As the more than average snow-melt is pouring from the snow-packed , Sierra Mountains, flood concerns are not over yet for the Central Valley
SACRAMENTO, Calif. – The recent atmospheric rivers brought substantial rainfall and record snowfall throughout California,even hitting the Central Valley so hard that a once dried up lakebed in Tulare County is now newly formed--it is not going anywhere for a while.
Tulare Lake, in California’s San Joaquin Valley, was once the largest freshwater lake west of the Mississippi River. The lake would grow every winter as rainfall and snowmelt from the nearby Sierra Nevada range flowed down and filled the basin.
By 1920, the rivers that fed the lake were dammed and diverted for uses such as irrigation. Since then, the lakebed has been covered with farms that grow a variety of crops.
Heavy rain and snow in the first three months of 2023 has once again brought water to Tulare’s lakebed.
“The Tulare basin floods occasionally, especially during extremely wet years and years with abundant snowpack on the Sierra Nevada mountains,” said Safeeq Khan, agricultural engineer and adjunct professor in civil and environmental engineering at the University of California, Merced. Khan noted that the lakebed flooded in 1969, 1983, and 1997. Until this year, 1969 and 1983 held the record for the wettest years with near-record levels of snow in the region.
“The basin is a powerhouse for agricultural production and the impact of the flooding is going to be prolonged,” Khan said. “The four counties within the basin—Fresno, Kern, Kings, and Tulare—are some of the top-producing counties in the state.” Khan also serves as an extension specialist for the University of California’s Division of Agriculture and Natural Resources (UC ANR), which helps connect farmers, industry, and communities with the latest scientific research.
As of 2022, the lakebed contained farms that produced cotton, tomatoes, dairy, safflower, pistachios, wheat, and almonds. According to the Western FarmPress, the floods in spring 2023 have forced numerous dairies to relocate cattle from the region.
In fact, the Fresno County snowpack is 300% above the average which will melt into at least 8-million-acre feet of water which will feed into the two main reservoirs, Millerton Lake and Pine Flat, and into the Kings and San Joaquin Rivers.
As a result of the high-water levels and hazardous conditions in the rivers, the Fresno County Sheriff’s Office issued a closure of these rivers to recreational users on March 14th, 2023, utilizing Fresno County Ordinance 13.32.080. Anyone accessing the rivers are considered to be in violation of Penal Code 409.5(c), unauthorized entry to an area closed for emergency purposes. This infraction comes with a minimum fine of $225.00.
Kings River - April 13, 2023 - Fresno County Sheriff - Coroner's Office PIO
On May 1, the Department of Water Resources (DWR) conducted the fifth snow survey of the season at Phillips Station. The manual survey recorded 59 inches of snow depth and a snow water equivalent of 30 inches, which is 241 percent of average for this location on May 1. The snow water equivalent measures the amount of water still contained in the snowpack and is a key component of DWR’s water supply run-off forecast. DWR’s electronic readings from 130 snow sensors placed throughout the state indicate the statewide snowpack’s snow water equivalent is 49.2 inches, or 254 percent of average for this date.
“While providing a significant boost to California’s water supplies, this year’s massive snowpack is posing continued flood risks in the San Joaquin Valley,” said DWR Director Karla Nemeth. “The snowpack will not disappear in one week or one month but will lead to sustained high flows across the San Joaquin and Tulare Basins over the next several months and this data will help us inform water managers and ultimately help protect communities in these regions.”
The last time there was measurable snow at the Phillips snow course on May 1 was 2020, when only 1.5 inches of snow and .5 inches of snow water equivalent was measured.
“No matter how you look at the data, only a handful of years in the historical record compared to this year’s results,” said Sean de Guzman, manager of DWR’s Snow Surveys and Water Supply Forecasting Unit. “Survey results from our partners in the California Cooperative Snow Surveys Program and other data, including data from Airborne Snow Observatory flights, allow us to incorporate these data into our models to provide the most accurate snowmelt runoff forecasts possible right now to inform water supply, flood control, and planning.”
According to historical records, only the April 1 measurements from the years 1952, 1969, 1983 and this year were above 200 percent, although it is difficult to directly compare individual years across the decades due to changes in the number of snow courses measured over time.
Due to the impact of climate change on California’s snowpack, since 2021, snowpack averages have been calculated using a timeframe of 1991 through 2020 so that results better reflect the current climate conditions.
DWR is maximizing the amount of water that can be stored and diverted from this record snowpack.
In April, DWR announced a 100 percent allocation of requested supplies from the State Water Project (SWP), which delivers water to 29 public water agencies that serve 27 million Californians and 750,000 acres of farmland. The last time the SWP allocated 100 percent was in 2006. DWR is also maximizing the amount of water that can be diverted towards recharging groundwater basins so more water is stored for future use in underground reservoirs.
At the end of April, the Governor visited several locations in the Tulare Basin to see flooding impacts firsthand, including the Allensworth community center, a project spearheaded by CAL FIRE to raise a critical access road to Alpaugh, and a dairy that has been partially submerged by flood water.
“California is here for the Tulare Basin, the Central Valley and all parts of our state still dealing with the impacts of the historic deluge of atmospheric rivers we experienced and preparing for future flooding due to snowmelt,” said Governor Gavin Newsom. “Our focus is keeping these communities safe, and we’re working with our federal and local counterparts to provide on-the-ground assistance and the support locals need. This weather whiplash is what the climate crisis looks like – and that’s why California is investing billions of dollars to protect our communities from weather extremes like flooding, drought and extreme heat.”
State officials have been on the ground since storms first started hitting, supporting and coordinating emergency response. Now, California is shifting focus to flood prevention and recovery efforts and will support local response in the coming weeks, months and years.
The state response to flooding, both in the Tulare Basin and across California, includes:
Over 1.7 million sandbags and roughly 20,000 supersacks distributed to help prevent flooding;
12,000 feet of muscle walls constructed;
Over 49 million pounds of rock and sand used to shore up rivers and levees;
Over 60 shelters opened for folks who got displaced by flooding and snowfall;
Over 600 comfort kits distributed to impacted families;
Over 3 million miles of California roads plowed or maintained.
The County of Fresno and FROG (Flood Response Operations Group)
The County of Fresno and FROG (Flood Response Operations Group) have released a Life Over Recreation Media Toolkit containing fliers, PSAs, and a long-form video to educate the public about the potential flooding from the record snowfall as well as encourage residents to choose “life over recreation.”
As the weather warms up, residents may be tempted to disregard the closures to cool off by spending time in or near the rivers and canals. The FROG toolkit is meant to be share informing residents on how to prepare County residents for potential flooding and prevent drownings.
