U.S. NUCLEAR REGULATORY COMMISSION REGULATORY GUIDE OFFICE OF STANDARDS DEVELOPMENT Revision 1 September 1976 REGULATORY GUIDE 1.102 FLOOD PROTECTION FOR NUCLEAR POWER PLANTS A. INTRODUCTION General Design Criterion 2, "Design Bases for Protec tion .Against Natural Phenomena," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Licensing of Production and Utiliza tion Facilities," requires that structures, systems, and components important to safety be designed to with stand the effects of natural phenomena such as floods, tsunami, and seiches without loss of capability to performntheir safety functions. Criterion 2 also requires that the design bases for these structures, systems, and components reflect: 1. Appropriate consideration of the most severe natural phenomena that have been historically reported for the site and surrounding region, with sufficient margin for the limited accuracy and quantity of the 2 historical data and the period of time in which the data have been accumulated; 2. Appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena; and 3. The importance of the safety functions to be performed. Paragraph 100.10(c) of 10 CFR Part 100, "Reactor Site Criteria," requires that physical characteristics of the site, including seismology, meteorology, geology, and hydrology, be taken into account in determining the acceptability of a site for a nuclear power reactor. Appendix A, "Seismic and Geologic Siting Criteria for Nuclear Power Plants," to 10 CFR Part 100 identifies the investigations necessary for a detailed study of seismically induced floods and water waves. The appendix requires that design bases for seismically induced floods and water waves take into consideration the results of geologic and seismic investigations and that these design bases be taken into account in the design of the nuclear power plant. Regulatory Guide 1.59, "Design Basis Floods for Nuclear Power Plants," describes acceptable methods of determining the design basis flood conditions that nuclear power plants located on sites along streams must withstand without loss of safety-related functions. It also discusses the phenomena producing comparable design basis floods for coastal, estuary, and Great Lakes sites. The guide states that examples of the type of flood protection to be provided for nuclear power plants will be the subject of a separate regulatory guide. This guide describes types of flood protection accept able to the NRC staff for the safety-related structures, systems, and components identified in Regulatory Guide 1.29.* In addition, this guide describes acceptable "Regulatory Guide 1.29, "Seismic Design Classification," Identi fies structures, systems; and components of light-water-cooled nuclear power plants that should be designed to withstand the effects of the Safe Shutdown Earthquake and remain func tionaL These structures, systems, andI components- are those necessary to ensure (1) the integrity of the reactor coolant pressure boundary, (2) the capability to shut down the reactor and maintain it in a safe shutdown condition, or (3) the capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures comparable to the guideline exposures of 10 CFR Part 100. These structures, systems, and components should also be designed to withstand conditions resulting from the design basis flood and remain functional. It is expected that safety-related structures, systems, and components of other types of nuclear power plants will be identified in futur6 regulatory guides. In the interim, Regula tory Guide 1.29 should be used as guidance when identifying safety-related structures, systems, and components of other types of nuclear power plants that need to be protected from floods by methods such as those suggested in this guide. USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Commission. Washington. D.C. U5. Attention: Dockoting end Regulatory Guides we issued to describe and make available to the public secesection. methods aiceptable to the NRC staff of Implementing specific parts of the Commission's regulations, to delineate techniques used by the staff in ovalu- The guides are issued in the following ton broad divisions: sting specific problems Or postulated accidents. or to provide guidance to appli cents. Regulatory Guides are not substitutes for regulations, and compliance I. Power Reactors S. Products with them is not required. Methods and solutions different from those set out in 2. Research and Test Reactors 7. Transportation the guides will be acceptable if they provide a basis for the findings requisite to 3. Fuels and Materials Facilities S. Occupational Health the issuance or continuance of a permit or license by the Commission. 4. Environmentel and Siting 9. Antitrust Review Comments and suggestions for improvements in these guides are encouraged S. Materials and Plant Protection 10. General at all times. and guides will be revised. as appropriate. to accommodate com ments and to reflect new information or experience. This guide was revised as a Copies of pub4ished guides may be obtained by written request indicating the result of substantive comments received from the public and additional st&ff divisions desired to the U.S. Nuclear Regulatory Commission. Washington. D.C. review. 2=5. Attention: Director. Office of Standards Development. methods of protecting nuclear power plants from the effects of Prbbable Maximum Precipitation (PMP) falling directly on the site.* B. DISCUSSION Nuclear power plant structures, systems, and com ponents important to safety should be designed to withstand, without loss of capability to perform their safety functions, the most severe flood conditions that can reasonably be postulated to occur at a site as a result of severe hydrometeorological conditions, seismic ac tivity, or both. The flood protection features necessary to protect the safety-related structures, systems, and components should be designed for the range of precipi tation, wind, and seismically induced flood conditions identified in Regulatory Guide 1.59. The water-induced effects, both static and dynamic, on the flood protection features are considered to constitute normal environ mental forces for use in the design of such features. The forces are developed from the hydrologic engineering analysis of the flood conditions. For purposes of this guide, the Design Basis Flooding Level (DBFL) is defined as the maximum water eleva tion attained by the controlling flood, including coinci dent wind-generated wave effects. The wind-generated wave component of elevation is generally controlled by fetch and water depth and may differ at locations around the plant. Further distinction must be made between estimates of"structural" effects (i.e., static and dynamic forces) and flooding or inundation effects. Additionally, the controlling flood event may be differ ent for evaluating structural effects than for evaluating inundation effects. For example, the Probable Maximum Flood (PMF) may produce the highest water level and static forces on a given structure, but the total static and dynamic forces on the structure may be greater during a smaller (in elevation) flood wave from the seismically induced failure of an upstream dam. For structural purposes, the significant wave height is used; for inundation considerations, the one-percent wave height Is used. Sgniflcant wave height (HA) is the average of the highest one-third of wind-generated waves In a representative -.pectrum. One-percent wave height (HI), sometimes erroneously called the mximum wye height, is the average of the highest 1 percent of **iwind-generated waves in a representative spectrum. Use of the relation H1 = 1.67Hs is acceptable for determin Iing the one-percent wave height. *Suggested criteria for the consideration of localized severe precipitation are contained it Section 2.4.2.3 of Regulatory Guide 1.70, "Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants." The definition of Probable Maximum Precipitation Is contained in "Regulatory Guide 1.59. **'Lne# indicate substantive changes from previous Issue. Methods of flood protection for nuclear power plants fall into one of the following three types (ocal flooding induced by severe local precipitation will be discussed later): 1. Dry Site The plant is built above the DBFL, and therefore safety-related structures, systems, and components are not affected by flooding. 2. Exterior Barrier Safety-related structures, systems, and components are protected from inundation and static and dynamic forces thereof by engineered features external to the immediate plant area. Such features may, when properly designed and maintained, produce the equivalent of a dry site, although care must be taken to ensure that safety-related structures, equipment, and components are not adversely affected by the differential hydraulic head. 3. Incorporated Barrier Safety-related structures, systemsi and components are protected from inundation and static and dynamic effects by engineered features in the structure/ environment interface. Regulatory Position 2 of Regulatory Guide 159 provides that those structures, systems, and components necessary for safe shutdown and maintenance thereof should be protected against the DBFL. The position also suggests that, if sufficient warning time Is shown to be available to bring the plant to a safe shutdown condi tion, some of the other safety-related structures, sys tems, and components identified in Regulatory Guide 1.29 do not require protection against a flood as severe as the DBFL Use of this method of protection as an acceptable alternative requires development of emer gency procedures and technical specifications. Substanti ation of the adequacy of the time available will require, in part: I. Estimating the time required to bring the plant from full-power operation to a safe shutdown mode. 2. Establishing the warning indicators that will initi ate shutdown procedures. Flood stage and rate of rise are common and generally acceptable indicators. How ever, sites along streams downstream from the conflu ence of major tributaries may require an assessment of flooding potential from floods that are less than the PMF, but could exhibit faster rates of rise than the PMF. 1.102-2 K K, 3. Documenting that sufficient time will remain after the warning for the safe shutdown to be accomplished before water-.can flood any safety-related structures, systems, or components. The regulatory positions of this guide identify several key items to be considered in developing acceptable flood-related emergency procedures. Local PMP may produce flooding at sites otherwise considered'immune from flooding. The intensity of this rainfall and the usual design of the drainage system may result in ponding in the plant yard that could produce the DBFL. Also, roofs may receive more precipitation than the roof drains are designed to discharge. Final plant grading is usually designed to cause ponded water to flow away from safety-related build ings. IEven so, some temporary ponding is to be expected. Such ponding is generally accommodated by locating penetrations above the level of temporary ponding. Plant structures, systems, and components subject to ponding are also subject to the static and dynamic forces of the ponded water. These forces are usually less, however, than the forces from other design basis events. C. REGULATORY POSITION 1. The following paragraphs provide working defini tions of the various types of flood protection acceptable to the NRC staff. a. Dry Site The dry site may be the result of natural terrain or it may be constructed using engineered fill. The latter type refers to the "plant island" concept, rather than the minor fill used to dress plant grade. When fill is required to raise the plant access level above design basis flood conditions, the fill is safety related and must be protected from flood effects in the same manner as safety-related dams, dikes, etc. b. Exterior Barriers (1) Levee. "A dike or embankment to protect land from inundation." Levees are generally earthen structures, trapezoidal in cross section, and protected from erosion by armor on the face exposed to waves and current.. (2) Seawall or Floodwall. "A structure separat ing land and water areas, primarily designed to prevent erosion and other damage due to wave action."* Seawalls are massive structures designed to take the full impact of the design wave. The seawall dissipates wave energy by throwing the water upward and downward. The upward deflection may result in wind-blown over topping; the downward deflection can cause severe erosion at the toe of the seawall. (3) Bulkhead Similar to a seawall. The prime purpose is to restrain the land area. A bulkhead should not be'used where it may be subject to direct wave attack. (4) Revetment. "A facing of stone, concrete, etc., built to protect a scarp, embankment, or. shore structure against erosion by wave action or currents."* Revetments are alternatives to seawalls and bulkheads. They protect the shore from direct wave attack by absorbing the wave energy in their interstices and on the surface of the revetment material. In this regard, riprap is more effective than smoother surfaces. Wave runup on the revetment is a function of incident wave height, revetment slope, and the nature of the revetment material. Rough surfaces reduce runup. When riprap is used, the placement of the material is critical to the effectiveness of the feature. Filling of the interstices with finer material destroys much of the energy absorbing capabilities of the installation and may result in overtopping a structure that is otherwise adequate to prevent such overtopping. (5) Breakwater. "A structure protecting a shore area, harbor, anchorage, or basin from waves." Breakwaters may be connected to the shore or may be located entirely offshore. Wave energy is dissipated in the same manner as it is by revetments. Offshore breakwaters are used principally to reduce the wave effects that might otherwise reach safety-related struc tures, facilities, or components. Shore-connected break waters may serve the same purpose and also may be used to train discharge or intake water flow paths to limit recirculation. c. Incorporated Barriers Protection is provided by special design of walls and penetration closures. Walls are usually reinforced concrete designed to resist the static and dynamic forces of the DBFL and incorporate special waterstops at construction joints to prevent inleakage. Penetrations include personnel access, equipment access, and through wall piping. Pipe penetrations are usually sealed with *Definition from the U.S. Army Coastal Engineering Research Center, "'Shore Protection Manual," Kingman Building, Fort Belvoir, Virginia 22060. Copies may be obtained from the Superintendent of Documents, U.S. Government Printing Of fice, Washington, D.C. 20402. 1.102-4 special rubber boots and flanges. Personnel access closures that have been found acceptable include sub marine doors and hatches. The hydraulic and seismic' design bases for all types of closures, including water stops, boots, and flanges, are the same as for the wall (i.e., water tightness and resistance to static and dynamic forces). In addition, the doors should open outward to ensure closure if the door is inadvertently opened during the flood event. Additionally, the plant should be designed and operated to keep doors necessary for flood protection closed during normal operation. Penetrations thit are too large to close with a single door (e.g., equipment and fuel loading access) generally require stop logs or flood panels for closure. The design bases for these features are the same as above, as is the need to maintain them normally in a closed position. Temporary flood barriers, such as sandbags, plastic sheeting, portable panels, etc., which must be installed prior to the advent of the DBFL, are not acceptable for issuance of a construction permit. How ever, unusual circumstances could arise after constriic tion that would warrant consideration of such barriers. One example of unusual circumstances that might justify use of temporary barriers is a post-construction change in the flood-producing characteristics of the drainage area, as discussed in Regulatory Position 3 of Regulatory Guide 1.59, "Design Basis Floods for Nuclear Power Plants." In such circumstances, and with strong justifica. tion, the staff may accept temporary barriers. 