Unlined Spillway Erosion Risk Assessment
Independent Variables
* Hydrograph
	- Peak unit discharges (cfs/ft)
	- Flood durations (hrs)
* Spillway Geometry
	- Lengths (ft)
	- Slopes (degrees)
* Material Index
	- Erosion Indexes

Unlined Spillway Erosion Risk Assessment
Ordinal Logistic Regression
Sj = F (Material, Peak Discharge, Duration, Average_Slope, and Length)
Data: Case Histories (USDA and COE)
Damage Levels:
No Damage 0  0.05%
Lightly Damage 0.06 - 15%
Moderately Damage 16  40%
Severely Damage 41  75%
Breach 76  100%

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Unlined Spillway Erosion Risk Assessment
Ordinal Logistic Regression
Sj = 1.515 Log_Kh + 8.635 Log_q  1.581 Log_Dura + 0.807 Slope_av + 3.975 Log_Length
Probability Formulation:
No Damage = 1/ (1 + exp (Sj-k1))
Lightly Damage = 1/ (1 + exp (Sj-k2)) - 1/ (1 + exp (Sj-k1))
Moderately Damage = 1/ (1 + exp (Sj-k3)) - 1/ (1 + exp (Sj-k2))
Severely Damage = 1/ (1 + exp (Sj-k4)) - 1/ (1 + exp (Sj-k3))
Breach = 1 - 1/ (1 + exp (Sj-k4))
K1, k2, k3, and k4 = boundary parameters from regression

Unlined Spillway Erosion Risk Assessment
Input
Unit Disch. (cfs/ft) 112.1 41.8 104.4 163.5
Duration (hours) 120 570 210 3
Erosion Index1 Kh 1/ 5340 28 103 0.01
Ave. Slope (deg) 1.4 1.32 14.04 1 7.2
Length (ft) 2200 520 230 1340 155
Probability Output
No Damage 0.001 0.990 0.000 0.029 0.000
Lightly 0.019 0.009 0.002 0.275 0.000
Moderate 0.305 0.001 0.047 0.609 0.000
Severe 0.629 0.000 0.639 0.085 0.003
Breach 00.046 0.000 0.312 0.002 0.997

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Unlined Spillway Erosion Risk Assessment
Photo of the Bluestone, WV dam
Photo of the Dalles, OR dam
The Dalles, OR Q = 2,290,000 cfs Bluestone WV Q = 430,000 cfs
Erosion Index (Kh) 1960 2734
Stream Power (Kw/mw) 125.4 22.3
Probability of Erosion 0.012 0.000

Unlined Spillway Erosion Risk Assessment
Simulation Using USDA Model
* Monte Carlo
* Latin Hyper-Cube
No Damage 0  0.05%
Lightly Damage 0.06  15%
Moderate Damage 16  40%
Severely Damage 41  75%
Breach 76% - 100%

Unlined Spillway Erosion Risk Assessment
Prioritizing Process
Ranking the outcome:
Risk = P occurrence * P failure * Consequences

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Unlined Spillway Erosion Risk Assessment
Future Research
* Erosion Index needs to be refined
* Geophysical Exploration will be useful for volcanic areas
* Effect of spillway channel geometry (curving, narrowing)
* Three dimensional erosion (side erosion)

