HOPKINTON-EVERETT LAKES

EVERETT LAKE - PISCATAQUOG RIVER - Merrimack River Basin - Weare, NH

DRAINAGE AREA: 64 sq.mi.
Combined HOP-EVT: 490 (Gross)

PERMANENT POOL: 130 Acre Recreation Pool
Elev: 340.5 ft NGVD

DAM
Type: Rolled earth and rock
Length: 2000 Feet
Top Elev: 435.0 ft NGVD

FLOOD CONTROL STORAGE
Everett-Only Capacity: 91,500 Acre Feet
26.8 Inches of Runoff
Area at Crest: 2,900 Acres
Combined Capacity: 161,600 Acre Feet
6.8 Inches of Runoff (Net)
Area at Crest: 6,600 Acres

CONTROL WORKS
Type: Conduit
Size: 8' Diameter
Length: 350 Feet
Invert Elev: 325.0 ft NGVD
Everett Weir Elevation (top of logs): 340.0 ft NGVD
Capacity (Full Pool): 2,900 cfs
Gates (Type): Hydraulic Slide
Number: 3
Size: 6.0' x 3.5'
Channel Capacity: 1500 cfs

SPILLWAY
Type: Ogee Weir
Length: 175 Feet
Elev: 418.0 ft NGVD

SPILLWAY DESIGN FLOOD

Original Design Criteria:
- Rainfall Excess: 18.2 inches
- Initial Pool Level: Full
- Flood Control Outlet Gates: Operable
- Peak Inflow: 195,000 cfs
- Peak Outflow: 106,000 cfs
- Max. Pool: 430 ft-NGVD
- Freeboard: 5.0 ft
Current HMR 51 & 52 Criteria:
- Rainfall Excess: 20.9 inches
- Initial Pool Level: Full
- Flood Control Outlet Gates: Operable
- Peak Inflow: 201,400 cfs
- Peak Outflow: 113,400 cfs
- Max. Pool: 430.6 ft-NGVD
- Freeboard: 4.4 ft

RECREATIONAL FACILITIES: State managed Clough State Park, 225 picnic tables with grills, beach, parking areas, change house, boat ramp, bathrooms, water and group picnic shelter.

TOTAL COST: $21,180,000 combined total

PLACED IN OPERATION: December 1961