2. Past experience suggests the need for guidance in establishing the shutdown technical specifications or emergency operating procedures necessary to utilize Regulatory Position 2 of Regulatory Guide 1.59. The following should be used in establishing the necessary procedures: a. Stage (elevation)-time relations should be devel oped using the appropriate flood hydrograph (with coincident wind-generated wave effects) and site char. acteristics. River sites downstream from the confluence of major tributaries may require assessment of the flood' potential from less severe flood events that may exhibit faster rates of rise than the PMF. b. The flood stage, including design basis wind generated wave effects and the time of occurrence within the flood event, at which any safety-related structure, system, or component (as defined in Regula. tory Guide 1.29) may become degraded or inoperative should establish the completion time for all shutdown procedures. c. Estimates of the time required for safe shut. down should be based on average rather than best-time operator performance. This time interval should be less Sthan the time for occurrence of the event in Regulatory Position 2.b to establish the limiting values of the selected warning indicators. The procedures should consider the total DBFL; however, the indicators (usu. ally flood stage and rate of rise) should be based on the stillwater level (i.e., DBFL less wind-generated wave effects). This precludes the masking of flood potential by less than design basis wind at the time of observation. d. A communication system should be established to alert both onsite and offsite company personnel of flood conditions that may require subsequent shut down of the plant. Such a system may use offsite facilities and services, such as upstream river gages and flood forecasting services, as well as direct communica tion between onsite and offsite company personnel. e. The procedures in 2.c should specify that onsite plant personnel will initiate a safe shutdown on their own volition when the limiting values of the indicators are attained. Only those warning systems located at the site and under control of plant personnel should be needed to determine the limiting values of the indica tors. 3. Analysis supporting the invulnerability of safety related structures, systems, and components from the effects of local PMP should be performed using the point rainfall value of the PMP for the site area. a. Regulatory Guide 1.59 provides guidance on obtaining PMP estimates. An analysis of the estimated depth of ponding in the plant area should also be made. b. Roofs are usually provided with drains designed to discharge precipitation intensities considerably less than that of the PMP. The following methods of preventing undesirable buildup of standing water on the roofs of safety-related buildings have been found accept able to the NRC staff: (1) The parapets (a common architectural fea ture of nuclear power plant structures) may be deleted on one or more sides of the building. This is the most common method. (2) The parapet height may be limited to preclude buildup of water in excess of the structural capacity of the roof for design loads. (3) Scuppers may be installed through the parapets to discharge the standing water over the edge of the building. (Note that limiting the parapet height or lip of the scupper to, for example, 6 inches above the roof will not necessarily limit the depth of water on the roof to 6 inches. Consideration should be given to the hydraulic head necessary to initiate flow.) 1.1024 c. The load induced by the maximum depth of standing water on the roofs (including antecedent or coincident snow or ice) during the design basis event 1 should be less than the structural capacity of the roof for design loads, and the discharge capacity of roof drains should be compared with the design basis dis charge. 0. IMPLEMENTATION The purpose of this section is to provide information to license applicants and licensees regarding the NRC staff's plans for using this regulatory guide. This guide reflects current NRC staff practice. There fore, except in those cases in which the license applicant or licensee proposes an acceptable alternative method for complying with specified portions of the Commis sion's regulations, the method described herein is being and will continue to be used in the evaluation of submittals for operating license or construction permit applications until this guide is revised as a result of suggestions from the public or additional staff review. I/ 1.102-. Revision 2 - U.S. NUCLEAR REGULATORY COMMISSION August 1077 C, REGULATORYGUIDE OFFICE OF STANDARDS DEVELOPMENT REGULATORY GUIDE 1.59 DESIGN BASIS FLOODS FOR NUCLEAR POWER PLANTS USNRC REGULATORY GUIDES Regulatory Guides or* ihsed to describe and make available to the public methods acceptable to the NRC staff of Implementing specific parts of the Commission's regulations, to delineate techniques used by the staff in evaluating specific problems at postulated accidents. or to provide guidance to applicants. Regulatory Guides are not sub•titute& for regulations, and compliance with them ia not required. Methods and solutions different from those mt out in the guides will be accept able if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission. Comments and suggestions for Improvements In these guides erai ncounrged at ll timnes. end guides will be revised, as appropriale. to accommnodate comments and to reflect new information or experience. This guide was revised as a result of substantive comments received from the public and additional staff review. Comments Ohould be sent to the Secretary of the Commission, US. Nuclear Regu latory Commision. Washington, D.C. 2055, Attention: Docketing and Service Branch. The gluides e issued in the following ten broad divisions: 1. Power Reactors 6. Products 2. Research and Test Reactors 7. Transportation 3. Fuels end Materials Facilities S. Occupational Health 4. Environmental end Siting 9. Antitrust Review S. Materials nd Plant Protection 10. General Requests for single copies of issued guides (which may be reproduced) or for place ment on an automatic distribution list for single copies of future guides in specific divisions should be made in writing to the US. Nuclear Regulatory Commision. Washington. D.C. 20555. Attention: Director. Division of Document Control. I UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 July 30, 1980 ERRATA Regulatory Guide 1.59, Revision 2, August 1977 "Design Basis Floods for Nuclear Power Plants" New information that affects the Probable Maximum the Upper Ohio River for drainage areas of 10,000 has been identified. The changes to the isolines in the Upper Ohio River Basin and do not have any the Design Basis Flood for existing plants. Flood (PMF) isolines for and 20,000 square miles affect only a small area significant impact on As a result of the new information, revised Figures B.6 and B.7 transmitted herewith should be used in future PMF discharge determinations when the simplified methods presented in Appendix B to the Regulatory Guide are being used. In addition, appropriate changes have been made to the PMF data on pages 28 and 30 of Table B.1, which are also transmitted herewith. TABLE OF CONTENTS Page A. INTRODUCTION ... ........................................ 1.59-5 B. DISCUSSION .. ............................................. 1.59-5 C. REGULATORY POSITION .................................... 1.59-7 D. IMPLEMENTATION ........................................ 1.59-8 APPENDIX A-Probable Maximum and Seismically Induced Floods on Streams and Coastal Areas 1.59-9 APPENDIX B-Alternative Methods of Estimating Probable Maximum Floods ........... 1.59-11 APPENDIX C-Simplified Methods of Estimating Probable Maximum Surges ............ 1.59-41 *Lines indicate substantive changes from previous issue. 1.59-3 A. INTRODUCTION General Design Criterion 2, "Design Bases for Protection Against Natural Phenomena," of Appen dix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Licensing of Produc tion and Utilization Facilities," requires, in part, that structures, systems, and components important to safety be designed to withstand the effects of natural phenomena such as floods, tsunami, and seiches without loss of capability to perform their safety functions. Criterion 2 also requires that design bases for these structures, systems, and components reflect (I) appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding region, with sufficient margin for the limited accuracy and quan tity of the historical data and the period of time in which the data have been accumulated, (2) ap propriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena, and (3) the importance of the safety functions to be performed. Paragraph 100.10(c) of 10 CFR Part 100, "Reactor Site Criteria," requires that physical characteristics of the site, including seismology, meteorology, geology, and hydrology, be taken into account in determining the acceptability of a site for a nuclear power reactor. Section IV(c) of Appendix A, "Seismic and Geologic Siting Criteria for Nuclear Power Plants," to 10 CFR Part 100 suggests investigations for a detailed study of seismically induced floods and water waves. The appendix also suggests [Section IV(cXiii)] that the determination of design bases for seismically induced floods and water waves be based on the results of the required geologic and seismic in vestigations and that these design bases be taken into account in the design of the nuclear power plant. This guide discusses the design basis floods that nuclear power plants should be designed to withstand without loss of capability for cold shutdown and maintenance thereof. The design requirements for flood protection are the subject of Regulatory Guide 1.102, "Flood Protection for Nuclear Power Plants." The material previously contained in Appendix A, "Probable Maximum and Seismically Induced Floods on Streams," has been replaced by American National Standards Institute (ANSI) Standard N170 1976, "Standards for Determining Design Basis Flooding at Power Reactor Sites,", which has been endorsed as acceptable by the NRC staff with the ex ception noted in Appendix A. In addition to informa tion on stream flooding, ANSI N170-1976 contains methodology for estimating probable maximum sur 'Copies of ANSI Standard N 170-1976 may be purchased from the American Nuclear Society. 555 North Kensington Avenue. La Grange Park, IL 60525. ges and seiches at estuaries and coastal areas on oceans and large lakes. Appendix B gives timesaving alternative methods of estimating the probable max imum flood along streams, and Appendix C gives a simplified method of estimating probable maximum surges on the Atlantic and Gulf coasts. The Advisory Committee on Reactor Safeguards has been con sulted concerning this guide and has concurred in the regulatory position. B. DISCUSSION Nuclear power plants should be designed to pre vent the loss of capability for cold shutdown and maintenance thereof resulting from the most severe flood conditions that can reasonably be predicted to occur at a site as a result of severe hydro meteorological conditions, seismic activity, or both. The Corps of Engineers for many years has studied conditions and circumstances relating to floods and flood control. As a result of these studies, it has developed a definition for a Probable Maximum Flood (PMFY and attendant analytical techniques for estimating, with an acceptable degree of conser vatism, flood levels on streams resulting from hydrometeorological conditions. For estimating seismically induced flood levels, an acceptable degree of conservatism for evaluating the effects of the in itiating event is provided by Appendix A to 10 CFR Part 100. The conditions resulting from the worst site-related flood probable at the nuclear power plant (e.g., PMF, seismically induced flood, seiche, surge, severe local precipitation) with attendant wind-generated wave activity constitute the design basis flood conditions that safety-related structures, systems, and compo nents identified in Regulatory Guide 1.291 should be 'Corps of Engineers' Probable Maximum Flood definition appears in many publications of that agency such as Engineering Circular EC 1110-2-27, Change 1, "Engineering and Design-Policies and Procedures Pertaining to Determination of Spillway Capacities and Freeboard Allowances for Dams," dated 19 Feb. 1968. The Probable Maximum Flood is also directly analogous to the Corps of Engineers' "Spillway Design Flood" as used for dams whose failures would result in a significant loss of life and property. 'Reguiatory Guide 1.29, "Seismic Design Classification," identifies structures, systems, and components of light-water cooled nuclear power plants that shouild be designed to withstand the effects of the Safe Shutdown Earthquake and remain func tional. These structures, systems, and components are those neces sary to ensure (1) the integrity of the reactor coolant pressure boundary, (2) the capability to shut down the reactor and maintain it in a safe shutdown condition, or (3) the capability to prevent or mitfgiate the consequences of accidents that could result in poten tial offsite exposures comparable to the guideline exposures of 10 CFR Part 100. These same structures, systems, and components should also be designed to withstand conditions resulting from the design basis flood and retain capability for cold shutdown and maintenance thereof of other types of nuclear power plants. It is expected that safety-related structures, systems, and components of other types of nuclear power plants will be identified in future regulatory guides. In the interim, Regulatory Guide 1.29 should be used as guidance when identifying safety-related structures, systems, and components of other types of nuclear power plants. 