VANCOUVER—A campaign by groups protesting the development of private power projects on British Columbia rivers has gone viral in an attempt to drown Liberal MLAs in a flood of messages tomorrow.

The Web-based event, called 10,000 Voices, will demand a moratorium on private hydropower projects—and it sends a signal that social networking through Twitter, Facebook, and e-mail will be a powerful tool in the May 12 provincial election.

"I think we'll easily meet the target of 10,000 people from across the province, from Vancouver to Prince George. They will take action on the day and say make sure we do green power right," said Gwen Barlee, policy director for the Wilderness Committee, one of 12 groups behind the initiative.

"We have over 1,000 supporters on the Facebook site, we have over 1,000 signed up on [the website] 10,000voices.org and then we have a multiplier effect. And that's just the Wilderness Committee," she said.

Ms. Barlee said the growing protest against independent power projects—which are proposed on some 600 BC rivers and streams—has "absolutely gone viral" heading into the election.

Ms. Barlee said when the groups agreed to join forces to pressure the government for policy change, the Wilderness Committee studied the communications strategy used by President Barack Obama in winning both the 2008 Democratic primaries and the national election.

"We were looking at Obama, at how he'd effectively used the Internet and Facebook," Ms. Barlee said.

"Facebook is a relatively new tool, at least in a campaign perspective for the Wilderness Committee. And it's also a tool that reaches out to a younger segment of the population that sometimes isn't a typical environmental supporter," she said.

Wilderness Committee staff are also using Twitter, the way Mr. Obama did in his campaign of change, urging people to help him get out the vote.

Andrew Radzik, outreach coordinator for the Wilderness Committee, said the multiplying effect of social networking is what makes the approach so powerful.

In the past, organizations like his would have had to launch massive and expensive advertising campaigns to reach such a large audience. Now they are relying on the message to spread from person to person, growing exponentially in the process. Everyone who gets involved is being asked to sign up at least one other supporter.

"One of the things we really wanted to do with this was to give people who really care about this issue the ability to take it and explain it to other people," Mr. Radzik said. "So it's not just, 'Hey, everybody we've got this thing happening' but it's asking people to be a part of it, to spread the word.

"What we found was that people are incredibly effective messengers when they go out and talk to the people they regularly would, to their friends, their family, their co-workers."

Mr. Radzik said while the aim of the campaign is to unleash a flood of e-mails, phone calls and faxes on the offices of government MLAs tomorrow, people have started doing their own events in advance.

He just got an e-mail from a group who heard about 10,000 Voices on a Facebook kayaking site. They used Facebook to plan a rally, got a poster from campaign organizers and then got coverage on a local news broadcast.

The 10,000 Voices campaign states that independent hydropower projects should be halted because they will damage BC rivers and put public resources in private hands.

The Independent Power Producers Association of British Columbia did not return calls. But the association has been doing its own outreach over the Internet, offering members news flashes, event alerts, issue flags and briefing papers through its website.