Flows and Recretion: A guide to studies for river professionals

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Objective Improve precision of estimated flow ranges for boating opportunities by having a panel of boaters evaluate several known (usually controlled) flows. Generally applicable to rivers without a gage or little history of previous use, the idea is to manipulate the independent variable — flow — which introduces a quasi - experimental format to evaluations. Assembled panels may also offer opportunities to roughly explore regional "supply" of similar rivers or "demand" for similar opportunities. Typical approach Level l and 2 information is used to determine flow range and opportunities of interest. Target flow increments are chosen and arranged for a short period of time (if possible). In some cases, the study may capitalize on natural flows instead of controlled flows. Boaters complete a pre- fieldwork survey on their experience and boating preferences, run the river at each flow, and evaluate flows and participate in a focus group after each run. After all flows have been observed, participants make overall evaluations using a "flow comparison" format. Photos and video footage of key rapids and conditions can provide useful documentation, particularly in combination with qualitative focus group notes and quantitative data from surveys. Quantitative ratings (by panels or experts) are commonly made for all relevant opportunities and conditions (see Whittaker et al. (1993) and Whittaker and Shelby (2002) for more detailed information about survey instruments and analysis options). Products Summary of methods and findings in a report. Methods should include descriptions of panel and instrument development. Findings typically include tables and graphs appropriate to the analysis. Appendices typically include 26 I Flows and Recreation: A Guide for River Professionals Controlled Flow Studies for Boating a list of participants, focus group notes, photo gallery, and survey instruments. The methods and findings may be presented as a report supplemental to Phase 1 and 2 reports. Some utilities produce an edited video that highlights study findings with footage of key flow effects and interviews /focus group comments; these need to be coordinated and consistent with report findings. Responsibilities These studies are more complicated and typically require substantial participation by utilities, their consultants, agencies, and stakeholders. Utilities (or their consultants) have primary responsibility, but agencies and stakeholders also play key roles (see sidebar with more detail on these potential roles). Additional issues There are several important issues in conducting controlled flow studies efficiently and effectively (Shelby et al, 1998). Some of these issues become even more challenging on higher gradient rivers with little previous use (Shelby et al. 2004). It is beyond the scope of this document to provide details on these issues, but key considerations are listed below: Study output. The relative precision of qualitative and quantitative data may vary depending upon the size of the panel and how data is analyzed. More precise "flow evaluation curves" or "optimal ranges" come from quantitative surveys of participants, but professional judgments by researchers may be sufficient if maintenance of a panel is difficult. More precise quantitative output becomes important when potential for controversy is high. Other resource studies typically generate specific incremental relationships between flows and resource values (e.g., IFIM studies), so parallel information for recreation is needed if careful assessments of trade -offs between resources are anticipate d. Sample. Sample issues trade -off "representativeness" against potential cost or logistical complexity. More participants improve precision, but they also increase complexity and make it difficult to maintain participation through a multi - day study. Most studies use "purposive sampling," inviting participants based on their 1) skill and safety record, 2) proximity to the river, and 3) ability to evaluate a diversity of whitewater opportunities. This requires close coordination with stakeholder groups. Flow control. This includes technical limitations of dams as well as administrative, political, and legal constraints, which should not be underestimated (Shelby et al., 2004). Technical limitations on releasing precise flows or narrow increments can be more problematic on higher gradient rivers, because small changes in flow may create substantial changes in difficulty. Lack of upstream storage may also constrain flow control (insufficient water in dry years; too much in wet years). Many studies require careful timing and contingency plans, which also may have administrative, political, or legal constraints. Flow choice. Choosing the number and increments of flows is a case -by -case decision that generally depends on Level 1 and 2 findings and requests from other resource specialists (e.g., fisheries researchers, etc.). Three to four flows are commonly assessed in these studies. Impacts on other resources. Timing of boating flows may be a major concern for other resources. If possible, releases should be timed to minimize adverse impacts to aquatic biota and power generation schedules, or at least to assess potential impacts (which may include biophysical benefits such as building beaches, cleaning spawning beds, introducing woody material, or removing encroaching vegetation).