Saturday, August 10, 2013

The mystique of Tulare Lake

The mystique of Tulare Lake

By Sakura Honda
The Daily Magi
October 25, 2050

Tulare Lake, named Laguna de Tache by the Spanish, is a freshwater dry lake with residual wetlands and marshes in southern San Joaquin Valley, California, United States. Until the late 19th century, Tulare Lake was the largest freshwater lake west of the Mississippi River and the second largest freshwater lake entirely in the United States, based upon surface area. The lake dried up after its tributary rivers were diverted for agricultural irrigation and municipal water uses.

The lake was named for the tule rush (Schoenoplectus acutus) that lined the marshes and sloughs of its shores. The lake was part of a 13,670-square-mile (35,400 km2) partially endorheic basin, at the south end of the San Joaquin Valley, where it received water from the Kern, Tule and Kaweah Rivers, as well as from southern distributaries of the Kings. It was separated from the rest of the San Joaquin Valley by tectonic subsidence and alluvial fans extending out from Los Gatos Creek in the Coast Ranges and the Kings River in the Sierra Nevada. Above a threshold elevation of 207 to 210 feet, it overflowed into the San Joaquin River. This happened in 19 of 29 years from 1850 to 1878. No overflows occurred after 1878 due to increasing diversions of tributary waters for agricultural irrigation and municipal water uses, and by 1899, the lake was dry except for residual wetlands and occasional floods.

Tulare Lake was the largest of several similar lakes in its lower basin. Most of the Kern River's flow first went into Kern Lake and Buena Vista Lake via the Kern River and Kern River Slough southwest and south of the site of Bakersfield. If they overflowed, it was through the Kern River channel northwest through tule marshland and Goose Lake, into Tulare Lake.

For centuries, the Tachi tribe or Tache, a Yokut people, built reed boats and fished in this lake in their homeland, until after the arrival of Spanish and American colonists. The Yokut had once numbered about 70,000. They had one of the highest regional population densities in precontact North America, which was possible because of the rich habitat. The Yokuts also hunted deer, elk and antelope, which were numerous along the lake's shoreline. During wet years, the rivers feeding into the lake were the terminus of the Western Hemisphere's southernmost chinook salmon run.

Even well after California became a state, Tulare Lake and its extensive marshes supported an important fishery: in 1888, in one three-month period, 73,500 pounds of fish were shipped through Hanford to San Francisco. It was also the source of a regional favorite, western pond turtles, which were relished as terrapin soup in San Francisco and elsewhere. The lake and surrounding wetlands were a significant stop for hundreds of thousands of birds migrating along the Pacific Flyway. Tulare Lake was written about by Mark Twain.

Once the largest freshwater lake west of the Great Lakes, in 1849, the lake measured 1,476 km2 (570 sq mi), and in 1879, 1,780 km2 (690 sq mi), as its size fluctuated due to varying levels of rainfall and snowfall. Following the floods of 1861-62 and 1867–68, the highest water on record reached between 216 and 220 ft above sea level. At that elevation, the lake overtopped the natural "spillway" (located five miles west of the current community of Halls Corner on state route 41) and flowed northward into the sea via the Boggs and Fresno sloughs and the San Joaquin River. In February and March 1938, heavy rains flooded the San Joaquin Valley causing Tulare Lake to break the levee near Corcoran and flood 28,000 acres of cropland. The expression "out in the tules", referring to the 3–10 ft-tall sedges lining the lakeshore, is still common in the dialect of old Californian families and means "beyond far away".

In the wake of the United States Civil War, late 19th-century settlers drained the surrounding marshes for early agriculture. The government dammed the Kaweah, Kern, Kings and Tule Rivers upstream in the Sierra Nevada Mountains, which turned their headwaters into a system of reservoirs. In the San Joaquin Valley, the state and counties built canals to deliver that water and divert the remaining flows for agricultural irrigation and municipal water uses. Tulare Lake was nearly dry by the early 20th century. Enough water remained so the Alameda Naval Air Station used Tulare Lake as an outlying seaplane base during World War II and the early years of the Cold War. Flying boats could land on Tulare Lake when landing conditions were unsafe on San Francisco Bay.

In 1938 and 1955, the lake flooded, which prompted the construction of the Terminus and Success Dams on the Kaweah and Tule Rivers in Tulare County and Pine Flat Dam on the Kings River in Fresno County. The lake bed is now a shallow basin of fertile soil, within the Central Valley of California, the most productive agricultural region of the United States. Farmers have irrigated the area for a century, so soil salination is becoming a concern. The destruction of the terrestrial wetlands and the lake ecosystem habitats resulted in substantial losses of terrestrial animals; plants; aquatic animals; water plants; and resident and migrating birds. Although now dry, the lake occasionally reappears during floods following unusually high levels of snow melt, as it did in 1997.

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