From the Los Angeles Times:

A 2003 water pact between the Imperial Valley and San Diego County was supposed to be good for both parties, and for California.

But the agreement — billed as the largest sale of water from farms to cities in the nation — is snared in litigation and the outcome is uncertain. No sooner had the pact been signed than it came under attack by environmentalists, farmers and the Imperial County Board of Supervisors.

One major point of contention is that the Salton Sea could become saltier and shrink if farmers reduce agricultural runoff into the sea because water is being sold to San Diego County. If the sea recedes further and becomes more saline, it could lead to massive fish die-offs, endanger migratory fowl and result in toxic dust storms.

The state Legislature, to help finalize the water deal, had promised to help fund restoration of the sea, but budget constraints have made that impossible.

Unless the state follows through on that promise, officials in San Diego and the Imperial Valley worry that the water deal could be struck down by the courts. If that happens, Southern California may be forced to seek more water from Northern California — the most incendiary issue in the state's historic water wars.

For more, see: Massive California farm-to-city water deal snared in litigation