1.59-5 I I designed to withstand and retain capability for cold shutdown and maintenance therof. For sites along streams, the PMF generally provides the design basis flood. For sites along lakes or seashores, a flood condition of comparable severity could be produced by the most severe com-. bination of hydrometeorological parameters reasonably possible, such as may be produced by a Probable Maximum Hurricane4 or by a Probable Maximum Seiche. On estuaries, a Probable Max imum River Flood, a Probable Maximum Surge, a Probable Maximum Seiche, or a reasonable com bination of less severe phenomenologically caused flooding events should be considered in arriving at design basis flood conditions comparable in fre quency of occurrenfe with a PMF on streams. In addition to floods produced by severe hydrometeorological conditions, the most severe seismically induced floods reasonably possible should be considered for each site. Along streams and es tuaries, seismically induced floods may be produced by dam failures or landslides. Along lakeshores, coastlines, and estuaries, seismically induced or tsunami-type flooding should be considered. Con sideration of seismically induced floods should in clude the same range of seismic events as is postulated for the design of the nuclear plant. For in stance, the analysis of floods caused by dam failures, landslides, or tsunami requires consideration of seismic events of the severity of the Safe Shutdown Earthquake occurring at the location that would produce the worst such flood at the nuclear power plant site. In the case of seismically induced floods along rivers, lakes, and estuaries that may be produced by events less severe than a Safe Shutdown Earthquake, consideration should be given to the coincident occurrence of floods due to severe hydrometeorological conditions, but only where the effects on the plant are worse than and the probability of such combined events may be greater than an individual occurrence of the most severe event of either type. Appendix A contains acceptable combinations of such events. For the specific case of seismically induced floods due to dam failures, an evaluation should be made of flood waves that may be caused by domino-type dam failures triggered by a seismically induced failure of a critically located dam and of flood -waves that may be caused by multiple dam failures in a region where dams may be located close enough together that a single seismic event can cause multiple failures. Each of the severe flood types discussed above should represent the upper limit of all potential phenomenologically caused flood combinations con sidered reasonably possible. Analytical techniques are available and should generally be used for predic "See References 2 and 5, Appendix C. tion at individual sites. Those techniques applicable to PMF and seismically induced flood estimates on streams are presented in Appendices A and B of this guide. For sites on coasts, estuaries, and large lakes, techniques are presented in Appendices A and C of this guide. Analyses of only the most severe flood conditions may not indicate potential threats to safety-related systems that might result from combinations of flood conditions thought to be less severe. Therefore, reasonable combinations of less-severe flood condi tions should also be considered to the extent needed for a consistent level of conservatism. Such combina tions should be evaluated in cases where the probability of their existing at the same time and hav ing significant consequences is at least comparable to that associated with the most severe hydro meteorological or seismically induced flood. For ex ample, a failure of relatively high levees adjacent to a plant could occur during floods less severe than the worst site-related flood, but would produce condi tions more severe than would result during a greater flood (where a levee failure elsewhere would produce less severe conditions at the plant site). Wind-generated wave activity may produce severe flood-induced static and dynamic conditions either independent of or coincident with severe hydrometeorological or seismic flood-producing mechanisms. For example, along a lake, reservoir, river, or seashore, reasonably severe wave action should be considered coincident with the probable maximum water level conditions.' The coincidence of wave activity with probable maximum water level conditions should take into account the fact that suf ficient time can elapse between the occurrence of the assumed meteorological mechanism and the max imum water level to allow subsequent meteorological activity to produce substantial wind-generated waves coincident with the high water level. In addition, the most severe wave activity at the site that can be generated by distant hydrometeorological activity should be considered' For instance, coastal locations may be subjected to severe wave action caused by a distant storm that, although not as severe as a local storm (e.g., a Probable Maximum Hurricane), may produce more severe wave action because of a very long wave-generating fetch. The most severe wave ac tivity at the site that may be generated by conditions at a distance from the site should be considered in such cases. In addition, assurance should be provided 'Probable Maximum Water Level is defined by the Corps of Engineers as "the maximum still water level (i.e., exclusive of local coincident wave runup) which can be produced by the most severe combination of hydrometeorological and/or seismic parameters reasonably possible for a particular location. Such phenomena are hurricanes, moving squall lines, other cyclonic meteorological events, tsunami, etc., which, when combined with the physical response of a body of water and severe ambient hydrological con ditions, would produce a still water level that has virtually no risk of being exceeded." 1.59-6 K S I I that safety systems necessary for cold shutdown and maintenance thereof are designed to withstand the static and dynamic effects resulting from frequent flood levels (i.e., the maximum operating level in reservoirs and the 10-year flood level in streams) coincident with the waves that would be produced by the Probable Maximum Gradient Wind' for the site (based on a study of historical regional meteorology). C. REGULATORY POSITION 1. The conditions resulting from the worst site related flood probable at a nuclear power plant (e.g., PMF, seismically induced flood, hurricane, seiche, surge, heavy local precipitation) with attendant wind generated wave activity constitute the design basis flood conditions that safety-related structures, systems, and components identified in Regulatory Guide 1.29 (see footnote 3) must be designed to withstand and retain capability for cold shutdown and maintenance thereof. a. The PMF on streams, as defined in Appendix A and based on the analytical techniques summarized in Appendices A and B of this guide, provides an ac ceptable level of conservatism for estimating flood levels caused by severe hydrometeorological con ditions. b. Along lakeshores, coastlines, and estuaries, estimates of flood levels resulting from severe surges, seiches, and wave action caused by hydrometeorological activity should be based on criteria comparable in conservatism to those used for Probable Maximum Floods. Criteria and analytical techniques providing this level of conservatism for the analysis of these events are summarized in Ap pendix A of this guide. Appendix C of this guide pre sents an acceptable method for estimating the still water level of the Probable Maximum Surge from hurricanes at open-coast sites on the Atlantic Ocean and Gulf of Mexico. c. Flood conditions that could be caused by dam failures from earthquakes should also be considered in establishing the design basis flood. Analytical techniques for evaluating the hydrologic effects of seismically induced dam failures discussed herein are presented in Appendix A of this guide. Techniques for evaluating the effects of tsunami will be presented in a future appendix. d. Where upstream dams or other features that provide flood protection are present, in addition to the analyses of the most severe floods that may be in duced by either hydrometeorological or seismic mechanisms, reasonable combinations of less-severe flood conditions and seismic events should also be 6Probable Maximum Gradient Wind is defined as a gradient wind of a designated duration, which there is virtually no risk of ex ceeding. considered to the extent needed for a consistent level of conservatism. The effect of such combinations on the flood conditions at the plant site should be evaluated in cases where the probability of such com binations occurring at the same time and having significant consequences is at least comparable to the probability associated with the most severe hydrometeorological or seismically induced flood. For relatively large streams, examples of acceptable combinations of runoff floods and seismic events that could affect the flood conditions at the plant arc con tained in Appendix A. Less-severe flood conditions, associated with the above seismic events, may be ac ceptable for small streams, that exhibit relatively short periods of flooding. e. The effects of coincident wind-generated wave activity to the water levels associated with the worst site-related flood possible (as determined from paragraphs a, b, c, or d above) should be added to generally define the upper limit of flood potential. Acceptable procedures are contained in Appendix A of this guide. 2. As an alternative to designing hardened proteo ton' for all safety-related structures, systems, And components as specified in Regulatory Position 1 above, it is permissible not to provide hardened protection for some of these features if: a. S ufficientt'warning time is shown to be available to shut the plant down and implement ade quate emergency procedures; b. All safety-related structures, systems, and components identified in Regulatory Guide 1.29 (see footnote 3) arc designed to withstand the flood condi tions resulting from a Standard Project events with attendant wind-generated wave activity that may be produced by the worst winds of record and remain functional; c. In addition to the analyses in paragraph 2.b -above, reasonable combinations of less-severe flood conditions are also considered to the extent needed for a consistent level of conservatism; and 'Hardened protction means structural provisions Incorporated in the plant design that will protect safety-related structures, systems, and components from the static and dynamic effects of floods. In addition, each component of the protection must be passive and In place, as it is to be used for flood protection, during normal plant operation. Examples of the types of flood protection. to be provided for nuclear power plants are contained in Regulatory Guide 1.102. sFor sites along streams, this event is characterized by the Corps of Engineers' definition of a Standard Project Flood. Such floods have been found to produce flow rates generally 40 to 60 percent of the PMF. For sites along seashores, this event may be characterized by the Corps of Engineers' definition of a Standard Project Hurricane. For other sites, a comparable level, of risk should be assumed. 1.59-7 d. In addition to paragraph 2.b above, at least those structures, systems, and components necessary fbr cold shutdown and molntenance thereof are designed with hardened protective features to remain functional while withstanding the entire range of flood conditions up to and including the worst site related flood probable (e.g., PMF, seismically in. duced flood, hurricane, surge, seiche, heavy local precipitation) with coincident wind-generated wave action as discussed in Regulatory Position I above. 3. During the economic life of a nuclear power plant, unanticipated changes to the site environs which may adversely affect the flood-producing characteristics of the environs are possible. Examples include construction of a dam upstream or downstream of the plant or, comparably, construc tion of a highway or railroad bridge and embank ment that obstructs the flood flow of a river and con struction of a harbor or deepening of an existing har bor near a coastal or lake site plant. Significantly adverse changes in the runoff or other flood-producing characteristics of the site environs, as they affect the design basis flood, should be iden tified and used as the basis to develop or modify emergency operating procedures, if necessary, to mitigate the effects of the increased flood. 4. Proper utilization of the data and procedures in Appendices B and C will result in PMF peak dis charges and PMS peak stiliwater levels which will in many cases be approved by the NRC staff with no further verification. The staff will continue to accept for review detailed PMF and PMS analyses that result in less conservative estimates than those ob tained by use of Appendices B and C. In addition, previously reviewed and approved detailed PMF and PMS analyses will continue to be acceptable even though the data and procedures in Appendices B and C result in more conservative estimates. D. IMPLEMENTATION The purpose of this section is to provide informa tion to license applicants and licensees regarding the NRC staff's plans for using this regulatory guide. This guide reflects current NRC practice. Therefore, except in those cases in which the appli cant or licensee proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the methods described herein are being. and will continue to be used in the evaluation of submittals for construction permit ap plications until this guide. is revised as a result of sug gestions from the public or additional'staff review. 1.59-8 APPENDIX A PROBABLE MAXIMUM AND SEISMICALLY INDUCED FLOODS ON STREAMS AND COASTAL AREAS The material preiiously contained in Appendix A has been replaced by American National Standards Institute (ANSI) Standard.N170-1976, "Standards for Determining Design Basis Flooding at Power Reactor Sites," with the following exception: Sections 5.5.4.2.3 and 5.5.5 of ANSI N170-1976 contain references to methods for evaluating the cro- sion failure of earthfill or roekfrdl dams and determin ing the resulting outflow hydrographs. The staff has found that some of these methods may not be conser vative because they predict slower rates of erosion than have historically occurred. Modifications to the models may be made to increase their conservatism. Such modifications will be reviewed by the NRC staff on a case-by-case basis. 1.59-9 APPENDIX B ALTERNATIVE METHODS OF ESTIMATING PROBABLE MAXIMUM FLOODS TABLE OF CONTENTS B.I INTRODUCTION ..................... B.2 SCOPE ........................... B.3 PROBABLE MAXIMUM FLOOD PEAK DISCHARGE B.3.1 Use of PMF Discharge Determinations ........ B.3.2 Enveloping Isolines of PMF Peak Discharge..... B.3.2.1 Preparation of Maps ................ B.3.2.2 Use of Maps ............. B.3.3 Probable Maximum Water Level ............ B.3.4 Wind-Wave Effects ................... B.4 LIMITATIONS ....................... REFERENCES ........................... FIGURES .............................. TABLE ............................. FIGURES Page .†.†††.†.†††.†.†††.†††††††††††††††1.59-12 1.59-12 1.59-12 1.59-12 1.59-12 1.59-12 1.59-13 1.59-13 1.59-13 1.59-13 1.59-14 1.59-15 1.59-23 1.59-15 1.59-16 1.59-17 1.59-18 1.59-19 1.59-20 1.59-21 1.59-22 Figure B. I-Water Resources Regions ..................... B.2-Probable Maximum Flood (Enveloping Isolines)-100 Sq. Mi. B.3-Probable Maximum Flood (Enveloping Isolines)-500 Sq. Mi. B.4-Probable Maximum Flood (Enveloping Isolines)-1,000 Sq. Mi. B.5-Probable Maximum Flood (Enveloping Isolines)-5,000 Sq. Mi. B.6-Probable Maximum Flood (Enveloping Isolines)-10,000 Sq. Mi. .B.7--Probable Maximum Flood (Enveloping Isolines)-20,000 Sq. Mi. B.8-Example of Use of Enveloping Isolines ................ TABLE Table B.I--Probable Maximum Flood Data 1.59..-23 1.59-11 . . . . . . . I g I D D I 0.1 INTRODUCTION This appendix presents timesaving alternative methods of estimating the probable maximum flood (PMF) peak discharge for nuclear facilities on non tidal streams in the contiguous United States. Use of the methods herein will reduce both the time neces sary for applicants to prepare license applications and the NRC staff's review effort. The procedures are based on PMF values deter mined by the U.S. Army Corps of Engineers, by ap plicants for licenses that have been reviewed and ab cepted by the NRC staff, and by the staff and its con. sultants. The information in this appendix was developed from a study made by Nunn, Snyder, and Associates, through a contract with NRC (Ref. 1). PMF peak discharge determinations for the entire contiguous United States are presented in Table B. I. Under some conditions, these may be used directly to evaluate the PMF at specific sites. In addition, maps showing enveloping isolines of PMF discharge for several index drainage areas are presented in Figures B.2 through B.7 for the contiguous United States east of the 103rd meridian, including instructions for and an example of their use (see Figure B.8). Because of the enveloping procedures used in preparing the maps, results from their use are highly conservative. Limitations on the use of these generalized methods of estimating PMFs aretidgntified in Section B.4. These limitations should be considered in detail in assessing the applicability of the methods at specific sites. Applicants for licenses for nuclear facilities at sites on nontidal streams in the contiguous United States have the option of using these methods in lieu of the more precise but laborious methods of Appendix A. The results of application of the methods in this ap pendix will in many cases be accepted by the NRC staff with no further verification. 