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Appendix D
References

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Hydraulic Design of Labyrinth Weirs and Fusegates - Falvey
Labyrinth Weirs
Afshar, A., (1988). The development of labyrinth weir design. Water Power and Dam Construction, 40(5), 36-39.
Cassidy, J.J., Gardner, C.A., and Peacock, R.T., (1985). Boardman labyrinth crest spillway. American Society of Civil Engineering, Journal of Hydraulic Engineering, 111(3), 398-416.
Cassidy, J.J., Gardner, C.A., and Peacock, R.T., (1985). Closure to Boardman labyrinth crest spillway. American Society of Civil Engineering, Journal of Hydraulic Engineering, 111(6), 808-819.
Chandrasekhara, T.R., and Loganathan, V., (1985). Discussion of Boardman labyrinth crest spillway. American Society of Civil Engineering, Journal of Hydraulic Engineering, 111(6), 808-819.
Darvas, L.A., (1971). Discussion of Performance and design of labyrinth weirs, by Hay and Taylor. American Society of Civil Engineering, Journal of Hydraulic Engineering, 97(80), 1246-1251.
El-Khashab, A.M.M., and Smith, K.V.M, (1976). Experimental investigations of flow over side weirs. American Society of Civil Engineering, Journal of Hydraulic Engineering, 102(9), 1255-1268.
Falvey, H.T., (2003), Hydraulic Design of Labyrinth Weirs, ASCE Press.
Hay, N., and Taylor, G., (1970). Performance and design of labyrinth weirs. American Society of Civil Engineering, Journal of Hydraulic Engineering, 96(11), 2337-2357.
Hinchliff, D., and Houston, K.L., (1984). Hydraulic design and application of labyrinth spillways. Proceedings of 4th Annual USCOLD Lecture, January.
Indlekofer, H., and Rouv, G., (1975). Discharge over polygonal weirs. American Society of Civil Engineering, Journal of the Hydraulics Division, 101(HY3), 385-401.
Lux, F., (1984). Discharge characteristics of labyrinth weirs. Proceedings of Conference on Water for Resource Development, Coeur dAlene, ID, Aug, American Society of Civil Engineering.
Lux, F. (1985). Discussion on Boardman labyrinth crest spillway. American Society of Civil Engineering, Journal of Hydraulic Engineering, 111(6), 808-819. 
FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-4  
Lux, F., and Hinchliff, D.L., (1985). Design and construction of labyrinth spillways. 15th Congress ICOLD, Vol. IV, Q59-R15, Lausanne, Switzerland, 249-274.
Lux, F., (1989), "Design and application of labyrinth weirs," Design of Hydraulic Structures 89, Edited by Albertson, M.L., and Kia, R.A., Balkema/Rotterdam/Brookfield.
Mayer, P.G., (1980). Bartletts Ferry Project, labyrinth weir model studies. Project No. E-20-610, Georgia Institute of Technology, Atlanta, Ga., Oct. Megalhes, A.P., (1985). Labyrinth weir spillway. Transactions of the 15th Congress ICOLD, Vol. VI, Q59-R24, Lausanne, Switzerland, 395-407.
Megalhes, A.P., and Melo, J.F., (1994). Hydraulic model study of a large labyrinth weir spillway. 2nd International Conference on Hydraulic Modeling, Stratford-upon-Avon, U.K., June. Metropolitan Water, Sewerage and Drainage Board, (1980). Investigation into spillway discharge noise at Avon Dam. ANCOLD Bulletin No. 57, 31-36.
Tacail, F.G., Evans, B., and Babb, A., (1990). Case study of a labyrinth spillway.Canadian Journal of Civil Engineering, 17, 1-7.
Tullis, J.P., Nosratollah, A., and Waldron, D., (1995). Design of labyrinth spillways. American Society of Civil Engineering, Journal of Hydraulic Engineering, 121(3), 247-255.
Vermeyen, T., (1991). Hydraulic model study of Ritschard Dam spillways. Report No. R-91-08, U.S. Bureau of Reclamations, Denver, Colo.
Waldron, D.R., (1994). Design of labyrinth spillways. MSc thesis, Utah State University, Logan, Utah.
Wormleaton, P.R., and Soufiani, E, (1998). "Aeration performance of triangular planform labyrinth weirs." American Society of Civil Engineering, Journal of Environmental Engineering, 124(8), 709-719.
Wormleaton, P.R., and Tsang, C.C., (2000). "Aeration performance of rectangular planform labyrinth weirs." American Society of Civil Engineering, Journal of Environmental Engineering, 127(5), 456-465.
Yildiz, D. and Uzecek, E., (1996). "Modeling the performance of labyrinth spillways." Hydropower, 3, 71-76.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-5 

Fusegates 
Ait Alla, A., 1996, The role of Fusegates in dam safety, Hydropower and Dams, Vol. 3, Issue 6.
Bowers, P.W., Mifkovic, C.S. and Rayssiguier, 2000, Searching for conventional spillway control system alternatives, Hydropower and Dams, Issue 3, Jul.
Brink, T.G, 1996, The Effects of Waves on Fusegates, MS Thesis, Colorado State University, Fort Collins, CO.
Compte, B., Golliard, D., Boillat, J.L., Chevalier, S., and Bremen, R., 2000, Advances in spillway design using Fusegates: Application to the Montsalvens Dam, International Commission on Large Dams, 20th Congress on Large Dams, Beijing, China.
Falvey, H.T., Snell, E.F.A, and Rayssiguier, J.,1994, Increasing Shongweni Dam Discharge Capacity with a Hydroplus Fusegate System, Dam Safety Modification and Rehabilitation, 14th Annual USCOLD Lecture Series, Phoenix, AZ, June.
Falvey, H.T. and Treille, P., 1995, Hydraulics and Design of Fusegates, ASCE Journal of Hydraulic Engineering, Vol. 121, NO. 7, July.
Fauquez, J.P., 1993, Hydroplus and the Fusegate principle, International Conference, Hydropower, Energy and the Environment, Stockholm, June.
Garrec, P., 1998, Fusegates increase storage capacity at four dams in Gujarat, Hydropower and Dams, Issue 5.
Golliard, D. and Chevalier, S., 1998, An innovative solution to a safety problem on Montsalvens dam, Hydropower and Dams, Issue 2.
Gulati, O.T., 1996, Increasing the capacity of the Mahi canal at Mahi, India, Hydropower and Dams, Issue 2.
Harshbarger, E.D., 1994, Hydroplus Fusegate Evaluation, Tennessee Valley Authority, Report No. WR 28-1-900-259.
Hite, J. Jr. and Mifkovic, C., 2000, Increasing Reservoir Storage or Spillway Capacity using Fusegates, U.S. Army Corps of Engineers, Apr.
Jones, S.J., Spencer, D., Rodionov, V.B., Lounatsi, M.E. and Ait Alla, A., 1996, The reliability of fuseible gates in ice-affected environments, Hydropower and Dams, Issue, 2.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-6 

