Ancient Water System in Peru Could Fix Water Shortages

07 July, 2019

蜗蜗牛小游戏网 Sometimes modern problems require ancient solutions.

A 1,400-year-old Peruvian method of diverting water could supply up to 40,000 Olympic-size swimming pools' worth of water to Lima each year. That information comes from a new study published in Nature Sustainability.

It's one example of how ancient methods could support existing modern ones in countries without enough water.

More than a billion people across the world face water shortages. Man-made reservoirs store rainwater and water overflow for use during drier times. But reservoirs are costly, require years to plan and can still fail to meet water needs. Recently, for example, the reservoirs in Chennai, India, went almost dry. The city's four million people had to then depend on water transports from the government.

Peru's capital, Lima, depends on water from rivers high in the Andes Mountains. It takes only a few days for water to flow down to the city. So when the dry season begins in the mountains, the water supply quickly disappears. The city suffers shortages of 43 million cubic meters during the dry season. It resolves this with modern structures such as man-made reservoirs.

View of the Andean highlands where Huamantanga is located. The city of Lima is located downstream in the horizon background.
View of the Andean highlands where Huamantanga is located. The city of Lima is located downstream in the horizon background.

These reservoirs are not the only solution, however. Over a thousand years ago, indigenous people developed another way to solve water problems.

Boris Ochoa-Tocachi is a researcher at Imperial College London and lead writer of the study. He explored one of the last remaining water-harvesting systems in the small mountain community of Huamantanga, Peru. The system was developed even before the ancient Inca civilization.

Water diverted, delayed

The 1,400-year-old system is designed to increase the water supply during the dry season by diverting and slowing water as it travels down the mountains.

This nature-based method is made of special canals that guide water from its source to a series of water bodies and hillsides. The water goes slowly into the ground, then flows downhill through the soil and reappears in water bodies near the community.

Its aim was to increase the water's travel time from days to months in order to provide water throughout the dry season.

But Ochoa-Tocachi said the amount of water that could be harvested was an unknown before the study.

The researchers measured how much the system slowed the flow of water by injecting special dye in the highlands and noting when it reappeared in water bodies. The dyed water started to surface two weeks later and continued flowing for eight months — a huge improvement over the hours or days it would normally take.

"I think probably the most exciting result is that we actually confirmed that this system works," Ochoa-Tocachi said. "It's not only trusting that, yeah, we know there are traditional practices, we know that indigenous knowledge is very useful." He said there is now proof the systems are valuable today and can be a tool to help solve modern problems.

Sizable increase in supply

The researchers next considered how using a larger version of the system could help Lima. They combined what they learned in Huamantanga with the knowledge of physical qualities of Lima's surroundings. The resulting estimates say the system could increase Lima's dry-season water supply by 7.5 percent overall and up to 33 percent at the start of the dry season. This amounts to nearly 100 million cubic meters of water each year — equal to 40,000 Olympic-size swimming pools.

Todd Gartner is director of the Natural Infrastructure Initiative at the World Resources Institute. He noted that this study "takes what we often just talk about...and it puts this into practice." He said it does a lot of evaluation and observation and "puts real numbers behind it."

The system is also economically sound. Ochoa-Tocachi estimated that building canals similar to those in Huamantanga would cost 10 times less than building a reservoir of the same size. He also said former highland societies in other parts of the world had methods for diverting and slowing water flow. And, they could use these methods today to support their costlier modern methods.

"I think there is a lot of potential in revaluing these water-harvesting practices that have a very long history," Ochoa-Tocachi said. He added that the idea of "using indigenous knowledge for solving modern engineering probably very valuable today."

I'm Alice Bryant. And I'm Caty Weaver.

Kerry Hensley wrote this story for VOA News. Alice Bryant adapted it for Learning English.


Words in This Story

divertv. to change the direction or use of something

reservoirn. a usually man-made lake used to store water for use in people's homes, businesses and other places

indigenousadj. describing ethnic groups who are the original settlers to a specific region

canaln. a long narrow place that is filled with water and was created by people

dyen. a substance used for changing the color of something

actuallyadv. used to refer to something that is true or real

evaluationn. o judge the value or condition of (someone or something) in a careful and thoughtful way

potentialn. a quality that something has that can be developed to make it better

游戏秘籍 | 广州代孕 | 美国代孕网站 | 高鹰代孕 | 广州助孕 | 代孕 |
  • 江苏灌云推动非遗进校园 传承乡土人才技艺_ikeymonitor
  • 浙江全面停止新增围填海项目审批_实用人体模特摄影
  • 婆婆不喜欢哪种类型的媳妇_北漂驿站
  • 北京市交管部门公布交通事故多发路段 8处路段昌平占7个_云南邵通
  • 干群热议"为基层减负":吃下定心丸 担当有作为_52kindle
  • 【视频】第三届金丹若国际微电影节举办 中韩众星云集_茶有几种
  • 盐城阜宁打造灾后农村建设样本 促进乡村振兴_win10系统怎么样
  • 恒丰银行启东支行正式开业 捐赠5万元慈善资金_坝的组词
  • 甲骨文表情包让传统文化“活”起来_兰芳大统制共和国
  • 城市副中心线年底先开通这4站!百年老火车站将重启_雷迪嘎嘎演唱会
  • 十九大代表、宜都市委书记罗联峰_火烧圆明园时间
  • 甘肃税务:服务走出办税厅 政策落实更贴心_金东文
  • 两院一部联合发文打击电信网络诈骗 3000元以上就就定罪_进进窗口化
  • 河南许昌:灞陵桥庙会带你开心过大年_恐龙危机2中文版下载
  • 杨光委员:持续推进“放管服”改革 优化营商环境_视频拼接app