Oral Presentation Society for Freshwater Science 2026 Annual Meeting

 Monitoring long-term water quality benefits of urban stream restoration (135188)

Kira D Burnett 1 , Shannon L Speir 1
  1. University of Arkansas, Fayetteville, ARKANSAS, United States

Urbanization without conscious environmental planning can result in the degradation of stream ecosystems. This tends to result in urban stream syndrome, which is often characterized by increased sediment and nutrient loading, decreased biodiversity, elevated flashiness, and overall water quality degradation. As such, stream restoration practices are often implemented to address urban stream syndrome. Commonly used restoration practices include applying natural channel design to alter a stream’s geomorphology and stabilize eroding channels and establishing diverse riparian vegetation to filter pollutant inputs. However, the benefits of restoration are not often quantified due to a lack of post-restoration monitoring, making it challenging to determine what restoration success looks like. Therefore, we monitored Mullins Creek, a partially restored urban stream in Fayetteville, Arkansas, for physical and chemical parameters. We sampled five sites in the watershed - two sites upstream of the unrestored reach, one site within the restored reach, and two downstream sites - for dissolved oxygen,  nitrate and nitrite (NO3-N + NO2-N), ammonium (NH3-N), specific conductivity, soluble reactive phosphorus, temperature, and turbidity. Importantly, there has been no active maintenance of the restoration since its establishment. Ten years post-restoration, we found that all parameters met Clean Water Act standards in 2024, including turbidity which exceeded limits in the previous year. We did document substantial variation in nutrient concentrations between years, with phosphorus and nitrate showing fewer extreme values in 2024 compared to 2023. The year-to-year variability indicates that the restoration may no longer be resilient and able to maintain water quality under typical interannual hydrologic variation. This year-to-year variation in water quality in Mullins Creek suggests that initial restoration benefits may degrade without continued management, highlighting the need for adaptive maintenance strategies to sustain water quality improvements in urban streams.