Journal of Student Research 2018

Journal Student Research

80

Precipitation was also low during the post-BMP summers of 2012 and 2013. In contrast, the summer mean exceeded long-term precipitation trends in 2014-16 (Fig. 7). Although mean summer precipitation was low in 1999, mean summer flow was high compared to other years that had much higher precipitation (Fig. 7). For instance, mean summer flow was much lower during the post-BMP years 2012, 2013, and 2017 under similar summer precipitation conditions (Fig. 7 and 8). Flow-weighted summer mean concentrations of total P were slightly higher in 1999 relative to post-BMP years (Fig. 7). However, there was no relationship between total P concentration and summer precipitation (Fig. 8) Figure 7. Total summer (June-September) precipitation and summer mean event flow, total phosphorus (P), and soluble reactive P (SRP) concentration for storm sewer 2 during various years. Red column denotes before BMP implementation while blue columns represent year after BMP implementation. Horizontal blue line represents mean summer precipitation over 10 years.