As Modesto rain year ends, there remains gratitude for the very wet 2016-17 season

Rain clouds hang over a cityscape in downtown Modesto-(11th street looking south) Monday April 16, 2018 in Modesto, Calif.
Rain clouds hang over a cityscape in downtown Modesto-(11th street looking south) Monday April 16, 2018 in Modesto, Calif.

It wasn't the best of times, it wasn't the worst of times.

With the Modesto Irrigation District's rainfall season — July 1 to June 30 — at its end, district and farming officials indicated they're feeling OK about the water picture. Especially since they're still feeling the benefits of the very wet 2016-17 year.

MID's recorded rainfall in downtown Modesto is just a small part of the local water picture. As of Friday, it stood at 7.87 inches, less than two-thirds of the historical seasonal rainfall average of 12.23 inches. For comparison, 2016-17 totaled 17.93 inches, and the wettest year on record is 1982-83, with 26.01 inches.

A more significant measure is Tuolumne Basin precipitation measure from six stations including Hetch Hetchy Reservoir, Cherry Lake, Moccasin Reservoir, Sonora and Yosemite National Park. MID and the Turlock Irrigation District draw from the Tuolumne River watershed.

The six-station index of cumulative precipitation is not too far off average this year, said Gordon Enas, MID’s senior civil engineer manager. The 1998-2017 average is 35.57 inches, and 2017-18 was 30.29. Of course, it's well below 2016-17, which at 64.78 inches was the index's wettest year.

On top of that is the San Joaquin River Basin snowpack, which is 53 percent of average, Enas said. Most of the snowpack already has melted, so there won't be much more runoff, he said. "What we're seeing this year is the benefit of last year we're still holding onto at Don Pedro Reservoir."

As of Friday, Don Pedro was storing about 1,851,200 acre-feet of water. Its maximum is 2,030,000 acre-feet.

MID set its sales allocations around the end of February, Enas said. Then March and April were above-average months — April way above, at 2.32 inches compared to the average 0.97 inches.

"We are fairly conservative in the allocations we set," he said. "...We're not going to change allocations at this point. What we have now, we'll hold onto the rest of the year."

Farmers feel good coming out of the rainfall season, said Stanislaus Farm Bureau Executive Director Wayne D. Zipser. "All the irrigation districts on this side of the San Joaquin are at full allocation. ... We were very, very fortunate that we had a rain event like last year (2016-17) to catch up on the drought years and fill our reservoirs," he said. "It's quite surprising we were able to catch up as fast as we did. The (irrigation) districts are doing a good job with allocations and their water storage."

Still, given the water supply and demands, MID remains under some regulatory pressure regarding relicensing of Don Pedro and river flow plans, district spokeswoman Melissa Williams said. MID and TID manage the reservoir. In October, the boards of both districts separately voted to submit their final application for a new 50-year federal license for the project.

The proposal, six years in the making and topping 6,000 pages, mainly deals with how to boost the number of salmon on the 52 miles of river below Don Pedro. The districts offer to increase reservoir releases from current levels, but much less than sought by environmental and fishing groups.

MID and TID completed Don Pedro under a license granted in 1966. It expired in 2016, but the Federal Energy Regulatory Commission has extended it so the new application could be completed. The new target is 2020, following public comment and further study by FERC.