Ice Jam Flooding and Mitigation
HISTORICAL DATA
Ice records
Hydrological data
Figure 2. AFDD at the National Weather Service Station at North Platte, Nebraska, during water year 1960
Summary of historical data collected
Site 1. Loup River from Genoa to Columbus-continue
Figure 4. Loup River flows and daily air temperatures, 15 November through 9 December 1993
Table 5. Maximum annual gage heights associated with ice at the USGS gage on the Loup River at Columbus
Figure 5. Identified recurring ice jam sites on the Platte River between North Bend and Ashland
Table 6. Summary of ice events at North Bend with a stage greater than the flood stage of 8 ft.
Site 3. Platte River: Big Island at Fremont
Site 4. Platte River: West Channel at Leshara
Site 6. Platte River: Highway 92 bridge
Table 9. Summary of ice-related flood events at the confluence of the Platte and Elkhorn Rivers near Ashland
ANALYSIS OF DATA - SR96_010023
Table 11. Ice events with normalized stage greater than 1.0
Figure 8. Statistics for the ice events shown in Figure 7
Figure 9. Relationships among normalized stage, maximum discharge and maximum AFDD for January through March
Hydraulic analysis
Loup River near Columbus
Table 12. Discharges used in HEC-2 model of lower Platte River
PREDICTIVE MODEL FOR ICE JAM OCCURRENCE
Lower Platte River predictive model
Table 13. Known ice events during the period 1950 through 1990
Figure 12. Relationship between the observed and predicted values of normalized stage at North Bend
Table 14. Results of applying AFDD and discharge criteria to historic data at North Bend
Figure 14. Minimum discharge required for ice jam vs. Julian Day
Figure 15. AFDD at Columbus vs. date for winter 1993-94
DATA COLLECTION PROGRAM DESIGN
Freeze-up conditions
Figure 17. Nebraska ice report data collection form
Figure 17. Continued
Jam formation and evolution
DATABASE STRUCTURE
Figure 20. Schematic of on-line data retrieval at branch site
ICE JAM MITIGATION MEASURES - SR96_010044
Permanent measures
Advance measures
Emergency measures - SR96_010047
Specific mitigation options within the study area
Ice dusting as a mitigation alternative
Table 18. Constituents of 1979 dusting material
Table 19. Example dusting plan for the lower Platte River based on the 1982 plan
Summary of 1994 ice dusting
Table 20. Spreadsheet for use in planning dusting operations
Missouri River, 1946
Platte River near Ashland, 911 February 1966
Suggested steps to take for blasting operations
Figure 23. Minimum charge placed below ice surface required to break ice
Example 1
Table 21. Sample calculations for blasting costs
CONCLUSIONS - SR96_010060
LITERATURE CITED - SR96_010061
LITERATURE CITED-continue - SR96_010062
APPENDIX A: MODEL RESULTS FOR THE LOUP RIVER NEAR COLUMBUS
Figure A2. Ice-flow water profiles
APPENDIX B. MODEL RESULTS FOR THE PLATTE RIVER ALONG SARPY COUNTY, NEBRASKA
Figure B2. Open-water flow profiles for the western section
Figure B4. Solid-ice-cover flow profiles for the western section
Figure B6. Freeze-up flow profiles for the western section
Figure B8. One-percent-duration flow profiles for open water, ice cover, freeze-up and breakup for the western section
APPENDIX C: NEBRASKA DISASTER AND CIVIL DEFENSE ACT
Cross Reference - SR96_010071
Terms, defined
Disaster and Civil Defense Agency; Governor; control
Civil Defense Agency; Adjutant General; act; administer
Civil Defense Agency; Adjutant General; act; administer.-continue
Governor's Emergency Fund; established; use
Disaster prevention, procedure
Cross Reference - SR96_010078
Civil Defense Agency; political subdivisions; suspension; Governor; director
Interjurisdictional arrangement; Governor; findings
Civil defense; local organization; mutual aid arrangements; interjurisdictional agreement
Civil defense; emergency; political subdivision; emergency expenditures; election; when
Civil Defense; mobile support units; personnel; powers; duties; rights; immunities; compensation
Interstate Civil Defense and Disaster Compact; enter into
Civil Defense; supplies; services; channeled through Governor; funds deposited in Military Department Cash Fund
Civil defense; personnel; oath; affirmation
Disaster emergency; proclaimed by Governor; powers
Major disaster; powers of Governor; apply for federal community disaster loans
APPENDIX D: LEGAL OPINION ON NEBRASKA LAW CONCERNING THE REMOVAL OF ICE JAMS
Actions Taken Other Than in Accordance with the Disaster Act
Report Documentation Page - SR96_010091
Abstract-continue - SR96_010092
SR96_01
HISTORICAL DATA
Ice records
Hydrological data
Figure 2. AFDD at the National Weather Service Station at North Platte, Nebraska, during water year 1960
Summary of historical data collected
Site 1. Loup River from Genoa to Columbus-continue
Figure 4. Loup River flows and daily air temperatures, 15 November through 9 December 1993
Table 5. Maximum annual gage heights associated with ice at the USGS gage on the Loup River at Columbus
Figure 5. Identified recurring ice jam sites on the Platte River between North Bend and Ashland
Table 6. Summary of ice events at North Bend with a stage greater than the flood stage of 8 ft.
