Constrained streams for biological integrity in California - median CSCI predictions by HUC12 watershed

Stream management goals for biological integrity may be difficult to achieve in developed landscapes where channel modification and other factors impose constraints on in-stream conditions. To evaluate potential constraints on biological integrity, we developed a statewide landscape model for California that estimates ranges of likely scores for a macroinvertebrate-based index that are typical at a site for the observed level of landscape alteration. This context can support prioritization decisions for stream management, like identifying reaches for restoration or enhanced protection based on how observed scores relate to the model expectations. This dataset is a shapefile of the model results for California that shows summarized median predictions for the California Stream Condition Index (CSCI, Mazor et al. 2016) aggregated by HUC12 watersheds. The medians indicate the most likely CSCI scores across all NHD flowlines in a watershed as a function of landscape development only. Note that these values are not the same as predicting biological condition in the absence of field data where bioassessment scores are estimated using all available data. Here we predict CSCI scores only as a function of landscape development to identify conditions that are expected given watershed alteration. All data are considered draft products that are currently under review. Details on modelling and data are in a manuscript under review in Freshwater Science.