Besides the 1938 hurricane, the 1955 flood was arguably the greatest natural disaster in Connecticut since colonial times. The amount of rain that fell in August 1955 is so off the charts no event has come anywhere close to it in the last 100 years. The monthly record of 21.87″ at Bradley Airport stands alone as the wettest month on record – the second highest 16.32″ from October 2005 lags far behind.
Hurricane Connie made landfall over the Outer Banks as a minimal hurricane on August 12, 1955. The storm moved slowly up the Chesapeake Bay and dumped 5″-10″ of rain in portions of northwest Connecticut. Connie barely produced any wind in Connecticut as she passed to the west but dropped enough rain to saturate the soil and raise river levels above flood stage.
5 days after Connie, Hurricane Diane made landfall in North Carolina very close to where Connie struck. The storm moved inland and then was picked up by a strong trough diving into the Great lakes. An exceptional band of rain setup over northwest Connecticut and western Massachusetts as the storm passed over Long Island. 10″-20″ of rain was common in many areas. When preceded by Connie’s 5″-10″ of rain Diane’s record 24 hour rainfall was enough to push rivers to levels that hadn’t been seen in hundreds of years.
The all-time 24 hour rain record in Connecticut occurred on August 19th in Burlington with 12.77″ falling. In Westfield, Massachusetts an incredible 1-day total of 19.75″ fell. A close up look at the 8-day rain totals from August 12, 1955 to August 20, 1955 reveal just how exceptional this flood event was.
A streamline analysis of Hurricane Diane in the August 1955 Monthly Weather Review shows a stalled out front across Connecticut between 0730 EST August 18, 1955 and 0730 EST August 19, 1955 out ahead of Diane’s circulation. For nearly 24 hours strong convergence setup across Connecticut with deep tropical moisture advecting northward from Diane.
A preliminary report by the U.S. Weather Bureau from August 25, 1955 includes hourly rainfall totals for Bradley Field which are incredible. Here’s an excerpt from that report.
The rains in southern New England were prolonged as the storm center which was moving eastward directly along the 40º parallel for about 12 hours from 5 p.m. of the 18th to about 5 a.m. of the 19th, recurved to an east-northeast direction paralleling the southern New England coast. The hourly precipitation rates recorded at the Weather Bureay office at Bradley Field, Windsor Locks, Conn., are shown on the map. Until about 9 p.m. on the 18th, the intensities fluctuated considerably, but from then to 10 a.m. on the 19th the rate was quite constant, averaging nearly .6 inch per hour for 15 hours. The greatest amount from this record in a 24-hour period, 12.05 inches, is from 10 a.m. August 18 to 9 a.m. August 19. This compared with the previous maximum 24-hour rainfall of record at Hartford, Conn., of 6.82 inches occurring on July 13, 1897.
The 1955 floods destroyed entire neighborhoods, entire downtowns, and entire families. Waterbury, Winsted, Naugatuck, Derby, Ansonia, Farmington, New Hartford, and Putnam are just some of the towns and cities that were changed forever.
With the amount of rain that fell it’s not surprising the 1955 floods set records on the Quinebaug, Farmington, and Naugatuck Rivers. The Army Corps of Engineers built a monstrous system of levees and dams on those rivers to prevent a flood like the ’55 one from happening again. Barring an unforeseen catastrophic failure of the dam and levee system a flood to the level of 1955 will never happen again on those
1955 Rain Totals (From Coop Stations)
Barkhamsted – 25.06″
- Connie – 9.11″
- Diane – 15.95″
Burlington – 24.65″
- Connie – 8.73″
- Diane – 15.92″
Norfolk – 21.81″
- Connie – 8.93″
- Diane – 12.88″
Warren – 18.60″
- Connie – 7.74″
- Diane – 10.86″
Windsor Locks – 18.42″
- Connie – 4.02″
- Diane – 14.40″
Falls Village – 16.83″
- Connie – 6.75″
- Diane – 10.08″
Danbury – 14.83″
- Connie – 8.74″
- Diane – 6.09″
Hartford – 11.75″
- Connie – 3.90″
- Diane – 7.85″
Prospect – 10.96″
- Connie – 3.41″
- Diane – 7.55″
Middletown – 10.90″
- Connie – 4.53″
- Diane – 6.37″
Bridgeport – 8.34″
- Connie – 5.32″
- Diane – 3.02″
WKNB Channel 30 “Flood Story” Special
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Flood Control Since the Floods
Following the 1955 flood the Army Corps of Engineers spent nearly 2 decades damming some of the most vulnerable rivers in Connecticut.
The city of Winsted was arguably the most vulnerable area in the state before the great flood. Several times in the 1800s the Mad River flowed over its banks and flooded downtown. The Mad River, a tributary of the Still and Farmington Rivers, is now dammed in Winchester 2 miles west of Winsted on Route 44.
In addition, Highland Lake, which is about 100 feet above the Mad River just southwest of downtown Winsted frequently overflowed its banks and added water to the typically swollen Mad River. During the ’55 flood the Mad River was raging down from the hills of Norfolk while the Sucker Brook raged into Highland Lake sending water cascading from the lake into Winsted. The combination destroyed most of Main Street in town. The southern side of Main street was never rebuilt and was paved over.
