Here’s a warning to the Senate minority leader, Chuck Schumer, and other environmentally inclined Senate Democrats, like Sheldon Whitehouse and Ed Markey: A legislative minefield lies dead ahead, pocked with destructive amendments of Republican origin hostile to clean air, clean water, endangered species and fragile landscapes. And here’s a plea: Stop these measures from becoming law.

Following its approval of the big budget deal on Feb. 9, Congress began writing the dozen appropriations bills that direct federal dollars to specific agencies. These bills are likely to be incorporated in one giant omnibus spending measure to be negotiated over the next few weeks by House and Senate leaders in advance of the March 23 expiration of the continuing budget resolution that has kept the government going.

Given its urgency, the bill is fertile ground for the kind of mischief the Republicans in particular have been notorious for over the years — loading up must-pass bills like this one with provisions, known as riders, that in most cases could not survive on their own and thus need protective cover. In years past, such riders were usually inserted at the last minute on the House or Senate floor. Here they are in plain sight, having been approved in earlier votes or endorsed by powerful committee chairmen or chairwomen who will do their level best to make sure they are included in the final bill. Mr. Schumer can prevent that from happening. The Democrats are effectively 49 in number, the Republicans 51. By holding his party together, he can deny the Republicans the 60 votes they need to overcome a filibuster — ensuring a clean bill, and a cleaner environment.

Public interest groups have counted nearly 90 of these riders, but here are several of the worst:

Clean water In 2015, the Obama administration adopted a landmark rule intended to clarify and broaden protections for smaller streams and wetlands vital to the country’s drinking water and wildlife. Although the bill simply reaffirmed the reach of the original 1972 Clean Water Act, developers and big farmers complained to Scott Pruitt, the industry-friendly head of the Environmental Protection Agency, who has begun the lengthy process of replacing the rule with something more favorable to commercial interests. That’s not fast enough for the leaders of three separate appropriations panels — in the House, the interior and environment subcommittee and the energy and water development subcommittee; and in the Senate, the interior and environment subcommittee — who are pushing nearly identical riders that would kill the rule right away, without consulting the public or conducting the scientific analysis required by law.