(The Christian Science Monitor) On the windy shore of Lake Nic­aragua, farmer Dayton Guzman surveys the vast expanse of water his family relies on for irrigation of the land they have been farming for generations.

“If something affects the lake,” he said, “it affects us.”

The lake’s future is in doubt since a Chinese-backed canal project was inaugurated late last year. The multi-billion-dollar Grand Canal is slated to stretch 170 miles from the Caribbean to the Pacific, and some 60 miles of it will cross through this lake.

The government argues that the project will create tens of thousands of jobs and boost GDP by up to 12 percent, in a country where nearly three-quarters of the population lives on less than $4 a day.

But the canal has encountered both careful criticism and fierce opposition from Nicaraguans. And the lake has become a potent symbol of what’s at stake. The 3,000-square-mile lake, Central America’s largest, is home to endangered species and a water source for hundreds of thousands of people.

Scientists warn that the dredging required for the canal would result in irrevocable damage. Concerns about land expropriation and pollution are spreading, with tens of thousands of demonstrators marching in more than 35 protests to date. The Nicaraguan Conference of Bishops has called on the government of President Daniel Ortega for open debate and increased transparency, saying it’s “worried” about the project.

President Ortega has been the target of protests before, but this time may be different. In recent years, public criticism has followed party lines. But the protests now include “many who are sympathetic to the government,” said Manuel Ortega Hegg, a Nicaraguan sociologist. “What’s new is they involve a wider range of groups, like campesinos.”

Those farmers are traditionally a San­dinista party base. But now, dissent goes “beyond political parties,” Hegg said.

As the afternoon sun turns amber on the island of Ometepe, a white egret stalks in the lake shallows and a woman washes clothes on a broad detergent-stained rock. A mother and her son fish from the shore, throwing in their lines again and again as the sun sets.  

The canal would pass within three miles of Ometepe. Some residents complain the government hasn’t given them any information.

“If the canal is going to hurt us fishermen, we need to know how it will affect us,” said Santos Lopes, who’s been fishing on the lake for 30 years. He said he would give up his nets to earn a wage working on the canal. But he doesn’t know if that trade-off is even possible.

A gathering of international scientists called for an independent environmental assessment, but the government hasn’t responded.

Jorge Huete-Pérez, a biologist and vice president of the Academy of Sciences of Nicaragua, hosted the conference about the canal in November. Both the government environmental consultants and the Hong Kong firm backing the project declined invitations.

“We know they’re going to damage the lake, because there’s no technology they can use that’s not going to be invasive and create damage,” Huete-Pérez said. “All of these questions need to be discussed transparently . . . Nicaragua is a democracy.”

But some say Nicaragua’s democracy is an illusion. As president during the Sandinista revolution in the 1980s, Ortega supported leftist policies such as land reform and nationalizing industries. On his return to power in 2006, he promised to help the poor and ensure access to free education and health care.

That year, he formed a strategic alliance with the Catholic Church. Since then, his government has consolidated independent media into state-controlled channels, enforced party loyalty from state employees, and restricted access to information. Civil society groups say their voices are suppressed, and legal efforts to modify the canal law have been blocked. 

Despite the alliance, the Conference of Bishops condemned the government’s “political practice” in its latest missive, accusing it of “abandonment of the common good” and calling its treatment of the conversation around the canal a sign of “ambition, authoritarianism . . . and corruption, a grave sin.”

The bishops also warned that communities on the canal route are determined in their opposition, which could lead to “armed conflict” if the government does not address dissent in a democratic manner.

Ometepe has been the site of several recent protests. Maria, a secondary school teacher on Ometepe, who asked that only her first name be used, said teachers were required to attend a canal presentation by a Sandinista party representative. They were told to teach their students that the canal has “no negative environmental impacts and would create jobs,” she said.

While many teachers are critical of the project, Maria fears losing her job if she speaks out. If you’re a state employee, she said, “you have to be in agreement” with the party.

The government is pushing forward, opening canal commission offices in communities slated for expropriation.

Meanwhile protests continue. Hegg, the sociologist, said that since Nicaraguans were shut out of dialogue, “their only recourse is to take to the streets.”

This article was edited on May 6, 2015.