THOMASTON DAM

NAUGATUCK RIVER - Naugatuck River Watershed - Thomaston, CT

DRAINAGE AREA: 97.2 sq.mi. (Gross)
70.8 (Net)

PERMANENT POOL: None

DAM
Type:Rolled earth fill and rock
Length: 2,000 Feet
Top Elev=517.0 Ft NGVD(137 Ft)

FLOOD CONTROL STORAGE
Capacity: 42,000 Acre Feet
8.1 Inches of Runoff (gross)
11.1 Inches of Runoff (net)
Area at Crest: 960 Acres

CONTROL WORKS
Type: Horseshoe Conduit
Size: 10' diameter
Length: 455 Feet
Invert. Elev = 380.0 Ft NGVD
Capacity (Full Pool): 5,500 cfs
Gate (Type): Hydraulic Slide
Number: 2
Size: 5'- 8" x 10'
Channel Capacity = 3500 cfs

SPILLWAY
Type: Conv. Side channel/Ogee Weir
Length: 435 Feet
Elev = 494.0 Ft NGVD (114 Ft)

SPILLWAY DESIGN FLOOD

• Original Design Criteria:
  • Rainfall Excess = 22.4 inches
  • Initial Pool Level = Full
  • Flood Control Outlet Gates = Operable
  • Peak Inflow = 158,000 cfs
  • Peak Outflow = 138,000 cfs
  • Max. Pool = 512.0 ft-NGVD
  • Freeboard = 5.0 ft
• Current HMR 51 & 52 Criteria:
  • Rainfall Excess = 27.4 inches
  • Initial Pool Level = Full
  • Flood Control Outlet Gates = Operable
  • Peak Inflow = 186,800 cfs
  • Peak Outflow = 146,200 cfs
  • Max. Pool = 513.1 ft-NGVD
  • Freeboard = 3.9 ft

RECREATIONAL FACILITIES: 20 Picnic tables with grills, parking area, water, bathroom, 50 miles of bike trails, parking, portable toilets, overlook recreation area, overlook trail area.

TOTAL COST: $14,240,000

PLACED IN OPERATION: December 1960

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