Lemprire, F. and Bessire, C., 1992, Hydroplus submersible fusegates for surface spillways, Modification of dams to accommodate major floods, Twelfth Annual USCOLD Lecture Series, Fort Worth, TX.
Lemprire, F., 1992, Overspill Fusegates, Water Power & Dam Construction, July Lemprire, F., 1995, Cost Effective improvements in fill dam safety, Hydropower and Dams, Jan.
Pittman, W.V, Watson, M.D., and Hakin, W.D., 1998, Impact of fusegate rotation on a reservoirs firm yield, Hydropower and Dams, Issue 6.
Shaw, Q.H.W., Cameron-Ellis, D.G., and Hakin, W.D., 1999, Fusegates enhance safety and increase capacity at Eikenhof, Hydropower and Dams, Issue 6, Dec.
Sikora, J., Ferns, L., Bailey, F. and Gavillet, M., 1995, MacClure dam spillway modifications with Fusegates, Proceedings of the 1995 Annual Conference of the Association of Dam Safety Officials, Sep., pp. 17-20, Atlanta, GA.
Taylor, G., Mahooty, D., and Rayssiguier, J., 2001, Historic Dam, Modern Upgrade, USSD Conference, Denver.
Trissler M. and Crawford, C., 1994, Installation of a Fusegate system at Shongweni dam, Hydropower and Dams, Nov.
Verrender, M., Mayo, N., Phillippe, M., 1994, Recent development with Hydroplus Fusegates, Australian National Committee on Large Dams, Dec., Hobart, Tasmania.
Yong, Liu, 1995, Application of Hydroplus Fusegates to flood-diversion areas of Huaihe river basin, Hydropower and Dams, Nov.
Yziquel, A., Monclar, J.M., and Chirwa, M.J., Heightening of Malawis Kamuzu II Dam Hydropower and Dams, Issue 6, Dec.

Fuse Plug Embankments - Wahl 
Tinney, E.R. and Hsu, H.Y., 1961. Mechanics of washout of an erodible fuse plug.
Journal of the Hydraulic Division, Proceedings, ASCE, Vol. 87, No. HY3, May 1961.
Pugh, C.A., 1985. Hydraulic Model Studies of Fuse Plug Embankments, U.S. Dept. of the Interior, Bureau of Reclamation, Research Report REC-ERC-85-7.
http://www.usbr.gov/pmts/hydraulics_lab/pubs/recerc/REC-ERC-85-07.pdf 
FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-7 
Crest Parapets and Dam Raising - Fuller 
Dam Safety Assurance Model Study of Tygart Dam, Tygart River, Grafton, West Virginia, Turner, Herman O., TR CHL-99-7, April 1999.
Bluestone Lake Dam, West Virginia, Rating Curve and Overtopping Study, Fuller, Billy D., ERDC/CHL TR-02-2, March 2002.
Gated Spillways Both Traditional and Rubber - Cohen 
Manuals Design of Arch Dams, 1977 
Design of Gravity Dams, 1976 
Design of Small Canal Structures, 1978 
Design of Small Dams, 1987 
Guide to Concrete Repair, 1999 
SEED (Safety Evaluation of Existing Dams), Revised Reprint 1983 

Design Standards 
Design Standards No. 3 (Revised), Water Conveyance Systems 
	Chap. 4, Tunnels, Shafts, and Caverns, 1994 
	Chap. 11, General Hydraulic Considerations, 1994 
	Chap. 12, General Structural Considerations, 1994 

Engineering Monographs 
No. 7, Friction Factors for Large Conduits Flowing Full, 1977 
No. 9, Discharge Coefficients for Irregular Overfall Spillways, 1952 
No. 25, Hydraulic Design of Stilling Basins and Energy Dissipators, Revised 1978 

