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<br />quality of a particular recreation activity which takes place in the <br />stream. <br /> <br />SlNGLE CROSS SECTlON METHOD <br /> <br />I <br /> <br />This method requires that only a single cross sectional measurement <br />be taken across a stream. The product of such an approach is a deter- <br />mination of the lowest flow acceptable for recreation. The approach is <br />based on the assumption that a single cross section, properly located, <br />can define a minimum flow requirement. Such a cross section is located <br />at an area di sp 1 ayi ng the 1 east depth across the entire stream. When <br />this area provides minimum depths for boat passage, the flow at this <br />level may be defined as a minimum acceptable flow. lt is assumed that <br />when sufficient water to support boating is available in these critical <br />areas, other areas will have sufficient water to support most of the <br />other instream recreation activities. This approach is best applied. to <br />those streams in which flows are expected to be higher than the minimum <br />most of the time. <br /> <br />'. <br /> <br />'. <br /> <br />Criteria for this approach are set forth in Table 1. Criteria have <br />been developed for boating activities only, but for various types of <br />boating craft. Only minimum criteria are presented because this <br />approach provides information on "minimum flows." Criteria are measured <br />in terms of stream depth and width. Velocity is not considered because <br />a minimum velocity is not considered necessary for this approach. <br /> <br />Table 1. Required stream width and depth for <br />various recreation craft as determined <br />by single cross section method. <br /> <br /> Recreation Required Required <br /> Craft depth (ft) width (ft) <br /> Canoe-kayak 0.5 4 <br /> Drift boat, row boat-raft 1.0 6 <br /> Tube 1.0 4 <br />, Power boat 3.0 6 <br />" Sail boat 3.0 25 <br /> <br />The criteria of Table 1 are minimal and would not provide a satis- <br />factory experience if the entire river was at this level. However, the <br />cross section measured for this method is the shallowest in the stream <br />reach. Therefore, these minimum conditions will only be encountered for <br /> <br />~ : <br /> <br />3 <br />