The presence of water gave us a means to stay here,“ says 65-year-old Hana Habshi, a resident of the Maronite Catholic town of Deir El Ahmar. The once-bustling agricultural hub nestles on the slopes of the fertile Bekaa Valley, about 60 miles northeast of Beirut, where Mr. Habshi has lived and worked since the height of civil war in the 1980’s. But for the past decade, thanks to several irrigation projects, Mr. Habshi has returned to his hometown every summer to farm his family’s ancestral lands. “It helped us come back and live off the land again.”

Lebanon’s civil war — which ravaged the country from 1975 to 1990 — destroyed much of the nation’s infrastructure, including its irrigation systems, and sounded the death knell for the Bekaa Valley’s agricultural economy.

Without reliable sources of water, and subsequent erosion, farmers could no longer cultivate the land that formerly nourished lush fields and bountiful yields. Desperate for work, inhabitants moved to Lebanon’s major coastal cities, such as Beirut, Saida and Tripoli. Some left the country altogether. The few who remained scraped by as sustenance farmers, growing crops that require little water such as wheat, hay and, in some cases, hashish.

Deir El Ahmar, like most settlements in the area, remains but a shadow of its former self. Its many empty homes and crumbling public buildings remind locals and visitors of a more prosperous past. Though municipal authorities register some 10,000 residents, in reality half as many actually live there — and only then in the summer months. In winter, the town’s population plunges to little more than 3,000.

However, in the last ten years, Deir El Ahmar has been slowly but surely bucking the trend. Locals attribute this reversal to one thing — water. Since 1999, when the town installed its first irrigation system drawing on natural spring water, residents such as Mr. Habshi have been trickling back to town and reviving their parched properties and the Christian identity of the town.

“Before it was all just trees and shrubs, but look what happens when water comes,” says Mr. Habshi, pointing to the surrounding hillsides and valley below.

The striking vista, indeed, is a visual testament to the power of irrigation. Patches of land covered with rows of neatly tended greenery and tilled, dark-brown soil intersperse with the otherwise arid terrain. The cultivated lots all run along lines of an irrigation network that crisscrosses the hillside and valley.

About 12 miles uphill, the network’s main lines come together at a vast, manmade lake. Designed and built by the staff of CNEWA’s Pontifical Mission in 2005 at a cost of $160,000, it sits atop the Ain el Naama Hill, some 1.3 miles above sea level. The 13.2 million-gallon capacity reservoir consists of a deep crater-lake basin, which is lined with a thick, black artificial membrane to seal the soil. The reservoir collects water from rainfall, melting snow and several pipes connected to natural springs at higher altitudes.

The reservoir and irrigation network provides a steady supply of water year-round to some six towns and surrounding farmland. Before the project, farmers could only irrigate limited sections of their property and grow few crops during the summer months. Now, beneficiaries cultivate more land and harvest a much wider variety of crops, including water-intensive produce such as apples, apricots, berries, peaches and many vegetables.

A major component of the project’s design — and a key to its success — has been ensuring the local community takes meaningful ownership of it. The Pontifical Mission requires beneficiaries to cover the operating costs as well as handle the day-to-day maintenance of the reservoir and irrigation network. To do so, beneficiaries established an agricultural collective.

“All members of the cooperative contribute to the upkeep fund, and therefore they feel more ownership of the project,” says 55-year-old Youssef Habshi, a Deir El Ahmar resident, farmer and member of the collective.

“We built the lake and network of pipes and provided a few hundred meters of irrigation pipes,” says Imad Abou Jaoude, an engineer and deputy program manager at the Pontifical Mission’s Beirut office. “We also provide $3,000 to $5,000 loans at low interest rates, so that they can buy additional drip irrigation pipes.”

The project has jump-started the local economy and is helping to revitalize Deir El Ahmar. Residents have pooled money to build a new church dedicated to St. Charbel. Still under construction, the Maronite church stands on a once desolate lot. Now, a lush, landscaped lawn and garden cover the grounds. On summer afternoons, locals often gather on the cool lawn in the shadows of the church to relax and take refuge from the sun’s sweltering rays.

“Water has brought us back to the lands,” says Mr. Habshi. “It has breathed life back into the community, and now it assures the completion of our church. What’s more, now I can afford to move back from Beirut and retire here.”

The reservoir is just one of many water projects the Pontifical Mission has spearheaded in Lebanon since 1993, when it became a key nongovernmental partner in the country’s post-war reconstruction. In the early days, the agency focused on restoring damaged water systems in rural communities, to ensure clean drinking water as well as to irrigate farms. In recent years, projects also include water collection and sewage treatment.