Research Report No. 4, Hydraulic Downpull Forces on Large Gates, 1966 

Research Reports 
REC-ERC Research Reports 
REC-ERC-78-8, Low Froude Number Stilling Basin Design, 1978 
REC-ERC-85-7, Hydraulic Model Studies of Fuse Plug Embankments, 1985 
REC-ERC-87-6, Hydraulic Model Studies of Upper Stillwater Dam Stepped Spillway and Outlet Works, 1987 
REC-ERC-88-1, Emergency Spillways Using Geomembranes, 1988 
REC-ERC-88-2, Hydraulic Model Study of Twin Buttes Dam Fuse Plug Spillway, 1988 REC-ERC-88-3, Overtopping Flow on Low Embankment Dam-Summary Report of Model Tests, 1988 
R-03-02, A Survey of Selective Withdrawal Systems, 2003 

ACER Technical Memoranda 
Freeboard Criteria and Guidelines for Computing Freeboard Allowances for Storage Dams, ACER Technical Memorandum No. 2, 1992 

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-8 

Criteria and Guidelines for Evacuating Storage Reservoirs and Sizing Low-Level Outlet Works, ACER Technical Memorandum No. 3, 1990 
Criteria for Bulkheading Outlet Works Intakes for Storage Dams, ACER Technical Memorandum No. 4, 1982 
Guidelines for Determining Whether Normally Inundated Outlet-Works Features Should Be Examined, ACER Technical Memorandum No. 6, 1985 
Guidelines for Designing and Constructing Roller-Compacted Concrete Dams, ACER Technical Memorandum No. 8, 1987 
Guidelines for Controlling Seepage Along Conduits through Embankments, ACER Technical Memorandum No. 9, 1987 
Guidelines for Using Fuse Plug Embankments in Auxiliary Spillways, ACER Technical Memorandum No. 10, 1987 

Earthen Spillways Design and Analysis  State of the Practice - Temple Annandale, G. W. (1995). Erodibility. Journal of Hydraulic Research, IAHR, Vol. 33, No. 4, 471-494.
Barton, N. 1988. Rock Mass Classification and Tunnel Reinforcement Selection Using the Q-System. Rock Classification Systems for Engineering Purposes. Kirkaldie, L., ed., ASTM STP 984, American Society for Testing and Materials, Philadelphia, 59-88.
Bollaert, E., Falvey, H.T., Schleiss, A. (2002). Turbulent jet impingement in plunge pools: the particular characteristics of a near-prototype physical model study. Proceedings of Riverflow 2002, Louvain-la-Neuve, Belgium, 395-403.
Cato, K.D. 1991. Performance of Geological Material Under Hydraulic Stress, Ph.D. diss., Texas A&M University, College Station, Texas.
Hanson, G.J., 1991, Development of a Jet Index to Characterize Erosion Resistance of Soils in Earthen Spillways, Trans. ASAE, Vol. 34, No. 5: 2015-2020.
Kirsten, H.A.D. 1988. Case Histories of Groundmass Characterization for Excavatability. Kirkaldie, L., ed., Rock Classification Systems for Engineering Purposes.
ASTM STP 984, American Society Society for Testing and Materials, Philadelphia, PA, pp. 102-120.
Mathewson, C., Cato, K.D., and May, J. 1998. Geotechnical Aspects of Rock Erosion in Emergency Spillway Channels. Supplemental Information on Prediction, Control, and Repair of Erosion in Emergency Spillway Channels, USACE-WE, Vicksburg, MS.
Moore, J.S., Temple, D.M., and Kirsten, H.A.D. 1994. Headcut Advance Threshold in Earth Spillways. Bulletin of the Association of Engineering Geologists, Vol. XXXI, No. 2, pp. 277-280.
Perlea, V.G., Mathews, D.L., and Walberg, F.C. 1997. Rock Erosion of Unlined Spillway Chute. Nineteenth Congress on Large Dams (ICOLD), Florence, Italy.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-9 

Temple, D.M., and Hanson, G.J. 1994. Headcut Development in Vegetated Earth Spillways, Applied Engineering in Agriculture, Vol 10, No 5: 677-682.
Temple, D.M., and Moore, J.S. 1997. Headcut Advance Prediction for Earth Spillways. Trans. ASAE, Vol. 40, No. 3: 557-562.
US Army Corps of Engineers. 1990. Hydraulic Design of Spillways, Engineer Manual EM 1110-2-1603, Washington, DC.
US Army Corps of Engineers. 1994. Hydraulic Design of Flood Control Channels, Engineer Manual EM-1110-2-1601, Washington, DC.
US Department of Agriculture, SCS. 1973. A guide for design and layout of earth emergency spillways as part of emergency spillway systems for earth dams. Technical Release No. 52.
US Department of Agriculture, NRCS. 1997. National Engineering Handbook, Part 628 Dams, Chapter 51, Earth Spillway Erosion Model. Washington, D.C.
US Department of Agriculture NRCS. 2001. National Engineering Handbook, Part 628 Dams, Chapter 52, Field Procedure Guide for the Headcut Erodibility Index. Washington, D.C.
Wibowo, J. L. And Murphy, 2002. Unlined Spillway Erosion Prediction Model WES Technical Report.

