Water Resources Collections and Archives

The effects of golf courses on water quality and biotic integrity have been of interest to researchers, managers, and companies (e.g. pesticide producers) since the 1980’s. In Milliken Creek, Napa, CA the impacts of golf courses on water quality are of special concern because of the creeks reputation of being one of the last few streams in Napa city to have a robust Steelhead population and it runs through a golf course. In this study I use benthic macroinvertebrates and the California Streamside Biosurvey to investigate potential effects of Silverado Country Club golf course on the health and integrity of Milliken Creek. I collected three benthic macroinvertebrate samples and conducted visual physical habitat surveys at four sites (n=12 total), upstream, downstream, and two within the course. I found no significant differences between the biotic index scores among the sites (p=0.29, d.f.=11, F=1.47) and slight differences in % EPT, taxa richness, and physical habitat. Based on the indices I was unable to show any significant effect of the golf course on benthic macroinvertebrates in Milliken Creek. However, I am unable to separate the effects of differences in habitat diversity among the sites and effects from the golf course. Therefore, further study is needed before we can say with certainty that there is not an effect. This study stresses the importance of reference sites and pre-disturbance or pre-restoration project benthic macroinvertebrate data is very important to understanding impacts, assessing success of restoration techniques, and making goals for restoration projects.