Getting down to basics

September 2006 » Feature Articles
Engineers Without Borders (EWB) is an extraordinary program devoted to assisting disadvantaged communities. In this story, EWB helps impoverished Thai villagers modernize a critical irrigation system.
David E. Beck, P.E.

Engineers Without Borders helps impoverished Thai villagers modernize a critical irrigation system

Engineers Without Borders (EWB) is an extraordinary program devoted to assisting disadvantaged communities. Like comparable programs in other countries, the United States group (EWB-USA) usually undertakes projects such as improving water resources and wastewater disposal, refining sanitation systems, improving energy availability, and other basic infrastructure. Each project also involves teaching recipients the technical and managerial skills needed to function independently when EWB volunteers depart. Concurrently, the program furthers the development of internationally responsible engineering students and professionals.

Established in 2000, EWB helps impoverished communities by improving their health and education services and bettering their employment opportunities. In many cases, their dilemma is caused by limited knowledge and resources about such basics as water purity, sanitation procedures, food production and processing, housing construction, energy supplies, transportation, and communications. EWB engineering professionals partner with such communities and help them develop appropriate solutions compliant with their natural and cultural systems. Community participation ¯ community workers are required to help EWB volunteers build the systems ¯ and training are integral to each project; EWB does not provide quick technical fixes, but instead builds competence within those communities for independent problem solving. Given the primitive conditions of most locations, new systems must be relatively uncomplicated, affordable, appropriate for the community, and environmentally and economically sustainable.

According to Dick Herring, retired chemical engineer and current EWB-USA project leader and board member, project proposals come from many sources. Each is reviewed by the EWB-USA Technical Advisory Committee and, if approved, is advertised on the EWB-USA website ( for implementation by one of more than 200 participating university chapters.

A water lifeline

The small Thai village of Santisuk, located near the country's northern border with Myanmar (Burma), is populated by about 250 persons who rely heavily upon the productivity of their rice paddies, fruit orchards, vegetable gardens, and cornfields. As one of more than a thousand small hilltribe villages in the sparsely inhabited Chiang Mai province, Santisuk is situated in a forested hilly region some miles from the nearest city. With minimal access roads, reaching the village's irrigation ditches requires a substantial walking trek.

Irrigation is vitally important for the year-round growth of rice and other crops in ample quantities to feed village residents. Sometimes, villagers have been able to market surplus crops, although such opportunities usually involved meager amounts that sold cheaply. To avoid buying rice or paying neighboring farmers for water, the villagers constructed a conduit from salvaged corrugated steel sheets. By curving and overlapping the sheeting, they assembled crude aqueducts to convey water from a nearby river to their crop fields. Without sealed joints and with unsupported reaches at several ravine crossings, a substantial amount of water ¯ some estimates indicated up to 50-percent loss ¯ leaked from the conduit during transportation. This marginally effective irrigation system was vastly insufficient for maintaining crop production, so the proposal to EWB was to create a suitable irrigation system with ravine-crossings to meet the Santisuk farmers' water requirements.

Herring, who served as project mentor, said, "These projects are very challenging because of their location, [they] must be low tech, and can require up to a year of planning and design for full implementation in just a week or two in-country. Like the Santisuk village, most communities we assist are hard to access and have very limited building skills. Consequently, we must be careful about our selection of materials, methods, and equipment." EWB usually makes early contact with the village elders and residents to make sure that the proposed work is culturally appropriate and sustainable.

Having prior experience with these villagers (they constructed a water treatment facility there in 2004), the University of New Hampshire (UNH) student chapter elected to assume the irrigation project. After considering various alternatives so that construction would require only basic building techniques yet provide sustainability and minimum maintenance, the design team picked PVC pipe for the irrigation system. The lightweight PVC pipe could be transported easily and put in place, and the simple assembly procedures were perfect for this project. Moreover, with sustainability being a primary goal, the community can more easily operate and maintain the PVC system without external assistance than with other materials considered. The final plan called for two parallel runs of 14-inch pipe, totaling about 3,000 feet.

Simplicity and sustainability were also principle factors for the ravine-crossings. Existing ravine crossings supporting the corrugated metal had been badly damaged by monsoon rains, and any replacement structures must be such that the villagers could perform any needed repairs. Consequently, the final design included pier-supported structures using pressure-treated timber (6- x 6-inch posts) connected by 2- x 8-inch beams. A maximum span length of 11 feet was selected based on the structural properties of 14-inch PVC pipes filled with water.

Funding for EWB projects comes from various non-governmental sources, such as student chapter fundraisers and corporate partners who donate materials and services. For the Santisuk irrigation pipeline project, J-M Manufacturing covered the full cost of the PVC pipe. The Uni-Bell PVC Pipe Association, British Petroleum, and the UNH College of Engineering and Physical Sciences provided additional support.
The new irrigation project was completed in 2005 and Herring reports that the villagers have since increased their crop yields substantially and become fully independent with respect to agriculture activities. The dramatically increased crop production has allowed them to establish a micro-business that allows the sale of their surplus rice through a Bangkok-based farm co-operative. Due to the larger surpluses now available through efficient irrigation, their revenues have increased tenfold.

Through the selfless efforts of EWB engineers and the generous support of participating organizations, the villagers of Santisuk are now experiencing some prosperity and an improved quality of life. "The people in these communities know what their problems are, but they may not know what's available to solve those problems," said Cathy Leslie, president of EWB-USA. "Once we show them what they can do, they really get it."

With all EWB projects being designed carefully for environmental fitness and economic sustainability, and EWB volunteers providing operating and maintenance training, the recipients gain a new independence for sustaining their improved conditions without further need for outside assistance. With the number of active projects at any given time ranging between 40 and 60, EWB is working to develop engineers capable of addressing the pressing needs of the developing communities worldwide.

David E. Beck, P.E., has held various positions with the Ohio Department of Transportation, the Construction Products Division of Armco Steel Corporation, and CONTECH Construction Products Inc., and has been a contributing editor for CE News. Presently, he works as a freelance technical writer. He can be contacted at

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