After 54 years of thirst, the U.S. and Mexico partner to save the Colorado River Delta

Since 1960, the Colorado River has not flowed regularly to the sea. While pockets of green remain, the Colorado in its delta is a parched river begging for relief. The dry, sandy channel glares in the bright sun, abandoned by the river that has been overtapped and overworked for too long.

Colorado River

It’s hard not to think of the lost potential of an ecosystem that once thrived. After an adventure there in 1922, American author, scientist and environmentalist Aldo Leopold wrote:

“On the map, the delta was bisected by the river, but in fact the river was nowhere and everywhere, for he could not decide which of a hundred green lagoons offered the most pleasant and least speedy path to the Gulf [of California].”

The Colorado’s delta was once a landscape of plenty, the basis of rural economic activity and local employment. Tourism, recreational hunting, sport and commercial fishing – all have been lost to overuse and over exhaustion of a limited resource.

For decades, it seemed nothing could be done. I spent much of the past 15 yearsshining a spotlight on the sorry state of the Colorado River Delta for audiences across the country. And while it is true that these conversations would quickly turn to the byzantine complexities of water law and the difficulties of caring for shared cross-border resources, it is also true that most people are truly unsettled by the reality that the Colorado stops short of its natural destination.

Now we are taking a major step to right the wrong that has been done to the Colorado River Delta. For the first time in history, the U.S. and Mexico will send a modest volume of water into the Colorado River Delta in the form of a temporary “pulse flow,” which will mimic the natural spring floods that once nourished the delta. Never before have we deliberately sent water below Morelos Dam, the last dam on the river just south of the U.S.-Mexico border, to benefit the environment. This month, water from the Colorado River will literally pulse through the border as a sign to the rest of the world of what we can accomplish through cooperation between nations. It feels like a triumph of human optimism over acquiescence.

Some may grumble that this is not the time to send water to the environment, but that objection ignores the broader context of the recent binational agreement and the many benefits it brings to both countries. In addition to breathing life back into the delta, this new framework more broadly allows the U.S. and Mexico to share surpluses in times of plenty and reductions in times of drought, provides incentives for leaving water in storage, and conserves water through joint investments in projects from water users in both countries. These benefits extend to water users throughout the Colorado River Basin – in all seven U.S. and two Mexican states.

By abandoning the old framework of “who gets what” and establishing cooperative management of our shared resource, the U.S. and Mexico are achieving benefits for communities and nature alike. With this kind of cooperation, I have renewed hope that in the not-so-distant future we will see delta ecosystems and economies thrive once again. More

On a potentially dying planet shared resources are a no-brainer. Editor

 

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Nile Delta disappearing beneath the sea

El Rashid, Egypt - It only takes a light covering of seawater to render land infertile, so Mohamed Saeed keeps a close watch on the sea as it advances, year after year, towards his two-hectare plot of land. The young farmer, whose clover field lies just 400 metres from Egypt's northern coast, reckons he has less than a decade before his field - and livelihood - submerges beneath the sea.

Nile Delta

But even before that, his crops will wither and die as seawater infiltrates the local aquifer. The process has already begun, he says, clutching a handful of white-caked soil.

"The land has become sick," says Saeed. "The soil is saline, the irrigation water is saline, and we have to use a lot of fertilisers to grow anything on it."

Spread over 25,000 square kilometres, the densely populated Nile Delta is the breadbasket of Egypt, accounting for two-thirds of the country's agricultural production, and home to 40 million people. Its northern flank, running 240 kilometres from Alexandria to Port Said, is one of the most vulnerable coastlines in the world, facing the triple threat of coastal erosion, saltwater infiltration, and rising sea levels.

According to Khaled Ouda, a geologist at Assiut University, a 30-centimetre rise in sea level would inundate 6,000 square kilometres of the Nile Delta. The flooding would create islands out of an additional 2,000 square kilometres of elevated land - isolating towns, roads, fields, and industrial facilities.

"The total [area of the Delta] expected to be impacted by a rising of the sea level by one metre during this century will be 8,033 square kilometres, which is nearly 33 percent of the total area of the Nile Delta," says Ouda.

You can build all the walls you want, but it won't stop the seawater from advancing underground. - Osman El-Rayis, chemistry professor at Alexandria University

In a report released in September 2013, the International Panel on Climate Change (IPCC) predicts a sea level rise of 28 to 98 centimetres by 2100, more than twice its 2007 projections. Even by the most conservative estimate, this would destroy 12.5 percent of Egypt's cultivated areas and displace about eight million people, or nearly 10 percent of the population.

But it is not just rising sea levels that threaten Egypt's northern coast: The delta itself is sinking.

Prior to the building of the Aswan High Dam in the 1960s, more than 120 million tonnes of silt washed down the Nile each year and accumulated in its delta. Without this annual silt flow to replenish it, the Nile Delta is shrinking - in some places the coastline is receding by as much as 175 metres a year.

The Egyptian government has attempted to slow the sea's advance by building a series of breakwaters and earthen dykes along the northern coast and its waterways. Piles of concrete blocks help reduce coastal erosion, but without new sedimentation, the delta land has compacted and thousands of hectares now lie at sea level.

"You can build all the walls you want, but it won't stop the seawater from advancing underground," says Osman el-Rayis, a chemistry professor at Alexandria University. "The saltwater rots fields from below, killing plant roots and leaving behind salts [as it evaporates] that render the soil infertile."

El-Rayis warns that as the delta substratum becomes more porous, seawater has begun to infiltrate the Nile Delta aquifer, a vital source of underground water spread over 2.5 million hectares.

Saltwater has always been a threat to coastal agricultural land, but salinity was traditionally kept in check by a steady flow of freshwater covering the soil and flushing out the salt. As Egypt's population has expanded, upstream demand on water has increased, reducing the amount of Nile water that reaches the Delta. What does trickle in these days is choked with sewage and industrial toxins.

Faced with rising water levels and increased salinity, many farmers have abandoned their land or switched to fish farming. Others have resorted to adding sand or soil to their fields to keep them above the brackish water.

The sand is drawn from the dunes that line much of Egypt's northern coast and act as natural barriers against the advancing sea. The plundering of these dunes for construction materials and fill has made the Nile Delta yet more vulnerable to a rise in sea level.

Scientists have proposed measures to protect the Delta lowlands from the sea's incursion. They say the priority is to slow beach erosion by preserving natural coastal defences such as sand dunes, while building seawalls along the 240-kilometre coast that are strong enough to hold back the Mediterranean.

"These walls would be built facing the sea in places where low-lying gaps occur along the beach," says Ouda.

He explains that, in order to be effective, the barriers must include an impermeable substructure extending from three to 13 metres below sea level that prevents seawater from infiltrating freshwater aquifers.

The size is as formidable as the expected cost. One proposal submitted by Egyptian engineer Mamdouh Hamza put the price tag at $3bn. The plan envisions building a concrete wall along the Delta's entire coastline and skirting it with a plastic diaphragm to prevent saltwater seepage.

Ouda says the mega-project would be cost-effective in that it would save the Nile Delta lands, but it is unlikely to attract the necessary capital. He doubts Egypt's cash-strapped government could cover the costs, while the international community appears unwilling to offer a lifeline.

"The project to establish the coastal walls is a service project… without economic gain and, thus, you will not find a financier for this project from companies or foreign governments," Ouda says.

Yet some have argued that as Western nations are most responsible for climate change, their governments should foot the bill on behalf of the developing nations most impacted by its consequences. More