In the U.S. midterm elections, which saw Democrats make sweeping gains across the country, environmentalists scored wins on key ballot measures in several states.

In California, voters defeated a measure that would have overhauled permitting, affording less time for environmental review while limiting legal challenges. Backers said the reforms were needed to speed the building of new homes and infrastructure. Opponents said the measure would allow projects to move forward without full consideration of their impact on air, water, and wildlife.

In Colorado, voters rejected an amendment to the state constitution that would have enshrined a right to produce and use natural gas. The proposal was a response to cities looking to block gas lines in new buildings and to moves by the state to tamp down on emissions from natural gas.…