The Trump administration's changes to the Clean Water Act would alter rules put in place by his predecessor Barack Obama

The US government on Tuesday unveiled a plan to roll back clean water rules protecting the nation's waterways and wetlands, fulfilling a pledge from President Donald Trump to farmers and supporters who view environmental regulations as too strict.

The proposed changes to the Clean Water Act would "remove and replace" rules set by the administration of Barack Obama in 2015, which was widely praised by environmental protection activists.

That rule limited the runoff from pesticide and fertilizer products allowed in a majority of the nation's waterways, from large rivers to swampy areas located on private property.

Trump had previously called the Obama-era regulation "horrible" and said it impeded economic development in rural areas—an issue that was important to his electoral base.

The new law, which was drafted by the Environmental Protection Agency (EPA), applies a stricter standard to determine which waterways would fall under federal control.

It would cover main shipping lanes, tributaries of those waterways, certain lakes and reservoirs created by using a dam.

But individual states, which often have more lenient standards, would have the final say over streams, "ephemeral" bodies of water created by precipitation and certain artificial lakes.

This reframing of the law "puts an end to the previous administration's power grab," said the acting head of the EPA, Andrew Wheeler, a former energy industry lobbyist.

The previous rules were "really about power in the hands of the federal government, over farmers, developers and land owners," he added.

Because it was the subject of several court challenges, the 2015 law had only taken effect in 22 of 50 states.

Representatives from rural states heralded the stripped-back regulations at a ceremony at the EPA headquarters in Washington.

The proposal "brings back some common sense with regulations which try to achieve this balance between federal and state relationships," Republican Senator Lisa Murkowski from Alaska said.

But environmental protection advocates said the new rules would cause significant damage.

"The Trump administration will stop at nothing to reward polluting industries and endanger our most treasured resources," said Jon Devine of the Natural Resources Defense Council.

The new guidelines are set to take effect in 2019, according to the EPA. They will be subject to a 60-day comment period, and then could be revised before being finalized.

After taking office, Trump immediately began rolling back many of the environmental rulings made during Obama's eight years in office.

In addition to withdrawing the US from the Paris accord on combatting , the Trump administration has canceled an anti-pollution plan targeting coal-fired power plants and made moves to undo car pollution restrictions that were set to start in 2025.

But the deregulation process has been challenged in court by multiple , which could delay its potential implementation.