A coalition of county, city and labor officials held a news conference Friday morning to make their case against two North County rural water districts leaving the San Diego County Water Authority (SDCWA).

In updated numbers released this week, the SDCWA reported that it would cost San Diegans nearly $200 million over a decade if Fallbrook Public Utility District and Rainbow Municipal Water District were allowed to leave the 24-member agency.

La Mesa Vice Mayor Colin Parent said that was unfair to his constituents. The Helix Water District, which services La Mesa, was projected to pay an additional $1.2 million-plus if those two agencies leave.