Building a Freshwater Supply Portfolio: Relieving Drought Conditions With Minimal Environmental Damage in California

Abstract

California is considering ways to stabilize freshwater usage in the residential, commercial, and agricultural sectors. Although existing water conservation measures are advancing with technology, they won’t be enough to offset future water consumption. This thesis examines the potential of Seawater Desalination Reverse Osmosis (SWRO), water by rail, and rainwater harvesting as long-term and sustainable sources of fresh water. The primary question this research addressed is: Which of these alternatives could have the smallest environmental impact, and greatest return on investment for California stakeholders? To determine if the water output would be worth the potential negative environmental effects, I hypothesized that desalination would be the most cost-effective freshwater alternative by volume compared to water by rail or rainwater harvesting from a financial appraisal perspective. Additionally, water transport by rail, if limited to avoid depleting sources, would be economically sound and environmentally sustainable. I further hypothesized that rebuilding the soil and natural water storage through use of rainwater harvesting would have positive economic benefits, taking into account environmental paybacks. Water by rail has the potential to be implemented quickly while maintaining the flexibility to supply water to different parts of the state. This flexibility makes it an ideal solution for long-term emergency drought relief, and could easily fit within California’s annual drought funding plan. The high transportation cost of this solution is the primary limiting factor, which diminished the feasibility of everyday use. The second option, desalination, provides the largest amount of fresh water. However, desalination facilities are extremely expensive to build. Desalination has the potential to be the environmentally damaging option due to the marine impacts of water intake and disposal, its energy intensity, and its utilization of non-recyclable single-use items. Careful site planning and technological innovation are lessening the these environmental impacts. The last option, rainwater harvesting, would merely supplement to the state’s water supply at first, but could have the greatest positive impact over time. Rainwater harvesting has aided in restoring the natural small water cycle when executed in other parts of the world. Large scale implementation, and monitoring the results across the state of California may be difficult. A multi-faceted approach was adopted to determine which of these options is ideal. The start-up and running costs of each served as the basis for determining the average cost of water to the consumer. This information was then used to discuss net present value, and which stakeholders could assume profitability. A cost benefit analysis was the final step in this study. The analysis was used to weigh the positive and negative impacts on the environment and decide which solution would not only be sustainable, but also economically feasible. This outcome of this study showed that a combination of all three sources would be most useful in meeting the needs of the state in varying capacities. Further, these analyses could aid policy makers in budgeting for long-term alternative water sources and emergency drought relief. This work will be significant in progressing California’s ability to proactively mitigate drought conditions, without further inciting harmful environmental impacts and depleting the supply of groundwater.