Objective: Investigate the feasibility of a rainwater collection system to provide for a sustainable source of non-potable or potable water at a potentially isolated solar observatory site (likely Mauna Loa Observatory in Hawaii).

Introduction: The National Center for Atmospheric Research/High Altitude Observatory (NCAR/HAO) proposes to build a solar observatory comprising a trio of instruments for studying solar coronal magnetism.

Methods: Each square foot of collection surface will experience approximately 0.62 gallons of runoff from 1 inch of rainfall (12 in x 12 in x 1 in = 0.62 gallons). Some water will be lost to evaporation, splashing, overflows, and other inefficiencies. Monthly normal rainfall data from 1981-2010 is available from NOAAs Mauna Loa weather station. Demand is estimated based on two observers working on site using water for toilets, sinks, washing instruments, and drinking. Storage is sized to meet water demand through the longest expected interval without rain. Water is collected for storage when rainfall volume exceeds the demand.

Conclusions: Monthly rainfall volumes exceed demand; making
collection, storage, and use, feasible at the Mauna Loa site. A storage
tank sized for two months of demand would be reasonable to maintain an
adequate water supply during a potential summer drought.


Architecture | Civil and Environmental Engineering


Scott Sewell

Lab site

National Center for Atmospheric Research (NCAR)

Funding Acknowledgement

This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).



URL: https://digitalcommons.calpoly.edu/star/230


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