Dec. 10: This post has been corrected.

This is one of our editors' picks from our ongoing roundup of Investigations Elsewhere.

Sen. Dianne Feinstein threw a wrench in plans to protect the fish population of a California delta after a deep-pocketed corporate farmer -- and campaign donor -- asked her to, reports California Watch, a project of the Center for Investigative Reporting.

Based on studies showing potential danger to the fish population, the federal government planned to curtail irrigation pumping at the Sacramento-San Joaquin River Delta. The plan was bad news for Stewart Resnick, who owns 118,000 acres of orchards in the water-strapped state.

So he wrote to Feinstein, a friend to whom he, his wife and the executives of his companies have donated over the past two decades, albeit a relatively modest $29,000. He urged her to intervene, calling the studies "sloppy science."

The senator promptly wrote to Interior Secretary Ken Salazar and Commerce Secretary Gary Locke, asking them to re-examine the science behind their plan. The administration agreed.

Feinstein’s spokesman, Gil Duran, said the senator's letter was "based on what she believes to be the best policy for California and the nation. No other factors play a role in her decisions."

In all, the Resnicks and their executives have made political donations to the tune of nearly $4 million, including $246,000 to Democratic political committees. Their donation pattern seems nonpartisan, reports California Watch, with the money following who's in power.

Correction:The headline on this story previously said that a study Sen. Feinstein supports is “helping slow down” a fish protection plan. In fact, the plan is already in place. While the study may delay it, it hasn’t yet done so.