1. Kansas City Industrial Council Hydrology and Hydraulics
Chance J. Bitner, PE
Chief, Hydrology and Hydraulics Section
Kansas City District
30 June 2015

2. Which river is the “toughest”?
The Kansas River peaked at Desoto on May 8 at 120,000 cfs.
In case asked, the 2011 flood peak was 32.6 ft at KC gage on the Missouri.
May 8, 2007 – 4 hours before the peak; 286,000 cfs,
120,000 cfs peak flow on the Kansas River at Desoto

3. Overview
Basic H&H
FEMA Floodplain
Climate Change

4. Overview
Basic H&H
FEMA Floodplain
Climate Change
Not to scale

5. Basic H&H Questions Hydrology How much water is coming?
How often does that much flooding occur?
How would it change if we build a reservoir?
How much time before the flooding starts?
Hydraulics
How high is the water going to get?
How fast is the water? Will that cause erosion?
What areas are prone to flooding?
How would the flow change if a levee is built?

6. Peaks at Kansas City ~705 kcfs w/out dams in place
~320 kcfs w/ today’s
Dams in place
541 kcfs
573kcfs
286kcfs

7. 1993 Flood w/out Dams
USGS post 1993 report

8. Hydrology Basic Options
Flow frequency based analysis
Rainfall / runoff model based analysis
Flood routings / event simulation
Sample USACE guidance
EM FLOOD-RUNOFF ANALYSIS
EM HYDROLOGIC FREQUENCY ANALYSIS
EM HYDROLOGIC ANALYSIS OF INTERIOR AREAS

9. USACE Hydrology for Kansas and Missouri Rivers
Flow frequency based
Kansas River – 2002 report ( )
Missouri River – 2003 report ( )
KS/MO river coincident peak – 2006 feasibility study
Some historic peak stages available (e.g. 1844)
Biggest effort: making the data sets consistent
Dates reservoirs were closed, when they were filling
Changes in consumptive uses

10. Hydraulic Study Options:
Steady flow vs unsteady flow
Fixed bed vs mobile bed
Numerical models; 1, 2 or 3 dimensional
Physical models
Sample USACE Guidance
EM – RIVER HYDRAULICS
EM – HYDRAULIC DESIGN OF FLOOD CONTROL CHANNELS

11. 1-d Hydraulic modeling

12. Example 2D model

13. Risk Based Analysis USACE requires uncertainty analysis for
Flow frequency
Stage / discharge
Levee performance
Stage vs damage functions
EM RISK-BASED ANALYSIS FOR FLOOD DAMAGE REDUCTION STUDIES

14. FEMA Floodplain Info
Focused on the flood with a 1% (1/100) annual chance of exceedance, but also map the 0.2% event (1/500)

15. Likely to be evolving…
30 Jan 2015 executive order

16. Missouri River Current Models
Missouri River FEMA floodplain
Based on 2003 USACE hydrology & profiles from unsteady flow model calibrated to 1993
FEMA Floodway model: Steady flow HEC-RAS model calibrated to 1% event
USACE developed for FEMA, contact FEMA for the official version

17. Climate Change USACE guidance in ECB 2014-10 (expires May 2016)
“USACE policy requires consideration of climate change in all current and future studies to reduce vulnerabilities and enhance the resilience of our water-resource infrastructure.”
Changes other than climate threats that affect inland hydrology will continue to be evaluated in the manner described in current USACE guidance (e.g., Chapter 18, Evaluating Change in EM , Flood-Runoff Analysis; and EM , Hydrologic Analysis of Interior Areas).

18. Current Study Requirements
A qualitative assessment of potential climate change threats and impacts potentially relevant to the particular USACE hydrologic analysis being performed.
Doesn’t change the numbers, but can inform future without project conditions hydrology
Future expansion to quantitative analyses is expected.

19. Example trend in Kansas, treated within hydrologic
Uncertainty analysis already performed

20. Particular hydrology analysis
Rainfall / runoff model study: extreme precipitation trends
Ex: Upper Turkey Creek Feasibility
Flow frequency: trends in peak stream flows and or reservoir inflow volume trends
Ex: Kansas Cities Levees Phase II
Ex: Manhattan, Kansas Feasibility Study

21. Resources NOAA regional climate change reports
Climate models online (ecb gives a link)

22. Challenge answer

23. Three days later… May 11, 2007 ~ 225,000 cfs (KS River ~40,000 cfs)
The Kansas River peaked at Desoto on May 8 at 120,000 cfs.
In case asked, the 2011 flood peak was 32.6 ft at KC gage on the Missouri.
May 11, 2007 ~ 225,000 cfs (KS River ~40,000 cfs)

24. Largest recorded flows: Kansas River
Both pre dam:
Kansas: 1951 flood – 510,000 cfs
Missouri: 1952 flood – 397,000 cfs
Kansas River at Bonner Springs or Desoto, Kansas
Missouri River at St Joseph, Missouri

25. Hydraulic Engineer’s Answer:
It depends…
Generally the Missouri River but the Kansas River is capable of very large flows
Post dam peaks: edge for Missouri River
Missouri: 335kcfs (1993); 277kcfs (2011); 207kcfs (1987)
Kansas: 170kcfs (1993); 146kcfs (1974); 121kcfs (1995)
0.2% (1/500 ACE) events about the same; but the Missouri produces big flows more often
200kcfs 1/50 ACE on KS vs 1/20 ACE on MO
150 kcfs 1/20 ACE on KS vs 1/5 ACE on MO