Lake Sakakawea watch begins
The level of Lake Sakakawea stood at 1,829.3 feet Sunday. While that mark is not considered out of the ordinary for Lake Sakakawea at this time of year, it is at the lower end of what might be considered a comfort zone. A further loss of lake level is expected in the months ahead as water is released for hydroelectric generation through the turbines at Garrison dam.
Therefore, those with lake interests, ranging from recreationists to biologists, will be watching to see how much snow accumulates over the Upper Missouri River and Yellowstone River drainages this winter. 2012 was considered a drought year on the Missouri. The Upper Missouri reservoirs are at low levels, and the U.S. Army Corps of Engineers has been operating them to prevent excess water from flowing downstream before it is known to what extent the reservoirs may recharge with runoff next spring.
To date, the Corps has denied requests from Mississippi River interests to receive additional water from Missouri River reservoirs. The reason, says the Corps, is that they are responsible for maintaining proper levels in the Missouri and that another season of below normal runoff could leave reservoirs far below normal operating levels.
Runoff into Lake Sakakawea in 2012 was calculated at 76 percent of normal. Only in February 2012 did Lake Sakakawea receive more water than normal, and February is a month of minimal runoff. May, June and July are considered key runoff months. In 2012, those months brought runoff equaling slightly more than 80 percent of normal. Other months fell fall below normal runoff, too.
The Corps’ initial forecast for runoff into the Missouri River Basin in 2013 is 20.5 million acre feet, or 82 percent of normal. That number is used for planning purposes at this early stage of the year. Weather forecasts and snowfall amounts throughout the next few months can be expected to alter the outlook, perhaps significantly.
It has not been fully calculated what the level of Lake Sakakawea will be during the coming summer months should runoff only reach 82 percent of normal. A number of variables will determine Lake Sakakawea’s 2013 peak elevation, including the amount of moisture in the snowpack and in the ground, the temperature during runoff and the amount of rainfall that may fall over the basin during the runoff season.
Current projections call for Lake Sakakawea to dip to 1,827.3 feet by the end of February.
The Corps will continue to issue monthly outlooks for Lake Sakakawea elevations. March and April outlooks generally produce a reliable trend of possible runoff that may occur. The current snowpack over the drainage, primarily in the mountains of western Montana, is trending near average. The snowpack normally peaks near April 15.