Waru Warn or Waru Waru is an agricultural

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

 technique developed by the Quechuas

Quechuas

Quechuas is the collective term for several indigenous ethnic groups in South America who speak a Quechua language , belonging to several ethnic groups in South America, especially in Peru, Ecuador, Bolivia, Chile, Colombia and Argentina.The Quechuas of Ecuador call themselves as well as their...

 in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 before the rise of the Inca Empire

Inca Empire

The Inca Empire, or Inka Empire , was the largest empire in pre-Columbian America. The administrative, political and military center of the empire was located in Cusco in modern-day Peru. The Inca civilization arose from the highlands of Peru sometime in the early 13th century...

. It is dated around 300 B.C.

The technique has been revived in 1984, in Tiawanaco, Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

, and Puno

Puno

Puno is a city in southeastern Peru, located on the shore of Lake Titicaca. It is the capital city of the Puno Region and the Puno Province with a population of approximately 100,000. The city was established in 1668 by viceroy Pedro Antonio Fernández de Castro as capital of the province of...

, Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

.

The technique consists in combining raised bed

Raised bed gardening

Raised bed gardening is a form of gardening in which the soil is formed in 3–4 foot wide beds, which can be of any length or shape. The soil is raised above the surrounding soil , sometimes enclosed by a frame generally made of wood, rock, or concrete blocks, and enriched with compost...

s with irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 channels so as to prevent damage due to soil erosion during floods. The technique ensures both collecting of water (either fluvial water, rainwater or phreatic water) and subsequent drainage. The drainage aspect makes it particularly interesting for areas subject to risks of brutal floods, such as tropical parts of Bolivia and Peru where it emerged.