WASHINGTON (AP) — Congress is on the cusp of passing its first infrastructure bill of the year.

The Senate is expected to vote Thursday on a $12.3 billion water resources bill that authorizes 34 water projects, from managing flood risks in Cedar Rapids, Iowa, and restoring environment in Louisiana to dredging Boston Harbor.

The Water Resources Reform and Development Act is a bipartisan compromise of companion bills passed separately by the House and Senate last year. After more than six months of negotiations, the House voted on the measure Tuesday, approving it 412-4.

The Senate will now have its say, potentially sending a bill to President Barack Obama that supporters have said will create jobs and provide needed investment in the nation's waterways.

The bill's backers include building associations and business interests, like the U.S. Chamber of Commerce, that have said the projects sketched out in the bill will provide construction jobs and make improvements needed to keep the U.S. competitive. In the House, it won support from virtually every constituency, with only four lawmakers — all Republicans — voting against it.

Some conservative and watchdog groups have criticized the bill, saying it does not go far enough to curb spending. The bill represents "specifically the sort of parochial-based, politics-laced decision-making process that the current earmark moratorium was meant to guard taxpayers against," Russ Vought, Heritage Action's director of grass-roots outreach, wrote ahead of the House vote.

The bill's authors have argued that the bill does more to rein in spending than any previous water bill. Rep. Bill Shuster, R-Pa., chairman of the House Transportation Committee, noted that in addition to approving 34 projects, the legislation puts an end to $18 billion of dormant water projects passed before 2007. The bill's potential price tag, at $12.3 billion, is a little more than half the $23.3 billion estimated cost of the last water projects bill Congress authorized, in 2007.

This year's bill authorizes an array of project from coast to coast.

In Iowa, the bill would authorize roughly $73.1 million in federal spending to help build up flood protections in Cedar Rapids, an eastern Iowa city that suffered devastating flooding in 2008. Along the Louisiana coast, the bill would allow more than $1 billion for environmental restoration. And in Massachusetts, the bill would permit some $216 million for dredging and expansion in Boston Harbor.

In addition to authorizing projects, the bill also makes changes to how future projects seek funding. It sets specific time and cost limits for studies on potential projects, eliminates redundant Army Corps of Engineers reviews and speeds up environmental reviews for potential projects.

The bill also increases spending from the Harbor Maintenance Trust Fund to pay for improvements to ports and creates a five-year pilot program to provide loans and loan guarantees for various projects.