Site 3. Platte River: Big Island at Fremont
Site 4. Platte River: West Channel at Leshara
Site 6. Platte River: Highway 92 bridge
Table 9. Summary of ice-related flood events at the confluence of the Platte and Elkhorn Rivers near Ashland
ANALYSIS OF DATA - SR96_010023
Table 11. Ice events with normalized stage greater than 1.0
Figure 8. Statistics for the ice events shown in Figure 7
Figure 9. Relationships among normalized stage, maximum discharge and maximum AFDD for January through March
Hydraulic analysis
Loup River near Columbus
Table 12. Discharges used in HEC-2 model of lower Platte River
PREDICTIVE MODEL FOR ICE JAM OCCURRENCE
Lower Platte River predictive model
Table 13. Known ice events during the period 1950 through 1990
Figure 12. Relationship between the observed and predicted values of normalized stage at North Bend
Table 14. Results of applying AFDD and discharge criteria to historic data at North Bend
Figure 14. Minimum discharge required for ice jam vs. Julian Day
Figure 15. AFDD at Columbus vs. date for winter 1993-94
DATA COLLECTION PROGRAM DESIGN
Freeze-up conditions
Figure 17. Nebraska ice report data collection form
Figure 17. Continued
Jam formation and evolution
DATABASE STRUCTURE
Figure 20. Schematic of on-line data retrieval at branch site
ICE JAM MITIGATION MEASURES - SR96_010044
Permanent measures
Advance measures
Emergency measures - SR96_010047
Specific mitigation options within the study area
Ice dusting as a mitigation alternative
Table 18. Constituents of 1979 dusting material
Table 19. Example dusting plan for the lower Platte River based on the 1982 plan
Summary of 1994 ice dusting
Table 20. Spreadsheet for use in planning dusting operations
Missouri River, 1946
Platte River near Ashland, 911 February 1966
Suggested steps to take for blasting operations
Figure 23. Minimum charge placed below ice surface required to break ice
Example 1
Table 21. Sample calculations for blasting costs
CONCLUSIONS - SR96_010060
LITERATURE CITED - SR96_010061
LITERATURE CITED-continue - SR96_010062
APPENDIX A: MODEL RESULTS FOR THE LOUP RIVER NEAR COLUMBUS
Figure A2. Ice-flow water profiles
APPENDIX B. MODEL RESULTS FOR THE PLATTE RIVER ALONG SARPY COUNTY, NEBRASKA
Figure B2. Open-water flow profiles for the western section
Figure B4. Solid-ice-cover flow profiles for the western section
Figure B6. Freeze-up flow profiles for the western section
Figure B8. One-percent-duration flow profiles for open water, ice cover, freeze-up and breakup for the western section
APPENDIX C: NEBRASKA DISASTER AND CIVIL DEFENSE ACT
Cross Reference - SR96_010071
Terms, defined
Disaster and Civil Defense Agency; Governor; control
Civil Defense Agency; Adjutant General; act; administer
Civil Defense Agency; Adjutant General; act; administer.-continue
Governor's Emergency Fund; established; use
Disaster prevention, procedure
Cross Reference - SR96_010078
Civil Defense Agency; political subdivisions; suspension; Governor; director
Interjurisdictional arrangement; Governor; findings
Civil defense; local organization; mutual aid arrangements; interjurisdictional agreement
Civil defense; emergency; political subdivision; emergency expenditures; election; when
Civil Defense; mobile support units; personnel; powers; duties; rights; immunities; compensation
Interstate Civil Defense and Disaster Compact; enter into
Civil Defense; supplies; services; channeled through Governor; funds deposited in Military Department Cash Fund
Civil defense; personnel; oath; affirmation
Disaster emergency; proclaimed by Governor; powers
Major disaster; powers of Governor; apply for federal community disaster loans
APPENDIX D: LEGAL OPINION ON NEBRASKA LAW CONCERNING THE REMOVAL OF ICE JAMS
Actions Taken Other Than in Accordance with the Disaster Act
Report Documentation Page - SR96_010091
Abstract-continue - SR96_010092
SR96_01
