COLUMN ONE : Old Canals Carry Hope to Andes : Farmers are using wise ways of the past to make their arid mountains verdant again. They are rebuilding ancient irrigation systems and reviving the innovative ideas of the Incas.

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

“Here comes the water!” shouted a man wearing a multicolored cap 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”--as there had been centuries before.

The Andean region of Peru, Bolivia and Ecuador was a land of plenty in pre-Hispanic 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 damaged. Many of the wise, ancient ways of using land, water, plants and animals have been forgotten or neglected.

But people are working to reclaim this 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 experimenting with ancestral native crops. Such interest in “applied archeology” and “traditional technology” has burgeoned into an unprecedented movement.

Archeologist Ann Kendall, who has been working with Ollantaytambo farmers on their canal project, is a leader of the movement.

Kendall, 54, is a petite Englishwoman with graying hair, glasses, ruddy cheeks and a soft voice. She is hardly Hollywood’s kind of archeologist, but she is as determined as Indiana Jones. From 1978 to 1983, she helped one rural community in this area, 50 miles from the old Inca capital of Cuzco, rebuild a pre-Inca canal almost five miles long. The project, in the Cusichaca Valley, was the first of its kind in the Andean region.

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.”

For the last 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, under a brilliant blue sky, members of the Ollantaytambo agricultural community were preparing to celebrate the completion of the Pumamarca Canal’s first stage, which will irrigate 120 acres of rehabilitated terraces. 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 searching for the right words.

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

More men gathered, then walked down the mountain to the spectacular Pumamarca ruins, an early Inca fortress overlooking a river valley several miles from Ollantaytambo. On a grassy courtyard in the ruins, they took part in a ceremony irrigated with chicha , a pre-Hispanic brew of fermented corn. Later, they feasted on roasted alpaca, mutton and potatoes.

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 project that is rebuilding ancient canals in the Cuzco area with concrete. Concrete cracks with earthquakes, slope slippage and water pressure, she warned, and poor farmers lack the resources or know-how for major repairs.

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 with cheap materials, close at hand.

Kendall invited an official of CARE International’s Cuzco office to the canal dedication, hoping that the well-endowed, non-governmental agency will sponsor canal rebuilding projects.

Agronomist Hido Felix was impressed. “This can be replicated,” he said. “CARE is interested.”

CARE is already working with 60 communities in the Cuzco area, helping them increase farm production and control erosion by planting native trees, restoring old terraces and building new ones.

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. In Peru, before the Spanish invaded in the 1530s, terraces may have totaled 2.5 million acres, experts estimate.

“During 500 years, we have lost more than 70% of the productive capacity of the terraces,” said archeologist Elias Mujica. “The Spanish were so dumb that instead of doing innovations with traditional things that were adequate to our conditions, they imported,” he said.

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 often were used in lower layers of fill to save topsoil, improve drainage and 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 semiarid 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. “The only way to preserve them is to give them the function they had, make them productive,” he said.

The Incas, who ruled Peru until the Spanish invasion, adopted much of their technology from previous cultures, which developed 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 trenches that handle drainage in flood times and 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.

Remains of similar raised fields have been found in Bolivia, Ecuador, Venezuela and other countries.

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.

In recent years, archeologists, anthropologists, agronomists and other experts have worked with peasant farmers in Peru and Bolivia to rehabilitate waru waru systems. Without them, the lands they once covered are virtually useless for agriculture. Using them, farmers have multiplied the yields of crops they grow on higher ground.

Since non-government and government groups began helping peasant communities re-create waru waru near the Peruvian city of Puno in the 1980s--sometimes giving families food in exchange for work--the fields have been rebuilt on about 750 acres.

Prehistoric Andean Indians developed many other agricultural technologies, always suited to conditions where they lived. In the highlands north of Lake Titicaca, they carved out large basins in the semiarid plains and cultivated the sloping sides with carefully designed systems of trickle-down furrows that made maximum use of scarce rainfall. Some of those basins, called cochas, are still in use but have yet to be studied.

In some coastal desert areas, early Indians dug big sunken fields called hoyadas , some 20 feet deep and covering more than seven acres. They were designed to reach the ground water in dry river valleys. Indians brought rich silt, washed down riverbeds by flash floods, to enrich the hoyada soils.

Some hoyadas are still in use near the town of Chilca, south of the Peruvian capital of Lima, and archeologists hope that others can be revived. “The ones at Chilca can serve as a model for rehabilitating them,” archeologist Bernardino Ojeda said.

North of Lima, ancient Indians built stone walls on seaside mountains known as the Lomas. Moisture from seasonal fog banks condensed on the walls and trickled into terraced gardens. The walls have been destroyed, and the Lomas have been stripped of vegetation, but a 5-year-old project at Lachay, 60 miles north of Lima, uses plastic screens to catch the fog for a park reforestation project.

Some pre-Hispanic technology remains a mystery. Anthropologist Jorge Recharte said he recently saw remains of furrows on several thousand acres of desert land near Arequipa in southern Peru. He said there was no sign of how the desert had once been irrigated.

Part and parcel of all pre-Hispanic agricultural technology in the Andean region was its rich menu of native crops. They included plants that have spread around the world since the Spanish Conquest: potatoes, sweet potatoes, tomatoes and corn.

Protein-rich quinoa, a grain staple in pre-Hispanic Andean diets, has become a popular health food item in the United States. But scores of potato varieties, other tubers and edible roots are virtually unknown outside the Andes, where they are underused compared to ancient times. Scientific research has been scant.

“Once the Spanish arrived, these plants were put in obscurity,” said Carlos Arbizu, an Andean crop specialist at the International Potato Center. “As they repressed the natives, so they repressed the food of the natives as well.”

The potato center, a multinational research agency based in Lima, is forming a consortium to exchange information and do research on technology for environmentally sound agricultural development in seven Andean countries.

The project will emphasize ways to use and improve lesser-known native root and tuber crops. It will also investigate ways to combine the crops with traditional methods of land and water management.

“Traditional technology” advocates also promote raising native llamas and alpacas instead of cattle, sheep and goats. The native species yield high-quality fiber and low-cholesterol meat and can be used as pack animals; they cause less erosion on mountain terrain with their hoofs and grazing.

Experts emphasize that the success of traditional agriculture depended greatly on pre-Hispanic cultural and social structures.

“The Incas were great masters of organization,” observed anthropologist Recharte. “I do think we should at least try some of those organizational methods that existed before.”