{{Use American English|date=July 2025}} {{Update|part= Failure threat section and Upgrades section |date=May 2019}} {{Infobox dam | name = Prado Dam | image = Prado Dam Coverimage.jpg | image_caption = Prado Dam above the Chino Valley Freeway (SR 71)/Riverside Freeway (SR 91) interchange | coordinates = {{coord|33.8902|-117.6408|type:landmark_region:US-CA|display=inline,title}} | dam_crosses = Santa Ana River | location = Riverside County, California | dam_type = Earth-fill dam | dam_length = {{convert|2280|ft|abbr=on}} | dam_height = {{convert|162|ft|abbr=on}} | dam_width_base = | dam_width_crest = {{convert|30|ft|abbr=on}} | dam_volume = {{convert|3389000|cuyd|abbr=on}} | spillway_type = | spillway_capacity = | construction_began = | opening = {{start date and age|1941|04}} | cost = | owner = 24px U.S. Army Corps of Engineers | operator = | res_name = Prado Flood Control Basin | res_capacity_total = {{convert|314400|acre.ft|dam3|abbr=on|lk=on}} | res_catchment = {{convert|2230|sqmi|km2|abbr=on}} | res_surface = {{convert|6600|acre|abbr=on}} | res_max_depth = | website = | extra = {{gnis|type=retired|247766}} }}
'''Prado Dam''' is an earth-fill dry dam across the Santa Ana River at the Chino Hills near Corona, California in Riverside County with the resulting impounded water creating Prado Flood Control Basin reservoir. The U.S. Army Corps of Engineers built the dam in Lower Santa Ana River Canyon. Its primary purpose is flood control and it is the downstream element of the Santa Ana River's flood control system, which is a natural constriction about {{convert|30.5|mi|abbr=on}} upstream from the ocean. The area upstream from the dam contains {{convert|2255|sqmi|abbr=on}} of the watershed's {{convert|2650|sqmi|abbr=on}}. The dam's construction was authorized in 1936 and the flood of 1938 demonstrated its necessity. Construction was completed in 1941. Prado Flood Control Basin also provides water storage for groundwater recharge operations.
==Failure threat== On January 14, 2005, after days of heavy rain, water began seeping through an earthen extension. Authorities released water in order to relieve pressure and sent a flood warning to areas downriver of the dam. Over 3,000 residents were evacuated from their homes for nearly twenty-four hours for fear of flooding. The gymnasium at Corona High School was converted by the American Red Cross into a temporary shelter.
== Upgrades == As of 2005 work to increase the downstream channel's capacity from {{convert|5000|to|30000|ft3|abbr=on}} per second is ongoing. The total costs of the improvements is estimated at $400 million.<ref>{{Cite web|url=https://www.latimes.com/local/lanow/la-me-ln-prado-dam-flood-risk-failure-20190516-story.html|title=Disneyland, dozens of cities could be flooded by dam failure from huge storm, engineers warn|last=Sahagun|first=Louis|website=Los Angeles Times|access-date=2019-05-17}}</ref>
[[File:Prado Dam Spillway, Santa Ana River, Riverside County, CA.jpg|thumb|none|Prado Dam Spillway, with American Bicentennial mural.<ref>{{Cite web|url=https://www.latimes.com/local/lanow/la-me-ln-dam-mural-20190305-story.html|title=Corona dam's bicentennial mural too degraded for historic listing|date=March 5, 2019|website=Los Angeles Times|access-date=6 March 2018}}</ref>]]
==See also== * List of dams and reservoirs in California * List of largest reservoirs of California
==References== {{Reflist}} * {{cite web | author=Department of Water Resources | title=Station Meta Data: Prado Dam (PRA) | url=http://cdec.water.ca.gov/cgi-progs/queryF?PRA | work=California Data Exchange Center | publisher=State of California | year=2010 | accessdate=9 October 2010}}
==External links== {{Commons category}} *[https://web.archive.org/web/20070311002529/http://www.spl.usace.army.mil/Pradodam/pradodam.htm U.S. Army Corps of Engineers – Prado Dam] *[https://web.archive.org/web/20070824040022/http://www.spl.usace.army.mil/resreg/htdocs/SevenOaks/SOAK_WCM_2003/Ch4_2.0.pdf U.S. Army Corps of Engineers– Seven Oaks Dam] *{{GNIS|type=retired|247766}} *{{GNIS|247767|Prado Flood Control Basin}} *Historic American Engineering Record (HAER) documentation, filed under Santa Ana River near junction of State Highways 71 and 91, Corona, Riverside County, CA: **{{HAER |survey=CA-178 |id=ca2249 |title=Prado Dam |photos=7 |data=109 |cap=2 |link=no}} **{{HAER |survey=CA-178-A |id=ca2456 |title=Prado Dam, Embankment |photos=12 |cap=2 |link=no}} **{{HAER |survey=CA-178-B |id=ca2457 |title=Prado Dam, Outlet Works |photos=50 |cap=4 |link=no}} **{{HAER |survey=CA-178-C |id=ca2458 |title=Prado Dam, Spillway |photos=35 |cap=3 |link=no}} **{{HAER |survey=CA-178-D |id=ca2459 |title=Prado Dam, Service Vehicle Garage |photos=2 |cap=1 |link=no}}
{{Authority control}}
Category:Dams in California Category:Historic American Engineering Record in California Category:Buildings and structures in Riverside County, California Category:Santa Ana River Category:Earth-filled dams Category:United States Army Corps of Engineers dams Category:Dams completed in 1941