FLOOD05132

• County: Larimer
• Community: Boulder
• Stream Name: Big Thompson, Cache La Poudre
• Basin: South Platte
• Title: Report on Floods in Omaha District, 1951
• Date: 1/1/1952
• Prepared For: State of Colorado
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Flood Documentation Report

Flood of 1-4 June

1. Cause.-. On 31 Maya heavy. rainstorm occurred over the
northwest portion of the state of Missouri and adjacent areas.
Runoff from this .storm caused Mill Creek and the Old Nishnabotna
River Chennel to overflow their banks.

2. Extent.- Local flooding occurred on the Missouri River
flood plain just above the point where Mill. Creek and the Old
Nishnabotna River Channel enter the. Missouri .River. ..'

3. Duration, - The floods wer.e of a flash n'l-ture. and over-
bank stages lasted less than 12 hours.. f~wever, because of poore.
drainage faciH ties., the overfl!)w areas did not drain fully:.for..
several weeks.

4. Sta{';es and dischar!';es.- None ..vailable. .Thefloocl.
discharges were of moderate magnitude, however, according to
local interests.

5. Dama{';8s.- Approximately 2,120 acres :wereflooded.. .Three
farmsteads were flooded to shallow depth.and .approximately 12 persons
evacuated the premises for 3 days. Several small breaks occurred
in the levees along Mill Creek and along the Old Niilhnabotna River
Channel. About 2 miles of graded earth r.Qad.were rendered impassable
for one week. Rather severe loss of potential. crop occurred due
to slow drainage of inundated areas. .

6. Estimate of damages.-

Areas .flooded:

900 acres cropland
800 acres pasture
420 acres swamp and timber
2,120 acres total

Damages:

Direct

Indirect Total
$15;000 $55,000 .
100 900
200 1,800
$15,300 $57,700

. Agriculture
Levees
Transportatioll

$40,000
800
1,600

Total damo.ges

$42,400

C. NISHNABOTNA RIVER AND TRIBUTARIES, IOWA AND MISSOURI

. Flood of 27-30 March..

..1. Cause.- During.the last week of March rising temperatures
caused the ice of the Nishnabotna River and its tributaries to break
up and start moving. Formation of ice blocks forced the stream out
of banks to cause minor flooding at various places.

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