0.2 SCOPE The data and procedures in this appendix apply only to nontidal streams in the contiguous United States. Two procedures are included for nontidal streams east of the 103rd meridian. Future studies are planned to determine the ap plicability of similar generalized methods and to develop such methods, if feasible, for other areas. These studies, to be included in similar appendices, are anticipated for the main stems of large rivers and the United States west of the 103rd meridian, in cluding Hawaii and Alaska. B.3 PROBABLE MAXIMUM FLOOD PEAK DISCHARGE The data presented in this section are as follows: 1. A tabulation of PMF peak discharge determina. tions at specific locations throughout the contiguous United States. These data are subdivided into water resources regions, delineated on Figure B.1, and are tabulated in Table B.1. 2. A set of six maps, Figures B.2 through B.7, covering index drainage areas of 100, 500, 1,000, 5,000, 10,000, and 20,000 square miles, containing isolines of equal PMF peak discharge for drainage areas of those sizes east of the 103rd meridian. B.3.1 Use of PMF Discharge Determinations The PMF peak discharge determinations listed in Table B.I are those computed by the Corps of Engineers, by the NRC staff and their consultants, or computed by applicants and accepted by the staff. For a nuclear facility located near or adjacent to one of the streams listed in the table and reasonably close to the location of the PMF determination, that PMF may be transposed, with proper adjustment, or routed to the nuclear facility site. Methods of trans. position, adjustment, and routing are given in stan dard hydrology texts and are not repeated here. B.3.2 Enveloping Isollnes of PMF Peak Discharge B.3.2.1 Preparation of Maps For each of the water resources regions, each PMF determination in Table B.A was plotted on logarithmic paper (cubic feet per second per square mile versus drainage area). It was found that there were insufficient data and too much scatter west of about the 103rd meridian, caused by variations in precipitation from orographic effects or by melting snowpack. Accordingly, the rest of the study was confined to the United States east of the 103rd meri dian. For sites west of the 103rd meridian, the methods of the preceding, section may be used. Envelope curves were drawn for each region east of the 103rd meridian. It was found that the envelope curves generally paralleled the Creager curve (Ref. 2), defined as Qi,46.0 CA (0.894A -0.048) -1 where Q is the discharge in cubic feet per second (cfs) C is a. constant, taken as 100 for this study A is the drainage area in square miles. 1.59-12 K Each PMF discharge determination of 50 square miles or more was adjusted to one or more of the six selected index drainage areas in accordance with the slope of the Creager curve. Such adjustments were made as follows: PMF Within Drainage Area Range, sq. mi. 50 to 500 100 to 1,000 500 to 5,000 1,000 to 10,000 5,000 to 50,000 10,000 or greater Adjusted to Index Drainage Area, sq. mil. 100 500 1,000 5,000 10,000 20,000 . The PMF values so adjusted were plotted on maps of the United States east of the 103rd meridian, one map for each of the six index drainage areas. It was found that there were areas on each map with insuf ficient points to define isolines. To fill in such gaps, conservative computations of approximate PMF peak discharge were made for each two-degree latitude-longitude intersection on each map. This was done by using enveloped relations between drainage area and PMF peak discharge (in cfs per inch of runoff), and applying appropriate probable max imum precipitation (PMP) at each two-degree latitude-longitude intersection. PMP values, obtained from References 3 and 4, were assumed to be for a 48 hour storm to which losses of 0.05 inch per hour were applied. These approximate PMF values were also plotted on the maps for each index drainage area and the enveloping isolines were drawn as shown on Figures B.2 through B.7. B.3.2.2 Use of Maps The maps may be used to determine PMF peak dis charge at a given site with a known drainage area as follows: 1. Locate the site on the 100-square-mile map, Figure B.2. 2. Read and record the 100-square-mile PMF peak discharge by straight-line interpolation between the isolines. 3. Repeat Steps 1 and 2 for 500, 1,000, 5,000, 10,000, and 20,000 square miles from Figures B.3 through B.7. 4. Plot the six PMF peak discharges so obtained on logarithmic paper against drainage area, as shown on Figure B.8. 5. Draw a smooth curve through the points. Reasonable extrapolations above and below the defined curve may be made. 6. Read the PMF peak discharge at the site from the curve at the appropriate drainage area. B.3.3 Probable Maximum Water Level When the PMF peak discharge has been obtained as outlined in the foregoing sections, the" PMF still water level should be determined. The methods given in Appendix A are acceptable for this purpose. B.3.4 Wind-Wave Effects Wind-wave effects should be superimposed on the PMF stillwater level. Criteria and acceptable methods are given in Appendihx A. BA LIMITATIONS 1. The NRC staff will continue to accept for review detailed PMF analyses that result in less con servative estimates. In addition, previously reviewed and approved detailed PMF analyses at specific sites will continue to be acceptable even though the data and procedures in this appendix result in more con servative estimates. 2 .The PMF estimates obtained as outlined in Sec tions B.3.1 and B.3.2 are peak discharges that should be converted to water level to which appropriate wind-wave effects should be added. 3. If there are one or more reservoirs in the drainage area upstream of the site, seismic and hydrologic dam failure' flood analyses should be made to determine whether such a flood will produce the design basis water level. Criteria and acceptable methods are included in Appendix A. 4. Because of the enveloping procedures used, PMF peak discharges estimated as outlined in Sec tion B.3.2 have a high degree of conservatism. If the PMF so estimated casts doubt on the-suitability of a site, or if protection from a flood of that magnitude would not be physically or economically feasible, consideration should be given to performing a detailed PMF analysis, as outlined in Appendix A. It is likely that such an analysis will result in ap preciably lower PMF levels. 'In this contest, "hydrologic dam failure" muama failure caused by a flood from the drainage area upstream of the dam. 1.59-13 REFERENCES 1. Nunn, Snyder, and Associates, "Probable Max imum Flood and Hurricane Surge Estimates," un published report to NRC, June 13, 1975 (available in the public document room). 2. W.P. Creager, J.D. Justin, and J. Hinds, "Engineering for Dams," J. Wiley and Sons, Inc., New York, 1945. 3. U.S. Weather Bureau (now U.S. Weather Service, NOAA), "Seasonal Variation of the Probable Max imum Precipitation East of the 105th Meridian," Hydrometeorological Report No. 33, 1956.' 4. U.S. Department of Commerce, NOAA, "All Season Probable Maximum Precipitation-United States East of the 105th Meridian, for Areas from 1,000 to 20,000 Square Miles and Durations from 6 to 72 Hours," draft report, July 1972.2 'Note References 3 and 4 are being updated and combined into a single report by NOAA. This report is expected to be published in the near future as Hydrometeorological Report No. 51 with the ti tle "Probable Maximum Precipitation Estimates, United States East or the 105th Meridian." 1.59-14 K y FIGURE I.1 WATER RESOURCES REGIONS K '0 iS -ISOLINE REPRESENTING PEAK-FLOW OF f--4 , PUF iN 1,000CFS. I I NOTE: PMF ISO UNIS ON TIS CHART REPRESENT ENVELOPED V~LESOF PEAK RUNOFF FROM 10"SUARE MILE DRAINAGE AREA UNDER NATURAL RIVER CONDITIONS. ACCORDINGLY. PMIF VALUES OBTAINED DO NOT INCLUDE POSSIBLE CONTRISU TIONS TO PEAK FLOW THAT WOULD RESULT FROM UPSTREAM DAM FAILURES OR OTHER UNNATURAL EVENTS. 11G 1170 1159 113° 1110 100 1076 106 FIGURE 8.2 PROBABLE MAXIMUM FLOOD (ENVELOPING PMF ISOLINES) FOR 100 SQUARE MILES ( LA '0 0% r 8f3 o 1 79* 770 750 730 710 ms 670 O6r IS-1 01dM REPRESENOIN PEAK FLOW OF S PMf IN 1.00 15 !m: P IJOUNIs OW TWS CHART REPRESENT ENVELOPED VAARELAU EUSN OM E PENAAKT RUURIANL RIVFFER RM C ON00IDS"CIOMURASR. EAMCLCEO RDDRINAGILNYA. GE0A j TPrUO, NVS ATLOU PEESA OKB FTLAOIWNE TDH A0To NW OOTU ILNDC LRUEDSEU LPTO MFRSSOBMLE U CPOSTNRTERAIMMU . DAM FAILURES OR OTHER UNNATURAL EVE•T OS. I I I• I I IZ3-• LI m o 190 1170 11 . 113ie • 1m110e 0 1070 105° 103 101° 99W 9w5o7 ° 3 9 89w 0o70r 0 3or FIGURE 8.3 PROBABLE MAXIMUM FLOOD (ENVELOPING PMF ISOLINES) FOR 500 SQUARE MILES K k -J 470 4v. 43. 41* 390 370 3s. 33. 310 29* 2r0 2SO 47r 470 [ 450 4V. 41 360 37. 33. 310 290 27r 2fie 121' 11g° 117 115° 113. I!I° 108' 1070 10° 103. 101° 9' 970 9i° o9 3w 91o 8w 870 85. 83w FIGURE BA PROBABLE MAXIMUM FLOOD (ENVELOPING PMF ISOLIIES) FOR 1,000 SQUARE MILES -C 45. 43. 410* 30. 370 35p 33. 310 2B° 270 2r r - ISOLINE REPRESENTING PEAK FLOW OF PMF IN 1.000 CFS. NOTS: PiF ISOLWINS ON THIS CHART REPRESENT ENVELOPED VALW EE OF PEAK RUNOFF FROM 1.Q0.04UARE MILE DRAINAGE LAiREA UNDER NATURAL RIVER CONDITIONS. ACCORDINGLY. IMF VALUES OBTAINED DO NOT INCLUDE POSSIBLE CONTRIBU TIONS TO PEAK FLOW THAT WOULD RESULT FROM UPSTREAM DAM FAILURES OR OTHER UNNATURAL EVENTS. I f I I I I !A -- t ( .,p ImO GO - ISOLINE REPRESENTING PEAK FLOW OF PMF IN 1,000 CFS. ----- N ' al • a a a a a a I NOTE: PMF ISOUNES ON THIS CHART REPRESENT ENVELOPED VALUES OF PEAK RUNOFF FROM 5,000.SQUARE MILE DRAINAGE AREA UNDER NATURAL RIVER CONDITIONS. ACCORDINGLY, PMF VALUES OBTAINED DO NOT INCLUDE POSSIBLE CONTRIBU TIONS TO PEAK FLOW THAT WOULD RESULT FROM UPSTREAM D) FAILURE Off OTHER UNNATURAL EVENTS. a a a a a a Ia -- - 1110 IO9 1070 100 103 1010 9 g7o 959 93 91m 90g or 0 8w 81° 790 770 75 FIGURE B.5 PROBABLE MAXIMUM FLOOD (ENVELOPING PMF ISOLINES) FOR 5.000 SQUARE MILES Q K "Ip Ga -"ISOLINE REPRESENTING PEAK FLOWOF PMF IN 11000 CFS. NOTE: PMF ISOLINES ON THIS CHART REPRESENT ENVELOPED VALUES OF PEAK RUNOFF FROM 10.OOO4OUARE MILE DRAINAGE AREA UNDER NATURAL RIVER CONDITIONS. ACCORDINGLY. PUF VALUES OBTAINED DO NOT INCLUDE POSSIBLE TIONS TO PEAK FLOW THAT WOULD RESULT FROM UCPOSTNRTERAIBMU .D AM FAILURES OR OTHER UNNATURAL EVENTS. .. . 121 1190 117,1 115o 1130 1110 19o 107 1050 1030 1010 990 970 B5e 930 910 o n 870 850 830 FIGURE 8.6 PROBABLE MAXIMUM FLOOD (ENVELOPING PMF ISOLINES) FOR 10.000 SQUARE MILES ... ( r Q I MI N1 ,0 IF ; 00 Z 6f i ý ROETE: PMF rJOt.NES ON THIS CHART REPRESENT ENVELOPED 1400, 100 VALUES OF PEAK RUNOFF FROM 20.000-SUARE MILE DRAINAGE "Pm VALUE•S OBTAINED 00 NOT INCLUDE POSSIBLE CONTRIt- •% 1IONS T'O PEAK FLOW THAT WOULD RESULT FROM UPSTREAM DAM P2 DAM FALRSOR OTHER UNNATUAL EVENTS. 1i11i*°9 7e 115° 113° 11 " i09° os i0o0°1,3 °i 01° 99p° g 95P g°93° 91° 89 87° 5 3 FIGURE B.7 PROBABLE MAXIMUM FLOOD (ENVELOPING PMF ISOLINES) FOR 20,000 SQUARE MILES y 'a I I I I I I I I 1 I -EXAMPLE: FOR DRAINAGE AREA OF .2,300 S. MI.AT LAT. 43@, LONG. 950, DETERMINE PMF PEAK DISCHAR.GE. I I II I • I i'- : I- -I . . .4 ;tI; ; i , - 4 -i4 4 I • • II- I Si Wil I I ii -%SLUTIUN: FOR DRAINAGE AREA OF 2,300 SO. MI., PMF PEAK 4,00CF&. " I I I, ,______.... __ I I I 11 I...11L..!. 100 1000 10,000 DRAINAGE AREA, SQUARE MILES FIGURE B.8 EXAMPLE OF USE OF ENVELOPING ISOLINES S-C I jul11 g *iWW IULm < co a 0. u: ,c< 0 00 L1A .j m 0 i . m. Im,,, 10 100,000 /'If]"POINTS FROM I .. ." FIGURES B;.2-B.7 d X X I I I I I I I I I I I air J!•d• I ilia y TABLE B.1 PROBABLE MAXIMUM FLOOD DATA (Page 1 of 17) K "Drainage Basin Average PM? Peak Project State River Basin Stream Area (n inches) Discharge North Atlantic Region (Northeast Atlantic Sub-reion) Ball Mountain Barre Falls Beaver Brook Birch Hill Black Rock Blackwater Buffumville Colebrook Conant Brook East Barre East Branch East Brimfield Edward McDowell Everett Franklin FClas Hal Meadow Hancock Hodges Village Hop Brook Hopkinton Knight••lle Littleville Mad River Mansfield Hollow Nookagee Northfield North Hartland North Springfield Otter Brook Phillips Sucker Brook S yMountain Thomaston Vt. Mass. N. He Mass. Conn. N. H. Mass. Conn. Mass* Vt. Conne Mass. N. H. N. He N.H. Conne Como. Mass. cozme No H. MaSs. Mass. Conn* Mass. come Vt. Vt. Maass Come. N. H. Conn. Connecticut Connecticut Connecticut Connecticut Housatonic Merrimack Thames Connecticut Connecticut Winooski Housatonic Thames Merrimack Merrimack Merrimack Connecticut Housatonic Thames Housatonic Merrimack Connecticut Connecticut Connecticut Thames Merrimack Housatonic Connecticut Connecticut Connecticut Merrimack Connecticut Connecticut Housatonic West River Ware River Beaver Brook Millers River Branch Brook Blackwater River Little River Farmington River Conant Brook Jail Branch Naugatuck River Quineaaug River Nubanusit River Piseataquog River Pemigewasset River Hall Meadow Brook Hancock Brook French River Hop Brook Contoocook River Westfield River Westfield River Mad River Natchaug River Phillips Brook Northfield Brook Ottauquechee River Black River Otter Brook Phillips Brook Sucker Brook Ashuelot River Naugatuck River '0 172 55 6.0 175 20 128 26 118 7.8 39 9s2 68 .44 64 1,000 17 12 31 16 426 162 52 18 159 11 5.7 220 158 47 5.0 100 97 20.6 20.1 21*3 18*3 22.2 18.3 26.6 22.? 24.4 21.5 24.0 24.2 19.5 20,7 15.8 24.0 24.0 26.2 25.0 17.4 18.8 25.1. 24.0 19.8 21.8 24.4 19.3 20.0 19.1 24.2 22.4 22.2 24.5 18.1 18.9 19.7 17.1 20.6 16,4 25.3 21.1 23.2 18.6 22.8 22.9 18.3 18,,2 13.3 22.8 22.8 22.3 23.8 14.7 17.6 22.4 22.8 18.5 20.2 23.2 17.2 18.3 17.9 23.0 21.4 19.6 22.4 16910,,000000 10,.00 88.500 35,000 95,000 36,500 165,000 11,900 52,500 15,500 73,900 43,000 68,000 300,000 26,600 20,700 35,600 26,400 135,000 160,000 98000 30,000 125,000 17,750 .9000 199,000 157,000 45,000 7,700 6,500 63,000 158,000 a TABLE 0.1 (Page 2 of 17) River Basin Stream Drainage Area ta m4 I Basin Average (in inches) Townshend Trumbull, Tully Union Village Vermont-Yankee Waterbury West Hill West Thompson Westville Whitemanville Wrightsville Vt. Conn. Mass. Vt. Vt. Vt. Mass. Coeme Mass. Mass. Vt. Connecticut Pequonnook Connecticut Connecticut Connecticut Winooski Blackstone Thames Thames Merrimack Winooski West River Pequonnook River Tully River Ompompanoosuc River Connecticut River Waterbury River West River Quinebaug River Quinebaug River Whitman River North Branch North Atlantic Region (Mid-Atlantic Sub-region) Almond Alvin R. Bush Aquashicola Arkport Aylesworth Baird Beltzville Bloomington Blue Marsh Burketown Cabins Chambersburg Christiana Cootes Store Coiaaesque Curwensavile Dawsonville Douglas Point East Sidney Edes Fort Fairview Foster Joseph Sayers Francis e. Walter N. Y. Pa. Pa. N. Y, Pa. w. Va. Pa. Md. Pa. Va. We Va* Md. Del. Va. Pa. Pa. Md. N. YO we Va* Md. Pao Pas Susquehanna Susquehanna Delaware Susquehanna Susquehanna Potomac Delaware Potomac Delaware Potomac Potomac Potomaa Delaware Potomac Susquehanna Susquehanna Pot •r•-c Potomac Susquehanna Potomac Potomac Susquehanna Delaware Canacadea Creek Kettle Creek Aquashicola Creek Canister River Aylesworth Creek Buffalo Creek Pohopoco Creek North branch Tulpehockan Creek North River South Branch Conococheague River Christiana River North Fork River Cowanesque River Susquehanna River Seneca Creek Poto mac River Oulelot River Cacapon River Conococleaque Creek Bald Eagle Creek Lehigh River 4r Project State PIF Peak Discharge --- ;% - wg*Ru"W . 1 R&O I 278 14 50 126 6,266 109 28 74 32 18 68 21.3 23.0 20.0 17.0 18.9 28.0 20.4 25.4 21.4 20.2 22.0 24.0 28.0 22.5 23.8 34.0 27.1 22.2 24.0 24.3 20.8 28.9 32.1 22.5 21.9 22.0 13.4 24.0 21.2 22.9 21.8 22.4 17.2 21.8 16.6 15.8 16.0 25.6 17'.5 22.8 19.8 17.3 18.8 21.1 24.2 17.7 22.0 30.2 25.6 17.6 21.3 21.2 16.8 26.0 28.3 19.1 18.5 18.9 27.1 10.2 22.1 17.3 18.8 19.0 19.8 228,000 26,700 47,000 110,0000 480,000 128.000 26,ooo 85,000 38,400 25,000 74,000 59.000 154,000 42.500 33.400 13,700 14,600 68,000 196,000 11o,600 272,200 l955,900 81,400 39,200 140,200 285,000 205. 