BIRCH HILL DAM

MILLERS RIVER - Connecticut River Basin - Royalston, MA

DRAINAGE AREA: 175 sq.mi.

PERMANENT POOL: None

DAM
Type: Rolled earth
Length: 1,400 Feet
Top Elev = 864.0 Ft NGVD (49 Ft)

FLOOD CONTROL STORAGE
Capacity: 49,900 Acre Feet
5.3 Inches of Runoff
Area at Crest: 3,200 Acres

CONTROL WORKS
Type: Four Outlets
Size: 6' x 12'
Length: 34 Feet
Invert Elev = 815.0 Ft NGVD
Capacity (Full Pool): 11,000 cfs
Gates (Type): Roller
Number: 4
Size: 6'x 12'
Channel Capacity = 2800 cfs

SPILLWAY
Type: 3 Chute Spillways Ogee Weirs
Length: 1,100 Feet (720'+350'+30')
Elev = 852.0 Ft NGVD (37 Ft)

SPILLWAY DESIGN FLOOD

• Original Design Criteria:
• Rainfall Excess = 21.1 inches
• Initial Pool Level = Full
• Flood Control Outlet Gates = Inoperable
• Peak Inflow = 59,000 cfs
• Peak Outflow = 56,600 cfs
• Max. Pool = 859 ft-NGVD
• Freeboard = 5.0 ft
• Current HMR 51 & 52 Criteria:
• Rainfall Excess = 22.3 inches
• Initial Pool Level = Full
• Flood Control Outlet Gates = Operable
• Peak Inflow = 93,170 cfs
• Peak Outflow = 87,970 cfs
• Max. Pool = 858.8 ft-NGVD
• Freeboard = 5.2 ft

RECREATIONAL FACILITIES: Lake Denison Campground and Day Use Recreation Area (State leased). 35 Picnic tables, 7 bathrooms, beach, parking areas, drinking water, and 152 campsites.

TOTAL COST: $4,440,000

PLACED IN OPERATION: December 1941

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