First, the good news: This winter, much of the Sierra had a near-average snowpack. Now, the bad news: It has melted early.

Word of the vanishing Sierra snowpack, which usually helps replenish reservoir levels later in the summer, arrives amid uncertainty over how California’s dams will be managed in coming months to protect endangered fish. It also comes at a critical juncture for urban water officials across the state. Wednesday is their deadline to submit updated drought conservation plans that lay out projections of how much water will be available to customers over the next three years.

Federal officials late last week signed off on a plan that would release more water from Shasta Dam through June. The decision came after nearly two weeks of pressure from California’s powerful farming lobby and members of Congress who argued that too much water was being held back to protect endangered fish.

The U.S. Bureau of Reclamation and federal fisheries officials on Friday adopted a temporary plan that would increase the amount of water rushing down the Sacramento River below Shasta Dam from 8,000 cubic feet per second to 9,000 for the rest of June, bureau spokesman Shane Hunt said Monday.

“We need to start increasing releases to meet our commitments to our contractors,” Hunt said.

News of the temporary plan led to sighs of relief throughout the state’s agricultural industry, as it means more water for crops in the short term, particularly for rice farmers in the Sacramento Valley.

However, federal officials still haven’t formalized a plan to protect endangered salmon and smelt later this summer by managing water behind Shasta and other Sacramento Valley dams. The lack of a formal plan has left growers anxious they won’t get enough water as they head into the hottest months. Meanwhile, environmentalists worry that fish won’t get the water they need to stave off extinction.

Hunt said he hopes an agreement that strikes a balance between those interests will be finalized sometime this week.

After two years of fallowing fields, rice farmers in the Sacramento Valley significantly ramped up planting this spring. A series of heavy storms this winter and early spring fueled expectations that water deliveries were returning to normal. But some farmers have said Sacramento River flows are lower than expected, leaving them worried they won’t have enough water to sustain their crops. More water from Shasta could help.

The additional June flows also could help San Joaquin Valley farmers reliant on water pumped from the Sacramento-San Joaquin Delta.

“It’s not just good for us,” said Johnny Amaral, deputy general manager for the sprawling Westlands Water District in the San Joaquin Valley. “It’s good news for the people who drink water or use water. … I would say level heads have prevailed.”

Environmentalists countered that increased releases from Shasta could threaten endangered fish that need cool water in the Sacramento River to survive. Maintaining a deeper pool of water behind Shasta makes for colder water. The idea is to release that colder water later in the summer and early fall, when critically endangered winter-run salmon make their annual return to their spawning grounds below the dam. Releasing water now could mean less cool water is available later.

The past two summers, excessively warm water in the Sacramento River killed off nearly all of the juvenile Chinook. Scientists say a third year of die-offs could mean the extinction of the winter-run as a wild species.

Jon Rosenfield, a conservation biologist at the nonprofit Bay Institute of San Francisco, said not maintaining cool temperatures in the Sacramento River “would push the winter run Chinook salmon very close to extinction.”

He noted that the U.S. Bureau of Reclamation has confidently increased water releases from Shasta in prior years, only to later fail to hold temperatures down.

“I’m dubious that they actually know they have enough water,” Rosenfield said. “It’s an irreversible thing – once the water is released, it can’t be put back. The damage done to the fish is irreversible, particularly if they go extinct.”

The increase in Shasta releases follows a June 9 letter from 15 members of Congress from California urging the Obama administration to reject two dam-management proposals they said could hurt the state’s water supply.

The first proposal involves keeping a substantial amount of water in Shasta Lake until summer to protect juvenile winter-run Chinook. The second plan aims to rescue the Delta smelt, which also teeter on the brink of extinction, by letting more water flow to the Pacific Ocean through the Sacramento-San Joaquin Delta.

The plan could have implications for Folsom Lake, since it may mean a second year in which regulators draw more heavily on the Sacramento region’s primary drinking water reservoir to help control salinity levels in the Delta. Local water officials say they anticipate being able to serve all their customers’ needs, even if the lake dips.

State and federal dam operators are required to maintain flows that ensure the survival of downstream fish. They are also required to ensure that enough freshwater flows through the Delta to keep seawater from rushing into the estuary and compromising salinity levels. The freshwater pumped from the Delta provides irrigation for millions of acres of farmland in the San Joaquin Valley and drinking water for 25 million residents.

Last week’s decision to release more water from Shasta comes amid fairly bleak news from state officials about the snowpack that officials had hoped would help sustain reservoir levels later in the year.

The Sierra snowpack has all but disappeared, state officials say. The vast majority of the Sierra has no measurable snow. The snowline in Yosemite National Park sits at roughly 10,000 feet, mostly covering a portion of the eastern side of the park.

Normally at this time of year, the Sierra has an average of about 3.3 inches of snow-water content. As of Monday, it averaged 0.1 inches