Flows and Recretion: A guide to studies for river professionals

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Problems with "Blind" Controlled Flow Studies for Boating When controlled flow studies for boating are proposed, the quasi - experimental nature of the effort sometimes leads agency staff or stakeholders to suggest that evaluations should be conducted "blind" (without boaters knowing which flow they are assessing). Although blind studies may increase "confidence" that evaluations are only based on the observed flow, there are several disadvantages (discussed below) that out weigh that advantage. There may be safety concerns in not knowing flows, or the amount of change from one study flow to another, particularly on challenging rivers. Although boaters in a blind study would probably know immediately whether a subsequent flow was higher or lower, information about the magnitude of change could be crucial for deciding whether they have the skill to handle it. Boaters are accustomed to estimating how specific flow changes affect the level of challenge on other rivers; they need similar information on a study river. Knowledge of study flows allows boaters to interpolate between flows or extrapolate beyond them for the flow comparison survey at the end of a study. If they don't know the flows they evaluated, flows between or outside the study flows cannot be evaluated. Boaters often think in terms of cfs, and it is one of the basic metrics they use in describing a boating run (along with gradient, and the height or width of specific drops). Asking them to evaluate a reach and flow without this metric reduces their ability to do so. Just as surfers pay attention to the height of waves or skiers to the depth of snow, quantitative information is something river runners integrate into their description of what they observed. Boaters can make more informed comparisons when they know the flows duringstudies. Right: California's Pit 5 bypass reach at 1,840 cfs (boaters rated six flows from 250 to 1,840 cfs). Eliminating this variable is likely to make them less systematic in their evaluations. Boaters often have a working knowledge of flows on many rivers that may be similar to the study reach; blind studies don't allow participants to capitalize on that knowledge. For example, it may be valuable to have boaters discuss how 500 cfs on the study reach is similar to or different from 500 cfs on another reach (something they can't do if they don't know the flow). Withholding flow information during a study may encourage participants to think the utility or researchers don't "trust" boaters. Accurate data provided to boaters as soon as it is available generally creates a greater sense of cooperation. Blind studies are probably not necessary to alleviate concerns about "strategic bias" (respondents answer questions in line with how they think data will be used). There has been little evidence to suggest strategic biases occur in recreation studies in general, or flow studies in particular. Based on focus group discussions and analyses of study results, differences in evaluations appear to reflect skill, equipment, or type of boating preferences rather than strategic biases. In addition, participants appear to understand that results could be used to develop flow releases, but they also know that requests for higher flows generally work against the likelihood of frequent releases. It is generally in their best interest to evaluate flows accurately so they can determine the lowest flow that provides a particular recreation opportunity. 5 12 Flows and Recreation: 29 A Guide for River Professionals