Glendale (PDF) - Hazard Mitigation Web Portal - State of California

Natural Hazards Mitigation PlanCity of Glendale, CaliforniaSection 8 – FloodsSimilarly, the winter storms in 1983-84 caused considerable damage in southern California, andmay have also washed out the gage.The City of Glendale most recently experienced some destruction during the 2005 floods.Residents and business owners who were impacted by flooding and the rain storms were able toreceive disaster assistance through the Federal Emergency Management Agency and the City.On February 4, 2005, President Bush declared that a major disaster existed in California andordered Federal aid to supplement State and local recovery efforts.Historic Flooding in Los Angeles County:There are several rivers in the southern California region, but the river with the best-recordedhistory is the Los Angeles River. The flood history of the Los Angeles River is generallyindicative of the flood history of much of southern California. Records show that since 1811, theLos Angeles River has flooded 30 times, roughly about once every 6 years. But averages aredeceiving, for the Los Angeles basin goes through periods of drought and then periods of aboveaveragerainfall. For example, between 1868 and 1884, a period of 16 years, there were nomajor floods, but this was followed by a series of wet years with floods in 1885, 1886, 1889 and1891. A similar cluster of wet years was recorded in the 1990s, as discussed above.Year1770-17711771-17721775-17761779-1780Table 8-1: Historical Floods in Los Angeles CountyCommentsGreat flooding on the L.A. River recorded by Father Juan Crespi. River overflowed itschannel.Flooding recorded by Spanish Mission Fathers. San Gabriel Mission crops destroyed.Due to heavy flooding, San Gabriel Mission was moved about 6 miles back from the river.Flooding recorded by Spanish Mission Fathers. Flows filled riverbed and flooded the lowlandswhere wheat and barley had been planted.1811 Flooding reported, although records are sparse.1815 Flooding washes away the original Plaza in L.A. River changes course at Alameda and 4 thStreet to cut west and join Ballona Creek. From there it emptied into Santa Monica Bay.1822 A great flood on the L.A. River “covered all the lowlands and reached a greater height thanwas ever known before.”1824-25The greatest of the earlier recorded floods. L.A. River changed its course back from theBallona wetlands to San Pedro. Before this storm, the river would spread over the entire area,filling depressions at the surface and forming lakes, ponds and marshes, rarely discharging itswaters into the sea. The 1825 floods cut a riverway to the ocean, draining the marshlands andcausing the forests to disappear.1832 Heavy flooding caused the drainage near Compton to change so that many lakes and pondsthat “had been permanent, became dry a few years thereafter.” Drainage of these ponds andlakes completed the destruction of the forests that used to cover a large part of southern L.A.County.1849 –1860Floods of various magnitudes occurred in 1849-1850, 1851-1852, and 1859-1860.2006 PAGE 8- 5