WATER AND BASEBALL are forever linked in this town. Consider the Mariners’ nautical name, Joey Cora’s playoff tears, and John

Ellis’ crocodile tears. And now a deal in the works to let the M’s irrigate their new natural-grass field with the groundwater beneath it could open the spigot for thirsty developers statewide.

The arrangement itself “makes lots of environmental sense,” says Dan Swenson, who oversees water resources for the Department of Ecology’s Northwest Region. Safeco Field sits on fill atop an historic floodplain. Its construction is bringing up groundwater, which crews are pumping to Metro’s stormwater treatment system. The baseball club would like to use this water on its soon-to-be-sodded 4 acres of grass. Doing so wouldn’t affect any streams, and would reduce the load on Metro’s facilities.

But there’s a catch. “As soon as they want to use the water [for irrigation] they’ve got to get a water right,” says Swenson. More than 5,000 water-right applications are already pending. State law requires that they be decided on a first-come, first-served basis. That means DOE would get to the M’s application in the middle of the next millennium.

That doesn’t mean Ken Griffey Jr. will be shagging fly balls against a brown field; the M’s could always buy water from Seattle. But water rights are free, and with stadium construction costs ballooning, even the water bill counts.

Fortunately, DOE has some wiggle room; under a provision called the “Hillis Rule,” it may focus on applications within a designated watershed or even sub-basin. In theory, this lets it address priority areas first. So, for the good of baseball, the agency drew up a sub-basin that covers a little more than a square mile around the stadium. The only water right applicant in this sub-basin? You guessed it. Swenson says he hopes to process the team’s application by next spring.

This seems an innocuous, even beneficial, tweaking of the rules (though the state might have held out for some concessions from the M’s—say, acquiring competent pitching). But environmentalists worry that it will open the floodgate on other, less-innocuous water requests, drawing from salmon runs and other habitat needs. Safeco Field isn’t the only place the Hillis Rule may get stretched. On the other side of the state, DOE has already proposed a special rule favoring Walla Walla’s Hilltop Acres development. If it can gerrymander a sub-basin’s boundaries around a baseball field, couldn’t it do the same for any development?

You bet, says Rob Caldwell, a water-law attorney with the Center for Environmental Law and Policy: “If you cut these sub-basins down small enough, you can grant water rights to anybody.”

When it comes to water rights, DOE is ready to play ball.