Existing Conditions of Chollas Creek Invasive Species and Recommendations for Effective Management

This study, conducted in collaboration with SDSU course Geography 570 and SDSU’s Sage Project, investigated the distribution of three invasive perennial plant species—Giant Reed (Arundo donax), Fountain Grass (Pennisetum setaceum), and Fan Palm (Washingtonia robusta)—along Chollas Creek between Market Street and 47th Street in the Encanto neighborhood of San Diego. Field surveys were conducted to identify and map invasive plant populations using ArcGIS Pro. Results showed that invasive species occupied approximately 22% of the project area, with Giant Reed accounting for the vast majority of invasive vegetation and occurring primarily west of 49th Street. Current literature was reviewed to identify and evaluate effective management strategies for invasive species removal. Based on overall effectiveness, cost, and minimizing impacts to water quality, the cutting-and-tarping method was identified as the preferred management strategy over herbicide-based approaches. These findings provide valuable information for habitat restoration efforts, helping inform decision-makers and community organizations working to improve ecological health, reduce flood risks, and strengthen climate resilience within the Chollas Creek watershed.