March 22, 2019

Current projections of the Big Sioux water level crest in North Sioux has decreased to 29.2 feet.  The projected crest time is Saturday, March 30th at 10am.  The river levels and crest times will continue to change as conditions change.  The downward crest trend it positive for North Sioux City.

In the North we can expect snow melt for another week.  There are no large precipitation events expected in Eastern South Dakota for the next week.  There will be scattered showers of ¼ of rain or less.

The Big Sioux River should see flooding events in Brookings, Dell Rapids, and Sioux Falls at 1-90 in the next week.

The Corp of Engineers are monitoring the releases from Gavin’s Point Dam.  Releases should remain steady at 24,000 cubic feet per second and will be dependent on the Niobrara River levels.  Fort Randal is not releasing water at this time.  The Corp will continue to monitor and will likely reduce the Gavin’s Point release rate to 20,000 cfs in the coming days.

City officials will continue to monitor the river levels of both the Big Sioux and Missouri Rivers.  River level elevations continue to fluctuate and will be monitored.  Continued updates will be sent out at later times.

River levels can be monitored at the following website.  https://water.weather.gov/ahps2/hydrograph.php?wfo=fsd&gage=sxci4

March 21, 2019

Regarding the alleged closure on I-29 at exit 4 (McCook Lake).

I have spoken to the Department of Transportation and state emergency operations center. There is no plan, at this time, to close the interstate. The projected forecast of river levels from the National Weather Service have been scaled slightly back. Please refer to www.weather.gov for current and future predictions of river level for the Big Sioux River.

In order to be fully prepared, all government agencies and residents should explore every possibility and contingency. The Department of Transportation has been reviewing the past flooding event of 2014. In order to ensure the safety of all residents, every plan must be taken into consideration. This is why several agencies have begun communicating with local contacts to facilitate a “just in case” plan. This is standard protocol for such an event.

Union County Emergency Management cannot stress enough that I-29 will NOT be closed at this time. If conditions would possibly deteriorate, all options would remain on the table. As of now, there are no plans to close I-29 at Exit 4.

March 21, 2019

The current projection on the Big Sioux River levels at North Sioux City show the water cresting on Saturday March 30th at approximately 2:00PM at a river level of 30.6 feet. This is 3 feet below the projections from yesterday.  The water levels will continue to decrease over the next week and then will rise some.  The temporary levee at Military Road Bridge is built to a river level of 45 feet, well above the projected crest next week.  Water levels are expected to be far below what was seen on Sunday March 16th, and well below the historical water mark of 37.7 feet.

The Corp of Engineers are monitoring the releases from Gavin’s Point Dam.  Releases should remain steady at 23,000 cubic feet per second and will be dependent on the Niobrara River levels.

The City is still obtaining information from the SD DOT regarding any plans for any temporary levees in the area.  At this time there is no need for any temporary levees at Hwy 105 or on I-29.  Information will be sent when the City has it.

City officials will continue to monitor the river levels of both the Big Sioux and Missouri Rivers.  River level elevations continue to fluctuate and will be monitored.  Continued updates will be sent out at later times.

River levels can be monitored at the following website.  https://water.weather.gov/ahps2/hydrograph.php?wfo=fsd&gage=sxci4

March 20, 2019

The City of North Sioux City will hold a public meeting tonight 3/20/2019 at 6:00 PM to update the public on the Big Sioux River water levels and ongoing efforts.  Current and future river levels will be discussed.

The meeting will be held at the Community Center connected to the Fire Hall at 205 Sodrac Drive

City officials will continue to monitor the river levels of both the Big Sioux and Missouri Rivers.  River level elevations continue to fluctuate and will be monitored.  Continued updates will be sent out at later times.

River levels can be monitored at the following website.  https://water.weather.gov/ahps2/hydrograph.php?wfo=fsd&gage=sxci4

March 26, 2019 Big Sioux River Event

March 19, 2019

The Big Sioux River levels have dropped significantly since the high-water mark of 37.42 feet on Saturday, March 16th.  At this time the City is preparing for increases to the River Level due to the snow melt from areas North of Sioux Falls.  At this time projections show the river rising to a level of 34.2 feet between March 28th and March 30th.  At this time there is no concern about water levels rising above the level that was seen last weekend.  The city is currently working with engineers, the Corp of Engineers, and other officials to ensure community stays dry and safe.