CNEWA’s Pontifical Mission is among a handful of charities and international organizations working to improve Lebanon’s water supply. But their combined efforts remain but a drop in the ocean, so to speak, given the country’s overall water situation.

“The current annual demand is around 1.35 billion cubic meters [35.7 billion gallons],” says Dr. Selim Catafago, president of the Litani Water Authority, a government agency that manages the public water infrastructure fed by the Litani River — Lebanon’s largest river and a principal source of its fresh water supply. “The annual supply capacity is around 80 percent of the needs in an average wet year, and around 60 percent in a dry year.”

“The deficit is projected to widen,” warns Rayan Makarem, a campaigner at Greenpeace Lebanon. “Unless the government enacts major reforms in its water sector, demand is expected to reach 2 billion cubic meters [52.8 billion gallons] within the next decade.”

Waste, says Mr. Makarem, lies at the root of the crisis. “Current irrigation practices allow for a 50 to 60 percent loss by evaporation. In the public infrastructure, there is a 50 percent loss through leaks,” he says. “Among the people, there is a ‘when there’s water, let’s use it’ attitude. There is a lot of waste in washing the streets and leaving taps running needlessly.”

The country’s unsustainable number of wells — most dug illegally during the civil war — also contributes to the shortage. According to Greenpeace Lebanon, the country’s hundreds of thousands of active wells are draining the freshwater aquifer at an alarming rate.

In many areas along Lebanon’s coast, where 60 percent of the population lives, the depleted aquifer has started absorbing seawater. In some places, it is not uncommon to turn on a faucet and receive salty water.

“During the years of the war, the government was absent and there was a lot of anarchy in the form of well drilling,” says Fadi Comair, general director of the Hydraulic and Electrical Resources Department of the Lebanese Ministry of Energy. “Now we don’t have this anarchy any more, so we must close up these illegal wells. We must find a solution to secure fresh water for the population.”

Last year, Minister of Energy Gebran Bassil proposed a comprehensive plan to solve the country’s water crisis. Based on a similar plan that was scrapped in the early 2000’s, it calls for nothing short of a complete overhaul of the nation’s water infrastructure.

Implemented over a 25-year period and at a cost of $8 billion, the plan involves constructing a network of dams and reservoirs, artificially recharging parts of the country’s freshwater aquifer, rebuilding Lebanon’s water delivery system and transitioning to more efficient irrigation practices, such as drip technology.

In the meantime, people such as Georges Abou Jaoude remain indispensable figures in Lebanese society. Commonly known as a waterman, Mr. Abou Jaoude owns a small business that delivers water to households using a 3,700-gallon-capacity tank truck.

On this hot July afternoon, Mr. Abou Jaoude parks his truck outside the home of one of his regular customers, Hassan Atrache. Mr. Atrache lives in Broumana, a leafy, middle-class village in the foothills just north of Beirut.

The men exchange a few friendly words before Mr. Atrache asks the waterman to fill his property’s 265-gallon water tank, for which he will pay roughly $10.

Without pause, Mr. Abou Jaoude removes equipment and a long pipe from his truck. He connects the pipe first to the truck’s tank, then to a valve leading to the tank beneath the house. He flicks a switch and a motor sputters into a roar, flushing water from the truck’s tank to the one underground. The refill will meet the Atrache family’s water needs for about two weeks.

When the water supply in the truck’s tank runs low, Mr. Abou Jaoude drives to one of several wells in the area to replenish his stock.

“Some clients call every two or three weeks,” he says. “This year my supply should be O.K., because there was a good rainy season. But last year it was terrible. Most of the wells were dry by September.”

Lebanon’s water crisis extends beyond shortages. Pollution also adds to the nation’s water woes.

The country’s antiquated water infrastructure lacks adequate treatment facilities. In addition, leaks throughout the piping often result in cross-contamination between the contents of pipes carrying clean water and wastewater.

At present, treatment facilities process only about 40 percent of the water used. “Roughly 50 percent of water in households passes through water treatment plants,” says Dr. Catafago of the Litani Water Authority. Over the next 20 years, he says, the agency plans to add 40 new treatment plants.

Untreated water endangers public health, even when it comes from wells or natural springs. In most areas of the country, raw sewage and fertilizers now seep into the freshwater aquifer, contaminating the supply.

“Wastewater, industrial waste, solid waste, toxins, pesticides, fertilizers, the penetration of the freshwater aquifer by seawater — all of the territory is affected,” says Mr. Makarem of Greenpeace Lebanon.

