Field Validation of Intermittent Stream Reference Sites in Eastern South Dakota

Vander Vorste, R., E. Rasmussen, and N.H. Troelstrup Jr.

Intermittent streams link the surrounding habitat to downstream waterbodies. These streams also provide vital habitat for threatened and endangered species. In South Dakota, approximately 90% of all flowing waters are categorized as intermittent. The majority of these streams are located in prairie regions, which are continuing to disappear, generating major concern for intermittent streams. The objectives of this study were to validate intermittency and habitat quality of reference streams chosen by ATtILA for the Northern Glaciated Plains ecoregion in Eastern South Dakota. Sixty stream sites were validated for intermittency and habitat quality. Intermittency was determined using the North Carolina Assessment of Hydrologic Permanency. Habitat quality was evaluated using modified Peterson’s Riparian, Channel, and Environmental Inventory (RCE) protocol. In addition, we collected macroinvertebrate samples and measured habitat parameters if water was still present in the streams. The majority of streams fell inside the range (19-30) for intermittency using the North Carolina method. Regionalizing the North Carolina Assessment method will better predict intermittency for streams in the Northern Glaciated Plains. ATtila predicted watershed condition scores that corresponded with the actual field scores from the RCE. Sites that were predicted to be in good quality scored good to excellent (154-340) using the RCE field inventory. Invertebrate and habitat data were collected for 37% of the 60 streams. Intermittent streams ranged from 0.1-6.6m in width and 0.5-50cm in depth. Future sampling efforts will focus on more intensive sampling of biological communities and habitat to describe reference quality intermittent streams. (Presentation pdf)