General

• Region (Map) : ............... Mid-Pacific
• State (Map) .................... California
• County ............................ Trinity
• Project: ............................ Central Valley
• Dam type: ....................... Earthfill
• Location: ........................ 7 mi below Trinity Dam
• Watercourse: ................. Trinity River
• Reservoir ........................ Lewiston Lake
• Construction Date: ....... 1960-1963
• National ID Number ...... CA10165
• Hydrologic Unit Code ....

Dimensions

• Crest Elevation of Dam: .................... 1910.00 ft
• Structural Height of Dam: ..................... 91.00 ft
• Crest Length: ........................................ 745.00 ft
• Top of Joint Use: .......................................... NA
• Top of Active Conservation: ........... 1902.00 ft
• Top of Inactive Conservation: ......... 1898.00 ft
• Spillway Crest: .....................................1874.50 ft
• Top of Dead Storage: ........................ 1843.25 ft
• Streambed at Dam Axis : ................... 1829.00 ft

Hydraulics

• Normal Water Surface Elev: ............... 1902.0 ft
• Hydraulic Height: .................................... 73.0 ft
• Service Spillway Type:
•    Uncontrolled  Crest    .................................No
•    Morning-Glory ............................................No
•    Crest Length    ..............................2x30x27.5 ft
•    Gated      ..................................................... Yes
•    Capacity at Elev:  1902.0  ft,............30,000 cfs
• Auxiliary Spillway ......................................... No
•     Capacity at Elev.   .................................... NA
• Outlet Works Capacity at
•     Elevation  1902.0 ft.,  .......................... 325 cfs

Hydrology

• Drainage Area: .................................. 25.6 sq mi
• Hydrometeorological Report               HMR 36
• Flood Type: .............................. Winter General
• Storm Duration: ........................................ 72 hrs
• Probable Maximum Flood (PMF) Report:¹
•   Peak Inflow: ..................................... 19,100 cfs
•   Inflow Volume: .......................... 35,000 acre-ft
•   Flow Duration: ...................................... 3 days
•   PMF Routing MWS Elev.: ....................... NA
•   Initial Routing Elev: .......................... 1902.0 ft
•   Study Date: ................................ January 1987