Moreover, the few water treatment plants in operation do not always clean water to a degree suitable for drinking. For instance, most people refuse to drink the water treated by the outdated and overburdened plant in Ghadir, a suburb south of Beirut. The plant, however, is the only one in metropolitan Beirut, serving all of the area’s nearly two million people.

Concerned about water quality, most residents prefer to drink purified bottled water. But even this does not protect them from pollution. Like it or not, all Lebanese ingest pollutants from time to time through food, especially fruits and vegetables grown or washed with untreated water.

“Infrastructure improvements that should have been done during the 70’s and 80’s to follow population growth were not done,” says Mr. Comair of the Ministry of Energy.

Minister Bassil’s new plan includes a wide range of measures to upgrade existing water treatment facilities and to construct numerous new ones throughout the country.

“The C.D.R. [the government’s development and reconstruction council, charged with state infrastructure construction projects] has already completed six water treatment plants,” says Mr. Comair. These projects, he says, represent about 10 percent of the total number planned. “Because of all the problems Lebanon has faced since 2000 — politics, war and business — we are not able to implement it on our own, without the political will.”

Once again in the hills of Lebanon, there is a glimmer of hope — this time from a Pontifical Mission project in the Chouf Mountains, 30 miles southeast of Beirut. Thankfully, the agency does not depend on broad political consensus in the chambers of the Lebanese parliament to make a difference.

On the outskirts of the mountain village of Maasser el Chouf stands a rather ordinary tower. Around its base cluster a handful of massive tanks.

Despite its unassuming appearance, the facility represents the cutting edge of water treatment technology in Lebanon. Built in 2003 by the Pontifical Mission’s staff in Beirut with funding from the United States Agency for International Development, the $300,000 project processes up to 120,000 gallons of wastewater each day using a minimal amount of energy. It and six similar plants in the Upper Chouf region treat the sewage from 12 neighboring villages and eject pollutant-free water into the Barouk River.

Before the plants, water pollution in the region posed a serious public health hazard. During the rainy season, septic tanks often overflowed. Human wastewater flooded people’s property and seeped into neighboring communities at lower altitudes.

“There were so many insects and health problems,” says Hassan Zeinnedine, a 63-year-old resident of the Moukhatara, a village just downhill from Maasser el Chouf.

Home to Walid Jumblatt, Lebanon’s most powerful Druze politician and the current leader of the Progressive Socialist Party, Moukhatara is a Druze stronghold. The immensely popular leader lives just a few paces up the road from the village Laundromat.

Though the Druze community enjoys considerable influence in Upper Chouf, the region remains mixed — Christian and Druze. During the civil war, the two communities engaged in warfare against each other. And in some corners, distrust and resentment still linger. But in areas served by the water treatment network, tensions have eased considerably.

“This is the reconciliation part of the mission,” says the Pontifical Mission’s Imad Abou Jaoude. “Christians and Druze are coming together through shared projects such as this.” It also reflects, he continues, “the pope’s mission to build bridges between Christians and other religious communities in the Middle East.”

Over the years, other charities and nongovernmental organizations have launched water treatment projects in Lebanon. However, most of them shut down within a few years as a result of funding shortfalls. Learning from these failures, the Pontifical Mission’s staff conceived the plants, even in their earliest stages, from the vantage point of long-term economic sustainability. Its engineers designed them to be as energy efficient and as easy to maintain as possible.

“Our plants are among the few in operation,” boasts the Pontifical Mission’s Mr. Abou Jaoude.

As the Pontifical Mission does with the beneficiaries of the reservoir lake near Deir El Ahmar, it requires villagers in the Upper Chouf region to take meaningful ownership of the treatment plants. The village municipalities cover approximately a third of the operating costs as well as those associated with expanding the sewage pipelines.

“I look out for fluctuation in the electricity voltage and problems with the pumps, and I pay attention to strange noises,” says 50-year-old Ghassan Riman, the caretaker of the Maasser el Chouf plant and a local resident. “I have a local mechanical engineer and two local technicians I can call if something goes wrong.”

“I take pride in the fact that I am not a source of pollution,” says 51-year-old Youssef Riman, an administrator in the village’s municipal offices who coordinates relations with the plant. “Neither to underground water nor to the land or trees around, nor to surrounding villages.”

A regular contributor to ONE, Don Duncan has covered the Middle East and Africa for The Wall Street Journal, The Guardian, The New York Times and Agence France Presse.