DROUGHT MITIGATION STRATEGY VIA 'RAIN FARMS,' A CASE STUDY FOR SACRAMENTO, CALIFORNIA

California is currently experiencing severe drought, with water years 2012-14 being the driest three-year period of the state historically. Such a drought event is not unexpected, as recorded droughts on similar time scales (e.g, 1929-34, 1976-77, and 1987-92) serve as precedents. Long-term response to multi-year droughts on a municipal level is based on water conversation practices by citizens. However, such an approach does not produce more water. We propose square-mile scale collection of rainwater to mitigate severe droughts, for billions of gallons of water can be harvested per square mile in certain areas of California. The City of Sacramento and Del Norte County are used as a case study showcasing how drought mitigation is possible by using rain as a supplemental water source. In 2012, areas of Del Norte County received 124 inches of rainfall, accounting for 2.16 billion gallons of water per square mile, which potentially could supply 15% of Sacramento’s indoor water usage.

The catchment system for our proposed ‘Rain Farm’ will be a matter of creative engineering, simply requiring a thin food-grade plastic sheet. Another possibility will be simultaneously using the area as a photovoltaic power station to create renewable energy and better utilize the land. Valid concerns are fiscal and environmental consequences of the required infrastructure for rain collection. Water management strategies to reduce desertification of the collection area will be implemented, but most importantly our proposal will lessen other drought-based expenses for California, including costly attempts to manage salt water encroachment in the Sacramento-San Joaquin Delta. Further, if adequate snow pack in the Sierra Nevada Range returns and the drought subsides, collected rainwater could be used to recharge the aquifers proximal to Sacramento via aquifer storage and recovery wells in preparation for the next drought.

The scarcity of water is a global issue. Areas in Columbia, Cameroon, and India average over 400 inches of rainfall annually, which begs the question: Could these countries export rain and aid neighboring countries? David Pyne, renowned hydrological engineer, noted that “water is power,” and rainwater could be powerful as well, for monsoons and rainy seasons around the world could be harnessed and sold as natural resources.