000 161,900 1,490,000 99,900 410,800 150,100 251,000 1700000 56 226 66" 31 6.2 10 97 263 175 375 314 141 41 215 298 365s 0l1 13,317 202 679 494 339 288 C t T" •o Q K1 Drainage Basin Average PMF Peak Project State River Basin Stream Area (in inches) Discharge (2.so.m _ Pec. Ruoff (cfs) Franklin Frederick Front Royal Fulton (Harrisbrg) Gathright Geun. Edgar Jadwin Great Cacapon Harriston Hawk Mountain Headsvifle John H. Kerr Karo Keyser Kitsmiller Leesburg Leidstown Licking Creek Little- Cacapon Maiden Creek Martinsburg Mikville Moorefield Moorefield Newark North Anna North Mountain Peach Bottom Perryman Petersburg Philpott Prompton Raystown Royal Glen Salem Church Savage River Seneca Sharpeburg V. Va.. Md. Va, Pa. Va, Pa. We Va. Va* Pa. W. Va. Va. V. Va. V,. Va. Md. Va. Mde W. Va@ W. Va. Pa. VV,, Vaa,. Del* Va. we Va. Pa. Md, V. Va, Va. Pat Pa. Md. Va., Md. Md. Mde Potomac Potomac Potomac Susquehanna James Delaware Potomac Potomac Delaware Potomac Roanoke Potomac Potomac Potomac Potomac Potomac Potomac Potomac Delaware Potomac Potomac Potomac Potomac Delaware Pamunkey(York) Potomac Susquehanna Chesapeake Bay Potomac Roanoke Delaware Susqiehanna Potomac Rappahannock Potomac Potomac Potomac South Branch Monocacy River SoFk.Shenandoah River Susquehanna River Jackson River Dyberry Creek Cacapon River South River E.Br. Delaware River Patterson Creek Roanoke River South Branch North Branch North Branch Goose Creek Fishing Creek Licking Creek Little Cacapon River Maiden Creek Opequon Creek Shenandoah River South Branch Soo Pl. South Branch White Clay River North Anna River Back Creek Susquehanna River Bush River South Branch Smith River Lackawaxen River Juniata River (Br.) South Branch Rappahannock River Savage River Potomac River Antietem Creek' T TABLE B.1 (Page 3 of 17) %0 urn 182 817 1,638 24,100 65 677 222 812 219 7,800 1,577 "495 225 338 7.1 158 101 161 272 3),o01 1,173 283 66 3143 231 27,000 118 642 212 60 960 640 1,598 105 11,400 281 24,2 23.2 18.0 12.7 ý24.11 24.8 21o2 29.6 .16.5 23.4 16.8 18.9 21.5 22.3 26.5 34.8 29.0 29.7 27.3 27.2 16.2 18.0 21.1 29.8 25.0 27.9 12.7 1903 27.5 25.0 21.4 19.3 23.6 26.3 13.5 26.6 20o.6 20.9 114.3 8.2 21.3 17.3 26.5 12.7 19.0 12.9 14.9 16.o 17.1 2*4.2 32.7 26.1 27.4 23.5 24.1 11.7 1*4.0 17.1 26.0 21.3 24.8 8.2 15.3 24•3. 24.2 17.5 15.3 19.6 22.2 10.3 23.5 174,000. •. 363,00 419,000 1,750,000 246,000 119,700 373,100 153,700 .202,000 176,000 1,000,000 *430,000 2799200 120,200 340,900 12,200 125,800 122,700 118,000 17?4.600 592,000 389,700 173,800 103,000 220,000 256,000 1,750,000 87,400 208,700 160,000 87,190 353,*400 208,700 552,000 107,400 1,393,000 154,900 TABLE B.1 (Page 4 of 17) Drainage Basin Average PMF Peak Project State River Basin Stream Area (in inches) Discha ge (sq.mi.) Prec. Runoff (cfre) Sherrill Drive Six Bridge Springfield Staunton Stillwater Summit Surry Tioga-Hammond Tocks Island Tonoloway Town Creek Trenton Trexler Tri-Towns Verplanck Washington, D, C, Wayneaboro West Branch Whitney Point Winchester York Indian Rock Allatoona Alvin W. Vogtle Bridgewater Buford Carters Catawba Cherokee Claiborne Clark Hill Coffeeville Cowans Ford Demopolis Falls Lake Md. Md. WO Va. Va. Pa. N. J, Va. Pa. N. Jo Md. Md. N. J. Pa. We Va. N. Y. Mid. Va. W. Va. No Y. Va. Pa. Potomac Potomac Potomac Potomac Susquehanna Delaware James Susquehanna Delaware Potomac Potomac Delaware Delaware Potomac Hudson Potomac Potomac Potomac Susquehanna Potomac Susqueha~nna Rock Creek Monocacy River South Branch South Branch Shen. Lacawanna River Delaware River James River Tioga River Delaware River Tonoloway Creek Town Creek Delaware River Jordon Creek North Branch Hudson River Potomac River South River Conococheague River Otselie River Opeqnon Creek Codorus Creek South Atlantic-Gulf Region Ca. Ga, N. C. Ga. Ga. N. C. N. C, Ala. Ga. Ala. N. C. Ala, N. C. Albaba-Coosa Savannah Santee Apalachicola Alabama-Coosa Santee Congaree-Santee Alabama-Coosa Savannah Toabigbee Santee Tombigbee Neuse Etowah River Savannah River Catawba River Chattahoochee River Coosawattee River Catawba River Broad River Alabama River Savannah River Black Warrior River Catawba River Tombigbee River Neuse River 62 308 1,471 325 37 11, 100 9,517 "402 3,827 112 144 6,780 52 478 12,65o 11,5460 136 78 255 120 94 1,110 6,144 380 1,040 376 3,020 1,550 21,520 .6,144 18,600 1,790 15,300 76o 30.6 27.1 17.5 25.0 27.3 23.5 13.3 29.9 27.5 25.2 21.6 14.0 13.4 29.6 30.7 20.7 28.9 22.1 28.3 24.0 15.5 21.3 24.1 19.2 10.5 26.8 25.2 22.6 16.4 9.7 10.2 26.5 27.0 19.1 25o8 1707 22.2 19.8 21.8 14.5 21.7 19.7 26.6 22.3 16.6 14.9 21.8 13.6 16.7 23.2 12.3 14,5 11.2 14.3 21.2 C 0% 111,900 225o,00 405, 000 226:000 39,600 1,000,000 1,000,000 318,000 576,300 117,600 102,900 830,000 5500 268,000 1,100,000 1,280,000 116,000 78,700 102,000 142,l00 74,300 44O,000 1,001,000 187,000 428,900 203,100 674,000 560,000 682,500 1,140,000 743,400 636,000 1,068,000 323,000 C 1" Q TABLE B.1 (Page 5 of 17) Drainage Basin Average PM? Peak Project State River Basin Stream Area (in inches) Discharge (soemi.) Prec, Runoff (4f8) k' Gainsville Hartwell Holt Howards Mill Jim Woodruff John H. Bankhead Jones Bluff Laser Creek Lookout Shoals Lower Auchumpkee MeGuire Millers Ferry Mountain Island New Hope Oconee Oconee Okatibbee Oxford Perkins Randleman Reddies Rhodhiss Shearon Harris Sprewell Bluff Trotters Shoals Walter F. George Warrior West Point V. Kerr Scott Bedford Bristol Fall Creek Ithaca Jamesville Linden Ala. Ga. Ala. N. C. Fla. Ala. Ala. Ga. N. Co Ga. N. C. Ala. N. C. N. C. S. C. S. C. Miss. N. Co N. Co N. C. N. C. N. C. N. C. Ga. Ga. Ga. Ala. Ga. N. Co Ohio N. Yo N. Y. N. Y. Tombigbee Savannah Warrior Cape Fear Apalachicola Tombigbee Alabama Apalachicola Santee Apalachicola Santee Alabama Santee Cape Fear Savannah Savannah Pascagoula Santee Pee Dee Cape Fear Pee Dee Santee Cape Fear Apalachicola Savannah Apalachicola Tombigbee Apalachioola Pee Dee Cuyahoga Oswego Oswego Oswego Oswego Niagara Tombigbee River Savannah River Warrior River Deep River Apalachicola River Black Warrior River Alabama River Laser Creek Catawba River Flint River Catawba River Alabama River Catawba River New Hope River Keowee River Little River Okatibb"e Creek Catawba River Yadkin River Deep River Red1dies River Catawba River White Oak Creek Flint River Savannah River Chattahoochee River Black Warrior River Chattahoochee River Yadkin River Great Lakes Region Tinkers Creek Mud Creek Fall Creek Six Mile Creek Butternut Creek Little Tonawanda Creek 7,142 2,088 49232 626 17,150 3,900 16,300 1, Ll0 1,450 1,970 1,770 20,700 1,860 1,690 439 148 154 1,310 2,t473 169 94 1I 090 . 79 1,210 2,900 7,460 5,828 3,440 348 91 29 123 43 37 22 19.6 16.8 24.8 18.8 22.1 19.2 26.8 24.2 17.6 12.3 22.3 19.4 14o.2 11.6 24.6 20.7 23.7 19.8 14.7 12.1 22.0 19.4 26.5 23.5 26.6 .33.0 28.4 28.6- 26.0 28.0 24.8 25.8 24.0 16.6 19.5 21.9 25.6 28.6 29.9 17.1 26.9 26.0 30.8 .21.3 19.1 15.2 16.6 17.4 21.5 25.9 28.1 16.1 25.1 24.1 29,0 -J 702,400 875,000 650,000 305.000 1,133,800 670,300 664,000 303,600 492,000 355,600 750.000 844,000 362,000 511,000 450,000 245,000 87,"00 479,000 440,600 126,000 174, 200 379,000 163,500 318,000 800,000 843,000 5549000 440,000 318,000 6749,,090000 63,400 77,900 35,200 64,400 TABLE 8.1 (Page 6 of 17) Pr ject Mount Morris Onondago Oran Portageville Quanicassee Quanicassee Qouanicassee Standard Corners Alum Creek Barkley Barren Beaver Valley Beech Fork Big Blue Big Darby Big Pine Big Walnut Birch Bluestone Booneville Brookville Buckhorn Burnsvlfle Cae.ar Creek Cagles Mill Carr Fork Cave Run Center Hill Clarence J. Brown Claytor Clifty Creek Dale Hollow Deer Creek Delaware Dewey State N. Y. N. Y. N. Y. N. Y. Mich. Mich. Mich. N. Y. Ohio Ky. Ky. Pa. W. Va. Ind. Ohio Ind. Ind, we Va. W. Va. Ky. Ind. Ky. W. Va. Ohio Ind. Ky. Ky. Temn. Ohio Va. TTmendn. . Ohio Ohio Ky. River Basin Genesee River Lake Ontario Oswego Genesee Saginaw Bay Saginaw Bay Saginaw Bay Genesee Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio SStream Genesee River Onondigo Greek Limestone Creek Genesee River Saginaw River Tittabawassee River Quanicassee River Genesee River Ohio Region Alum Creek Cumberland River Barren River Ohio River Twelve Pole Creek Big Blue River Big Darby Creek Big Pine Creek Big Walnut Creek Birch River Nea River So. Fk. Kentucky River White.ater River M. Fk.Kentucky River Little Kanawha River Caesar Creek Mill Creek No; Fk. Kentucky River Licking River Caney Fork Buck Creek New River Clifty Creek Obey River Deer Creek Olentangy River Big Sandy River Ara ae Area. 1,077 68 47 983 6,260 2,o40 70 265 123 8,700 940 23,000 78 269 326 197 142 4,565 665 379 408 165 237 295 58 826 2,174 82 2,382 145 935 278 381 207 Basin Average 7P(r,eicn. incRhuenso)f f PreRcu off (cfsm 17.0 14.6 24.2 23.3 25.1 23.4 17.8 15.8 22.3 20.3 24.6 22.6 17.6 26.4 23.5 24.1 22.4 24-0 28.:4 23.2 24.2 23.8 24.8 24.1 24.6 27.4 22.8 22.-3 29.0 22.3 24.9 23.8 22.9 22.7 25.0 21.8 21.5 16.9 23.5 21.2 21.3 20.4 22.0 25.2 13.8 21.0 22.1 21.5 22.3 21.9 22.7 25.0 20.6 21.8 26.7 18.0 23.0 23.3 20.1 20.4 22.6 r Go PJ? Peak Discharge 385,000 61,800 80,790 359,000 440,000 270,000 46,000 189,900 3.10,000 1,000,000 531,000 1,500,000 84,000 161,000 294,000 174,000 144,ooo 102,000 410,000 425,000 272,000 239,000 138,800 230,200 159,000 132,500 510,000 696,0oo0 121,000 1,1091000 112,900 435to00 160,000 296,000 75,500 ( r TABLE B.1 (Page 6 of 17) Q TABLE B.1 (Page 7 of 17) River Basin Drainage stream Area f- '- Basin Average (in inches) Dillon Dyes Eagle Creek N. Br. Clarion East Fork East Lynn Pishtrap Grayson Green River Helm John W. Flannagan J. Percy Priest Kehoe Kinzua Lafayette Laurel Leading Creek Lincoln Logan Louisville Mansfield Martins Fork Meigs Meigs Mill Creek Mississinena Michael J. Kirwin Monroe Nuddy Creek Nolin N. Br. Kokosing N. Fk. Pound River Paint Creek Paintsville Panthers Creek Patoka R. D. Bailey Rough River Ohio Ohio Ky. Pa. Ohio w. Va. Ky. Ky. Ky. Ill. Va. Tenn. Ky. Pa. Ind. Ky. W. Va. Ill' Ohio Ill. Ind. Ky. Ohio Ohio Ohio Ind. Ohio Ind. Pa. Ky. Ohio Va. Ohio Ky. V. Va. Ind. W. Va. Ky. Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Licking River Dyes Fork Eagle Creek E. Br. Clarion River E. Fk. Little Miami River Twelve Pole Creek Levisa Fk. Sandy River Little Sandy River Green River Skillet Fk. Wabash River Pound River Stones River Tygarts Creek Allegheny River Wildcat Creek Laurel River Leading Creek Eabarras River Clear Creek Little Wabash River Raccoon Creek Cumberland River Meigs Creek Meige Creek Mill Creek Mississinewa River Mahoning River Salt Creek Muddy Creek Nolin River N. Br. Kokosing River N. Fk. Pound River Paint Creek Paint Creek, Panther Creek Patoka River Guyandotte River Rough River y Project State K PNF Peak PMF Peak Discharge (vcfa %0 t0 748 44 292 ?2 342 133 395 196 682 210 222 892 127 2,180 791 282 146 915 84 661 216 56 72 27 181 809 80 441 61 703 44 18 573 92 24 168 540 454 19.8 30.? 24.? 22.7 23.8 29.4 26.1 27.5 26.5 24.8 27.6 25.9 26.0 16.4 20.6 25.9 25.0 21.2 29.5 22.1 25.9 27.9 29.5 32.2 24.0 20,6 26.0 25.9 22.8 14.2 25.4 35.3 21.8 26.3 36.7 .25.6 23.1 27.6 16.3 27.8 22.1 18.9 21.2 26.5 23.2 24.7 231.9 22.6 24.9 18.8 23.4 12.8 18.5 20.7 22.5 19.0 27.0 19.9 23.0 22.7 26.6 29.3 21.4 18.4 20.1 25.4 19.6 13.2 22.6 32.2 18.8 23.8 33.9 23.5 20.3 25.1 thinnff k L 246,000 49,500 172,800 41,500 313,200 72,000 320,000 83,300 "109,000 152,800 235,800 430,000 105,900 115,000 182,000 120,000 131,000 502,000 78,000 310,000 175,800 61,800 72,100 45,500 92,000 196,000 51,800 366,000 59,300 158,000 50,000 51,200 305,000 ?7,500 59,800 292,000 349,000 358,000 TABLE B.1 (Page 8 of 17) River Basin Stroaa Drainage Area .~n4 Basin Average t(in inches) =1 I e a aw 0 t&*E Rowlesbsrg Salamonia Stonewall Jackson Sumersville Sutton Taylorville Tom Jenkins Union City Utica West Fork West Fk. Mill Ck. Whiteoak Wolf Creek Woodcock Yatesville Youghiogheny Zimmer, Vm. H. Bellefonte Browns Ferry Sequoyah Ames Byron Bear Creek Blue Earth Blue Earth Carlyle Clarence Cannon Clinton Coralville Duane Arnold Faradale Fondulac Friends Creek w. Va. Ind. W. Va. V. Va. W. Va. Ky. Ohio Pa. Ohio W. Va. Ohio Uhio Ky. Pa. Ky. Pa. Ohio Ala. Tenn. Tenn. Iowa Ill. Mo. Minn. Hinn. Ill, Mo. I Li. Iowa Iowa Ill. Ill. Il1. Ohio Ohio Ohio Ohlo Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Ohio Upper Upper Upper Upper Upper Upper Upper Upper Upper Upper Upper Upper Upper Miss. Miss. Miss. Miss. Miss. Miss. Miss. Miss. Miss. Miss. Miss. Miss. Miss. Cheat River Salamonla River West Fork River Gauley River Elk River Salt River Hocking River French Creek N. Fk. Licking River W. Fk. Little Kanawha Mill Creek Whiteoak Creek Cumberland River Woodcock Creek Blaine Creek Youghiogheny River Ohio River Tennessee Region Tennessee River Tennessee River Tennessee River Upper Mississippi Region Skunk River Rock River Bear Creek Minnesota River Blue Earth River Kaskaskia River Salt River Salt Creek Iowa River Cedar River Farm Creek Fondulac Creek Friends Creek 936 553 102 803 537 353 33 222 112 238 30 214 5789 46 208 "434. 70,800 23.340 27,130 20,650 314 8,000 28 11,250 3,550 2,680 2,318 296 3,084 6,250 26 5,4 133 21.2 21.3 24, N 23.8 20.4 24.8 26.? 20.*3 24.7 24.4 31.9 24.5 20.6 23.5 25.2 18.4 .19.0 22.2 21.1 20.4 22.2 25.8 17.8 22.1 21.8 30.0 21.6 20.0 20.9 22.6 25.4 21.3 18.4 29.0 26.2 14.2 10.9 18.4 14.8 19.2 15.8 21.8 15.7 20.8 14.4 24.0 21.4 27.8 22.1 19.9 21.6 C Project State PMF Peak Discharge Ut %0 331.000 201,000 85,500 "412,000 222,400 "426,000 "43000 87,500 73,700 156,4oo 81,600 134,000 9969000 37,700 l8, 000 151,000 2,150,000 1,160,000 1,200,000 1,205,000 87,200 308,000 38o000 283,&00 206,000 246,000 4?76,200 99,500 326,000 316,000 67,300 21,200 83,160 C C Q TABLE B.1 (Page 9 of 17) River Basin Stream . Drainage Area (sa.mi. ) Basin Average (in inches) Prec. Runoff Jefferson Lapa'ge Mankato Meramec Park Montevideo Monticello New Ulm New Ulm Oakley Prairie Island Red Rock Rend Saylorville Shelbyville Arkabutla Enid Grenada Sardis Union Vappapello Burlington Fox Hole Homoe Kindred Lake Ashtabula Orwell Bear Creek Big Bend Blue Springs Blue Stem Bowman-Haley Branched Oak Iowa Wisc. Minna Mo. Minn. Minn. Minn. Minn. Ill. Minn. Iowa Ill. Iowa Ill, Miss. Miss. Miss. Miss. Mo. Mot N. D. N. D. N. D. N. D.o N. D. Minn. Colo. S. D. Mo. Nebr. N. D. Nebr. Upper Miss. Upper Miss. Upper Miss.. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Upper Miss. Lower Lower Lower Lower Lower Lower Souris Souris Red of Red of Red of Red of Miss. Miss. Miss. Miss. Miss. Miss. North North North North Missouri Missouri Missouri Missouri Missouri Missouri Raccoon River Kickapoo River Minnesota River Meramec River Minnesota River Mississippi River Minnesota River Cottonwood River Sangamon River Mississippi River Des Moines River Big Muddy River .Des Moines River Kaskaskia River Lower Mississippi Region Coldwater River Yacona River Yalobusha River Tallahatchia River Bourbeuse River St. Francis River Souris-Red-Rainy Region Souris River Des Lacs. River Park River Sheyenne River Sheyenne River dtter Taln River Missouri Region Bear Creek Missouri River Blue Springs Creek Olive Br. Salt Creek Grand River Oak Creek Project State K PMF Peak Discharge (of s) "Ih 1,532 266 14,900 1,407 6,180 13,900 9,500 1,280 808 44,755 12,323 "488 5o823 1,030 1,000 560 1,320 '1, 545 771 1,310 9,490 939 229 3,020 983 1,820 2,6 5,840 33 17 446 89 21.7 22.8 13.9 22.9 15.2 14o4 21.2 23.5 12,1 2?.5 13.8 22.1 22.5 25.4 24.0 32.5 25.0 13.0 13.2 19.9 15.2 13.4 12.4 17.1 24.4 26.5 25.0 15.5 20.1 19.0 18.9 10.6 17.5 11.6 11.1 ]1.6 17.2 7.5 21.5 10.3 19.1 21o2 24.? 