Recent Rainfall and Flow Conditions Relative to The Housatonic River

Posted: October 15, 2005 in General, in Debris

FROM NORTHEAST GENERATION: Ladies & Gentlemen, The purpose of this memo is to describe the rainfall and flow conditions that have occurred over the past day relative to the Housatonic River as well as to show how rapidly river flow conditions can change even when the rainfall predictions and resulting hydrologic projections are made by experts. The rainfall over the Housatonic Watershed has fallen heavily from about 1:00 p.m. through the end of the Friday. The storm early on Friday centered around the lower sections of the Housatonic River, however, the heart of the river (Kent, New Milford, Roxbury, Southbury, etc.) received excessive rainfall during the afternoon and nighttime hours. The 1:00 p.m. predictions from the National Weather Service hydrologic models have been doubled, and in some cases, tripled as of this hour. The various river gages show a steady rise, however, I expect the river flows to level off Saturday morning as the rainfall has stopped and it appears that there is no significant rain forecasted for the next few days. NGS has operated the floodgates to minimize damage both upstream of the Shepaug Dam and downstream of the Stevenson Dam, however, these areas are being impacted. Falls Village maximum flow for electric generation purposes is 1,800 cfs (cubic feet per second) - current inflow as of 4:00 a.m. is 4,752 cfs, up from 3,264 cfs as of 1:00 p.m. on Friday Bulls Bridge maximum flow for electric generation purposes is 1,200 cfs - current inflow as of 4:00 a.m. is 20,537 cfs up from 6,119 cfs as of 1:00 p.m. on Friday Shepaug maximum flow for electric generation purposes is 6,200 cfs - current inflow as of 4:00 a.m. is 29,783 cfs up from 8,275 cfs as of 1:00 p.m. on Friday Stevenson maximum flow for electric generation purposes is 6,200 cfs - current inflow as of 4:00 a.m. is 35,337 cfs up from about 10,000 cfs as of 1:00 p.m. on Friday The inflow into Shepaug is sufficient enough to cause flooding of businesses in New Milford even though the elevation of Lake Lillinonah has been kept very low in anticipation of flooding per our FERC approved standard operating procedures. Similarly, homes and cottages downstream of the Stevenson Dam have been evacuated as flood waters have inundated many of these homes. Candlewood Lake had been at its lowest allowed water surface elevation for the season due to the drought, but now is full to its normal maximum operating point. CT Hydro personnel have been at the dams operating flood gates and generators throughout the evening. Operations personnel have been managing the river to minimize the impacts in both New Milford and the towns south of Stevenson. This past week we have experienced intense periods of rainfall, resulting in varying flows and lake elevations. Many people have been inconvenienced from these conditions and have suffered property losses and damage. The operating challenges have been many, however, I am proud of the people who have had to manage and operate their way through these conditions with the weight of their actions on their shoulders, for they have responded well to the many challenges that they faced. If you have any questions concerning these events, don't hesitate to e-mail me. Thank you. Bob Gates - Northeast Generation We will continue to forward and post all communication from Northeast Generation.