TERRACE HEIGHTS, Wash. — Central Washington’s irrigation season may depend on how wet this month turns out to be.

“We’re at a pivot point,” said Chris Lynch, a hydrologist and engineer with the U.S. Bureau of Reclamation.

Reclamation officials presented their monthly report at the Yakima Field Office on Thursday, just hours before Gov. Jay Inslee declared a drought emergency for the Upper Yakima River Basin.

With water storage at 79 percent of average for the entire Yakima Basin, Lynch and other Reclamation officials say significant rainfall in April and May can mean the difference between having enough water and cutbacks for those who have less than senior rights to water.

If the water outlook remains the same, those who have prorated rights to water would receive 77 percent of their allotment, Lynch said.

The Roza Irrigation District, one of the largest in the area, is bracing for possible drought conditions, with plans in place to restrict water distribution if necessary to ensure it can deliver water through September, when many of its customers need it for late-growing grape and apple harvests.

“At Roza, we’re ready to pull the trigger earlier,” said Scott Revell, the district’s manager.

Drought emergency

Thursday afternoon, Inslee issued a drought emergency for the Upper Yakima Basin, where water supplies are forecast at 74 percent of normal, 1 percentage point below the 75 percent trigger point for a drought emergency. His order also included the Methow and Okanogan basins, which are at 72 percent and 58 percent of normal, respectively.

The Upper Yakima Basin covers Kittitas County and a sliver of Yakima County from the Wenas Valley to Selah Gap. The state Department of Ecology forecasts summer water supplies using data from state and national agencies.

The state Department of Ecology is requesting $2 million from the state Office of Financial Management for drought-response programs, such as installing emergency water supply infrastructure, leasing water for critical needs and supporting changes to move water in tributaries to help fish, a release from Inslee’s office said.

The drought declaration allows for expedited water transfers between willing buyers and sellers or irrigation districts, Ecology spokeswoman Joye Redfield-Wilder said. It also allows fisheries managers to prioritize their projects to better maintain stream flows and temperatures for fish.

Drought well pumping is triggered by a lower threshold of 60 to 70 percent of normal, under the Yakima Basin integrated water management plan.

Precipitation, snowpack

While precipitation measured at the Yakima Air Terminal was 117 percent above average, regionally it was 31 percent of normal as measured from March through April, said Mik Lewicki, a Bureau of Reclamation hydrologist.

Part of the problem is that storms came in from the south this winter, providing adequate snowfall in the lower parts of the Yakima Basin but leaving upper parts below normal.

Things could bounce back in the Yakima Basin, however.

Lynch said when the basin faced a similar situation in 2010, a drought was averted when extra rain came in April and May. And the long-range forecast shows that precipitation levels are expected to be above average in the next 45 days, although the summer looks like it may be hot and dry.

Roza is considered a prorated district, meaning that it will receive a percentage of its full water allotment to ensure that those who have senior rights — meaning they acquired a right to use water prior to May 10, 1905 — will receive their full allotments. Currently, it would receive 77 percent of its allotment.

Revell said Roza’s drought response plan includes cutting back on water deliveries or, as it did in 2015, shutting down the system for a couple of weeks in the summer to conserve water for the end of the irrigation system, when two-thirds of the crops planted in the district need water.

Roza crews have been sealing cracks in concrete canal walls and piping sections of the canal to make it more efficient and prevent water loss, Revell said.