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VENTURA COUNTY, CALIFORNIA  
  
 
 
 



Facts and History
Matilija Dam Facts
Location
15.6 miles from the ocean
Owner
Ventura County Watershed Protection District (VCWPD)
Date Constructed
1947
Purpose
Water supply and flood control
Preconstruction estimated cost
$682,000
Actual total dam cost
~$4 million
Constructed height
198 feet (1,125 elevation)
Current height
168 feet (1,095 elevation) (notched in 1965, 1977)
Width
620 feet
Thickness
8 feet at crest, 35 feet at base
Reservoir Capacity: Design
7,018 acre feet
Reservoir Capacity: After notching
3,800 acre feet (excluding sedimentation losses)
Reservoir Capacity: Current
Less than 500 acre feet (combined notching & sedimentation losses)
Reservoir Capacity: Projected
Zero capacity by 2020
Original Reservoir Area
126.8 acres
Drainage area of Matilija Creek above dam site
55 square miles
Original Spillway Capacity
60,000 cubic feet per second at water elevation 1,137 feet
Matilija Dam History
Prior to 1940 Viable steelhead/salmon population (over 5,000) and other wildlife/natural resources
1941 Corps of Engineers Study - concludes that Matilija would not provide adequate benefits to be cost effective for flood control & water supply
1945 County Bond issued passed - cost for Matilija to be $682,000
1946 June 18 - Construction begins
1947 Mr. Harold E. Burket, architect, warns County Supervisors of alkali-reactive aggregate
1948 March 14 - Dam completed - Report estimated 39 years before siltation would eliminate capacity - County sued engineers for cost overruns and lost
1949 Major fish kill behind dam due to stagnant/hot water
1952 Reservoir filled
1959 Casitas Municipal Water District assumes responsibility of dam
1964 Bechtel Corp. Safety study condemns dam and presents removal as an option
1965 Bechtel Corp. estimates dam removal cost at $300,000 - County elects to notch dam (remove a section 30 feet deep and 285 feet wide) to reduce reservoir capacity to 65% to relieve strain and allow dam to remain in place
1973 Study on littoral processes (Bickel) highlights impact to beaches - USFS estimates sediment contribution of Matilija's dammed watershed to be 116,000 cubic yards per year
1978 Dam notched second time (358 feet wide)
1998 County resolves to remove dam - study begins on dam removal
2000 Bureau of Reclamation - Appraisal Study - Secretary of the Interior Bruce Babbitt visits demonstration project
2001 Initiated the Matilija Dam Ecosystem Restoration Study between the Ventura County Watershed Protection District and the US Army Corps of Engineers
2004 Consensus on preferred project points by all stakeholders
2004 Completed Feasibility Study
2004 Ventura County Board of Supervisors approved the Final EIR/EIS
2004 US Army Corps of Engineers Chief's Report sent to Assistant Secretary of the Army
2005 Initiated the Design Phase of the Matilija Dam Ecosystem Restoration Project between the Ventura County Watershed Protection District and the US Army Corps of Engineers