Missouri River Levee Units L-561, L-550, and L-536 have provided flood protection to Atchison and Holt counties for 70 years. The top six historical crests are listed in Table 1.
|Historical Crest (ft.)
Flood of 1952
Picture: South of Langdon looking northeast up the old Nishnabotna river channel
Flood of 1984
Picture: North of the Brownville bridge looking southwest
Flood of 1993
Picture: Hwy 111 I-29 intersection looking west
Flood of 2010
Picture: Nishnabotana River near Hartman's Curve
Flood of 2011
Picture: Hwy 136 looking east towards I-29
Flood of 2019
The “Bomb Cyclone”. With record snowfall in the central plains and eastern Iowa a 3-day (March 11-13) temperature rise to 60 degrees combined with 1.5-3 inches of rainfall caused a rapid melt. The frozen ground conditions could not absorb any of the moisture and an unprecedented amount of runoff hit the local streams and rivers with massive chucks of ice traveling downstream acting like a plow. On March 14th the Spencer Dam collapsed on the Niobrara River sending more unregulated water downstream. Every levee system south of Council Bluffs, IA to Craig, MO was breached. The Missouri River gauge at Brownville set a new record of 45.7 feet, 1 foot higher than the previous record. ACLD’s levees sustained miles of crest damage and 14 total breaches. All this would start the multi-year rehabilitation process with new levee setbacks on a portion of the system.
Picture: Upper L-550 Breach looking southeast towards Phelps, MO