CalGEO Emerging Geoprofessionals  Meeting

CalGEO Emerging Geoprofessionals Presents:

100th Anniversary of Sweetwater Dam Failure in San Diego, CA

Jennilynn L. Felias, PE                                                                                               Water Resource Engineer, California Department of Water Resources


Sweetwater Dam was the tallest masonry arch dam of its time, standing at 90 feet tall upon its completion in 1888.  The dam was built by the San Diego Land and Town Company for water supply to stimulate land sales in the surrounding area.  A huge tourist attraction, people came from all over by rail, horse and buggy, and foot to see this engineering marvel.  Some questioned its spillway capacity from the start.  Consequently, the dam crest was overtopped several times in the first 20 years.  Still, people continued to marvel at the height of the dam and the fact that it stood tall showing no damage.  Despite these overtopping events, engineers and city officials were more focused on increasing the reservoir capacity and as a result raised the dam crest several times.  Then, after a 3-year drought beginning in 1912, the City of San Diego had a desperate water crisis and sought out Charles Hatfield, a self-proclaimed rainmaker.  He promised the city enough rain to fill the nearby Morena Reservoir for  $10,000.  Mr. Hatfield started his magical chemical concoctions under secrecy and sure enough it started raining.  The Lower Otay Dam, located downstream of Morena Reservoir and about five miles south in an adjacent watershed, breached and flooded agricultural areas.  The rain continued for three more days and on the 30th of January, 1916, both sandstone abutments at Sweetwater Dam failed from 3.5 feet of overtopping.  The peak flow of 45,500 cfs was about 9 times greater than the spillway capacity.  The dam “survived.”  However, eight people died and the breach flooded San Diego, causing more than 3 million dollars of damage (about $68 million today).  Was it engineering overconfidence or oversight, biased objectives, or was it all the rainmaker’s fault that caused the catastrophic failure?  This paper explores the unique history of this dam and the rainmaker, lessons learned, and the influence the Sweetwater Dam failure had on dam safety legislation. 


Jennilynn Felias is a licensed engineer for the California Department of Water Resources, Division of Safety of Dams.  She has 5 years of experience in dam safety including over 30+ projects covering hydraulic, geotechnical, and structural evaluations of dams.  She also manages the Division’s student program.  

Meeting Details
Wednesday, March 29, 2017 6:30pm to 8:30pm  

North Natomas Public Library
4660 Via Ingoglia
Sacramento, CA 95835                                                
Link to Map and Directions

Suggested Donation: 
Professionals: $20       Students: Free  

Please RSVP to  by 2pm Tuesday, March 28, 2017 
Casual dinner included.  

Upcoming Meetings:

April 19, 2017

May 17, 2017

June 28, 2017 (4th Wednesday)