SURRY MOUNTAIN DAM

ASHUELOT RIVER - Connecticut River Basin - Surry, NH

DRAINAGE AREA: 100 sq.mi.

PERMANENT POOL: 260 Acre Recreation Pool
Stage: 15 ft

FLOOD CONTROL STORAGE
Capacity: 31,680 Acre Feet
5.9 Inches of Runoff
Area at Crest: 970 Areas

DAM
Type: Rolled earth
Length: 1,800 Feet
Top Elev: 568.0 ft NGVD (83 ft)

CONTROL WORKS
Type: Boston Horshoe Conduit
Size: 10' horseshoe
Length: 383 Feet
Invert Elev: 485.0 ft NGVD
Weir Elevation (top of logs): 499.5 ft NGVD (14.5 ft)
Capacity (Full Pool): 3,700 cfs
Gates (Type): Broome
Number: 2
Size: 4'-6" x 10'-0"
Channel Capacity: 1250 cfs

SPILLWAY
Type: L-shaped Side Channel
Length: 338 Feet
Elev: 550.0 ft NGVD (65 ft)

SPILLWAY DESIGN FLOOD

Original Design Criteria:
- Rainfall Excess: 15.6 inches
- Initial Pool Level: Full
- Flood Control Outlet Gates: Inoperable
- Peak Inflow: 59,000 cfs
- Peak Outflow: 51,000 cfs
- Max. Pool: 563.0 ft-NGVD
- Freeboard: 5.0 ft
Current HMR 51 & 52 Criteria:
- Rainfall Excess: 22.4 inches
- Initial Pool Level: Full
- Flood Control Outlet Gates: Operable
- Peak Inflow: 68,900 cfs
- Peak Outflow: 58,900 cfs
- Max. Pool: 562.6 ft-NGVD
- Freeboard: 5.4 ft

RECREATIONAL FACILITIES: 75 Picnic tables with grills, beach, parking areas, one boat ramp, drinking water, bathrooms, group picnic shelter.

TOTAL COST: $2,551,000

PLACED IN OPERATION: October 1941