Spillway Foundation Erosion - Ruff 
Jet Scour 
Annandale, G.W., (1995), Erodibility. Journal of Hydraulic Research, Vol. 33, No. 4, pp. 471-494.
Bollaert, Eric, (2002), Transient water pressures in joints and formation of rock scour due to high-velocity jet impact, Thesis, Swiss Federal Institute of Technology, Lausanne, Switzerland.
Annandale, G.W., Wittler, R.J., Scott, G., (2000), Scour Downstream of Dams Proceedings of the GeoEng 2000 Conference, Melbourne, Australia. Ed. Jean Louis Briaud. November.
Bohrer, J., Abt, S.R., Wittler, R.J., (1998), Predicting Plunge Pool Velocity Decay of a Free falling, Rectangular Jet. Journal of Hydraulic Engineering, American Society of Civil Engineers. October 1998, vol. 124, issue 10. pp 1043-1048.
Harza Engineering Company, (1993), Plunge pool performance  Project data review/Literature search, Theodore Roosevelt Dam, Lower Colorado Region, Salt River Project, Arizona, Report prepared for U.S. Bureau of Reclamation, Denver Colorado.
Hoffman, G., (1998), Jet scouring equilibrium phase. Journal of Hydraulic Engineering, American Society of Civil Engineers. October, vol. 124, issue 10. pp 430- 437.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-10 

Kuroiwa, J.M, Ruff, J.F., Wittler, R.J., Annandale, G.W., (1998), Prototype Scour Experiments in Simulated Fractured Rock and Granular Media. Proceedings of 1998 ASCE International Water Resources Engineering Conference, Memphis, TN, August.
Kuroiwa, J.M, (1999), Scour caused by rectangular jets in cohesionless beds, Dissertation, Colorado State University, Fort Collins, Colorado.
Mason, P.J., Arumugam, K., (1985), Free Jet Scour Below Dams and Flip Buckets. Journal of Hydraulic Engineering, vol. 111, No. 2, A.S.C.E., February.
Wittler, R.J., Annandale, G.W., Abt, S.R., Ruff, J.F., (1998), New Technology for Estimating Plunge Pool or Spillway Scour. Proceedings of Association of State Dam Safety Officials, Dam Safety 98. Las Vegas, NV. October 11-15.

Riprap and Concrete Wedge Blocks 
Gaston, M. L., (1995), Air entrainment and energy dissipation on s stepped block spillway, Thesis, Colorado State University, Fort Collins, Colorado.
Mishra, S. K., (1998), Riprap design for overtopped embankments, Dissertation, Colorado State University, Fort Collins, Colorado.
Slovensky, G. G., (1993), Near-prototype testing of wedge-block overtopping protection, Thesis, Colorado State University, Fort Collins, Colorado.
Wittler, R. J., (1994), Mechanics of riprap in overtopping flow, Dissertation, Colorado State University, Fort Collins, Colorado.

Dam Overtopping Protection Technologies - State-of-Practice and Research Needs - Frizell 
Embankment Overlays 
Matos, Jorge, Antonio N. Pinheiro, Antonio de Carvalho Quintela, Kathleen H. Frizell. 2001, On the Role of Stepped Overlays to Increase Spillway Capacity of Embankment Dams, International Journal of Hydraulic Research, 2001 
Hydraulics of Stepped Spillways, Proc Intl. Workshop on Hydraulics of Stepped Spillways, Zrich, Switzerland, H.E. Minor & W.H. Hager (eds). Balkema: 163-170, 2000.
Oswalt, N.R., L.E. Buck, T.E. Hepler, and H.E. Jackson, Alternatives for Overtopping Protection of Dams, ASCE Hydraulics Division Task Committee on Alternatives for Overtopping Protection for Dams, New York.
Frizell, K.H., B.W. Mefford, R. A. Dodge, T. B. Vermeyen, Embankment Dams: Methods of Protection During Overtopping, Hydro Review, Vol. X, No. 2, April 1991.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-11 

