THE WATER RESOURCE INVENTORY IN RECREATIONAL PLANNING 



The importance of water in comprehensive resource planning is clear to all. The man- 

 agement and development of the water resource is a difficult and complex task which must be 

 carried out according to the multiple use concept of public land management. 



In planning for recreational water use, a complete inventory of lakes and streams in a 

 given area is a necessity. Such an inventory ideally provides information about the location and 

 size of the water body; about water volume fluctuations and water characteristics such as clarity, 

 temperature, and pH; and about insect life and the presence of plankton and underwater vegetation. 



To date, any attempts at making such inventories have been confined to the larger lakes 

 and streams. There are many obstacles to the collection of water resource information, par- 

 ticularly in mountainous areas, which are of major interest for recreation. The field season for 

 exploration is often short. Roads may be few, and even trails may be lacking to many of the 

 smaller lakes and streams. Travel on the ground is blocked by snow and ice during much of the 

 year and is strenuous at any time. Also, great fluctuations in water volume leave only a short 

 time in late summer when comparative measurements can be made. The roaring spring torrent 

 mav dwindle to a trickle by fall. 



Thus, a field survey of the smaller lakes and streams is generally too time consuming 

 and costly to be practical. Other possibilities, such as individual air surveys using planes or 

 helicopters, are both expensive and hazardous in rugged mountains. 



A survey made from maps alone is unsatisfactory. The scale of the aerial photography 

 from which maps are usually made is not large enough to allow for identification of some of the 

 smaller water bodies, and much desired detail is not normally included on maps. Meadows are 

 sometimes mislabeled as lakes, and dry ravines are not consistently distinguished from year- 

 round watercourses. 



A step toward the solution of the problem is the use of aerial photographs of 1:20,000 

 scale. Photogrammetric techniques may be used to make rapid and reasonably accurate inven- 

 tories of mountain lakes and streams. By this means, existing maps may be corrected and sup- 

 plemented, and additional information useful for recreational planning may be gathered. 



A TEST OF PHOTOGRAPHIC SURVEY TECHNIQUES 



To test the procedures in a photographic survey, a study was conducted on the North 

 Slope of the Uinta Mountains in northeastern Utah (fig. 1). An attempt was made to collect as 

 much information as possible from the photographs, for use in an initial reconnaissance inven- 

 tory of recreational water resources. The data gained from interpretation of photos was checked 

 for accviracy by ground surveys. The test showed that although some of the information desirable 

 for such a survey can be collected only in the field, a substantial amount of general descriptive 

 detail can be obtained rapidly and at reasonable cost from aerial photographs . 



The study area was fairly typical of mountainous areas offering recreational possibilities. 

 Several hundred miles of streams and several hundred lakes lie within the 677,000 acres studied, 

 most of which is administered by the U.S. Forest Service, although scattered tracts are pri- 

 vately owned. The mountains are composed primarily of quartzites and other sedimentary rocks 

 and have been heavily glaciated, although no glaciers are now present. Elevations range from 



I 



