SACRAMENTO — After a long, acrimonious debate, urban lawmakers in the Assembly overwhelmed their rural colleagues Tuesday and won passage of a landmark measure that will make it easier for agricultural water to be distributed to cities.

In a 46-25 vote that demonstrated the emergence of a new alliance between urban Northern and urban Southern California, the Assembly passed legislation by Assemblyman Richard Katz (D-Sylmar) that would allow farmers to sell their water without interference from their local irrigation districts.

Assemblyman Phillip Isenberg (D-Sacramento) said the vote not only represented the first significant break in the philosophical bond between urban Southern California and corporate agriculture on water issues, but demonstrated the growing dissatisfaction within the state over the way its water is distributed.

In the past, Southern California and corporate agricultural interests joined to provide the political clout to construct the state's massive water projects. Traditionally, Northern California has opposed efforts to expand these projects, contending that the south was taking too much water from the north.

On Tuesday, the old divisions seemed to dissolve as urban interests banded together to oppose agriculture.

Isenberg said the bill would remove a major impediment to the transfer of water between agriculture and cities by preventing local water agencies from stopping sales between farmers and urban interests. For years, he said, agricultural water districts have "artificially prevented any interested property owner who wished to transfer water . . . to urban areas or anywhere outside their boundaries . . . from doing that."

The agencies, on the other hand, have maintained that water-rights water belongs to the district and not to individual farmers. If a farmer fallows his land and does not use all his water, it should be sold back to the district for farm use, they have insisted.

Echoing an argument presented repeatedly by urban lawmakers, Isenberg said agriculture, which in most years uses 80% of the state's water captured for consumption, has to be willing to share more with urban areas.

"Water is the lifeblood of our society and we've had a system to deliver that lifeblood that makes no sense," agreed Assemblyman Pat Nolan (R-Glendale).

"It is directed by politics, by muscle, by everything other than the people's need."