KU GEOTECHNICAL CONFERENCE

2019 MISSOURI RIVER FLOOD EVENT

JOHN D. HOLMCHIEF, ENGINEERING DIVISIONKANSAS CITY DISTRICT

14 NOVEMBER 2019

AGENDA

Introduction

Missouri River Background Information

March 2019 Flood Event

May-July 2019 Flood Event

Levee Damages Summary

Wrap-Up

Questions

DEFINITIONS

• Federal Levee – USACE Federally constructed, owned and maintained by local sponsors

• Non-Federal Levee – Non-Federally constructed, owned and maintained by local sponsors

• Other Levees – All other levee systems• Public Law (PL) 84-99 – Flood Control and Coastal Emergency

Act - Provides the Corps of Engineers with the authority to prepare for, respond to, and recover from floods and coastal emergencies

• USACE – US Army Corps of Engineers• NWK – Kansas City District – Missouri below Rulu, NE• NWO – Omaha District – Missouri above Rulu, NE• NWD – Northwestern Division

OUR MISSIONREGULATE MISSOURI RIVER MAINSTEM RESERVOIRS

• Priority: Life and Safety• Operational Decisions: Driven by Annual Runoff ConditionsWater captured in System flood control storage zones each year, must leave System each year.• Master Manual: Storage and release decisions designed significantly around

Flood Control, Navigation, & Water Supply purposes

• Authorized Purposes: Funds power plant projects, allows food plots for wildlife, reservoirs stocked with fish, irrigation intakes, boat ramps, water quality testing, etc.

The Corps does not store more water in the System for Threatened and Endangered Species.

Flood Control Navigation Hydropower Water Supply Fish & Wildlife Irrigation Water Quality Control

Recreation

HYDROPOWER

NAVIGATIONFLOOD CONTROL WATER SUPPLY

RECREATIONIRRIGATIONWATER QUALITY

CONTROLFISH & WILDLIFE

Eight Authorized Purposes Flood Control – Requires Empty Space Navigation Hydropower Water Supply Water Quality Control Recreation Irrigation Fish and Wildlife (including T&E*)

Purpose = PriorityRunoff Driven System – The runoff drives system releases, and is

managed on an annual basis. We do not carryover water in the flood control zones

Basically operate for flood control or meeting downstream targets (nav)

* - As Hydrologic Conditions Allow

Requires Access to Water or Releases

MISSOURI RIVER AUTHORIZATION/MISSION

0

10

20

30

40

50

60

70

1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

MIL

LIO

N A

CR

E FE

ET (M

AF)

YEARS

Actual Drought Periods Current Forecast MED

ANNUAL RUNOFF ABOVE SIOUX CITY, IA

2019

Historic Drought Periods

Median

2019 Runoff Forecast … 61.0 MAF*Average Runoff … 25.3 MAF*October 1 forecast (ties record set in 2011)

MISSOURI RIVER MAINSTEM RESERVOIR SYSTEMFORT PECK GARRISON

BIG BEND

GAVINS POINT

OAHE

FORT RANDALL Bank Stabilization and Navigation Project, Sioux City, IA to St. Louis, MO

MAINSTEM PROJECTS - STORAGE

Flood Control Storage of Gavins Point:2/3 Cup Measuring Cup = 0.13 MAF

Combined Flood Control Storage of:Fort Peck, Garrison, Oahe, Big Bend, Ft. Randall5 Gallon Bucket = 16.2 MAF

MAINSTEM PROJECTS – FLOOD CONTROL STORAGE

Kansas City District Dams and Reservoirs

KANSAS CITY DISTRICT RESERVOIR STORAGE

Federal Levees – 58 systemsNon-Federal Levees - 83 systems, 94 segmentsOther – Not Shown

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LEVEES: FEDERAL VS NON-FEDERAL

MISSOURI RIVER BASIN – RUNOFF ABOVE SIOUX CITY, IA

Plains Snowpack+ Rainfall

March & April

Mountain Snowpack+ Rainfall

May – July

Rainfall

August – February

~ 25% annual runoff ~ 50% annual runoff

Average Annual Runoff ~ 25.3 million acre-feetFeb Forecasted 2019 Runoff ~ 25.6 million acre-feet

MARCH FLOOD EVENT - SNOWPACK• Mountain snowpack was

about average in 2019

• One difference between 2019 and 2011 … mountain snowpack was MUCH ABOVE average in 2011.

• Plains snowpack was present in the entire upper basin, Nebraska and Iowa

• Heavy to very heavy plains snowpack in portions of the central and eastern Dakotas

• Deeply frozen soils resulted in little to no infiltration during March snowmelt/rainfall events

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File Name

16BOMB CYCLONE

MARCH FLOOD EVENT - FLOWS

- 14 levee systems breached north of Kansas City on Missouri River.

