Back To The Future: Incas Bring Water -- Ancient Irrigation Methods Being Revived

OLLANTAYTAMBO, Peru - High on a dry Andean mountain, the excitement began to surge over a group of farmers gathered to witness the revival of an ancient Inca canal they had rebuilt with stones, clay and painstaking labor.

"Here comes the water!" shouted one man as he and others scrambled out of the canal before a muddy stream went glistening and gurgling by.

Smiling broadly, another farmer observed: "There will be plenty of water now."

The Andean region of Peru, Bolivia and Ecuador was a land of plenty in pre-Columbian times, with highly developed systems of irrigation canals, agricultural terraces and other elaborate field works. Deserts and arid mountainsides produced abundant crops that included hundreds of varieties of tubers and roots and nutritious grains, such as quinoa and corn.

Today, agriculture in much of the region is backward. Malnutrition is rampant. The delicate environment is badly deteriorated. Many of the wise, ancient ways of using land, water, plants and animals have been forgotten or neglected.

But in a variety of projects, people are working to reclaim this region's ancient agricultural legacy. Academic experts, field agents and peasant farmers are rehabilitating thousand-year-old canals and terraces. They are rediscovering ingenious methods of cultivation on raised and sunken fields and studying and experimenting with ancestral native crops.

Ann Kendall, an English archeologist who has been working with

Ollantaytambo farmers on their canal project, is a leader of the movement.

From 1978 to 1983, Kendall, 54, helped one rural community in the Cusichaca Valley rebuild a pre-Inca canal almost five miles long.

With the canal's water, farmers irrigate almost 150 mountainside acres in a rehabilitated system of ancient terraces.

"It is their best land now," Kendall said. "Before, it wasn't being used at all."

REBUILDING ANOTHER CANAL

For the past three years, Kendall and her nonprofit Cusichaca Trust have been struggling to get another canal rebuilt - researching and planning the work, soliciting donations, persuading peasants to invest their time and labor.

On a recent Saturday, members of the Ollantaytambo agricultural community were preparing to celebrate the completion of the Pumamarca Canal's first stage. When the canal is completed, it will serve more than 400 acres of Inca and pre-Inca agricultural terraces.

As the water flowed from its source, a glacial stream almost two miles away, Kendall watched it gush down a ditch from the canal when Guido Alarcon, the mayor of Ollantaytambo, came over to congratulate her.

"It's a work of engineering . . . " Alarcon said, pausing apparently to search for the right words.

". . . by the Incas," said Kendall, completing his sentence in fluent Spanish. "We have followed what they taught."

Kendall hopes her two projects will prove to other peasant communities and aid agencies that they should rebuild ancient canals using traditional materials and techniques.

Early builders, for example, knew that to keep water from racing down precipitous grades and causing damage, they needed to set protruding stones in their canals' walls and floors. Or they built steep sections in a dogleg or zigzag course to slow the water's rush.

Kendall criticized a German aid project that is rebuilding ancient canals in the Cuzco area with concrete. Concrete cracks and crumbles with earthquakes, slope slippage and water pressure, she warned, and poor farmers will not have the resources or know-how to make major repairs.

But canals made the ancient way, with earth and stone and clay, are more durable because they are more flexible, she said. Grass and shrubs grow on the banks, reinforcing and protecting them. Repairs can be made easily with cheap materials close at hand.

Since the mid-1980s, private and government groups, including the U.S. Agency for International Development, have promoted and financed the use of traditional terrace agriculture in Peru and other Latin American countries.

"During 500 years, we have lost more than 70 percent of the productive capacity of the terraces," said Elias Mujica, a Peruvian archeologist.

The best Inca terraces had finely fitted retainer walls that sloped in at carefully calculated angles to support the weight of the fill. Small rocks and pebbles often were used in lower layers of fill to save topsoil, improve drainage and to prevent land from becoming waterlogged. Water flowed down from one terrace to the next through stone drains, chutes and drop canals.

Terraces stop erosion, permit deeper topsoil accumulation, help retain moisture and humus in the soil, and guard against frost, advocates say. They are an efficient method for managing scarce water in the semi-arid mountain climate of the central Andes.

At Machu Picchu, the famed Inca ruins near here, big terrace systems are out of use and crumbling in places. Archeologist Mujica said he hopes to help people repair and plant them with crops.

SAVE THEM BY USING THEM

"The only way to preserve them is to give them the function they had, make them productive," he said.

The Incas, who ruled during the 15th and 16th centuries, adopted much of their technology from previous cultures, which developed Andean crops and farming methods over thousands of years. But one method that had been largely abandoned even before the Inca empire was raised fields, or "waru waru."

The large, rectangular fields are separated by a grid of wide trenches that serve for drainage in flood times and for irrigation during dry seasons. The water seeps into the fields from the sides at root level. Muck from the trenches is thrown up on the fields to enrich poor soils. The water retains solar heat to prevent frost damage at night and cools fields during the day.

The pre-Inca Tiwanaku civilization built waru waru around Lake Titicaca, a spectacular body of water shared by Peru and Bolivia. Remains of these fields cover more than 200,000 acres.