Besides the Mad River dam in Winchester the Sucker Brook dam along to the west of Highland Lake helps regulate the lake’s level and prevent more water from reaching the Mad River in downtown. The flood control for Highland Lake and the Mad River reduces flows on the Mad River which flows into the Still River and eventually the West Branch of the Farmington River.
The Farmington River surged to levels never seen before during the 1955 flood. On the West Branch of the Farmington River the Metropolitan District Commission had completed the Hogback Dam and the West Branch Reservoir behind it before the flood. Plans for the Colebrook River Dam were already in place when the flood occurred and the Army Corps took over the project for flood control purposes.
The Colebrook River Dam in Hartland and Colebrook is a major part of the flood control system on the Farmington River. The watershed upstream, including the western Massachusetts towns of Becket, Otis, Sandisfield, Tolland, and Granville help feed Colebrook River Lake and the West Branch Reservoir. The Army Corps maintains the flow leaving the Colebrook Dam for both flood control and low flow augmentation, according to the MDC. Both the lake and reservoir may be used as water supplies in the future according to the MDC.
The combination of the flood control on the Mad River (Sucker Brook dam and Mad River dam) and the Colebrook River dam provides significant flood control on the Farmington River. Barring some type of catastrophic failure of the flood control system a flood like 1955 will not happen again in towns like Winsted, New Hartford, and Unionville. That said, if rain like August 1955 happened again, major flooding would be likely along the length of the river with devastating results likely.
The Naugatuck River flooded virtually every town from Torrington to Derby in 1955. Waterbury, Thomaston, Naugatuck, Ansonia, and Derby were particularly hard hit.
7 dams were constructed by the Army Corps which has significantly reduced the flow of the Naugatuck River particularly in times of heavy rain. The first 2 dams control the river north of Torrington. The East Branch Dam in Torrington and the Hall Meadow Brook Dam protect Torrington.
Downstream the Thomaston Dam on the Naugatuck River provides additional protection. 3 tributaries of the Naugatuck downstream are flood controlled as well. Northfield Brook Lake, Black Rock Lake, Hancock Brook Lake, and Hop Brook Lake.
The Naugatuck River has barely reached flood stage in many locations following the construction of these dams. In fact in Beacon Falls the flood stage of 12 feet has only been exceeded 6 times in 50 years since the dams have been built. Of those crests 4 have been “minor floods”, 1 has been a “moderate flood” and 1 has been a “major flood”. Incidentally, of those 6 floods since 1955 on the Naugatuck River, 4 have occurred in the last 6 years!
The Quinebaug River was another river to rage on August 19th flooding downtown Putnam and sparking a spectacular fire at a magnesium factory in the city.
The Quinebaug River actually begins in Union at Mashapaug Lake and flows north across the border into Massachusetts. The Quinebaug connects a number of small lakes in Massachusetts some of which occur naturally and others that exist now thanks to the Army Corps flood controls that have been built.
The first dam on East Brimfield Lake covers the towns of Sturbridge, Holland and Brimfield. A second dam on the Quinebaug, the Westville Lake dam in Southbridge, also provides flood control on the river for the towns of Southbridge and Dudley.
The river continues south over the Connecticut border into Thompson where the massive West Thompson dam created West Thompson Lake and provides siginficant flood control for Thompson, Putnam and downstream towns through Jewett City. The dam is located just upstream of the confluence of the French and Quinebaug Rivers and several miles upstream of the confluence of the 5 Mile and Quinebaug Rivers in Putnam.
The Buffumville Dam on the Little River (a tributary of the French) and the Hodges Village Dam on the French River in Massachusetts provide additional flood control on those rivers which are tributaries to the Quinebaug.
Additional flood controls in the Thames River basin include the Mansfield Hollow Lake Dam at the confluence of the Natchaug, Fenton, and Mt. Hope Rivers in Mansfield. The Natchaug River flows into the Shetucket River and eventually into the Thames. The dam was built before the 1955 flood which likely saved Willimantic from devastating flooding in August of 1955.
The 6 dams throughout the Thames River Basin have virtually eliminated the threat of a ’55 flood repeat. Still, we have seen significant flooding especially well downstream of the dams. The Quinebaug River in Jewett City overflowed its banks in the March 2010 flood causing significant damage. Since the flood controls have been in place the Quinebaug River in Putnam has yet to reach flood stage (10 feet). The crest on August 19, 1955 was 26.5 feet! The highest crest since the dams were built was 8.67ft on March 10, 1998.
Some rivers in the Thames River basin are still vulnerable to flooding. The Yantic River is not flood controlled. Other rivers upstream of dams are also vulnerable. The Mt. Hope River in Ashford reached “major” flood stage in October 2005. The Willimantic River from Willimantic north through Storrs is also vulnerable having reached “major” flood levels in October 2005. The 2 highest crests for the river in Coventry remain the 1955 and 1938 floods.