WASHINGTON — Big multimillion-dollar water projects, once a favorite target of good-government reformers who made them a poster child of political pork, are back in vogue as a rare force of concord in a dysfunctional Congress.

Republicans and Democrats who found little common ground in 2013 are rallying around a bill they hope to pass early next year authorizing up to $12.5 billion over the next decade for flood diversion in North Dakota, widening a Texas-Louisiana waterway, deepening Georgia’s rapidly growing Port of Savannah and other projects.

That’s the Senate bill’s total. The House version would cost about $8.2 billion. Negotiators are confident they can merge the two and pass the package for President Barack Obama’s signature early in 2014.

Unlike a farm policy-food stamp bill also the subject of ongoing House-Senate negotiations, the differences in the two houses’ water project bills are modest and the acrimony is less.

Negotiators say the roughly $4 billion gap between the two bills is more about how they are written than substantive policy or political differences.

“The important thing is that we all care about reform,” said Rep. Bill Shuster, R-Pa., chairman of the House Transportation and Infrastructure Committee.

Shuster’s Senate counterpart, Sen. Barbara Boxer, D-Calif., has said much the same thing.

The last time Congress enacted a water projects bill was 2007, and it took two-thirds majorities in both houses to override President George W. Bush’s veto of it.

Negotiators held their first formal meeting just before Thanksgiving on blending the two versions. Staff talks continued until Congress left for its year-end break and will resume in January.

Lawmakers have been drawn to the big investment in infrastructure sketched out in both bills — and the promise of jobs that entails. Business groups, led by the U.S. Chamber of Commerce, have lobbied members to support the bills, saying they’ll help keep American businesses competitive.

The bills try to address perceptions of years past that water project legislation was loaded with favors inserted by key lawmakers for their home districts and states. This time, both bills eliminate billions of dollars in dormant and duplicative projects. Shuster stressed that this bill contains no such “earmarks.”

Those reforms still aren’t enough for some conservative groups that pressed lawmakers to oppose the bills, saying they are reform in name only and don’t do enough to cut spending.

“Even before the predictable increase in authorizations as this bill goes through the process, this legislation would only shave a few billion dollars off the backlog,” Heritage Action and other groups wrote House members.

Tea party sympathizers in the House largely brushed off conservative critics, buying into the idea that this water projects bill represents both reform and needed investment. To wavering Republicans, Schuster cited Article 1, Section 8 of the Constitution, which directs Congress to establish roads and regulate interstate commerce.

For their part, Democrats breezed past environmental groups concerned about language that speeds up the environmental review process for projects.

The House bill passed 417-3 in late October, winning support of everyone from Democratic leader Nancy Pelosi to tea party stalwarts like Rep. Tim Huelskamp, R-Kan. The Senate easily passed its version of the bill in May by a vote of 83-14.

Both bills accelerate environmental reviews and allow more money from the Harbor Maintenance Trust Fund to be spent on harbor improvements, but the House version of the bill ramps up spending from the fund more slowly.

The legislation would affect virtually every facet of America’s waterways and authorizes or reauthorizes dozens of projects, though Congress still has to pass separate bills appropriating money for them.

Among them:

—Dredging and widening the Sabine-Neches Waterway, billed as “America’s Energy Gateway” because the nearly 80-mile waterway services many oil and natural gas refineries in Texas and Louisiana.

—$954 million for environmental restoration along the Louisiana coast.

—Expanding the Port of Savannah. Georgia officials have long lobbied for federal backing to improve one of the country’s fastest growing ports; the bills designate up to $461 million for that purpose.

—Flood diversion for the flood-prone Red River Valley region of North Dakota and parts of Minnesota. The bills authorize spending of about $800 million to relieve flooding in a region that includes the cities of Fargo, N.D., and Moorhead, Minn. The region has suffered major floods in four of the past five years.

—Up to $43 million to reduce hurricane and storm damage risks along the San Clemente, Calif., shoreline.

The bills would shelve about $12 billion in old, inactive projects that had been approved in water resources bills prior to 2007.

Follow Henry C. Jackson on Twitter at www.twitter.com/hjacksonap