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American River - Chronology and Facts
by the American River Authority

images of the American River1800 — Native Americans occupy the floodplain seasonally; abundant native vegetation, fish and wildlife extends for miles on both sides of the river.

1839 — Sutter’s Fort established: early travelers introduce non-native plants such as Scotch broom and yellow star thistle and build permanent structures in the floodplain.

1848 — Discovery of gold on the banks of the American River brings major influx of people into the region from around the world and leads to widespread construction in the floodplain.

1849 – 1909 — Large-scale hydraulic mining transforms the river, surrounding floodplain; the first dams, levees and conveyance ditches are built.

1850 — California gains statehood; a major flood forces people to temporarily move to safer ground (on what is now the CSUS campus); the flood leads to fundraising for levees on the American and Sacramento Rivers.

1862 — Worst flood to date leads to raising of downtown Sacramento.

1864 – 1868 — American River is rechannelized to create faster flows by straightening the final two miles of the river.

1880 — The first Flood Control Plan is written by William Hammond Hall, California’s first State Engineer.

Early 1900s — Sacramento streets are raised due to previous floods.

1907 — Major flood in Sacramento.
1909 — Major flood in Sacramento.

1917 — William Hammond Hall’s Flood Control System is authorized by Congress.

1939 — North Fork Debris Dam is built to reduce the effects of hydraulic mining; resulting lack of sediment begins to cause incision of the riverbed.

1944 — Construction of Folsom Dam is approved.

1955 — Folsom and Nimbus Dams are completed, and modern levee systems are built to provide flood protection to the growing Sacramento region: a record breaking flood fills the newly built Folsom Dam in a week, with the reservoir growing from 200,000 acre-feet to 1 million acre-feet.

1956 — U.S. Representative Clair Engle introduces legislation to authorize the Auburn Dam project.

1959 — U.S. Representative Harold “Bizz” Johnson introduces legislation in the House to authorize construction of the Auburn Dam.

1964 — Christmas week flood fills Folsom Dam in two days and poses “spill over” threat to Sacramento.

1965 — Congress authorizes the Auburn Dam as an integral part of the Bureau of Reclamation’s Central Valley Project’s flood control effort; water and hydroelectric power generation are also part of the package.

1968 — Pre-construction work begins on Auburn Dam; plans call for 700-foot high dam with 2.5 million acre-feet capacity.

1972 — Three environmental groups sue the Bureau of Reclamation over what they say is inadequate environmental documentation.

1973 — The year originally estimated for completion of Auburn Dam.

1974 — Federal judge allows dam construction to continue; amended environmental documents required and submitted later in the year.

1975 — Oroville earthquake sparks concerns over seismic safety of dam.

1977 — President Carter issues plan to cut $39.7 million from the budget previously earmarked for the Auburn Dam, but later backs down.

1980 — Dam shuts down construction after more than $200 million spent on project.

1981 — American River is recognized as the most heavily used recreation river in California; designated a federal wild and scenic river from Nimbus Dam to the confluence with the Sacramento River.

1986 — Sacramento is hit by another record flood, with a recorded 10 inches of rain in 11 days; new study drops Sacramento’s “level” of protection from a catastrophic flood from once every 125 years to once every 78 years.

1992 — Central Valley Improvement Act passed by Congress and signed into law; Auburn Dam bill defeated in Congress, forcing another study on flood control and water supply alternatives.

1995 — CALFED Program initiated to develop a long-term strategy to restore environmental health and resolve water management problems in the Bay-Delta and its watersheds.

1996 — A second Auburn Dam bill fails in Congress; federal support found to upgrade Sacramento’s flood-control levees.

1998 — Floodway Management Plan for the Lower American River developed by the Sacramento Area Flood Control Agency and stakeholders.

2001 — Federal funding and support comes for tunnel closure and restoration of the streambed on the American River through the Auburn Dam site.

2002 — Work begins on the Placer Water Agency’s pump project and river restoration.
image of the American River
2003 — Agreement reached on federal project to raise Folsom Dam to increase downstream flood protection, raising flood safety level to 1 in 200 years.

2005 — $1 million authorized by Congress for new study to determine cost to construct Auburn Dam today.


Water Forum’s State of the River Report (2005), the Sacramento Area Flood Control Agency and Auburn Journal; All photos are from the El Dorady County Photo Library.