Poster Presentation Society for Freshwater Science 2026 Annual Meeting

Uncovering the ecological upshots of uncovering urban streams. (135822)

Brynn E Kayhill 1 , Lily A Smith 1 , Deb S Finn 1
  1. College of Natural and Applied Science, Missouri State University, Springfield, Missouri, United States

Ecological restoration of urban streams has become common globally. However, many restoration projects lack quantitative measures of success. An engineering-intensive form of restoration involves “daylighting” of buried, culverted reaches, which typically occur in high-density urban areas. The City of Springfield, Missouri (USA) is currently implementing a daylighting project on a headwater stream that has been culverted for nearly a century. We are using macroinvertebrates to evaluate trends in water quality in two stream reaches, one ~3 km and the other ~8 km downstream from the project. The watershed of the upper reach is nearly 100% urbanized, and the lower reach ~85% urbanized. To assess the ecological effects of the daylighting project, we have thus far collected macroinvertebrates and basic abiotic data both before and during the restoration activities. We collected macroinvertebrates semi-quantitatively from three habitats (riffles, pools, and rootmats) and identified them to the highest possible taxonomic resolution. “Before” data indicated relatively good physical habitat structure and high taxa richness overall (75 unique taxa), although a third were Chironomidae, and Plecoptera were absent, indicating poor water quality. A pattern of decreasing specific conductivity (595-533 uS/cm) and increasing taxa richness (43-52) between upstream and downstream sites suggested some improvement of water quality with downstream distance. Macroinvertebrate data are still being processed for the “during” samples, but preliminary results indicate minimal change in the communities between the two time periods. This is likely evidence of resistance and/or resilience of invertebrates already conditioned to the effects of urbanization to any disturbance associated with the ongoing daylighting project. Abiotic characteristics were also comparable between the two time periods. We will continue quantitative monitoring of these sites after the daylighting project is complete, and we hypothesize gradual improvement of water quality over time. Even if ecological effects are minimal, there are other advantages to daylighting urban streams, including a variety of socio-economic benefits.