Flows and Recretion: A guide to studies for river professionals

Home Browse Search

Years of low flows allow vegetation to encroach on river channels, which may affect boatingsafety or castingspace for anglers. Right: Vegetation obstructed visibility and blocked boating routes in California's Pit 5 Bypass Reach at 250 cfs. beaches and other geomorphic features, and no work has addressed direct connections between these features and the quality of recreation experiences in the canyon (GCMRC, 2005). There is a need for more research into how recreation users evaluate biological and physical conditions affected by flow regimes. For example, social science studies can identify important biophysical attributes for certain activities, compare different beach sizes or camp environments, or assess trade- offs between different types of fisheries. However, to do so they need biological and physical scientists to specify alternative futures under different flow regimes. Our experience with interdisciplinary studies suggests it will be challenging to get agreement about those potential futures, even for the purposes of studying recreation users' evaluations. There may be reasons for restoring certain riparian vegetation types, geomorphic features, or associated biological communities to a "natural" condition, but it should not be assumed that this is possible or even desirable in all cases. On regulated rivers, all alternative flow regimes are essentially "designed" or "artificial," and it may not make sense to consider the pre - project regime as the "standard." In most cases, the trade -offs are between alternative futures with different resource conditions and ecologies, or between different combinations of recreation opportunities (Schmidt et al., 1998); a priori value judgments that label certain combinations as being more "natural" is not a scientific position. There may be good reasons to recover specific ecological attributes that were present pre - project, but these goals need to be specified explicitly rather than assumed as "inherently better." Flow regimes have long term effects on biophysical resources such as fisheries. Modeling helps identify flow regimes to improve habitat, but doesn't predict specific changes in fish populations or anglers' fishing success. Above: Bull trout are threatened on some western rivers, where relicensing efforts may suggest habitat improvements. Flows and Recreation: 21 A Guide for River Professionals