Rainwater Harvesting: A Simple Means of Supplementing California's Thirst for Water

EPA Grant Number: SU832493
Title: Rainwater Harvesting: A Simple Means of Supplementing California's Thirst for Water
Investigators: Chin, Andrew , Cusick, Roland , Gebelin, Steven , Guillen, Greg , Matsumoto, Mark , Ogunyoku, Temi , Tam, Kawai
Current Investigators: Chin, Andrew , Cusick, Roland , Guillen, Greg , Matsumoto, Mark , Ogunyoku, Temi , Tam, Kawai
Institution: University of California - Riverside
EPA Project Officer: Nolt-Helms, Cynthia
Phase: I
Project Period: September 30, 2005 through May 30, 2006
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2005) RFA Text |  Recipients Lists
Research Category: P3 Challenge Area - Water , Pollution Prevention/Sustainable Development , P3 Awards , Sustainability


(1) Technical challenge to sustainability: Water is a highly valuable yet scarce resource. Arid regions are especially hard hit by water shortages. Areas such as Southern California are faced with the dilemma of large populations and low local water supply. In order to meet these huge demands, water must be obtained from outside sources. This spreads water supply strain to outside watersheds. Urban sprawl has paved over large areas of land which increases runoff. This also results in the need for increased water distribution measures. The combination of urbanization and population growth has greatly reduced the amount of local available water.

(2) Development of an innovative design approach with technical merit to address the challenge: This project will design and develop methods and technologies of rainwater harvesting to supplement local water supplies including proposed policies and incentives to help implement the technologies.

(3) Discussion of how the challenge and proposed design relate relating to sustainability including people, prosperity, and the planet: Challenges include actual implementation of a locally unproven conservation design. Rooftop particulate matter, which may carry sorbed contaminants, can accumulate in the storage tank and will need to be examined as a possible source of water pollution and pumping hazard. The capture and use of rainwater for use as local water supply will offset the demand placed on outside water sources. Rainwater can be harvested and utilized at the same location thus reducing the need for the expansion of water distribution systems. For example, a local warehouse harvests rainwater and uses it for irrigation and toilets. This has the following effects: 1) the warehouse purchases less water from the local municipality (saving money); 2) the local municipality distributes less water to the warehouse (reducing distribution requirements); 3) less demand is placed on outside watersheds; and 4) less runoff is created by the impermeable warehouse (reduces flooding events and strain placed on wastewater treatment facilities, limits amount of runoff leaching chemicals to groundwater).

(4) Description of strategy for measuring results, evaluation and implementation: Results can be measured in terms of acre-feet of water harvested and dollars saved. Evaluation can be measured in terms of a cost-benefit analysis and the quality of water harvested. Implementation can be measured in terms of the willingness-to-pay for principal costs, the ease of retrofitting existing structures, and need to conserve water in local areas.

(5) Description of how P3 concepts will be implemented as an educational tool at the university: A team consisting of fourth year undergraduate environmental and chemical engineers will develop the relevant rainwater harvesting technologies, policies, and incentives over the course of a two-quarter design course.

Supplemental Keywords:

drinking water, groundwater, land, precipitation, chemical transport, health effects, ecological effects, ethnic groups, cumulative effects, chemicals, toxics, particulates, metals, organics, DNAPL, NAPL, acid rain, effluent, discharge, dissolved solids, ecosystem, scaling, alternatives, sustainable development, clean technologies, innovative technology, renewable, waste reduction, waste minimization, public policy, community-based, observation, preferences, public good, socio-economic, conservation, environmental assets, environmental chemistry, social science, hydrology, mathematics, modeling, monitoring, analytical, surveys, measurement methods, Southwest, Southern California, CA, EPA Region 4, EPA Region 7, EPA Region 8, EPA Region 9, buildings, schools, commercial, business,, RFA, Scientific Discipline, Sustainable Industry/Business, Sustainable Environment, Technology for Sustainable Environment, Ecology and Ecosystems, Urban and Regional Planning, Environmental Engineering, sustainable water use, urban planning, environmental sustainability, recovery, conservation, cost benefit, sustainable urban environment, resource recovery, water conservation, rainfall harvesting, environmental cost analysis, environmental education

Progress and Final Reports:

  • Final Report