Design of a Water Tower System for Rural Water Supply: A Case Study of an Ecuadorian Village

Keywords: Rural water towers, Ecuadorian wood, rural water systems, material characterization, structural analysis

Abstract

Rural community water supplies often require the construction of a village water tower. Safe tower design requires careful planning and properly selected materials. In remote villages, transport of concrete or steel materials is cost prohibitive, and locally sourced construction materials are required. This paper presents a case study of a remote Ecuadorian village in the Amazon which used locally available hardwood (referred to locally as “Ecuadorian ironwood”) for water tower construction in conjunction with a local aid-organization. Typical samples of the wood were obtained and important structural properties measured. Wood identification was attempted, but matching mechanical properties and optical microscopy imaging to known woods was inconclusive. Using international building codes, an existing tower design was evaluated for principal failure modes. Because the tower was originally designed without verifying the material’s mechanical properties, the tower was found to be far overdesigned. By considering water flow requirements for various village sizes, this paper shows how the overall tower height, material thickness, and overall material quantity can be reduced while still maintaining adequate factors of safety. By reducing the amount of required material, villager effort and time are significantly reduced in harvesting the required wood from the forest. The measurement and design process in this paper could be replicated for other rural development projects which rely on locally available, but possibly imperfectly characterized, materials for engineering projects.

Author Biographies

Samar Malek, United States Naval Academy
Assistant Professor, Mechanical Engineering Department
Patrick Caton, United States Naval Academy
Professor, Mechanical Engineering Department

References

ADINA R&D Inc. ADINA Theory and Modeling Guide Volume I: Solids and Structures, Watertown, MA 02172, USA; 2015.

American Society of Civil Engineers, 2003. Minimum Design Loads for Buildings and Other Structures. Technical Report. American Society of Civil Engineers. Reston, VA.

Arnalich, S., 2010. Gravity Flow Water Supply: Conception, Design and Sizing for Cooperation Projects.

ASTM International, 2007. Standard Test Methods for Specific Gravity of Wood and Wood-Based Materials, ASTM Standard D 2395-07a. Technical Report. ASTM International. West Conshohocken, PA.

ASTM International. Standard Test Methods for Small Clear Specimens of Timber, ASTM Standard D143-14, 2015. Technical Report. West Conshohocken, PA.

ASTM International. Standard Test Methods for Mechanical Properties of Lumber and Wood-Base Structural Material, ASTM Standard D4761-13, 2013. Technical Report. West Conshohocken, PA.

Bond, B., Hammer, P., 2002. Wood Identification for Hardwood and Softwood Species Native to Tennessee. Agricultural Extension Service, University of Tennessee.

Fair, G. M. Geyer, J. C., and Okun, D. A., 1966. Water and Wastewater Engineering, Volume 1: Water Supply and Wastewater Removal. John Wiley and Sons.

Forest Products Laboratory, 2010. Wood Handbook – Wood as an Engineering Material. Technical Report. United States Department of Agriculture Forest Service. Madison, Wisconsin.

International Code Council, 2012. International Building Code. Technical Re- port. International Code Council. Country Club Hills, IL.

Jordan, T. D., Jr., 1980. Handbook of Gravity-Flow Water Systems for Small Communities. UNICEF.

Kiyu, A. and Hardin, S., 1982. Functioning and utilization of rural water supplies in Sarawak, Malaysia. Technical Report.

Kiyu, A. and Hardin, S., 2012. GLAAS 2012 Report: UN-Water Global Analysis and Assessment of Sanitation and Drinking Water. World Health Organization.

Mihelcic, J. R., Fry, L. M., Myre, E. A., Phillips, L. D., Barkdoll, B. D., 2009. Field Guide to Environmental Engineering for Development Workers. ASCE Press.

Munson, B.R., Young, D.F., Okiishi, T.H., 2005. Fundamentals of Fluid Mechanics. Wiley.

Niskanen, M. A., 2003. The Design, Construction, and Maintenance of Gravity- Fed Water System in the Dominican Republic. Technical Report.

Smet, J. and van Wijk, C. (Ed.), 2002. Small Community Water Supplies: Technology, People and Partnership. IRC International Water and Sanitation Centre, Delft, The Netherlands.

Timoshenko, S., 1961. Theory of Elastic Stability. 2nd ed., McGraw-Hill, New York.

United Nations, 2015. The Millennium Development Goals Report. Technical Report. Available at: http://www.un.org/millenniumgoals/2015_MDG_ Report/pdf/MDG%202015%20rev%20(July%201).pdf. [Accessed June 2016].

United Nations, 2015. United Nations General Assembly Draft outcome document of the United Nations summit for the adoption of the post-2015 development agenda. Technical Report. Available at: http://www.un.org/ga/search/view_doc.asp? symbol=A/69/L.85&Lang=E. [Accessed May 2016].

U.S. Environmental Protection Agency, 2016. EPANET, Software to model water distribution systems. Technical Report. Available at: https://www.epa.gov/water-research/epanet. [Accessed May 2016].

U.S. Environmental Protection Agency, 2014. WaterSense New Home Specification. Technical Report. Available at: https:// www3.epa.gov/watersense/docs/home_finalspec508.pdf. [Accessed June 2016].

Published
2017-05-30
Section
Articles