23P1 26.0 19.9 11.7 5.7 12.4 12.3 8,6 9.5 14.7 6.7 9.0 23.8 2J.7 12.7 16.8 267,300 128,000 329,000 552,000 263,0oo 365,000 263,000 128,000 178,000 910,000 613o000 308,200 277,800 142,000 430,000 204,900 310,800 2Q0,400 264,000 344,000 89,100 52,700 35,000 68.700 86,500 25,500 225,000 725,000 42,400 69,200 110,000 93,600 TABLE B.1 (Page 10 of 17) River Basin Stream Drinage Area • 1A Basin Average (in inches) -' =- & ** ,m-A.I B•raymar MO. Brookfield mo. Bull Hook Mont. Chatfield Colo. Cherry Creek Colo. Clinton Kans. Cold Brook S. Do Conestoga Nebr. Cottonwood Springs S. D. Dry Fork Ko. East Fork Mo. Fort Scott Kans. Fort Peck Mont. Fort Randall S. D. Fort St. Vrain Colo. Garrison No D, Gavins Point Nebr. Grove Kans. Harlan County Nebr. Ha=y S. Truman Mo. Hillsdale Kane. Holmes Nebr. Kanopolls Kane. LUnneus Mo. Long Branch Mo. Longview Mo. Melvern Kans. Mercer Mo. Milford Kanso Mill Lake Mo. Oahe So Do Olive Creek Nebr. Onag Kans. Pattonsburg Mo. Pawnee Nebr. Perry Kano, Pioneer Colo. Pause do Terre Mo. Missouri Missouri Missouri Missouri Missouri Missouri Missouri Hissouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Shoal Creek West Yellow Creek Bull Hook Creek South Platte River Cherry Creek Wakarusa River Cold Brook Holmes Creek Cheyenne River Fishing River Fishing River Marmaton River Missouri River Missouri River South Platte River Missouri River Missouri River Soldier Creek Republican River Osage River Big Bull Creek Antelope Creek smoky Hill River. Locust River So Fk. Little Chariton Blue River Marias des Cygnes River Weldon River Republican River Mill Creek Missouri River Olive Br. Salt Creek Vermillion Creek Grand River Pawnee Br. Salt Creek Delawre River Republican River Poaue do Terre River 390 140 54 3,018 .385 367 15 26 30.2 19 279 57,725 14:150 4,700 123,215 16,000 259 7,141 7,856 144 5,4 2,560 546 109 50 349 "427 3,620 9.5 62,550 8.2 301 2,232 36 1,U17 918 611 24.7 22.2 24.5 22.0 10.8 13.2 2.0 2309 9.5 23.6 22.4 6.4 25.2 21.9 18.7 11.1 26.1 22.5 25.7 24ol 23.8 22.7 3.2 3.7, 2.7 3.3 23.8 22.7 7.6 2.8 13.1 25.4 24.3 27.1 23.8 6.9 3.6 2397 21.2 •4.5 21.9 26.2 23.4 23.1 22.1 21.0 17.8 8.8 5.0 27.7 26.4 6.5 26.0 22o7 23.5 22.2 18.8 16.3 23.5 2O02 21.5 18.4 15.0 8.3 23.9 21.6 . Project State PM? Peak Discharge U' 173,800 64,5S00 26,2oo .584,500 350,000 153,500 95,700 52,000 74,700 19,460, 62,700 198.000 360,000 80,000 500,000 1,026,000 642,000 79,800 "485, 000 1,060,000 190,500 41,600 456,300 242,300 66,500 74,800 182,000 274,000 757,400 13,000 946,000 36,650 251,000 400,100 59,000 387,400 390,000 362,000 C r Q TABLE B.1 (Page 11 of 17) River Basin Stroam Drainage Area t. m,4. Basin Average fin Inches)... Pomona Rathbun Smithville Stagecoach Stockton Thomas Hill Tomahawk Trenton Tuttle Creek Twin Lakes Wagon Train Wilson Wolf-Coffee Yankee Hill Arcadia Bayou Bodcau Beaver Bell Foley Big Hill Big Pine Birch Blakely Mountain Blue Mountain Boswell Broken Bow Bull Shoals Candy Canton Cedar Point Clayton Cleariater Conchas Cooper Copan Council Grove County Line Kans. Iowa Mo. Nebr. Mo. Mo. Kane. Mo. Kans* Nebr. Nebr. Kans. Kans. Nebr. Okla. La. Ark. Ark. Kans. Tex. Okla. Ark. Ark. Okla, Okla. Ark. Okla, Okla. Kans. Okla. Mo. N. Mex. Tex. Okla, Kan.s Moo Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Missouri Arkansas Red White Arkansas Arkansas Red Arkansas Red Arkansas Red Red White. Arkansas Arkansas Arkansas Red White .Arkansas Red Arkansas Arkansas. White 110 Mile Creek Chariton River Little Platte River Hickman Br. Salt Creek Sac River Little Chariton River Tomahawk Creek Thompson River Big Blue River S. Br. Middle Creek Hickman Br. Salt Creek Saline River Blue River Cardwell Br. Salt Creek Arkansas-White-Red Region Deev Fork River Bayou Bodcau White River Strawberry River Big Hill Creek Big Pine Creek Birch Creek Ouachita River Petit Jean River Boggy Creek Mountain Fork White River Candy Creek North Canadian River Cedar Creek Jackfort Creek Black River South Canadian River South Sulphur River Little Caney River Grand River James River Project State K Discharge refs)~ Ut 322 549 213 9e7 1,160 147 24 1,079 9,556 11 16 1,917 45 8.,4 105 656 1,186 78 37 95 66 1,105 500 2,273 7.54 6,036 43 7,600 119 275. 898 7.409 476 505 246 153 26.2 23.7 23.9 26.o 19.7 25.0 26.4 22.6 14.5 25.9 25.2 20.2 26.1 26.0 28.5 35.3 24.3 26.4 25.4 31.3 29.0 21.5 21.8 27.6 32.5 15.2 29.3 12.4 25.4 31.3 16.0 4,8 30.9 26.2 25.5 27.2 25.2 21.1 20.2 22.7 18.9 23.,0 24.8 20.1 8.1 22.6. 21.9 10.8 24.5 22.7 24.9 33.6 22.4 23.5 23.6 29.3 26.0 19.6 18.2 29,4 1.0 27.5 4.1 22.6 29.3 13.8 3.0 29.2 21.1 22U7 25.3 186,000 188.000 185,000 50,500 4?0,000 ?79000 26,800 342,400 798,000 56,000 53,500 252,000 58,000 58,400 144,000 168,?00 480,000 57,000 47,500 86,000 91,000 418,000 258'000 405,000 569,000 ?65,000 67,500 371,000 208,000 240,000 432,000 582,000 194,400 169,000 250,000 133,000 A Pver 0 It Rnf TABLE B.1 (Page 12 of 17) Drainage Basin Average PM? Peak Project State River Basin Stream Area (in inches) Discharge (S,.Ml. Prec, Lng.of (cfs)_ DeGray Denison DeQueen Dierks Douglas El Dorado Elk City Efaula Fall River Ferrells Bridge Fort Gibson Fort Supply Gillhaa Great Salt Plains Greers Ferry Heyburn Hugo Hulah John Martin John Redmond Kaw Keystone Lake Kemp Lukfata Marion Milluood Narrows Neodesha Nimrod Norfolk Oologah Optima Pat Mayse Pine Creek Robert S. Kerr Sand Shidler Skiatook Lable Rock Ark. Okla. Ark. Ark. Kans. Kans. Kans. Okla. Kans. Tex. Okla. Okla. Ark. Okla. Ark. Okla. Okla. Okla. Colo. Kans. Okla. Okla. Tex. Okla. Kans. Ark. Ark. Kans. Ark. Ark. Okla, Okla. Tex. Okla. Okla, Okla. Okla. Okla. Mo. Red Rod Red Red Arkansas Arkansas Arkansas Arkansas Arkansas Red Arkansas Arkansas Red Arkansas Red Arkansas Red Arkansas Arkansas Arkansas Arkansas Arkansas Red Red Arkansas Red Red Arkansas Arkansas White Arkansas Arkansas Red Red Arkansas Arkansas Arkansas Arkansas White Caddo River Red River Rolling Fork Saline River Little Walnut Creek Walnut River Elk River Canadian River Fall River Cypress Creek Grand River Wolf Greek Cossatot River Salt Fk. Arkansas River Little Red River Polecat Creek Kianichi River Caney River Arkansas River Grand River Arkansas River Arkansas River Wichita River Glover Creek Cottonwood River Little River Little Missouri River Verdigris River Fourche La Fave River North Fork White River Verdigris River North Canadian River Sanders Creek Little River Arkansas River Sand Creek Salt Creek Hominy Creek White River C U, 453 33,783 169 113 238 234 634 8,405 556 880 9,477 271 3,200 1,146 123 1,709 732 18,130 3,015 7,250 22,351 2,086 291 200 4,144 239 1,160 68o 1,#765 4,339 2,341 175 635 64.386 137 99 354 4,020 28.4 12.9 35.5 36.2 26.7 26.8 23.0 15.9 27.1 31.1 16.2 20.5 34.,6 16.? 17.9 26-3 Z7.1 16.5 7.4 18.2 14.5 12.9 23.7 34.6 24.8 28.4 25.0 18.? 20.2 15.7 17.8 13.8 31.8 32.8 10.0 31.3 27.3 27..8 18.3 26.0 6.5 32.5 33.2 22.9 22.8 20.3 10.9 23.0 28.1 12.6 15.7 31.5 9.3 17.5 24.2 25.8 13.5 2.0 15.6 9.9 6.7 19.2 31.5 21.9 25.3 23.0 16.6 17.2 12.8 13.9 9.0 29.4 29.8 5.8 28.3 24.0 23.8 15.4 397,000 1,830,000 254,000 202,000 156,000 .119966,, o0o0o0 319,000 700,000 "442.000 367,000 865,000 54?7000 355,000 412,000 630,000 151,000 339,000 239,000 630.00O 638,000 774.000 1,035,000 566,000 349,000 160,000 "442,000 194,000 287.000 228,000 372,000 451,000 386,000 150,000 523,000 1,884,000 154,000 104,100 147,800 657,000 C r Q Project Tenkiller Ferry Texarkana Toronto Towanda Trinidad Tuskahoma Wallace Lake Vaurika Webbers Falls Vister Addicks Aquilla Aubrey Bardwell Barker Belton Benbrook Big Sandy Blieders Creek Droimwood .Canyon Lake Carl L. Estes Coleman Comanche Peak Ferguson Gonzales Grapevine Horde Creek Lake Fork Lakeview Laneport Lavon Lewisville Millioan Navarro Minle Navasota State Okla. Tex. Kans. Kans. Colo. Okla. La. Okla. Okla. Okla. Tex. Tex* Tex. Tex.. Tex. Tex, Tex. Tex. Tex. Tex. Tex. Tex. Tex. Tex. Tex. Tex. Tex. Tex. Teax Tax, Tex. Tex. Tex. Teax Tex* Tex. River Basin Arkansas Red Arkansas Arkansas Arkansas Red Red Red Arkansas Arkansas .San Jacinto Brazos Trinity Trinity San Jacinto Bre•zos Trinity Sabine Guadalupe Colorado Guadalupe Sabine Colorado Brazos Brazos Guadalupe Trinity Colorado Sabine Trinity Brazos Trinity Trinity Brazos Trinity Brazos Stream Drainage Area Illinois River Sulphur River Verdigris River Whitewater River Purgatorie River Kiamichi River Cypress Bayou Beaver Creek Arkansas River Poteau River Texas-Gulf Region South Mayde Creek Aquilla Creek Elm Fork Trinity River Waxahachie Creek Buffalo Bayou Leon River Clear Fork Trinity River Big Sandy Creek Blieders Creek Pecan Bayou Guadalupe River Sabine River Colorado River Squaw Creek Navasota River San Marcos River Denton Creek Horde Creek Lake Fork Creek Mountain Creek San Gatriel Pivor Eset Fork, Trinity River Elm Fork, Trinity River Navasota River Riohland Creek Navasota River 1,6 10 3,400 730 422 671 347 260 562 "W8,127 99.3 129 2914 692 178 150 3,560 429 196 15 1,544 1,432 1,146 287 64 1,782 1,344 695 48 507 232 /09 770 3,660 2,120 320 1,241 Basin Average In Rnofhes) Pree. Runnff 20.e4 26.6 23.9 24.3 10*0 16.5 2368..54 10.7 25.9 29.7 31.2 28.5 31.1 29.4 29.4 28.2 36.2 43.8 27.8 24o5 34.5 30.9 39.1 26.0 24.9 26.5 28.9 33.8 31.6 28.9 26,2 23.2 25.5 33.6 27.2 17.6 20.1 21.1 20.5 4.5 14.6 35.6 22.2 6.1 23.2 27.9 28.6 26.0 28.3 27.9 20.6 21.1 32.2 34.6 21.0 16.9 30.4 24•. 1 34.1 22.4 15.4 21.5 23.4 29.7 28.8 23.7 23.o4 20.5 22.4 30.5 24.2 TABLE B.1 (Page 13 of 17) K Ut PMF Peak Discharge 406,000 451,000 "400,000 198,000 296,000 188,g400 197,000 354,000 1,518,000 339,000 68,670 283,800 445,300 163,500 55,900 608,400 290,100 125,200 70,300 676,200 687,000 277,000 267,800 149,000 355,800 633,900 319,400 .92,400 247,600 335,000 521,000 430,?00 632,200 393,v40o 280,500 327,400 TABLE B.1 (Page 14 of 17) -Project *N orth Fork Pecan Bayou Proctor Roanoke -Rockland Sam Raybrn San Angelo Somerville South Fork Stillhouse Hollow Tennessee Colony Town Bluff Waco Lake Whitney Abiquiu Alamogordo Cochita Jemez Canyon Los Esteroa Two Rivers Alamo Mcoicken Whitlow Ranch Painted Rock Little Dell Mathews Canyon Pine Canyon Applegate Blue River State River Basin' Tex. Tex. Te,:. Tex. Tex. Tex. Tex. Tex. Tex. Tex, Tea. Tex, Tex. Tex. No N. N. N. N. N. Brazos Colorado Brazoa Trinity Neches Neches -Colorado Brazos Brazos Brazos Trinity Neches Brazoa Brazos Rio Grande Rio Grande Rio Graude Rio Grande Rio Grande Rio Grande me H. MI H. H. H. Ariz. Ariz. Ariz. Ariz. Utah N.y. No. Colorado Colorado Colorado Colorado Jordon (Great) Great Basin Great Basin Oreg. Rogue Ore&. Columbia Stream Drainage Area f,.4 N. Fk. San Gabriel River .Pecan Bayou Leon River Denton Creek Neches River Angelina River North Concho River. Yogua Creek S. Fk. San Gabriel River Lam pasas River Trinity River Neches River B•sque River Brazos River Rio Grande. Region Rio Grande Pecos River Rio Grande Jemez Canycn Peccs River Rio Hondo Lower Colorado Region Bill Williams River Aqua Fria River Queen Creek Gila River Great Basin Region Dell Creek Mathews Canyon Pine Canyon Columbia-North Pacific Region Applegate River S. Fk. McKenzie River Basin Average (in inches) D~n D..n 246 316 1,265 604 39557 3,449 1,511 1,006 1 123 1,318 12,687 7,v73 1,670 17,656 3,159 3,917 4,065 1,034 2,434 1,027 4,770 247 143 50,800 16 34 45 223 88 31.7 30.7 27.0 28.9 21.0 23.7 21.2 22.0 32.6 27.? 25.1 18.9 25.7 15.7 4.6 9.2 12.2 26.6 23.8 21.4 17.2 20.6 13.1 13.6 27.4 22.5 20.4, 15.7 20.6 7.7 8.2 1.9 1.9 3.7 4.7 12.0 3.5 3.3 11.5 9.7 7.7 2.8 8.1 6.0 6.6 7.4 8.2 6.6 28.9 22.7 ( P1F Peak Discharge /'-..'_ '0 Ch 265,800 236,200 459,200 313.600 150,400 395,600 614,5c0 4 15,700 145,300 686s400 575o600 326,000 •622,900 700,000 130,000 277,000 320,000 .220.000 352,000 281,400 5B0,000 52,000 230,000 620,000 23,000 "35,000 38.000 C 99, 500 .39.500 tC 0 L&Wý* LIVA& LCIRI Q TABLE B.1 (Page 15 of 17) sin Stream Lrainaee Area 1 4 K Basin Average P1• Peak ( in inches) Discharge Prec,_ -noff (efa) Bonneville Caseadia Chief Joseph Cottage Grove Cougar Detroit Dorena Dworshak Elk Creek Fall Creek Fern Ridge Poster Green Peter Gate Creek Hills Creek Holley 'Howard A. Hanson lee Harbor John Day Libby Little Goose Lookout Point Lost Fork Lower Granite Lower Monumental Lucky Peak MPeNary Mud Mountain Ririe The Dallee Wynoochee Zintel Bear Big Dry Creek Black Butte Brea Oreg. Oreg. Wash. Oreg. Oreg. Oreg. Oreg. Ida. Oreg. Oreg. Oreg. Oreg. Oreg. Oreg. Oreg. Oreg. Wash. Wash. Ore. Mont. Wash. Oreg. Oreg. Wash. Wash, Ida, Oreg. Wash, Ida. Oreg. Wash. Wash. Cal. Cal. Cal. Cal. Columbia Columbia Columbia Columbia Columbia Columbia Columbia Columbia Rogue Columbia Columbia Columbia Columbia Columbia Columbia Columbia Green Columbia Columbia Columbia Columbia Columbia Rogue Columbia Columbia Columbia Columbia Puyallup Columbia Columbia Chechalis Columbia San Joaquin San Joaquin Sacranento Santa Ana Columbia River 240,000 South Santian River 179 Columbia River 7.5,000 Coast Fk. Willamette River 104 S. Fk. McKenzie River 208 North Santiam River 438 Row River 26. N. Fk. Clearwater River 2,440 Elk Creek 132 Willamette River 184 Long Tom River 252 South Santiam River 4144 Middle Santiam River 27? Gate Ck. McKenzie River 50 Middle Fk. Willamette River 38q Calapooia River 105 Green River 221ý Snake River 109,000 Columbia River 226,00O Kootenai River 9,070 Snake River 10i4900 Middle Fk. Vilaette Aiver 991 Lost Pk. Rogue River 6,7' Snake River 101,,4O0 Snake River 108,500 Boise River 2,650. Columbia River 214,000 White River '400 Willow Ck. Snake River 620 Columbia River 237,000 Wynoochee River 41 Zintel Canyon Snake River IQ California Region Bear Creek Big Dry Creek Stony Creek Brea Creek 72 ]3.b 91 19.0 741 19.? 23 10.6 K Project State River Bas 22.1 42.2 29.0 29.7 34.2 36.0 34.6 70.5 32.6 33.8 20.3 40.8 41.3 146..3 31.0 35.8 26.8 13.9 2191 3' 5 14,6 10.8 22.7 14•? 1400 32.5 23.0 31.9 21,14 21.1 69.9 7.8 13.6 13.8 12.3 6.6 2,720,000 1159,000 1,550,000 45,000 98,000 203,000 131,600 280,000 63,500 100,000 148,600 260,000 160,000 37,000 197,000 59,000 164,000 95,%000 2,650,000 282,000 850,0C0 360,000 169,0Cc 850.000 850,000 123,000 2,610,000 !86,000 4?,000 2,660,000 52,500 "4O, 500 30,0400 17,000 1 54,000 37000 = a 9 TABLE B.1 (Page 16 of 17) River Basin Stream Drainage Area (sq.mi.) Basin Average (in inches) Prec. Runoff Buchanan Burns Butler Valley Carbon Canyon Cherry Valley Comanche Coyote Valley Dry Creek Farmington Folsom Fullerton Hansen Hidden Lake Isabella Knights Valley Lakeport Lopes Mariposa Kartis Creek Marysville Mojave River N•ew Dullards Bar New Exchequer New Hogm New Melones Oroville Owens Pine Flat Prado San Antonio Santa Fe Sepulveda Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. Cal. San Joaquin San Joaquin had Santa Ana San Joaquin San Joaquin Russian Russian San Joaquin Sacramento Santa Ana Los Angeles San Joaquin San Joaquin Russian Sacramento Los Angeles San Joaquin Truckee Sacramento Mojave Sacramento San Joaquin San Joaquin San Joaquin Sacramento San Joaquin San Joaquin Santa Ana Santa Ana San Gabriel Los Angeles Chowchilla River Burns Creek Mad River Santa Am River Cherry Creek Mokeluane River Fast Fk. Russian River Dry Creek Little John Creek American River Fullerton Creek Tujunga Wash Fresno River Kern River Franz-Maacama Creek Scotts Creek Pacoima Creek Mariposa Creek Martis Creek Yuba River Mojave River North Yuba River Merced River Calaveras River Stanislaus River Feather River Owens Creek Kings River Santa Ama River San Antonio Creek San Gabriel River Los Angeles River 235 74 352 19 117 618' 105 82 212 1,875 5.0 147 234 2,073 59 52 34 108 39 1,324 215 L489 1,031 362 897 2,600 26 1,542 2,233 27 236 152 26.0 20.1 17.*4 10.6 35.2 10.4 10.3 24.3 23.1 25.0 19.9 22.9 21.3 15.6 11.3 10.9 21.2 17.5 9.0 6.8 9.8 29.9 18.4 27.1 6.5 31.6 28.9 30.9 24.0 20.8 18.6 13.0 26.5 12.7 38.9 27.0 40.4 30.4 38.9 25.7 27.1 15.9 18.3 25.8 16.3 23.3 22.8 14.4 9.2 28.5 14.4 26.3 13.0 13.0 35.*5 15.0 r Project State PM? Peak Discharge (ofe) I.A 00 127,000 26,800 137,000 56.000 60,000 261,000 57,000 "45,000 56,000 615,000 16,000 130,000 114,000 235,000 "44,300 36,100 32,000 "43,000 12,400 460,00oc 186,000 226,ooo 396,000 132,000 355,000 720,000 11.400 437,000 700,000 60,000 194,000 220,000 C r Q River Basin Stream Drain..te Area (sa.mi.) Basin Average (in Inches) Pree. Runoff Success Terminus Tuolumne Whittier Narrows Cale Cal$ cal. Cal. San Joaquin San Joaquin San Joaquin San Gabriel Tule River Kaweah River Tuolumne River San Gabriel River TABLE B.1 (Page 17 of 17) K Pro.iect '0 '0 State F Peak Discharve (ofa) 383 560 it 5133 "40.1 25.1 1.•, i2.6 2468 20. ? 13.7 200,000 290,000 602,000 305,000 APPENDIX C SIMPLIFIED METHODS OF ESTIMATING PROBABLE MAXIMUM SURGES TABLE OF CONTENTS Page C.A INTRODUCTION ...... .................................... 1.59-42 C.2 SCOPE . ............................................. 1.59-42 C.3 PROBABLE MAXIMUM SURGELEVELS FROM HURRICANES ............... 1.59-42 C.3.1 Methods Used ............. ........................ 1.59-42 C.3'2 Use of Data in Estimating PMS ............ 