Mayfield, NY – Precipitation received and forecast during the next several days, when combined with the last of the melting mountain snow, is producing expected increases in the reservoir elevations at the New York State reservoirs operated by the Hudson River-Black River Regulating District. While many of the Regulating District’s reservoirs are now at full capacity, the design of those impoundments ensures that only a small fraction of the water flowing into the reservoirs will get released over the dam. For example, even when water crests the spillway, only one sixth of the water flowing into Great Sacandaga Lake in the next few days will immediately flow over the Conklingville dam spillway down to the Sacandaga and Hudson Rivers. The rest is retained for release once the natural flow of the Hudson River returns to predetermined target elevations. While the torrent of water flowing over the Conklingville Dam makes for interesting photography, the volume released over the spillway is a fraction of the water typically released through the dam’s Dow valves and the adjacent E.J. West hydropower plant.
Winter-time drawdown of the state’s river regulating reservoirs occurred on schedule and as planned. The Great Sacandaga Lake was lowered according to the Upper Hudson/Sacandaga River Offer of Settlement and reached a minimum elevation of 749.07 feet on March 5, 2011 consistent with the Offer of Settlement elevation target curve. Since that date, above average steady rain and snow melt has brought the elevation of the Great Sacandaga Lake to nearly 773 feet. Weather and river forecasts by the National Weather Service (NWS) and the United States Geologic Service (USGS) yield a prediction of a peak elevation at Great Sacandaga Lake at 774.4 feet on Sunday May 1, 2011. This elevation will be an all-time high. Because natural flow of the Hudson River is already above flood stage, the Regulating District will continue to impound as much water as possible until the weather improves.
Once the weather does improve, the inflow into the Hudson River’s headwaters in the Adirondacks will decrease. At that time, the Regulating District will begin daily Reservoir releases to drawdown Great Sacandaga Lake in anticipation of continued spring and summer rains. Significant additional rainfall, which could be expected to cause the Great Sacandaga Lake’s elevation to rise, may require immediate release of water at Conklingville to the Sacandaga and Hudson Rivers at or near flood stage in order to prevent triggering larger volume releases designed to protect the impoundment itself. None-the-less, even should additional significant rainfall occur, the Reservoir’s remaining storage capacity and design ensure that the Reservoir will continue to mitigate the potential for widespread flooding by limiting releases at Conklingville to levels below the inflow to the Reservoir from the headwaters of the Sacandaga River.