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Facts & Statistics

Blackburn Crossing Dam

Type:

Length:
Maximum Height:
Top Width:
Top of Dam Elevation:
Drainage Area:

Rolled Earth Fill with impervious core and compacted pervious outer zones
5,720 feet (including spillway)
75 feet
20 to 21.3 feet
364.0 feet-msi
847 square miles total

Service Spillway

Type:
Location:
Crest Length:
Crest Elevation:
Capacity at 348 ft-msl:
Capacity at 350 ft-msl:
Capacity at 354 ft-msl:
Capacity at 361 ft-msl:

Uncontrolled Concrete Ogee Weir
East side of dam
500 feet
345.0 feet-msl
8,430 cfs approx.
20,000 cfs approx.
60,000 cfs approx.
132,000 cfs approx.

Inlet-Outlet Works

Type:



Location:
Invert Elevation:


Two 5x7 foot gates connected to 8.5 foot diameter concrete conduit
Two 3-foot diameter by-pass outlets for low flow
Center of dam
298.0 feet-msl for 8.5 ft conduit
309.5 feet-msl (lowest slide gate)
312.5, 322.5 and 332.5 ft-msl for other slide gate

Reservoir

Top of Conservation Pool Elevation:
Capacity at Conservation Pool:
Capacity at Top of Dam:

345.0 feet-msl
Formerly 411,840 acre feet
1,045,000 acre-feet