Environmentalists say it’s past time for California water officials to halt Los Angeles’ diversion of Mono Lake’s tributaries. But L.A. officials insist that water is a tiny but vital part of the city’s supply.

Environmentalists say it’s past time for California water officials to halt Los Angeles’ diversion of Mono Lake’s tributaries. But L.A. officials insist that water is a tiny but vital part of the city’s supply.