WASHINGTON — The House has torpedoed a proposal to allow limited boating on Hetch Hetchy Reservoir in Yosemite National Park.

Critics feared the plan could introduce contaminants to the reservoir that supplies famously pure drinking water for 2.7 million people in the Bay Area. Boating on its waters has been banned for nearly a century.

House Speaker Nancy Pelosi, D-San Francisco, claimed the decision as a victory for her city, which runs the Hetch Hetchy water and power system. The prohibition was included in a $1.37 trillion spending plan the House approved Tuesday to keep the federal government funded through September.

Interior Secretary David Bernhardt, who oversees the national parks system, had been considering a proposal to allow rental kayaks, canoes and electric-powered boats for the first time. His predecessor, Ryan Zinke, had said the department was “taking a fresh look at different opportunities and options to restore public access and recreation” to Hetch Hetchy Valley.

The plan for “environmentally healthy access” by boaters to Hetch Hetchy was advanced by California Trout, a conservation group that says it works “to ensure resilient wild fish thrive in healthy waters for a better California.” It was also backed by Restore Hetch Hetchy, which wants to drain the reservoir and restore Hetch Hetchy Valley to its natural state.

The plan would have excluded gas-powered motorboats from Hetch Hetchy, but that didn’t sway Pelosi.

Since Hetch Hetchy was filled in 1923, “boating has been prohibited to prevent the introduction of contaminants, and the quality of the water from Hetch Hetchy is so pristine that it does not require filtration,” her office said.

The San Francisco Public Utilities Commission, which operates the Hetch Hetchy system, applauded the House’s move.

“We commend the House’s decision to preserve the Hetch Hetchy Reservoir’s purpose to provide safe, fresh and clean water to the SFPUC’s 2.7 million customers,” said Will Reisman, a spokesman for the agency.

The spending plan still needs final authorization from the Senate, which is expected to approve it before the government runs out of funding on Friday. President Trump’s administration has signaled he plans to sign the legislation.

Restore Hetch Hetchy’s executive director, Spreck Rosekrans, said keeping the prohibition on recreational boating at Hetch Hetchy was representative of a “campaign” by San Francisco officials “to severely limit public access to Yosemite’s spectacular Hetch Hetchy canyon.” The organization will review its legal options in light of the move, he said.

Curtis Knight, executive director of California Trout, said it was “unfortunate that the public will continue to be shut out from enjoying the beauty and benefits of this natural treasure. It’s more important than ever that people get out and experience the extraordinary gifts nature provides in order to understand the need to protect it.”

Pelosi’s office touted several other victories in the spending plan approved in the House:

• Congress rejected the Trump administration’s proposal to earmark money for a project to raise Shasta Dam. California Republicans and farming interests in the Central Valley want to raise the dam by nearly 20 feet to store more water. Environmentalists say it would endanger chinook salmon habitat, and the Winnemem Wintu Tribe says the project would inundate sacred lands. California Attorney General Xavier Becerra won a lawsuit halting the project.

• The plan includes $10 million in loans to fund restoration of historic buildings and maintenance in the Presidio. The Treasury Department would loan money to the Presidio Trust, an autonomous federal agency, to continue projects in the park — loans it would have to repay with interest.

San Francisco Chronicle

staff writer Dominic Fracassa contributed to this report.

Dustin Gardiner is a San Francisco Chronicle staff writer. Email: dustin.gardiner@sfchronicle.com Twitter: @dustingardiner