Abstract
California faces several uncertainties on how to provide its public a reliable water supply for years to come due to challenges such as climate change, aging infrastructure, population growth, tough water quality standards and environmental regulations. The shortage of a reliable water supply has the potential to have a damaging impact on the economy, the environment and California citizens. The time to come up with creative solutions to address this problem is now. This study showcases the potential for rainwater harvesting as part of the solution to California’s water problems. Case studies of two climatically different locations, namely Sacramento California and Santa Rosa California, are carried out to investigate the effectiveness of this practice. Analyses of local rainfall data, collected from the PRISM climate group, and water use data from city water master plans were used to create a rainwater behavioral model. This model was utilized to evaluate the performance of the rainwater harvesting systems if they were installed at the selected sites. Two operation scenarios were modeled to determine the best option. One scenario consists of a continuous, year-round operation. The other operation features a July through November operation, providing water during dry periods and times of low reservoir supply storage. The study revealed that rainwater harvesting potential substantially varies depending on geographic location and climate. With an average of 13 more inches of rainfall annually, Santa Rosa sites showed far greater potential for effective rainwater harvesting practice than comparable sites in Sacramento. Additionally, though harvesting systems can meet a good portion of demand, large storage facilities to make these systems possible may form an economic barrier between this technology and mainstream building practices at locations with inconsistent rainfall throughout the year.