Schweiger, Paul. G., The State-of-the-Art of Armoring Embankment Dams Using Articulating Concrete Blocks, Proceedings ASDSO.
Baker, R. 2000a. The CIRIA guide for the design of stepped-block spillways. Proc Intl.
Workshop on Hydraulics of Stepped Spillways, Zrich, Switzerland, H.E. Minor & W.H.
Hager (eds). Balkema: 155-161.
Frizell, K.H., Matos, J. & Pinheiro, A.N. 2000. Design of concrete stepped overlay protection for embankment dams. Proc Intl. Workshop on Hydraulics of Stepped Spillways, Zrich, Switzerland, H.E. Minor & W.H. Hager (eds). Balkema: 179-186.
Frizell, K.H., Smith, D.H. & Ruff, J.F. 1994. Stepped overlays proven for use in protecting overtopped embankment dams. Proc. of the Association of State Dam Safety Officials, 11th Annual Conference, USA.

Riprap 
Frizell, K.H., J.F. Ruff, and S. Mishra, "Simplified Design Guidelines for Riprap Subjected to Overtopping Flow, Proceedings of the Annual Association of State Dam Safety Officials (ASDSO) Conference, Las Vegas, NV, October 1998.
Mishra, S. K., (1998), Riprap design for overtopped embankments, Dissertation, Colorado State University, Fort Collins, Colorado.
Timblin, Jr. L.O., P.G. Grey, B.C. Muller, and W.R. Morrison, Emergency Spillways Using Geomembranes, REC-ERC-88-1, US Department of Interior, Bureau of Reclamation, Denver CO, April 1988.

Gabions 
Oswalt, N.R., L.E. Buck, T.E. Hepler, and H.E. Jackson, Alternatives for Overtopping Protection of Dams, ASCE Hydraulics Division Task Committee on Alternatives for Overtopping Protection for Dams, New York.

RCC Overtopping Protection for Increasing Spillway Capacity - Hansen 
Hansen, K.D. and J. France, RCC  A Dam Rehab Solution Unearthed, Civil Engineering  ASCE, September 1986.
Hansen, K.D. RCC for Rehabilitation of Dams in the USA  An Overview, Roller Compacted Concrete III, Proceedings of the RCC Specialty Conference, San Diego, CA, ASCE, New York, February 1992, pp 22-46.
Hansen, K.D. and Bass, R.P. How Old Dams are Reborn, International Water Power & Dam Construction, June 1999.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-12 

McLean, F.G. and K.D. Hansen, Roller Compacted Concrete for Embankment Overtopping Protection, Geotechnical Practice in Dam Rehabilitation, Geotechnical Special Publication No. 35, Proceedings of the Geotechnical Engineering Division of ASCE, Raleigh, NC, April 1993, pp 188-209.

General discussion - NRCS Designs and Research Needs  James Moore 
NRCS Technical Release No. 60  Earth Dams and Reservoirs 

Spillways - An Owners Perspective - Weldon 
NONE 

General discussion  Consultants Spillway Design and Research Needs - Wade Moore 
NONE 

Vegetated Earth Spillways - Inspection, Maintenance and Monitoring - Lobrecht 
USDA  NRCS  National Engineering Manual 210-VI-NEM Part 628 Dams 
210-VI-NEH-628.50 Chapters 50 Earth Spillway Design, 
210-VI-NEH-628.51 Chapter 51 Earth Spillway Erosion Model, 
210-VI-NEH-628.52 Chapter 52 Field Procedures Guide for the Headcut Erodibility Index.
210-VI-TR-60 TR-60 Earth Dams and Reservoirs 
210-VI-NEH-728.50 SITES  Water Resource Site Analysis Computer Program 

Earth Spillways  State of Practice and Research Needs - Greg Hammer 
HEC-RAS River Analysis System  Hydraulic Reference Manual, US Army Corps of Engineers, Hydrologic Engineering Center, Davis, CA, July 1995 
Brater, Ernest F., King, Horace W., Handbook of Hydraulics, Sixth Edition, McGraw- Hill Book Company, 1976.

Issues and Research Needs Related to Hydraulics for Spillways for State Regulated Dams - Fiegle .
Fiegle, E., Issues and Research Needs Related to Hydraulics for Spillways for State Regulated Dams  State Survey Responses, Georgia Safe Dams Program, Georgia Department of Natural Resources, August 2003.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-13 

Concrete Spillway Repairs - McDonald 
Vaysburd, A.M., Emmons, P.H., McDonald, J.E., Poston, R.W., and Kesner, K.E., Performance Criteria for Concrete Repair Materials, Summary Report, Technical Report REMR-CS-62, 72 pp, US Army Engineer Waterways Experiment Station, Vicksburg, MS, March, 1999.
McDonald, J.E., Vaysburd, A.M., and Poston, R.W., Performance Criteria for Dimensionally Compatible Repair Materials, HPM&S Information Bulletin, Vol 00-1, 13 pp, Engineer Research and Development Center, Vicksburg, MS, January 2000.

