Basin, where few lakes occur naturally, the creation of large water bodies is of great recreational importance. This is especially true in the large, arid, lower portions of the basin. The higher portions of the basin are fairly well supplied with clear, year- round streams and attractive small lakes. Here reservoirs play a much less important role in the general recreation picture. On the whole, a reservoir on a mountain stream will be of less benefit for fishing than one on a lowland stream, at least in the Colorado River Basin, and may be seriously detrimental to fishing. One reason for this is that the mountain streams usually are silt- free, and provide a fair- to- excellent habitat for fish even before construction of the reservoir. Another reason is that in the Colorado River Basin the majority of the potential mountain reservoirs as now planned will have a large drawdown. Thus, fluctuating shore lines, with their drastic curtailment of aquatic food production, are substituted for the relative stability of the original mountain stream condition. As will be shown, the potential productivity of a reservoir is rather closely limited to the area of shallow bottom that is kept at a favorable depth for plants, rather than by mere volume of water. The productive area of a proposed deep reservoir usually will occur only along the shallow margins, whereas the productive area of the mountain stream that it is to replace usually comprises the entire stream bed from bank to bank. Extreme examples occur, particularly in Colorado, wherein existing fish production and extremely important attendant recreational values on various beautiful mountain streams would be jeopardized by the substitution of relatively barren reservoirs with bleak, fluctuating shore lines. One of the best of such examples is afforded by the Gunnison River, which is one of the finest natural trout fishing streams in the United States. Reservoirs on the upper reaches of this river and its major tributaries would, in most cases, destroy more recreational values than they could supply. On the other hand, reservoirs near the headwaters of these tributaries sometimes bring an increase in production and furnish good fishing, as in the case of the Taylor Park Reservoir near the upper end of the Taylor River. In this case, improvement may have resulted from the substitution of a large body of water with extensive, shallow shore lines for a previously existing small streamway. It illustrates again the need of estimating the effects of each proposed reservoir separately. Reservoirs in national forest primitive areas and other high mountain country usually add little if anything to the general recreational value of the area and frequently destroy more than they create. They alter natural conditions just as do roads and other facilities. Construction of the dam requires roads for the transportation of men, materials, and machinery. Aggregate or fill for the dam is usually obtained as near as possible to the dam site, eliminating a piece of wilderness. Stock piles and construction camps take more. Tunnels and canals for transporting the water from the reservoir to the area of use further spreads the effects of the project. The cuts and fills required for highline canals on mountainsides are frequently visible for long distances. This is not all. The mere fact that these works exist eliminates the important intangible value of an area undisturbed by works of man. There are a number of instances in the Colorado Basin where the economy of the nearby communities is dependent to a large degree on the income from fishermen and vacationists attracted to the region from considerable distances. If the rarer trout stream fishing is replaced by the more com- 102 |
