page_title: Pit River
section_title: Irrigation and power
hierarchical_section_title: Pit River / History / Irrigation and power
caption_attribution_description: English: Pit River Falls Subject: Waterfalls--California, Pit River Falls (California) Geographic Subject: United States--California--Pit River Falls Tag: Limnology
context_page_description: The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S. that cross the Cascade Range.
  The longest tributary of the Sacramento River, it contributes as much as eighty percent of their combined water volume into the Shasta Lake reservoir; the junction of their Shasta Lake arms is 4 miles northeast of Shasta Dam. The main stem of the Pit River is 207 miles long, and some water in the system flows 265 miles to the Sacramento River measuring from the Pit River's longest source.
  The Pit River drains a sparsely populated volcanic highlands area in Modoc County's Warner Mountains, passing through the south end of the Cascade Range in a deep canyon northeast of Redding. The river is so named because of the pits, along with other bands of what is now the Pit River Tribe, the Achumawi dug to trap game that came to water at the river.
  The river is a popular destination for fishing, fly fishing, rafting in its lower reaches, and is used to generate hydroelectricity in the powerhouses below Fall River Mills where the Pit and Fall rivers join, and at Shasta Dam.
context_section_description: Due to the arid climate, poor soils and rugged topography of the Pit River basin and northeastern California in general, settlement and development of the region was difficult. Ranching became the primary economic activity, thanks to the expansive seasonal grasslands, along with some mining and logging. Although the lower portions of the Pit River contain abundant water, the western watershed is too mountainous for agriculture. On the other hand, the drier eastern part of the watershed contains a number of flat river valleys with deep alluvial soils. Throughout the early part of the 20th century, about 63 reservoirs were built on tributary streams in this region, to support irrigation. Due to limited and uncertain streamflow from these snowfed desert streams, the amount of farmland in the Pit River system remained small, and water rights were a contentious issue. Some of these disputes were resolved in court in the 1930s, with water allocations now managed by the California Department of Water Resources.
  In the early 1900s and 1910s the Pit River was identified by the recently formed Reclamation Service (now Bureau of Reclamation) as the most important water source in the upper Sacramento River system; the river provides not only the majority of the annual flow, but nearly the entire dependable summer water supply. One of the first proposals to dam the Pit River was in 1915 and was known as the "Lower Pit River Project". A 139-foot (42 m) dam would have been built across the river at Sheep Rocks, above the confluence with Squaw Creek. About one-quarter of the river's flow would be diverted to irrigate some 60,000 acres (24,000 ha) of fertile benchland in the upper Sacramento Valley, east of Redding. The Lower Pit River Project was technically superseded by the Central Valley Project for which Shasta Dam was completed in 1945. Shasta Lake raised the level of the Pit River more than 100 feet (30 m) above the elevation of the proposed Sheep Rocks dam. It also flooded the majority of the Wintun peoples' traditional lands along the Pit and McCloud rivers, still controversial today.
  Hydroelectric development of the Pit River system also began early. One of the first major hydroelectric projects was the Hat Creek project, built in 1920 and generating the first power in 1921. The Fall River was developed soon afterwards with a powerhouse coming online by 1922. Pit 3 Dam (Lake Britton) was completed in 1925 and its powerhouse began operation on July 18, 1925. Pit 4 and 5, located further downstream, were completed between the mid-1940s and mid-1950s. The lower Pit River was dammed in the 1960s, forming Reservoirs 6 and 7. A diversion from the McCloud River was also completed during this time to increase water flowing through powerhouses on the Pit River. Pit 2 Powerhouse was planned but never built: due to an error in the topographic maps, the elevation drop between Fall River and Lake Britton, where the powerhouse was to have been situated, was too small for economical power generation.
caption: Pit River Falls, photographed by Cloudsley Rutter, c. 1904
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