- Estimated that 350 miles of levee systems impacted in some manner by flood waters

- Over 4.8 million acres inundated throughout Missouri River basin, March 8-21

Henry Pohl Levee March 27th 2019Atchison County, KS

Craig, MOMarch 2019

MARCH 2019 - DAMAGES

BREACHES

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- Overtoppping and breaching of left bank levee systems resulted in overland flow above the Mill Creek private levee

- Mill Creek private levee overtopped and breached allowing water to flank the main levees

- Ultimately water overtopped and breached the Big Tarkio private levees

MILL CREEK BREACH

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Breach DimensionsLength 600 feetScour Depth 80 feet

MILL CREEK BREACH

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BIG TARKIO BREACH

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Breach DimensionsLength 1,100 feetScour Depth 50 feet

PHASE I: STOP BREACH FLOWS

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Temporary Emergency MeasuresHolt County, Missouri• Temporary closure of levee breaches

at two locations on Mill Creek and Big Tarkio River

• Affected communities include Corning, Craig, Big Lake and Fortescue, Missouri

• 23,000 acres affected, with estimated property value of $185 million

• $28M Effort

BIG TARKIO BREACH

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BIG TARKIO BREACH

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03/23/2019

03/28/2019

• 1st Federal levee to overtop and breach since 1993

• Doniphan County, KS

MRLS 500-R

Buchanan CO, MO/Doniphan CO, KS

MRLS 471-460-R

MARCH 23 2019 – R471-460 LEVEE

MARCH 23 2019 – R471-460 LEVEE

NWK RESERVOIRS – MID APRIL

MAY - JUNE FLOODING

• May rainfall in KS averaged 10.4”; largest monthly rainfall, (exceeded July 1993).

• Precipitation in WY, SD, NE, IA, MO, KS … all much above average and on VERY saturated soils.

PEAK RESERVOIR CONDITIONS

TUTTLE CREEK SURFACE AREA

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PERCENT OF FLOOD CONTROL POOL OCCUPIED – 04 JUN 2019

IMPACTS TO RESERVOIRS

Kansas City District

On peak day, 9 MAF of 11 MAF of flood control storage was occupied

Surcharge operations at Harry S Truman, Tuttle Creek, Perry and Long Branch

Record pools at 9 reservoirs: Perry, Clinton, Truman, Pomona, Melvern, Hillsdale, Pomme de Terre, Harlan County and Long Branch

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• May precipitation ranged between 10-15 inches across a majority of the NWK AOR.

• Wettest May on record• JAN 2019 – JUN 2019 – record

precipitation levels for time span• NWK reservoirs continue to store runoff

due to high flows on Missouri River.• 9M of 11M acre-feet of flood control

storage utilized.

MAY 2019 FLOOD EVENT

MAY-JUNE FLOODING: LEVEE STATUS

• 50 levee systems Overtopped, or Overtopped and Subsequently Breached, 23 May - 17 June 2019

• All on the Missouri and Grand River located downstream of Kansas City

• NWK estimates approx. 655 additional levee miles from Kansas City – St. Louis damaged in May 2019

Garden of Eden Levee SystemGrand River

OBSERVATIONS

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y

Slide

Chariton River

Grand River RR Bridge, RR working to move debris downstream

OBSERVATIONS

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y

Emergency Repair ~ Sta. 95+00 L246

OBSERVATIONS

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y

L246 Sta. 64+00 Sandbagged Low Spot

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MRLS-246L• 2nd Federal levee to Overtop

and Breach since 1993 • Protects 25.8K acres• 35.2mil estimated property

value

IMPACTS TO LEVEES

Kansas City District

2 Federal Levees overtopped, 2 breaches

64 Non-Federal Levees overtopped, 43 breaches

LEVEE REHABILITATION AND USACE ASSISTANCE

Levee rehabilitation basic details• Goal is to repair eligible “Active” projects damaged by flooding prior to

the next flood season• Assistance must be requested by levee sponsor and is limited to pre-

disaster condition and level of protection• Repairs must be economically justified and are prioritized based on

consequences and severity of damage• Active federal levee rehabilitation projects are repaired at 100% federal

cost• Active non-federal projects are cost-shared 80% federal, 20% non-

federal• Levee sponsors must provide land access easements, rights-of-way,

relocations and borrow (earthen material to repair levee) at no cost to the federal government

LEVEE REHABILITATION AND USACE ASSISTANCE

Levee rehabilitation status• Mainstem releases from Gavins to continue at 80,000 cfs through

November – plan is to evacuate all flood storage before winter freeze• NWK continues to make releases from the Kanas reservoirs with the

goal to evacuate all flood storage over the next 6 weeks• NWK has completed all but four of the PIRs (Project Investigation

Report)• Challenged due to ongoing high water

• NWD is approving PIR’s • Emergency repairs for Mill Creek and Big Tarkio awarded early August• NWK has advertised four repair contracts• As PIR’s are approved by NWD, NWK staff are developing contract

documents for future advertisements• All advertisements are dependent upon the sponsors providing land

access easements, rights-of-way, relocations and borrow (earthen material to repair levee) at no cost to the federal government

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PERCENT OF FLOOD CONTROL POOL OCCUPIED 04 NOV 2019

QUESTIONS

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