In 1800, Tulare Lake extended from over 790 to 1,000 square miles in California’s San Joaquin Valley and today’s Kings County—When it was a like. A phantom lake fills up seasonally and is dry at certain times of the year, appearing and reappearing, like a phantom. The southern end of the Sierra Nevada Mountain Range flanks Tulare Lake on the east and sends snowmelt along with the rains and a few rivers to fill it up.
The Kings River supplied most of Tulare Lake’s water. Today, Tulare Lake is revenant, meaning one that returns after death or a long absence. Tulare Lake was a marshy lake lined with cattails, reeds, and rushes and only about 37-feet deep maximum and 20 to 30-feet deep on average. Oak woodlands and riparian forests emerged as green corridors on the prairie along the eastern edge of Tulare Basin.
Tulare Lake sustained a tremendous maze complex of wetland ecosystems. Significant numbers of resident and migratory water birds nested by the thousands on this lake. When dry, Tulare Basin was a mixture of sloughs and permanent standing water, which supported the fish populations when it was full.
Tulare Lake historically filled up in the spring and early summer when the Sierra Nevada snowpack melted and flowed down the riverways and shrunk in the dry summer and fall seasons. European settlers moving into the area in the mid-1800s realized the rich soil bed when Tulare Lake was dry as ideal farmland.
Conversion of the Tulare Basin from a lake and slough wetland to agriculture lands began by building structures to divert water through canals. This process allowed settlers to irrigate crops but also slowly disconnected the lake from its inflowing waters. These diversion developments continued up until the mid-1900s and beyond. In 1899, Tulare Lake completely dried up for the first time in recorded history.
In 1899, settlers rushed to file claims on the “new” farmland, which was the Tulare Lake lakebed. Then, they began building the canals and modifying natural waterways upstream from Tulare Lake to irrigate their crops. Tulare Lake kept shrinking and was dry for most of the 20th century, except in 1938, 1955, 1969, 1983, and 1997. And for the first time in the 21st century, Tulare Lake comes alive in 2023.
When Tulare Lake flooded in 1938, the U.S. Army Corps of Engineers began building dams on Tulare Lake’s four primary rivers, the Kaweah, Kern, Kings, and Tule Rivers. The dams are: Terminus Dam (1953), Kaweah River, Isabella Dam (1953), Kern River, Pine Flat Dam (1954), Kings River, Courtright Dam (1958), a few miles downstream of Kings River, Wishon Dam (1958), Kings River, and Success Dam (1961), Tule River.
Why Is the Tulare Basin in a Flooding State of Emergency?
Most of the snowpack from the southern Sierra Nevada mountain range will melt and flow into the San Joaquin watershed with a huge percentage of that flow entering the Tulare Basin. The temperatures in the San Joaquin Valley typically begin melting the snowpack in late spring. As spring turns into summer, and the temperatures rise higher in June to the 80s, the snowpack typically melts slowly.
The southern Sierra Nevada snowpack had piled up on the eastern side of this mountain range over 300% above average by April 1, 2023, and by the first of April, it was still growing. Rainfall fell over Central California to the deluge of 400% above average by March 2023, including the San Joaquin Valley.
What Happened to Create Current Tulare Basin Flood Conditions?
Two factors played primary roles leading up to the current Spring 2023 Tulare Basin situation, long-term human mitigation to create prime farmlands and extreme weather events. The Tulare Basin, if left alone to nature, would have continued to rise and fall as a phantom lake. Since the mid-1800s, humans have altered and re-altered the natural waterways of the Tulare Basin and extracted ground water.
Historic ground water extraction caused areas of Tulare Basin to sink. Long-term ground water pumping negatively affected the flood infrastructure installed over the years and made flood control much less efficient. A warm atmospheric river developed over Central California, which caused heavy rainfall and snowfall in the first three months of 2023.
In tropical regions, atmospheric rivers are moist air streams that cause ocean water to evaporate and rise into the atmosphere. Strong winds carry the evaporated ocean water over land. Once over land, the ocean water vapor cools and forms water droplets and snowflakes. Atmospheric rivers commonly form in the Western United States and the cause of up to 50% of annual precipitation over the West Coast.
San Joaquin Valley Flood Prognosis for Spring and Summer 2023
A “flood warning” means to move immediately to higher ground because a dangerous flood will happen or is already happening. A “flood advisory” means to be aware; a flood will happen or is happening and will cause significant inconvenience. A “flood watch” means to be prepared; conditions are favorable for a flood warning or advisory.
The Tulare Basin provides water for an estimated four million people according to 2020 U.S. census data. Andy Bollenbacher, a meteorologist with the National Weather Service in Hanford, California, reported on April 8, 2023, “It’s difficult to speculate when this is going to happen… There’s no real good analogue, especially because there’s so much water up there.”
While grains, cotton, and corn are the main agricultural crops in the Tulare Basin, on April 8, 2023, Tricia Stever Blattler, executive director of the Tulare County Farm Bureau, reported “From the citrus, olive, and pistachio trees that line parts of the valley floor to the fields of alfalfa and corn, farmers and workers in recent weeks have been grappling with the loss of crops and wages. Dairy farmers have been forced to abandon fields and move thousands of cows to higher ground, costing the industry millions of dollars.”
On April 14, 2023, the National Weather Service of Hanford, California, issued a flood advisory for Tulare Basin:
Flood Advisory for a Dam Floodgate Release until Further Notice:
WHAT…Flooding caused by upstream dam release continues.
WHERE…A portion of central California, including the following counties, Fresno, Kings and Tulare.
WHEN…Until further notice.
IMPACTS…Minor flooding in low-lying and poor drainage areas. Water over roadways. River or stream flows are elevated.
At 7:10 p.m., PDT, an upstream floodgate release is expected to cause minor flooding in the advisory area. Some locations that will experience flooding include Sanger, Reedley, Kingsburg, and Laton.