1.59-42 C.3.3 Wind-Wave Effects ...................................... 1.59-43 C.4 LIMITATIONS . .......................................... 1.59-43 REFERENCES . ............................................. 1.59-43 FIG URES .. .............................................. 1.59-44 TABLES . ............................................... 1.59.46 FIGURES Figure C.1-Probable Maximum Surge Estimates, Gulf Coast .................... 1.59-44 C.2-Probable Maximum Surge Estimates, Atlantic Coast .................. 1.59-45 TABLES Table C. I-Probable Maximum Surge Data .............................. 1.59-46 C. 2-Probable Maximum Hurricane, Surge, and Water Level-Port Isabel .......... 1.59.47 C. 3-Probable Maximum Hurricane, Surge, and Water Level-Freeport ............ 1.59.48 C. 4-Probable Maximum Hurricane, Surge, and Water Level-Eugene Island ........ 1.59.49 C. 5-Probable Maximum Hurricane, Surge, and Water Level-Isle Dernieres ......... 1.59-50 C. 6-Probable Maximum Hurricane, Surge, and Water Level-Biloxi .... ........... 1.59-51 C. 7-Probable Maximum Hurricane, Surge, and Water Level-Santa Rosa Island ..... .1.59-52 C. 8-Probable Maximum Hurricane, Surge, and Water Level-Pitts Creek ........... 1.59-53 C. 9-Probable Maximum Hurricane, Surge, and Water Level-Naples .... ......... 1.59-54 C.-10-Probable Maximum Hurricane, Surge, and Water Level-Miami .............. 1.59-55 C.A I-Probable Maximum Hurricane, Surge, and Water Level-Jacksonville ........... 1.59-56 C. 12-Probable Maximum Hurricane, Surge, and Water Level-Jeckyll Island ........ 1.59-57 C.13-Probable Maximum Hurricane, Surge, and Water Level-Folly Island ........... 1.59-58 C.14-Probable Maximum Hurricane, Surge, and Water Level-Raleigh Bay .......... 1.59-59 C.15-Probable Maximum Hurricane, Surge, and Water Level-Ocean City ........... 1.59-60 C.16-Probable Maximum Hurricane, Surge, and Water Level-Atlantic City .......... 1.59-61 C.17-Probable Maximum Hurricane, Surge, and Water Level-Long Island ........... 1.59-62 C.18-Probable Maximum Hurricane, Surge, and Water Level-Watch Hill Point ....... 1.59-63 C.19-Probable Maximum Hurricane, Surge, and Water Level-Hampton Beach ...... .. 1.59-64 C.20-Probable Maximum Hurricane, Surge, and Water Level-Great Spruce Island . . . . 1.59-65 C.21-Ocean-Bed Profiles ........... . .... ............................ 1.59-66 1.59-41 C.1 INTRODUCTION This appendix presents timesaving methods of es timating the maximum stiilwater level of the probable maximum surge (PMS) from hurricanes at open coast sites on the Atlantic Ocean and Gulf of Mexico. Use of the methods herein will reduce both the time necessary for applicants to prepare license applica tions and the NRC staff's review effort. The procedures are based on PMS values deter mined by the NRC staff and its consultants and by applicants for licenses that have been reviewed and accepted by the staff. The information in this appen dix was developed from a study made by Nunn, Snyder, and Associates, through a contract with NRC (Ref. 1). The PMS data are shown in Tables C.I through C.21 and on maps of the Atlantic and Gulf Coasts (Figures C.I and C.2). Suggestions for interpolating between these values are included. Limitations on the use of these generalized methods of estimating PMS are identified in Section C.4. These limitations should be considered in detail in assessing the applicability of the methods at specific sites. Applicants for licenses for nuclear facilities at sites on the open coast of the Atlantic Ocean or the Gulf of Mexico have the option of-using these methods in lieu of more precise but laborious methods contained in Appendix A. The results of application of the methods in this appendix will in many cases be ac cepted by the NRC staff with no further verification. C.2 SCOPE The data and procedures in this appendix apply only to open-coast areas of the Gulf of Mexico and the Atlantic Ocean. Future studies are planned to determine the ap plicability of similar generalized methods and to develop such methods, if feasible, for other areas. These studies, to be included in similar appendices, are anticipated for the Great Lakes and the Pacific Coast, including Hawaii and Alaska. C.3 PROBABLE MAXIMUM SURGE LEVELS FROM HURRICANES The data presented in this appendix consist of all determinations of hurricane-induced PMS peak levels at open-coast locations computed by the NRC staff or their consultants, or by applicants and ac cepted by the staff. The data are shown in Tables C. 1 through C.21 and on Figures C.I and C.2. All repre sent stillwater levels for open-coast conditions. SAll PMS determinations in Table C.1 were made by NRC consultants for this study (Ref. 1) or for earlier studies except Pass Christian, Brunswick, Chesapeake. Bay Entrance, Forked River-Oyster .Creek, Millstone, Pilgrim, and Hampton Beach. The computations by the consultants were made using the NRC surge computer program, which is adapted from References 2, 3, and 4. Probable max imum hurricane data were taken from Reference 5. Ocean bottom topography for the computations was obtained from the most detailed available Nautical Charts published by the National Ocean Survey, NOAA. The traverse line used for the probable max imum hurricane surge estimate was drawn from the selected coastal point to the edge of the continental shelf or to an ocean depth of 600 feet. MLW and was one hurricane radius to the right of the storm track. The radius to maximum winds was oriented at an angle of 1150 from the storm track. The traverse was oriented perpendicular to the ocean-bed contours near shore. The ocean-bed profile along the traverse line was determined by roughly averaging the topography of cross sections perpendicular to the traverse line and extending a maximum of 5 nautical miles to either side. The 10-mile-wide cross sections were narrowed uniformly to zero at the selected site starting 10 nautical miles from shore. It was assumed that the peak of the PMS coincided with the 10% ex ceedance high spring tide' plus initial rise.' Slightly different procedures were used for postulating the traverse lines and profiles for the Crystal River and St. Lucie determinations. In each case the maximum water level resulted from use of the high translation speed for the hur ricane in combination with the large radius to max imum wind as defined in Reference 5. Detailed data for the computed PMS values are shown in Tables C.1 through C.20. Ocean-bed profile data for Pass Christian, Crystal River, St. Lucie, Chesapeake Bay Mouth, and Hampton Beach are shown in Table C.21. The water levels resulting from these computations are open-coast stillwater levels upon which waves and wave runup should be superimposed. C.3.2 Use of Data In Estimating PMS Estimates of the PMS stillwater level at open-coast sites other than those shown in Tables C.1 through C.21 and on Figures C.1 and C.2 may be obtained as follows: 'The 10% exceedance high spring tide is the predicted maximum monthly astronomical tide exceeded by 10%.of the predicted max imum monthly astronomical tides over a 21-year period. 'Initial rise (also called forerunner or sea level anomaly) is an anomalous departure of the tide level from the predicted axtronomical tide. 1.59-42 C.3.1 Methods Used I I I. Using topographic maps or maps showing soundings, such as the Nautical Charts, determine an ocean bed profile to a depth of 600 ft MLW, using the methods outlined above. Compare this profile with the profiles of the locations shown in Tables C.2 through C.21. With particular emphasis on shallow water depths, select the location or locations in the general area with the most similar profiles. An es timate of the wind setup may be interpolated from the wind setup data for these locations. 2. Pressure setup may be interpolated between locations on either side of the site. 3. Initial rise, as shown in Table C.1, may be inter polated between locations on either side of the site. 4. The 10% exceedance high spring tide may be computed from predicted tide levels in Reference 6; it may be obtained from the Coastal Engineering Research Center, U.S. Army Corps of Engineers, Ft. Belvoir, Va.; it may be interpolated, using the tide relations in Reference 6; or it may be obtained from Appendix A. 5. An estimate of the PMS open-coast stillwater level at the desired site will be the sum of the values from Steps I through 4, above. C.3.3 Wind-Wave Effects Coincident wave heights and wave runup should be computed and superimposed on the PMS stillwater level obtained by the foregoing procedures. Accep table methods are given in Reference 2 and in Appen dix A. CA LIMITATIONS I. The NRC staff will continue to accept for review detailed PMS analyses that result in less con servative estimates. In addition, previously reviewed and approved detailed PMS analyses at specific sites will continue to be acceptable even though the data and procedures in this appendix result in more con servative estimates. 2. The PMS estimates obtained as outlined in Sec tion C.3.2 arc maximum stillwater levels. Coincident wind-wave effects should be added. 3. The PMS estimates obtained from the methods in Section C.3.2 are valid only for open-coast sites, i.e., at the point at which the surge mikes initial land fall. If the site of interest has appreciably different off-shore bathymetry, or if the coastal geometry dif fers or is complex, such as for sites on an estuary, ad jacent to an inlet, inshore of barrier islands, etc., detailed studies of the effect of such local conditions should be made. Reference 2 provides guidance on such studies. REFERENCES I. Nunn, Snyder, and Associates, "Probable Max imum Flood and Hurricane Surge Estimates," un published report to NRC, June 13, 1975 (available in the public document room). 2. U. S. Army Coastal Engineering Research Center, "Shore Protection Manual," Second Edition, 1975. 3. B. R. Bodine, "Storm Surge on the Open Coast: Fundamental and Simplified Prediction," Technical Memorandum No. 35, U.S. Army Coastal Engineer ing Research Center, 1971. 4. George Pararas-Caryannis, "Verification Study of a Bathystrophic Storm Surge Model," Technical Memorandum No. 50, U.S. Army Coastal Engineer ing Research Center, May 1975. 5. U. S. Weather Bureau (now U.S. Weather Service, NOAA), "Meteorological Characteristics of the Probable Maximum Hurricane, Atlantic and Gulf Coasts of the United States," Hurricane Research Interim Report, HUR 7-97 and HUR 7-97A, 1968. 6. U. S. Department of Commerce, NOAA, "Tide Tables," annual publications. 1.59-43 96° 960 940 329 310 200 27r 260 250 240 93? 92r 910 90p 89W 88e 870 860 860 840 8r3 820 810 FIGURE Ci PROBABLE MAXIMUM SURGE ESTIMATES - GULF COAST C 34° 340 C f( 830 820 810 800 790 780 770 760 750 8o 85o- 840 830 820 81 800 70r 0 780 770 760 750 740 730 720 71' FIGURE C.2 PROBABLE MAXIMUM SURGE ESTIMATES - ATLANTIC COAST 1.59-45 TABLE C. 1 PROBABLE MPAXfl04 SURGE DATA (W)CATIONS INDICATED ON FIGURES C.1 and C.2) DISTANCE FR0OMSH ORELINE, NAUTICAL MILES, FOR SELECTED WATER DEPTHS, FEET HIM OPEN-COAST LOCATION AND TRAVESE PORT ISABEL FREEPORT EUGENE ISLAND ISLE DERNIERE PASS CHRISTIAN (a) BILOXI SANTA ROSA ISLAND PITTS CREEK CRYSTAL RIVER (a) NAPLES MIAMI ST. LUCIEW() JACKSONVILLE JEKYLL ISLAND FOLLY ISLAND BRUNSWICK RALEIGH CHESAPEAKE BAY ENTRANCE (a) OCEAN CITY ATLANTIC CITY FORKED RIVER OYSTER CREEK LONG ISLAND MILLSTONE WATCH HILL POINT PILGRIM HAMPTON EAM (a) GREAT SPRUCE ISLAND I N TRAVERSE AZIMUTH DEG. - HIN. DEPTH, FEET, ALONG TRAVERSE FROM OPEN COAST SHORE LINE 10 20 50 100 200 600 DISTANCE, NAUTICAL MILES, TO DEPTH INDICATED 1 1 ii 86 152 192 165 160 183 205 248 100 90 108 150 135 30 00 30 00 00 00 00 00 00 00 00 00 00 110 00 146 00 166 166 115 148 00 00 00 no 0.23 0.49 1.94 11.10 33.10 44.0 0.20 0.55 5.50 24.0 55.5 70.9 2.00 20.00 30.00 44.1 60.0 90.0 0.62 1.75 11.90 30.4 45.3 58.5 77.0 3.40 11.20 30.00 50.1 69.2 78.0 0.09 0.18 0.48 11.9 20.9 45.0 8.84 9.23 24.30 69.4 107.0 132.0 2.31 31.40 127.0 0.17 0.79 15.70 45.6 85.8 145.0 0.17 0.94 2.01 2.2 2.7 3.9 0.10 18.7 0.10 0.20 2.58 30.0 55.0 62.5 2.60 4.00 15.60 39.6 64.3 72.6 0.19 2.17 12.00 32.8 47.0 57.6 0.12 0.30 1.75 12.0 25.4 35.2 62.0 0.12 0.26 3.67 17.8 45.0 59.0 0.20 0.85 5.00 23.1 58.4 70.0 0.09 0.07 0.22 0.04 0.18 1.35 0.14 0.64 0.31 0.71 0.08 0.20 4.8 1.6 2.0 1.1 27.2 34.3 7.2 6.1 68.4 "84.0 40.0 1 7R .0 1. 6 1 PROBABLE MAXIMUM SURGE AT OPEN COAST SHORE LINB WIND SETUP, FT. PRESSURE SETUP, FT. 10.07 15.99 29.74 18.61 28.87 27.77 .9.12 24.67 26.55 18.47 2.51 8.25 16.46 20.63 17.15 12.94 8.84 17.30(b) 14.30 15.32 18.08(b) 8.73 12.41 10.01 4.25 9.73 3.57 2.89 3.29 3.29 2.88 2.98 3.25 2.31 2.65 2.90 3.90 3.80 3.23 3.34 3.23 2.20 3.09 (b) 2.83 2.57 (b) 2.46 2.20 2.42 2.23 1.82 INITIAL 102 EXC. HIGH TOTAL RISE, TIDE, SURGE, FT. FT. ML (C) PT. mL (C) 2.50 2.40 2.00 2.00 0.80 1.50 1.50 1.20 0.60 1.00 0.90 0.98 1.30 1.20 1.00 1.00 1.00 1.10 1.14 1.10 1.00 0.97 1.00 0.96 0.83 0.56 1.70 2.20 2.30 2.40 2.30 2.50 2.10 4.10 4.30 3,50 3.60 3.70 6.90 8.70 6.80 5.80 4.70 3.80 5.00 5.70 4.70 3.10 3.80 4.00 11.90 10.50 16. OC 17.84 23.48 37.34 26.30 34.85 34.76 15.97 32.28 34.10 25.87 10.91 16.73 27.90 33.87 28.18 21.94 17,63 22.20 23.27 24.70 23.78 15.26 19.41 17.39 19.60 17.81 28.11 a. See Table C.21 for ocean-bed profile. b. Combined wind and pressure setup. c. Host values in these columns have been C updated by the U.S. Army Coastal Engineering Research Center and differ from those in the orilinal documents. ( ( '0 0% I I 9.73 Q Note: maximm wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. -!/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Stdrm diameter between 20 mph isovels is approxi mately double the initial distance. OCEAN BED PROFILE WATER BELOW MWM 0 9.0o 20.5 35.0 43.0. 51.0. 58.5. 69.0 95.5 116 138 171 266 6oo 19,850o TRAVERSE DISTANCE FROM SHORE (NAUT.MI.) 0 0.2 - 0.5 1.0 - 1.5 , 2.0 _ 5.0 1O .15 20 30 40 _4 50 DEGREE AT TRAVERSE MID-POINr FROM SHORE T6 600-FOO DanT K TABLE C.2 SUMMARY-PERTINT PROBABLE MAXIMIh hURRICANE (•MH), STOR.M SURGE COMPUTATIONAL DATA AND RESULTANT WATER LE LOCATION PORT ISABEL T. 26004.3' LONG. 97 09.41: TRAVERSE-AIMUTH86 0-30 GREEI LENTH 4.2.1 NAUTIICAL MILES """&mla K -J PROBABLE MAXIMUM HURRICANE IN PARCThISTICS ZONE C AT LOCATION 260 04 EREE NOM PARAMETER DESIGNATIONS SLW MODERATF HIGH GEMMEAL PRESSURE IDEX P0 INCHE 26.412 26.412 26.112 2 - PERIPHERAL PRESSURE INCHES 31.30 31.30 31.30 RADIUS TO MAXIMUM WIND LARGERADIUS RnAU. MIe. 20 20 20 TRANLATION SPEED V (FORWARD )KNOTS I ... 28 ,'!xIMUM WIND SPEED) V M.P.H. 147 151 161 ATAMLM2RZO MDP1S2rA0N INE-DW INDU .NI. 398 374, 318 •O' TO MlAX. IN PMH cCMnPUATIONAL ComD71CrT AD WATE LEVEL (SURGE) ESTIMATES CO EFFI CI MNTS B0TIO FMICTION FACTOR 0.0030 WIND STRESS CORRECTION FACTOR 1.10 WATER L.EVEL DATA (AT OPEN CanB SHORELINE) pM SpEISD OF TPANMSIATIOVq OOMP0NERTS H WIND SETUP 10007 PRESSURE SETUP 35 INITIAL WATER LEV. .• ASTRONOMICAL 1.70 TIDETLESM• TOTAL-SURGE STILL WATER Lhs'J. 17.84 PETL W- - - TABLE C.3 SuMMARY-PEITINE•rT PRUMBLE MAXIMUI. HURRICANE (FMH). STORKM S;GIO COMPUIATIONAL ITA. AND RESULTANT WATER LEVEL LOCATION FREEPOR'. LUT. 280 56' LONG. 95' TEXAS Note: Nax-- wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. --/nitial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. C ) . . . .. ......... . . . . . . 22' : TRAVERSE-AZIMUTH 152 PROBABLE MAXIMUM HUiRICANE INDEX CHARACTI•$ISTICS ZONE C AT LOCATION 280 561 MHZE NORTH S1PEE D OF UNSITION PARAMETER DESIGNATIONS SLOW HODERATF HIGH •.." •(sT) NOm' (Hr,) CflI!VAL PRESSURE INDEX Po INCHES 26.69 26.69 26.69 PERIPHERAL P 0SRE P n INCHES 31.25 31.25 31.25 ADIUS 70 KMAXDIUM WIND LiRGE SAhMS iUT. I. 26.0 26.0 26.0 TRUN•LATION SPEED V (voawRD SPEED) I S 139 U 8. KiXD= WIND SPEED Yx M.P.H. 139 143 153 INITIAL DISTAN(CE--&U.I ,• l9 MPH WIND 491 458 390 AT SHORE TO MAX. WIND DiXRE, o LENGTH 70.9 NAUTICAL MILES PMH COUPUTATIONAL C0EWICIENT AND WATER LEVU (SUGE) ESTIMATES CooFFIOIENT§ BOT'iM FkICTION FACTOR 0.0030 WIND STRE CORRCION FACTOR 1.10 WATEH LVEL DATA (AT OPEN COAST SHOP.LIIE) . U' OCEAN BED PROFILE TRAVERSE WATE DISTANCE DEPTH FROM BELOW SORE MI ( TmI. (FEw-) 0 0 " .1.0 30 _ 2.0 32 _ 3.0 37 4.0 40 - 5.0 47 10.0 66 _ 15.0 78 _ 20.0 90 . _ 30.0 114 - 40.0 132 50.0 168 - 60.0 240 _ 70.0 570 70.9 600 IATITUDE • 280 26' DEGREE AT TRAVERSE KID-POINT FROM SHOR9 1'O 600-FOOT DEPTH PMH SPEED OF TRANSLATION COMPONENTS ST I HTr HT F E E T WIND SEiTUP 15.99 PRLSSURE SETUP 2.89 INITIAL WATIR LEV. 2.40 &STRONOMICAL 2.20 TIDE LEVEL. TOTAL-SURGE STILL WAT1E Lhl,. 