Amid punishing drought, federal water managers projected Tuesday that — by a very narrow margin— the crucial Lake Mead reservoir on the Colorado River won’t have enough water to make full deliveries to Nevada and Arizona in 2018. A federal report shows the surface level of the lake behind Hoover Dam is expected to remain high enough this year to avoid a shortage declaration in 2017. But it’ll still be a mere 4 feet above a 1,075-foot elevation action point. For 2018, the U.S. Bureau of Reclamation projects the lake level could fall short — by less than 1 foot.