Advertisement

Mississippi River headwater reservoirs being drawn down

Error message

  • Warning: array_merge(): Expected parameter 1 to be an array, bool given in _simpleads_render_ajax_template() (line 133 of /home/pdccourier/www/www/sites/all/modules/simpleads/includes/simpleads.helper.inc).
  • Notice: Trying to get property 'settings' of non-object in _simpleads_adgroup_settings() (line 343 of /home/pdccourier/www/www/sites/all/modules/simpleads/includes/simpleads.helper.inc).
  • Warning: array_merge(): Expected parameter 1 to be an array, bool given in _simpleads_render_ajax_template() (line 157 of /home/pdccourier/www/www/sites/all/modules/simpleads/includes/simpleads.helper.inc).
  • Notice: Trying to access array offset on value of type null in include() (line 24 of /home/pdccourier/www/www/sites/all/modules/simpleads/templates/simpleads_ajax_call.tpl.php).

Water goes over Ambro Road near the intersection of County K Sunday. The Mississippi River was at 15.9 feet at 7:45 a.m. on Monday, March 18. It is predicted to reach 17.3 feet by March 21. Minor flood stage at McGregor is 16 feet. (Photo by Ted Pennekamp)

 

River flow continually monitored

By Ted Pennekamp

 

The U.S. Army Corps of Engineers, St. Paul District, continues to lower water elevations within its six Mississippi River headwaters reservoirs in anticipation of spring snow melt.

All elevations are given using National Geodetic Vertical Datum of 1929.

The Corps is lowering the elevation of Gull Lake, located near Brainerd, Minn. The current elevation is 1,193.16 feet, which is 10 inches below the middle of the normal summer range. Changing conditions will determine the final drawdown elevation, which would be no lower than 1,192.75 feet.

Elevation at the Cross Lake, near Crosslake, Minn., is currently at 1,277.93 feet and, based on winter snow pack, the reservoir will be drawn down to near elevation 1,277.3 feet.

Big Sandy Lake, near McGregor, Minn., is currently at 1,214.4 feet and will be drawn down to elevation 1,214.31 feet (one more inch). At that point the lake will be two feet lower than the middle of the normal summer range and it will be at its lowest level allowed, per congressional legislation.

The pool elevation at Pokegama Lake, near Grand Rapids, Minn., is approximately 1,271.5 feet. The pool will be lowered to 1,270.42 feet. 

Drawdowns are complete at Leech Lake, near Federal Dam, Minn., and Lake Winnibigoshish, near Deer River, Minn.

The pool at Leech Lake is currently 1,294.2 feet, with the reservoir drawn down six inches below normal summer range.

The pool at Lake Winnibigoshish is currently 1,297.51 feet, with the reservoir drawn down 0.68 feet below summer range. 

Late winter snow surveys show an extensive snow pack, with more than enough water content to fill volume created by the winter drawdowns. Property (docks, boat lifts, etc.) at or near the normal summer lake level should be moved to higher elevations to be safe from rising reservoir levels this spring.

Patrick Loch, public affairs specialist with the U.S. Army Corps of Engineers - St. Paul District, said the drawdowns have been going on all winter and is something the Corps does every winter regardless of whether widespread flooding is predicted or not.

“We do drawdowns every season in order to maintain a slow and steady release of water,” said Loch. “These reservoirs are like a very large bathtub with a very small drain.”

Loch also said that the Corps of Engineers is in the preparation stage regarding the expected spring flood. He said the Corps has recently conducted training for the residents of various counties, including Buffalo County in Wisconsin. They have also inspected levies to make sure they are structurally sound.

“We have been in the preparation stage since the March 7 hydrological survey by the National Weather Service predicted a good chance of widespread flooding,” said Loch.

Loch noted that all of the dams on the Upper Mississippi River have been maintaining pool levels in accordance with the operating manual. He said it can be a delicate balance, with much communication between all locks and dams and the Corps of Engineers, St. Paul District.

He said the Corps continually has been monitoring the situation and hopes there will be a gradual snow melt in Minnesota and northern Wisconsin. Numerous rivers are being monitored.

Each dam has a different threshold at which that dam would have to open all gates wide open to let as much water through as possible. Loch said the threshold at Dam 9 near Lynxville is a flow of 64,000 cubic feet per second. The threshold flow at Dam 10 at Guttenberg is 73,000 cubic feet per second. Flows at or beyond these thresholds mean that these dams can no longer hold any water back.

“We relieve the impact as much as we can,” said Loch. “The dams were not designed for flood control, they were designed to maintain the navigation channel.”

Rate this article: 
No votes yet