CONANT BROOK DAM - Monson, MA (Unstaffed)

CONANT BROOK - Connecticut River Basin

DRAINAGE AREA= 7.8 sq.mi.

PERMANENT POOL= None

DAM
Type= Rolled earth fill and rock
Length= 1,050 Feet
Top Elev = 771.0 Ft NGVD (78 ft)

FLOOD CONTROL STORAGE
Capacity= 3,740 Acre Feet
9.0 Inches of Runoff
Area at Crest= 158 Acres

CONTROL WORKS
Type= Precast R.C. Pipe
Size= 3' diameter
Length= 405 Feet
Invert Elev = 693.0 Ft-NGVD
Capacity (Full Pool)= 225 cfs
Gates= None
Channel Capacity = 225 cfs

SPILLWAY
Type= Chute Spillway with Ogee Weir
Length= l00 Feet
Crest Elev = 757.0 Ft-NGVD (63 Ft)

SPILLWAY DESIGN FLOOD

Original Design Criteria:
- Rainfall Excess = 23.1 inches
- Initial Pool Level = Full
- Flood Control Outlet Gates = Operable
- Peak Inflow = 11,900 cfs
- Peak Outflow = 11,000 cfs
- Max. Pool = 766.0 ft-NGVD
- Freeboard = 5.0 ft
Current HMR 51 & 52 Criteria:
- Rainfall Excess = 32.7 inches
- Initial Pool Level = Full
- Flood Control Outlet Gates = Operable
- Peak Inflow = 20,770 cfs
- Peak Outflow = 16,500 cfs
- Max. Pool = 769.0 ft-NGVD
- Freeboard = 2.0 ft

RECREATIONAL FACILITIES: Hunting, stream fishing and hiking.

TOTAL COST: $2,950,000

PLACED IN OPERATION: June 1966