Hahamongna Interim Sediment Removal Project 

Los Angeles County Flood Control has been directed by the Board of Supervisors to complete an environmental impact report before removing over one million and a half cubic yards of sediment from behind Devil's Gate Dam in Hahamongna.  To insure public safety in the year or two which will be necessary to complete the EIR, Flood Control will be carrying out an interim sediment removal project.

Beginning in July, 2011, 25,000 cubic yards of sediment will be moved from the area immediately behind the dam.  Preparatory work began March 31, 2011.  Actual sediment removal is anticipated to take 16 to 20 days with the moving of 1600 cubic yards of dirt per day away from the dam.  The bulk of the sediment will be temporarily stored on Johnson Field on the east side of the park until the final sediment removal project when it will be trucked offsite.  Only the organic materials, ten to fifteen percent  of the total, will be trucked offsite this summer.  All work must be completed by October 15 which is considered the beginning of the rainy season.

The most controversial aspect of the proposal is the haul route chosen by the County which goes north along an access road on the east side of the park to just below the east JPL parking lot where the trucks will then turn south and go down Windsor Avenue to the 210 Freeway.  At community meetings, there were many questions about why the much shorter and less environmentally destructive haul routes at the south of the park could not be used for the interim project.  County Flood Control responded that these were not feasible within the time constraints placed upon them by the need to finish the project before the rainy season begins.  These will, however, be considered as alternatives in the environmental impact report.