Inspection of Concrete Spillways  Gated and Uncontrolled - Bill Bouley 
NONE 

Geophysics for Spillway and Seepage Evaluation - Dunscomb 
Corwin, R.W., and Butler, D.K., 1989, Geotechnical Applications of the Self-Potential Methods; Report 3: Development of Self-Potential Interpretation Techniques for Seepage Detection, Technical Report REMR-GT-6, Department of the Army, US Army Corps of Engineers, Washington, DC.
Dunscomb, Mark H. and Rehwoldt, Eric, 1999, Two-Dimensional Resistivity Profiling; Geophysical Weapon of Choice in Karst Terrain for Engineering Applications, Proceedings from the 7th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst, Harrisburg, PA 
Dunscomb, Mark H., Rehwoldt, Eric, Matheson, Gordon M., 1999, The New View: Two- Dimensional Resistivity, 1999 Mid-Atlantic ASDSO Regional Conference, Matamoras, Pennsylvania.
Environmental & Engineering Geophysical Society, http://www.eegs.org/ 
Loke, M.H., 2001, Electrical Imaging Surveys for Environmental and Engineering Studies - A Practical Guide to 2D and 3D Electrical Imaging Surveys, Minden Heights, Malaysia, Distributed by http://www.geoelectrical.com 
Reynolds, J.M., 1997, An Introduction to Applied and Environmental Geophysics, John Wiley and Sons, New York.
US Army Corps of Engineers, 1995, Geophysical Exploration for Engineering and Environmental Investigations, CECW-EG, EM 1110-1-1802, Washington, DC, for download at http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-1- 1802/entire.pdf 
Ward, S.H., ed., 1990, Geotechnical and Environmental Geophysics, Vol. 1, Society of Exploration Geophysicists, Tulsa, OK.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways D-14 

Inspection, Maintenance and Monitoring of Service and Emergency Spillways - Johnson 
NONE 

Unlined Spillway Erosion Risk Assessment - Koester 
Annandale, G. W. 1995. "Erodibility." Journal of Hydraulic Research, IAHR, Vol. 33, No. 4, pp. 471-494.
Moore, J. S., Temple, D. M., and Kirsten, H. A. D. 1994. "Headcut Advance Threshold in Earth Spillways." Bulletin of the Association of Engineering Geologists, Vol. XXXI, No. 2, pp. 277-280.
Wibowo, J. L., and Murphy, W. L., 2004. "Unlined Spillway Erosion Prediction Model." WES Technical Report. in publication.
Mathewson, C., Cato, K. D., and May, J. 1998. "Geotechnical Aspect of Rock Erosion in Emergency Spillway Channels." Suplemental Information on Prediction, Control, and Repair o Erosion in Emergency Spillway Channels, USACE-WE, Vicksburg, MS.

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways E-1 

Appendix E 
Individual Topic Voting Results 
This appendix is a compilation of each topic difficulty and benefit result shown graphically. Each topic is shown side by side with benefit on the left and difficulty on the right of the figure box. The ratings were 1=not very beneficial, 10= very beneficial; 1=low difficulty or easy to accomplish, 10=high difficulty or very hard to accomplish. The numbers of votes received for each level of benefit or difficulty are shown across the bottom of each graph The bars show the results of voting graphically in terms of percent votes for each level divided by the total number of votes received. The mean is also shown for the category giving the voting distribution.

Topic A
Benefit
Mean: 4.8 Total: 24 Slide: 1

Topic A
Difficulty
Mean: 5.8 Total: 26 Slide: 2

Topic B
Benefit
Mean: 3.6 Total: 23
Slide: 3

Topic B
Difficulty
Mean: 5.5 Total: 22 Slide: 4

Topic C
Benefit
Mean: 5.2 Total: 25 Slide: 5

Topic C
Difficulty
Mean: 4.3 Total: 24 Slide: 6

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic D
Benefit
Mean: 5.5 Total: 25 Slide: 7

Topic D
Difficulty
Mean: 4.1 Total: 25 Slide: 8

Topic E
Benefit
Mean: 5.2 Total: 25 Slide: 9

Topic E
Difficulty
Mean: 2.9 Total: 26 Slide: 10

Topic F
Benefit
Mean: 6.1 Total: 24 Slide: 11

Topic F
Difficulty
Mean: 7.9 Total: 24 Slide: 12

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic G
Benefit
Mean: 6.0 Total: 25 Slide: 13