Missouri River levels are also decreasing at this time. The Corp of Engineers expects to reduce the release from Gavin’s Point Dam to approximately 28,000 cubic feet per second (cfs). This is a reduction of approximately 75,000 cfs.  The North Sioux area would see that reduction in levels in a few days.  This reduction in the Missouri River will help drain the Big Sioux river basin.

City officials will continue to monitor the river levels of both the Big Sioux and Missouri Rivers.  River level elevations continue to fluctuate and will be monitored.  Continued updates will be sent out at later times.

River levels can be monitored at the following website.  https://water.weather.gov/ahps2/hydrograph.php?wfo=fsd&gage=sxci4

March 16, 2019

The Big Sioux River water levels have risen to 34.35 feet.  The model still shows a crest of the river in North Sioux City at 35.6 feet at approximately 12:00 PM on Sunday March 17th.  At this time the models are trending higher than originally thought.  The City will be raising the temporary ring levee at Military Road Bridge to a height of 44 feet, an increase of 4 feet of what is currently in place.  The crest of the river has gone through Elk Point and is close to Jefferson at this time.

The new level of 44 feet is 6.3 feet above the historical high flood event of 37.7 feet seen in 2014.

Missouri River level is holding steady at this time and should slowly recede as less water is being released from Gavin’s Point Dam.  Thawing temperatures and increased flows from tributary creeks are putting more water into each of the river systems.

River levels can be monitored at the following website.  https://water.weather.gov/ahps2/hydrograph.php?wfo=fsd&gage=sxci4

March 16, 2019

The Big Sioux River water levels have risen to 32.7 feet.  The new predictions show a crest of 35.6 feet at approximately 12:00 PM on Sunday March 17th.  These levels are 2.5 feet higher than originally predicted and will take place approximately 12 hours earlier than expected.  The City continues to monitor the river levels with the assistance of Union County Emergency Management and City Engineers.  The temporary ring levee is built to 40 feet, 4.4 feet higher than the predicted crest.  Should the models change, action will be taken to increase the height of the temporary levee.  Thawing temperatures continue to change the river level models.

The water has crested in Hawarden, IA and Akron, IA and the water is receding in those communities.

The Missouri River is holding steady and is likely to slowly recede.

City officials will continue to monitor the river levels of both the Big Sioux and Missouri Rivers.  River level elevations continue to fluctuate and will be monitored.

March 15, 2019

The Big Sioux River is expected to crest at 32.8 feet at approximately 1:00 am Monday, March 18th.  The City is currently undergoing a construction project on the levee which has created an opening in the levee.  The City has built a temporary ring levee around the opening of the levee.  This temporary ring levee will protect the City against any rising water up to a river level of 40 feet.  This level is over 7 feet higher than the expected crest height on Monday.

The Missouri river is expected to crest at an elevation 1,093 above sea level in the Dakota Dunes area.  At this time the City should see no movement of water toward McCook Lake and we do not expect water from the Missouri River levels to endanger any of the homes on the lake or in City Limits. The Army Corp of Engineers has stated the peak flow from the Spencer, NE dam break has reached Gavin’s Point Dam and is moving toward the Sioux City area.  The Corp of Engineers has reduced the amount of water it is releasing from the dam at this time.

City officials will continue to monitor the river levels of both the Big Sioux and Missouri Rivers.  River level elevations continue to fluctuate and will be monitored.

March 14, 2019

As many of you are aware the water levels of the Big Sioux River are rising due to heavy rains, snow melt, and a deep frost line.  The latest projections show the river cresting early Monday morning at a level of 32.4 feet.  We do not anticipate any water flowing into the community from the river as these are lower levels than what was seen during the Fall 2018 rain events.

The City is currently undertaking a levee improvement project.  At Military Road Bridge there is a portion of the levee that has been removed for this project.  Beginning tomorrow morning a temporary ring levee will be constructed to a level of 40 feet, well above the anticipated river level.  There should be no concern with the river breaching the levee and overflowing into the City.  The City is also prepared for the event at our lower culverts and will begin pumping water out of the City in the event the water rises too high.

You can monitor river levels at this website.  https://water.weather.gov/ahps2/hydrograph.php?wfo=fsd&gage=sxci4

Please contact City Hall with any questions.