The U.S. Chamber of Commerce is attacking Democratic Sen. Barbara Boxer of California in two ads accusing her of favoring a "three-inch smelt," a freshwater fish, over water and jobs. The ads aren’t quite accurate, however.

According to The Associated Press, the ads began running Sept. 8 in Sacramento, Fresno, Bakersfield and San Diego. Both ads say "Boxer is famous for protecting the three-inch smelt" and accuse her of voting to "cut water" to San Diego and the Central Valley. Strictly speaking, both ads are untrue. Boxer didn’t vote to "cut water." Water had already been restricted in December 2008, because of a biological opinion from the U.S. Fish and Wildlife Service to protect the delta smelt, a two- to three-inch long freshwater fish, which the FWS has classified as "threatened."

It’s true, however, that Boxer voted to keep those water restrictions in place. Both ads refer to a Senate vote on Sept. 22, 2009, on an amendment offered by Republican Sen. Jim DeMint of South Carolina. As DeMint himself explained on the floor of the Senate, the measure "turns the water back on for 1 year." (Water hadn’t been cut off completely, of course. Rather, restrictions on pumping had reduced the flow.) The Senate voted overwhelmingly to kill DeMint’s amendment, 61 to 36, on a mostly party-line vote. No Democrats supported the measure, and four Republicans joined them in voting to kill it.

The San Diego ad blames Boxer’s vote to protect the delta smelt for rapidly rising water rates in the city. That’s only partly true. The ad cites an April 13 press release by the Metropolitan Water District of Southern California announcing mandatory water restrictions for the second year in a row. It quotes manager Jeffrey Kightlinger as blaming the pumping restrictions for increasing rates.

Kightlinger, April 13: The historic pumping restrictions in the Delta because of endangered fish species are compromising the statewide water system’s ability to capture adequate supplies.

But a newspaper story that the ad cites as support for its claim actually makes no mention of the delta smelt or pumping restrictions. In addition to rising wholesale costs, the San Diego Union-Tribune story cites a four-year drought and added spending to upgrade the city water system as factors, as well as "poor budgeting" by the water authority.

The U.S. Chamber of Commerce has endorsed Boxer’s opponent, Republican Carly Fiorina.