Topic G
Difficulty
Mean: 5.8 Total: 25 Slide: 14

Topic H
Benefit
Mean: 8.3 Total: 26 Slide: 15

Topic H
Difficulty
Mean: 6.4 Total: 26 Slide: 16

Topic I
Benefit
Mean: 8.4 Total: 25 Slide: 17

Topic I
Difficulty
Mean: 6.8 Total: 25 Slide: 18

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic J
Benefit
Mean: 2.2 Total: 23 Slide: 19

Topic J
Difficulty
Mean: 7.1 Total: 23 Slide: 20

Topic K
Benefit
Mean: 4.0 Total: 24 Slide: 21

Topic K
Difficulty
Mean: 4.6 Total: 23 Slide: 22

Topic L
Benefit
Mean: 8.6 Total: 27 Slide: 23

Topic L
Difficulty
Mean: 7.8 Total: 26 Slide: 24

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic M
Benefit
Mean: 7.4 Total: 27 Slide: 25

Topic M
Difficulty
Mean: 4.5 Total: 26 Slide: 26
Topic N
Benefit
Mean: 6.8 Total: 25 Slide: 27

Topic N
Difficulty
Mean: 4.0 Total: 24 Slide: 28

Topic O
Benefit
Mean: 3.2 Total: 24 Slide: 29

Topic O
Difficulty
Mean: 4.6 Total: 23 Slide: 30

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic P
Benefit
Mean: 3.3 Total: 22 Slide: 31

Topic P
Difficulty
Mean: 6.1 Total: 23 Slide: 32

Topic Q
Benefit
Mean: 4.4 Total: 24 Slide: 33

Topic Q
Difficulty
Mean: 6.8 Total: 25 Slide: 34

Topic R
Benefit
Mean: 7.8 Total: 25 Slide: 35

Topic R
Difficulty
Mean: 6.8 Total: 25 Slide: 36

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic S
Benefit
Mean: 5.4 Total: 22 Slide: 37

Topic S
Difficulty
Mean: 5.8 Total: 22 Slide: 38

Topic T
Benefit
Mean: 5.6 Total: 25 Slide: 39

Topic T
Difficulty
Mean: 6.2 Total: 25 Slide: 40

Topic U
Benefit
Mean: 5.6 Total: 23 Slide: 41

Topic U
Difficulty
Mean: 6.3 Total: 23 Slide: 42

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic V
Benefit
Mean: 5.1 Total: 23 Slide: 43

Topic V
Difficulty
Mean: 4.9 Total: 24 Slide: 44

Topic W
Benefit
Mean: 4.8 Total: 22 Slide: 45

Topic W
Difficulty
Mean: 4.5 Total: 23 Slide: 46

Topic X
Benefit
Mean: 5.7 Total: 20 Slide: 47

Topic X
Difficulty
Mean: 5.0 Total: 22 Slide: 48

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic Y
Benefit
Mean: 4.4 Total: 25 Slide: 49

Topic Y
Difficulty
Mean: 6.3 Total: 25 Slide: 50

Topic Z
Benefit
Mean: 8.1 Total: 24 Slide: 51

Topic Z
Difficulty
Mean: 7.4 Total: 24 Slide: 52

Topic AA
Benefit
Mean: 3.8 Total: 25 Slide: 53

Topic AA
Difficulty
Mean: 5.7 Total: 25 Slide: 54

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic AB
Benefit
Mean: 5.5 Total: 25 Slide: 55

Topic AB
Difficulty
Mean: 6.4 Total: 24 Slide: 56

Topic AC
Benefit
Mean: 6.5 Total: 24 Slide: 57

Topic AC
Difficulty
Mean: 5.8 Total: 25 Slide: 58

Topic AD
Benefit
Mean: 4.8 Total: 24 Slide: 59

Topic AD
Difficulty
Mean: 4.7 Total: 24 Slide: 60

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways

Topic AE
Benefit
Mean: 5.3 Total: 24 Slide: 61

Topic AE
Difficulty
Mean: 4.7 Total: 23 Slide: 62

Topic AF
Benefit
Mean: 6.1 Total: 23 Slide: 63

Topic AF
Difficulty
Mean: 3.8 Total: 24 Slide: 64

Topic AG
Benefit
Mean: 5.3 Total: 24 Slide: 65

Topic AG
Difficulty
Mean: 6.0 Total: 23 Slide: 66

FEMA Workshop - Issues, Remedies and Research Needs Relating to Service and/or Emergency Spillways