Xylem Inc. has released a white paper outlining strategies to increase the resilience of cities around the world.
According to the United...
How can a town that is only 2,000 ft from a major river suffer severe water shortage? It's easy when that distance is measured vertically.
In mountainous western Honduras, the city of Santa Rose de Copan sits 3,900 ft above sea level and half a mile above the Higuito River. Its high elevation makes every day feel like spring, and for centuries, Santa Rosa's 25,000 residents depended solely on year-round spring-like rains to replenish their wells.
Over the past few years, droughts blanketed much of Central America and Santa Rosa found itself in a serious water shortage. Wells were losing water at alarming rates, so the city began rationing its water supplies. As a result, some neighborhoods received water just once every five days, and residents started wondering how they could pump water from the river below.
The answer came in the form of an innovative water delivery system utilizing vertical turbine pumps.
In 2001, the humanitarian organization USAID agreed to fund a pump-and-piping project. The design company Hazen & Sawyer contracted Bomohsa, a Goulds Pumps vertical turbine pump distributor in Honduras, who offered two suggestions to ensure the project's success.
"First, we suggested that the project have three pump stations to boost the water uphill and deliver it into the town's water tank," said George Faraj, Bomohsa general manager. "Then we recommended they use ITT Industries' Goulds Pumps' vertical turbine pumps at each station because they have the highest efficiency and can be integrated into the piping, which saves costs."
In 2002, USAID engineers began construction on the water delivery system. First, they located a spot five miles downriver where an infiltration gallery could be built into the river bank. The water flows naturally into a collection area, runs through a sophisticated filtration system, and is then propelled by three sets of powerful, high-efficiency vertical turbine pumps on its six-mile journey—five-and-a-half miles horizontally and another half mile vertically.
The climb nearly killed the project.
"When you are pumping water up, there is always the danger of creating a ‘water hammer' when it meets the water coming back down," explained Carlos Restrepo, ITT's territory manager for Central America and northern South America. "In this case, because we were dealing with such high pressures produced by the pumps to push the water up the mountain, the water hammer explosions were tremendous, and the project suffered many pipe failures during the testing period."
The project engineers solved the problem with the installation of special flow sensors and pressure transducers. With these modifications, the pumps and pipes passed all further tests, and now all that's left is the final pipe connection to Santa Rosa's distribution tank, which should be completed in August 2005. When the system is fully operational, it will provide 1,600 gpm, of water to Santa Rosa.