Saving water, saving the river

Posted: 21 June 2006

Author: Brian Thomson

Water is a scarce and valuable commodity in the Chihuahuan desert region of northern Mexico. But in the Delicias district, which lies about 90km south of Chihuahua City - the state capital - there's an abundance of water rushing into the fields to irrigate extensive alfalfa crops and pecan tree plantations.

Advancing front irrigation, Chihuahua Desert, Mexico
Advancing front irrigation, Chihuahua Desert, Mexico
Advancing front irrigation is one of the irrigation systems used in the agricultural zones of Delicias, Chihuahua Desert, Mexico. © WWF-Canon/Edward Parker

Here, farmers, together with the local water authority, have been working to improve the irrigation system, resulting in water savings of up to 40 per cent.

It's hard to believe that not far from Delicias, the mighty Rio Grande - one of North America's longest rivers - is drying up. The Rio Grande supports an exceptional array of life, including more than 250 species of birds, hundreds of native mammals and more than nine million people. But agricultural pollution and overuse of water to irrigate fields and supply towns is threatening the health of this all important cross-border ecosystem.

Saving water upstream and in the river's tributaries will be a key part to the Rio Grande's recovery.

Solving the water crisisShaded from the noon day heat by a leafy pecan tree, Miguel Maciel, president of the Delicias district farmers association, has been farming here for the past 15 years. He explained just how serious the problem regarding water is for local farmers.

"The main problem is obviously a lack of water because in the last ten years the low level of rains has been well below the average," explained Maciel. "So it hasn't been possible to produce as much from the land as we used to."

With agriculture sucking up over 90 per cent of this arid region's precious water supplies, farmers are the first to realize that if nothing is done to farm and irrigate in a smarter way the water will eventually run out. They also are beginning to realize that this would be a catastrophe for people, the economy and the environment.

In response, farmers, the government and WWF have come together to develop sustainable solutions so that communities dependant on agriculture, particularly downstream water users, can continue to prosper, while also easing the pressures on water resources and natural ecosystems such as wetlands.

Melchor Lopez, a hydrologist with Mexico's national water authority, explained that the main thrust of their work in the Delicias district has been to reduce water consumption.

"We've done this by putting in place a more efficient irrigation system," said Lopez. "There's been a very high level of investment from the government and we would like to see these types of projects rolled out in other parts of the country and elsewhere."

Chihuahua Desert map
Chihuahua Desert map

Sharing the waterFrom its headwaters in the Sierra Madre mountains of western Chihuahua, down to the point where it reaches the dried out Rio Grande below the US state of Texas, the Rio Conchos River - a major tributary of the Rio Grande - is the main source of water for 1.3 million people in Chihuahua. The river also feeds water to 200 hectares worth of fields in other irrigation districts and border towns in Mexico, and 100,000 hectares of fields in irrigation districts and border towns in the US.

The Rio Grande rises in the San Juan Mountains of Colorado, US, flowing south into New Mexico through Albuquerque to El Paso, Texas, on the US-Mexican border. The Rio Conchos enters at Presidio, below El Paso and supplies most of the water in the 2,019km Texas border segment.

"Water here is being shared between Mexican and Texan farmers," said Lopez. "So any investment in water savings by Mexico will have an impact on both sides of the border."

"Since most of the water is being used by the agricultural sector the Mexican government has invested its resources in improving the irrigation systems at work in the Rio Conchos basin. This, in the end, has the most direct impact on reducing the amount of water taken from the Rio Conchos, while at the same time supporting local farmers."

WWF is working with Mexican and American government agencies, landowners and local NGOs on a four-year project in the bi-national Rio Grande basin, which includes a large portion of the Chihuahuan Desert Ecoregion.

In particular, the project is: helping to implement water policy reforms that allocate water for ecological uses; demonstrating better water management practices through integrated watershed management pilot projects; and involving key stakeholders in the implementation of water policy reforms and restoration strategies that benefit the basin.

Smart irrigationOn a tour of the district's farmlands, Hector Manuel Arias Rojo, WWF-Mexico's Chihuahuan Desert coordinator, was keen to explain how by lining irrigation channels with concrete, chanelling water in pipes and applying pressurized irrigation techniques, farmers in Delicias have managed to save around 35 per cent of the water. This had previously been lost as water soaked into the earth before it got to the crops it was intended for.

Miguel Marciel, president of the Delicias district farmers association
Miguel Marciel, president of the Delicias district farmers association
WWF works with farmers like Miguel Marciel, president of the Delicias district farmers association, to develop alternative irrigation methods. Chihuahua, Mexico. © WWF Mexico/Jenny Zapata

"Traditionally farmers have flood irrigated their fields, now with alfalfa and pecan tree plantations the farmers have installed high pressure sprinklers," said Arias.

"This allows water to be applied more evenly and in lower volumes. In the case of the pecan plantations, there is a 90 per cent efficiency saving in water use."

A wide variety of techniques are being used to save water in the district, including the use of lasers which are used to level fields. This means that when water is applied it doesn't pool unevenly on an undulating surface, but is instead allowed to soak in evenly across the field. Another way that water is being saved is by using low-pressure irrigated techniques with water flowing to the fields in pipes instead of running through the fields in earthen channels.

"Instead a large plastic pipe supplies the water to the field with individual gates that then let the water flow into each row," added Arias. "This means the water flows faster and there's less soaking when the water first enters the field. This is important because when you irrigate a crop you want it to soak to the roots but no further, any deeper and that water is being wasted."

Farmers, such as Miguel Maciel, are happy not only to see water being saved but also to see production levels rising, sometimes by up to 50 per cent. Adjusting his trademark white cowboy hat, Miguel is keen to explain how with the new methods in place and water savings being made he's more positive in his vision of the future.

"All the producers want to use less chemicals, avoid pollution and stop soil erosion," he said. "But the truth is the most important thing to take care of is the water because in this part of the world there's a lot of land but little water. We hear that two-thirds of the planet is made of water, but very little of that is freshwater, and that's what we need."

Mexico has invaluable lessons to teach other countries in the region about the "do's and don'ts" of sustainable production. The project in Delicias is spearheading efforts to ensure long-term sustainability for the environment and farmers in a region where annual rainfall barely reaches 300mm.

According to WWF, about 54 per cent of the world's accessible freshwater is diverted and 70 per cent of this is used for irrigated agriculture. The rapid growth of water consumption - set to double in coming decades - is creating a crisis for people and the environment.

However, in this one corner of Chihuahua, farmers, conservationists and government authorities are pulling together to find sustainable solutions and are looking to put back water helping efforts to save the Rio Grande.