Courtesy of Kings River Water Association
The 2023-24 WATER YEAR still has a week to go but Kings River runoff has already established an all-time record as a result of the past winter’s massive Sierra Nevada snowstorms and significant summer rainfall. The Kings River Water Association now expects that when the current water year concludes Saturday, September 30, the river’s annual runoff will total approximately 4.5 million acre-feet.
Kings River Watermaster Steve Haugen said this year’s total runoff eclipsed the river’s 40-yearold water supply record on Sunday, September 17. That’s when the 2022-23 total passed 4.4763 million acre-feet, the amount of unimpeded full calculated natural flow that occurred in another big central Sierra water year, 1982-83. Dropping to the Kings River’s third place position was Water Year 1968-69. In that heavy snow-producing year, Kings River runoff reached 4.3862 million acre-feet. Now fourth on the list is Water Year 2016-17 at 4.0961 million acre-feet. Fifth is 1905-06, 3.8996 million acre-feet.
“What makes this record all the more remarkable is that a quarter of the way through Water Year 2022-23, Central California appeared certain to be headed for a fourth consecutive drought year,” said Haugen, the Kings River Water Association manager. “Then, after the many atmospheric river storm events in January, February and March dumped snow by the hundreds of inches above the 5,000-foot elevation, April and May provided surprisingly little precipitation.”
April 1, 2023, Kings River watershed snow surveys — taken at the time when snow conditions in a normal year are generally assumed to have peaked — found snowpack water content averaging 261% of average with the most snow at any watershed course measured at 233 inches. Significant accumulations occurred at lower elevations. A year earlier, same-site surveys found water contents averaging only 41% with the greatest course accumulation at 57 inches.
Fairly dry later spring conditions proved to be a blessing. A flood release imposed by the U.S. Army Corps of Engineers to manage high water conditions coupled with above-normal off-season irrigation demands resulted in Pine Flat Dam’s water year releases of more than 3.8 million acrefeet. High flows downstream from Pine Flat did result in some localized flooding and erosion. Haugen said that had April and May produced normal or greater foothill and mountain precipitation, high lower-river water levels would likely have been much more severe.
“There is no question that Pine Flat Reservoir did its flood control job,” Haugen said. “Corps of Engineers flood management, with assistance locally by KRWA’s staff, resulted in the reservoir not quite filling, despite the big inflows experienced at Pine Flat.” The peak release from Pine Flat this year was 13,371 cubic feet per second. The highest natural flow above Pine Flat was 42,371 c.f.s. during a March 10 storm. Unregulated flows entering the river from foothill creeks added to lower river concerns.
Reservoir storage peaked July 25 at 982,634 acre-feet, 98% of the lake’s capacity of one million acre-feet. Pine Flat began the water year October 1, 2022, at just over 150,000 acre-feet, 15% of capacity.
Kings River water districts and canal companies maximized diversions for months to recharge groundwater and provide much-needed surface irrigation.
Still, significant amounts of flood release water had to be directed downstream to the San Joaquin River and the Tulare Lake bed. High flows into the valley from rivers and streams to the south, along with Kings River flood releases, led to the re-emergence of Tulare Lake in Kings County for the first time in many years. Lake water is being beneficially used on surrounding lands.