23.48 FELT MLW ..... - tC Q LOCTION EUGENE LAT. 29o 20' LONG. 91' ISLAND, LOUISIANA Note: Maximm wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. - Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels Is approxi mately double the initial distance. 21 . T-RAVmRSE-AZImuTH19230'DE2REEs LENGTH 90 NAUTICAL MILES OC]AN BED PROFILE TRAVEiSk WATER DISTANCE DEPTH FROM BELOW SHORE MKU NAUT* FEET) - 0.0 0 - 1.0 5 - 2.0 10 - 3.0 12 - 5.0 15 - 10.0 15 - 15.0 18 - 20.0 20 - 30.0 50 - 40 60 - 50 140 - 60 200 - 70 260 - 80 320 - 90 600. L&TrTUDE %2o 4d DEGREE AT TRAVERSE MID-POINT FROM SHORE 600:= TABLE C.4 SUMMARY-PERTINENT PROBULE MAXIMLI. HURRICANE (PMH), STORM SURGE COMPUTATIONAL rATA AND RESULTANT WATER LEVEL K .ub PROBABLE 1AXIMUM HURRICANE INE CHARACThWISTICS ZONE B AT LOCATION 29P 20' DGREE NORTH PARAMETER DESIGNATIONS SLOW TODERATF HIGH CENTRAL PRESSURE I•NDE P0 INCHES 26.87 26.87 26.87 PDtIPHEAL PRESSURE INCHES 31.24 31.24 31.24 IUS TO MAXIMUM WIND J.-ARE RADIUS NUT*. MI. 29.0 29.0 29.0 T SLATION SPEED , (FORWARD SPED) KNOTS I 4 1 28.0 AIMUM WIND SPED Vx M.P.H. 141 144 153 INITIAL DISTArCE-NMAT.M.I.-/ FROM 20 MPH WIND 534 184 412 AT SHORE To MAX. WID-1) PMH OCHPUTATIONAL COEFFICIENT AND WATER LEVM (SURGE) ESTINATES ICTJIM 'iFICTION FACTOR 0.0030 WIND STRESS CORRECTION FACTOR 1.10 WAT E Lh VEL DATA (AT OPEN OCAST SHORELINE) PMH SPEED OF TRANSLATION COMPONENTS ST MS T HiT F E, T WIND SETIUP -29.74 PRESSURE SETUP 3.29 INITIAL WLATER LEV. 2.00 ATRONOMICAL 2.30 hIDE LEVEL SUAL-RGE STILL L kA . 37.34 SET= L : TABLE C.5 SUMMY-PERTINENT PROALE MAXI M1,. HU•RIlCANE (PMH) ' STORM SMGE 00MFUTTIONAL WA AND RESULTANT WATER LEVEL LOIATION ISLE L&T. 29002.91 LONG. 90"42.5'; "TAVERSE-AzIMUTH 165 DiEEaLe LG 58.5 NAuTICAL muILs DERNIERES, IOUISIAM Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maxlmum wind. -!/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. C ( 0o PROBLE MAXIDUH HURRICANE INDEX CHARAMTUISTICS ZONE B AT LOC&TION 290 3 D0G'EENOTNO SPEED•OF TMNSL§T:0I. PARAMETER DESIGNATIONS SLOW 14OD91ATF HIGH MH PRESSURE INDEM P0 INCHES 26.88 26.88 26.88 PERIPHERAL PRESSURE P INCHES 31.25 31.25 31.25 RADIUS TO MAXIMUM WIND IARGZ RADIUS NALT. HI. 29 29 29 MANSIATION SPEED ? (FORWARD SPME) KNOTS 4I 11 \2 IAXIMUM WIND SPEED !V M.P.H. 140 144 153 INITIAL D =h-N .MI.1/ PROM 20 MPH WIND 528 48? 394 KT SHORE TO MAX. WIND I I PMW OCKWPUATION&L COiUVICIERT AND AMAELE VEL (SUlGE) ESTIMATES, COEFFICI-ENTS "BMiOFTR ICTION FACTOR 0.0030 WIND SRESS, C0HHEION FACTOR 1.10 WATER LEVEL DATA (AT OPEN CCAST sFMlEJNS) P1W SPEED OF TRANSLI'TIO COMPONENTS ST I -14 ! 9 F E E" T WIND SETUP 8b RESSURE SETUP 3 INITIAL MATES LEW. 2.00 ATRNOMICAL 2.40 TIDE LEME TOTAL-SURGE SILL jATa7 LEV. 26.30 = MHW K TABLE C.6 SURY-PFERTINENT PR"OBBLE MAX IMU. hURRICANE (Pml'. STORM SURGE COMPUTATIONAL DATA AND RESULTANT WATER LEVEL LOTION BIIOXI LAT. 30023.6' LONG. 88"53.6't TRAVMsSE-AZIMUTH 160 DECREEs LEVGTH 77 NAUTICAL MILES MISSISSIPPI Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. 1-Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. PROBABLE MAXIMUM HURRICANE IN=• CHARACMISTICS ZONE B AT LOCATION 300 24 DECREE NORTH K r Lft '0 OCEAN BED PROFILE TRAVERSE WATER DISTANCE DET FROM BELOW SHORE MLW 0 0 - 0.2 3.0 0.5 2.0 1.0 6.5 1.5 9.0 _ 2.0 9.0 _ 3.0 9.5. 5.0 12.0 _ 9.0 9.5 _ _ 9.5 U-.0 _ 10.0 14.0 - 10.5 18.5 - 11.0 17.5 _ 11.5 23.0 - 12.0 29.0 113 34.5 - 15 41.5 20 45.0 25 47.0 30 50.0 40 65.0 50 99.0 60 164 " 70 203 78 6oo 80 7* LATITUDE 2?9 0 508 DEGREE AT TRAVERSE MID-POINT FROM SHORE TO k00--1 RMP' ISPOFE TRAENSATDION_ PARAMETER DESIGNATIONS SLW MODERATF HIGH METRAL PRESSURE INDEI o INC= 26.9 26.9 26.9 PERIPHERAL PRESSURE P INCHES 31.23 31.23 31.23 RADIUS TO MAXIMUM WIND laRGE RADIUS NAUT. MI. 30 30 30 rRANSLATION SPEED ! (FORWARD SPEED) KEATS 4 11 28 MAXIMUM WIND SPEED vx M*.P.H. 139 143 153 INITIAL DiSr~C-niuT.MI.X FROM 20 MPH WIND 525 498 396 IT SHORE 32 MAX. WIND - - I P10 OCCUATIONAL COEFFICIENT AND WATER LEVEL. (SURGE) SrIMATES COEFFICIENTS WM'OK FRICTION FACTOR 0.0030 WIND STRESS CORRECTION FACTOR 1.10 (ATER L .VCST DATA (AT OPEN OCs sMREiNZ) TABLE C.7 SUMMARY-YERUNENT ?RUMABLE MAX IMU h1JRRIC&NE (FMH) * STORM SUItGh. OOIPULAT1ONAL IATA AND RESULTANT WATER LEVEL LOCATION SANTA ROSA LIT. 30 023.769 LONG. 86"37.7': TR"AVERSE-AZIMUTH 183 =BflE&# LQWGTH 4e4.7 NAUTICAL MILES ISLAND, AUEAZAM l.A Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. - Initial distance is.-distance along tra .verse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. PROBABLE MAXIMUM HURRICANE INDEX CHARACMh~ISTICS ZONE B AT LOCATION 300 24' DNEGR N0ORTH PARMLERDESIGNATION$ SLOWV I40DM1TFI HIGH , (sr) (N) (T CENTRAL PRESSURE INDEX P0 INCHES .26.88 26.88 26.88 PEtWIPERAL.PRESSURE in IziCi~s 31.20 310 3.2 RADIUS TO MAXIMUM WIND IARGE RADIUS HAUT. MI. 29 29 29 fAnWSIATION SPEED ? (FMonAiiD SPEED) KNOTS 4 11 28 MIAXIMUM WIND. SPEED V XMeP9*H 140 144 153, INITIAL DIST&NCE-NAUT.H 2 '8 9 PRtOM 20 MPH WIND 47 '9 KT SHORE TO MAX. WIND 1___ - PMH OMPUTATI0NAL GOiFFICILUT AND WATER LLY&i (SURiGE) ESTIMATES C 0 E F. F I C I E N T S 10rj'0M FRIICTION FACTORB 0.0030 WIND MSTRSS COURiCYIO FACTOR 1.10 WATEft LEVEL DATA (AT OPENI COAST SI RELINE) PKH SPEED OF TRANSLATIOIb COMPONENTS ST I T H ___ __E F ET WIND SETUJP 9.12 PRESSURE SETUP 3.25 INITIAL WATER LEV* 1.50 LSTROHORIC&L 2.10 riDE LEVEL lOTAL-SURCE STILL WATER LEV. 15.97 ý=7I MLW ___ C OCEAN BED PROFILE .TRAVERSE WATER DISrANCE DEPTH FROM BELOW swagR HMW Nt .AUT.H. LF2TL 0 0 S 0.2 22 S 0.5 5 : 1.0 66 1.5 66 290 66 - 3.0 73 5.0 76. 10 88 - 15 120 20 182 30377 40 510 - 45 600. - 0 756 LATITUDE 3601-36 DEG~REE AT TRAVERSE MID-POINT FROM SHORE ro600-F DEPTH K Q LOCATIONPITTs CREEK LAT. 30001.1' LONG. 83"" FLORIDA Note: Maxima wind speed Is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. -/Initial distance is distance along traverse from shoreline to maximum wind when leading .20 mph isovel intersects shoreline. Storm ,diameter between 20 mph isovels is approxi mately double the initial distance. 53': -TRAVERSE-AZIMUTH 205 DE•EEs LENGITH 110 NAUTICAL MILES PROBABLE MA•INUM HURRICANE INIM CHARACTERISTICS ZON. A AT WC&TION 300 01o DEGR NORTH SLSPEED OF TNSA TION PARAMEI DEINAIN SLOW HOIERATF HIGH RADIUS PRESXUME INDEX Po0 INCHES 26-79 26.79 26.79 PERIPHItA PRESSURE SPn INCHES 30.ZZ 30.22 30.22 RADIUýS TO MAIMU WIND JAUME RADIUS NAUT. MI. 26 26 26 rRANSIATION SPEED rV (1OiM I)DS PEED) KNOTs 1 4 11 21 AXIMUM WIND SPEED v_ M.P.H. 138 142 146 naTIAT, DIST-ANCE-NUT.MIX FROM 20 MPH~ WIN 3514 322 278. AT MOMK To MAX. WIND- - - TABLE C.8 SUMART-PERTINENT PROBABLE MAXIMU1. hfJRRIC&NE (PMH), STORM SURGE COMPUTATIONAL LATA AND RESULTANT WATER LEVEL A 'a I,' t.h OCEAN BED PROFILE TRAVERSE WATER DISTANCE DEPTH FROM BELOW SHORE MLW NAUT.MI. IFEET) 0 0 _ 0.2. 1.0 _ 0.5 2.0 _ 1.0 3.0 _ 1.5 4.o0 _ 2.0 5.0. . 3.0 6.5. _ 5.0 9.0. _ 10 22. 0. _ 15 31.o0 - 20 41.0 _ 30 62.0 _ 40 78.0 _ 50 81.0o - 60 84.0 . 70 101.0.. - 80 117.0. _ 90 144.0._ _ 100 180.0 _ 110 210.0_ 120 280.0 . 130 543.o L. 132 600.0. 140 846 TITUDE • 29° 03' DEREE AT TRAVEMSE, ID-POINT FROM SHORE §2L60-=0T = PMH OCUTATIONAL COEFFICIENT AND WATE UWEL (SURGL) ESTIMATES COEFF ICI ENTS B uM FIIcrTION FACTOR 0.0030 WIND STRESS COHREMTION FACTOR 1,10 WA T Eh Lh9VEL DAT.T (AT OPEN CAST SHORELINE) PIMH SPEED OF TRANSIATION COMPOONETS ST I MT I T F E E T WIND SETUP 24.67 RESSURN SETUJP23 INITIAL WATER LE. 1.20 ASRNOMICAL 4.10 TIDE LEVEL TOTAL-SURGE 322 STILL VATIr LIU". 32.28 LW - - TABLE C.9 SUMMARY-PERTINENT PRUbABLE MAX IMt:? HURRICANE (PNJO, STORM SUC COMPULATIONAL rATA AND RESULTANT WATER LEVEL LOCATION NAPLES FLORIDA LkT. 26001.41 IONG. 81'46.2'; TRAVERSE-AZINUTH 248 DIUREEa LENGTH 14e NAUTI-CL MILES 1P Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. -!/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. PMH ONPUTATIONAL COXFICIeNT AND WATER LEVEL (SUiRGE) ESTIMATES PROBABLE MAXIMUM HURRICANE IN=X CHARACeTUISTICS ZONE A AT LOCATION 260 01' DEGRE NORTH SPEED OF NSLATION PARAMETER DESIGNATIONS . SLOW MODERATF HIGH ~(ST) "T (0 Sa~RYlAL PRESSURE INDEX P0 INCHES 26.24' 26.24 26.24 PERIPHERAL PRESSURE % INCHES 31.30 31.30 31.30 ADniS TO MAXIMUM WIND LRGE RAIUS wNAMUI.. 15 15 1.i LIANSLATION SPEED rv (FOAD SPEED) KOTS 4 - '17 4AXIMUM WIND SPEED Vx M.P.H* 19) 3ejL 158 ENITIAL DISTAN.-NWUT.MIND FROKM 20 MPH WIND 2952 270 256 kT SHORE TO MAX. WIND - -C COJFFI CIENTS BOIO FRICTION FACTR 0-0030 WIND STRESS CORETIN FACTOR 1,10 .WATEh LE~VEL DATA (AT OPEN OCAST SHORELINE) PHH SPLWD OF TRANSLATION COMPONETS SIT I mT HT F S E T WIND SETUP 13.49 15.87 18.47 PRESSURE SETUP 3.29 2.87 2.90 7NITIAL WATER LEV. l.0)0 1.00 1.00 ASTRON0MICAL 3.60 3.60 3.50 TIDE LEVEL ýVAL-SURGX TILL WATia L"V. 21.3:8 23.35 25.87 MEE.L W , E,,I ( K TABLE C.10 SJMMARY-PERTINENT PROBABLE MAXIMUP. hURRICANE (PMH) , STORM SURGE COMPUTATIONAL DATA AND RESULTANT WATER LEVEL LOCATION MIAMI LAT. 25%?.2' LONG. 80'07.8'; TRAVErSE-AZIMUTH 100 DEREEs LENGTH 3-.9 NAUTICAL MILES FLORIrA Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. -1/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. .P Ius PROBABLE MAXIMUM HURRICANE I .DEXg CKRACTISTICS ZONE 1 AT IOCATION 250 47.2 DEGREE NORTH PAR~A M ~ S1P•E E OFIG~TIN IO PARAMETER DESIGNATIONS S IlW HODERATF HIGH ... (ST) (MT) CHT) CENTAL PRESSURE INDEX P INCS 26.09 26.09 26.0 PERIPHEAL PRESSURE Pn INCHES 31.30 31.30 31.0, RADIUS TO MAXIMUM WIND LARGE RADIUS NAUT.MI. 1 14 14 TNSLATION SPEED F (FORWARD SPEED) OTS 1 4 13 17 WMUM WIND SPEED v M.P.H. 152 156 160 INITIAL DISTANCE-NAUT.MI.YJ ROM 20 MPH MWIND 274 258 243 AT SHORE TO MAX, WND - PMH CCMPUTATIONAL COEFTICIENT AND WATER LEE (SURGE) ESTIMATES CON? I CI ENTS WFIVMF1RXIC TION FACTOR 0.0025 WIND STRESS CORRECTION FACTOR 1.10 WATER LEVEL DATA (AT OPEN OCAST SMFRNLINN) PMH SPEED OF TRANSIATION COMPONENTS ST 1I ' HT S.. [ F E E T WIND SETUP 2.06 2.37. 2.51 PRESSURE SETUP 3.97 3.82 3.90 INITIAL WATR LEV. 0.90 0.90 0.90 ASTRONOM.ICAL 3.6o 3.60 3.60 ITDE LEEL ffU AL-SURGE STILL WATER IJS. 10.53 10.68 10.91 =V - - - TABLE C.11 SUM •Y-P~iRTINr PROBABLE M&XIMVP. WIRICANS (PMH), STORM SUNG•r, COMPUI•ATIOMAL rATA AND RESULTANT WATER LEVEL. LOC&TIONJACKSONVILLELAT. 300 21' LONG. 81" FLORIDA PRORARL/ MAXIMUM HURRICANE IND12 CHARACTIhISTICS ZONE 2 AT LOCATION 300 21' nwRHU NOMTH ANE GN OQ F IATTRI ON P ETER ESIGNATIONS LOW HODEATF HIGH C01TH&L •PRESSUR INDEX P0 INCHES 26.67 26.67 26.6? PENIPHHEAL PRESSURE -P INCHES 31.21 31.21 31.21 ADIUS 1• MAXIMUM WIND LAE RAMDUS NAUT. MI. 38 38 38 TIOU SPEED v(FORWARD SPEED) KNOTS 1 4 11 22 MAXIMUM WIND SPEED vX M.P.H. 138 142 149 IPNROITMI A2L0 MDPIMH tNWCINED- NAJT*.HIJI 407 372 334 kT SHORE TO MAX. WIND Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. 1Y/Initial distance is distance along traveree froe shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. 24•.. rmvEasE-AzimuTH 9o OCEAN BED PhOFILE TRAVERSE WATER DISTANCE DIETH FROM BELOW SHORE MIM. (NAUT.MI. ) FEET 0 0 0.2 20 0.5 25 1.0 32 1.5 37 2.0 43 3.0 55 5.0 59 10.0 66 "12.0 66 14.0 72 15.0 73 20.0 8o 30.0 100 40.0 117 50.0 131 - o.o noi r" 60.0 270 62.5 6oo 70.0 9W8 LATITUDE % 300 21' DE•REE AT TRAVERSE IMID-POINT FROM SHORE P600-FOOT Dwri Domes LENGTH 62.5 xL'UiIC&L MILEm PMH (IHUTATIONAL COXYTICIENT -AN WATER LEVEL (stihz) ESLTIMTE COEFFICIENT_4 LOTIVI1 FRICTION FACTOR 0.0025 WIND SRES CORRECTION FAC!TOR 1.10 WATEh LSVNL DATA (AT OPEN OCAST SHORELINE) PMH SPEED OF TRANSLATION COoMP0MERS sT MT HT __ _E E T WIND SETUP 16.46 PRESSURE SEUP 3.23 INITIAL kAT/R LEV. 1.30 NORICAL 6.90 rIDE LEVEL - , -, tAL-SURGE ILL WAT12 LLY. 27.90 EET MLW 0'i r -_ - j K Q LOCATION JEKYLL IAT. 310 05' LONG. 81"24.5': TRAVESE-AZImuTH 108 DIXRE', LENGTH 72.6 NA•TICAL MILES ISLAND, GEORGIA PROBBLE MAXIMUM HURICANE INDEX CHARACT10ISTICS ZONE 2 AT LOCATION 310 56 •DREZ NORTH Note: Maxim=m wind speed is assumed to be on "the traverse that is to right of storm track a "distance equal to the radius-to maximum wind. -!/initial dist ance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline., Storm diameter between 20 mph isovels is approxi mately double the initial distance. OCEAN BED PROFILE TRAVERSE WATER DISTANCE DEPTH FROM BELOW SHORE MLW (NAuT.mi. (* c 0 0 0.2 3.0 0.5 4.o0 1.0 6.o 1.5 6.5 2,0 7.0 3.0 12.0 4.0 20.0 5.0 2365_ 6.0 29.5_ 7.0 35.5. 8.0 35.0. 10.0 39.5 15.0 49.0. 20.0 57.0. 25.0 65.0 _ 30.0 73.0 4.0.0 101.0 50.0 115.0o 60.0 131.0o "700. 291.0 72.6 600.0 80.0 1,030.0 LATITUD' 300 53' DRGREE AT TRAVERSE MID-POINT FROM SHORE S600-FOOT DEPrT TABLE C.12 SUMMARY-PERTINENT PROBABLE MAXIMvI. h'URRICAE (PMH). STORM SURGE COMPUTATIONAL LATA AND RESULTANT WATER LEVEL A" '0 SPEE OF TANS ATIONn PARAMETER DESIGNATIONS [LOW HODERATF HIGH _ _ _ _) (n (HT) C RAL PRESSURE N X P0 INCHES 26.72 26.72 26.72 PERIPH1RKL PRESSURE Pn INCHES 31.19 31.19 31.19 RDUSe TO MAXIMUM WIND IARGE RADIUS NAM. MI. 10 40 40 TRIATrON SPEED IMUR WIND SPED yxM.P.H. 135 1541 147 INITIAL DISTAxacT-mW.mI S20 MPH WIND 400 380 336 TSH TO -AX, pMH O•H PUTATIONAL COODTICIE3T AND WATER LEVEL (SURGE) ESTIMATES CO0 E FF I C I E NTS3 TIMTOFHNIC TION FACTOR 0.0025 WIND STRESS CORRECTION FACTOR 1.10 WAT B L. EVEL DATA (AT OPEN OCAS SORELINE) PMH SPEED OF TRANSLATION COMPONErTS ST HWT T S~F E. E _T WIND SETUP 20.63 PREESUR, SETUP 3.34 INITIAL WATES LEW. 1.20 ASTRONOMICAL 8.70 IDE LEVEL AL-SURGE STTIILLLL WVATTSERu vL3h3`V.8. 7 EEIT MLW TABLE C.13 su5mHAY-PjmTINENT PROBaBLE MAXmIMp. hUICIANE (PmIl), STORM SURGE (OmPUTATIOMAL rATA AND RESULTANT WATER LEVEL LOCATION FOLLY ISIANIL&T. 32e 39' LONG. 79"56.6': TRAVIMSE-AZIMUTH 150 SOUTH CAROLINA -Note: Maxi'm- wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. !/Initial distance Is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. PROEABLE MAXIMUM HIURRICANE INDEX CHABAC'M"ISTICS ZONE 2 AT LOCATION 320 39' DOtEES NORTH J SPEED OF TASLTION PARANMET DESIGNATIONS SLOW MODERATF HIGH S(ST) NO' NO? MAL PRESSURE INDEX P 0INCHES 26.81 26.81 26.81 PERIPHE•AL PRESSURE 'n INCHES 31.13 31.13 31.13 RADIU8 TO MAXIMUM WIND R09 RADIUJS NAUT. MI. 40 40 40 &RANSIATIONSP EED ?v (FAD SPEED) KNOTS 1 4 13 4AXDOJM WIND SPEED Vx M.P.H. 134 139 148 [NITIAL DISTANIE-NAUT.MI.1 'PROM 20 MPH WIND 400 364 311 kT SHORE TO MAX. WIND II DEGREE$ LENGTH 57.6 NAUTICAL MILES PMH OCHPUTATIONAL CO ZICIENT AND WATER LEVEL (SURGcE) ESTIMATES OCEAN BED P"OFIL TRAVERSE WATER DISTANCE DEPTH FROM BELDW SHORE HIM (NAUT.HI.) (FEET) 0 0 00 .2 10.5 _ 0.5 12.0. _ 1.0 14.0 _ 1.5 16.5 _ 2.0 18.0. _ 3.0 29.5 , 5.0 39.0 - 10.0 460. _ 15.0 56.o - 20.0 65.o L30.0 85.0. _ 40.0 138.o0 _ 50.0 227.0o - 57.6 6o0.0 _ 60.0 1,800.0 LATIT UME 320 25' DEGREE AT TRAVERSE MID-POINT FROM SHORE ro600-= DE BOT1I0M FRICTION FACTOR 0.0025 WIND STRESS COM=ION FACTOR 1.10 WATEEB LE~VEL DATA (AT OPEN OGAST SHOELINE) PMHl SPEED OF TRANISLATION COMPONENTS ST I M __....____ F.E j T WIND SETUP 17.15 PRESSURE SETUlP 3-*23 INITIAL WATER LEV. 1.00 ST1'ONOOICAL 6.80 rFiD LEVEL TOT1AL-SURGE STILL WATER LW. 28.18 Pwr MLW _C ( 0, K. TABLE C.14 SUMMARy-PETINENT pROBABLE MAXIMUM. hVRRICAMM (PMH), MWTOM SJRGE COMPUTATIONAL DATA AND RESULTANT WATER LEVEL LOCATION RALEIGH BAY,IAT. 340 54' LONG. 76 15.3': TRAVIMSE-AZIMIUTH 135 WOWPH OAROLINA Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. !/lnitial distance is distance along traverse from shoreline to maximum wind when. leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. PROBABLE MAXIMUM HURRICANE INDEX CHARACTMISTICS IZONE 3 AT LOCATION 34°0 54' DEREE VNOTH DEREE, LENGTH 35.2 NAUTICAL MILES K '0 'C NORTH CAROLINA 0OEF TAN-5 ION PARAMETER DESIGNATIONS !SLW OMODERATHIFG H IfNtR PRESSURE INDEX P, INCHES 26.89 26.89 26.89 LERIPHEAL PRESSURE Pn INCHES 31.00 31.00 31.00 RtADI1US TO MAXIMUM WIND LARGE RADIUS NlUT. MI. 35 35 35 IRANS•ATION SPEED Fv (FOWVARD SPEED) KNOTS 5 17 38 MAXIMUM WIND SPEED Vx M.P.H. 130 137 119 INfiTAL DISTANCE-NAUT.I.i -" FROM 2O MP IND 385 346 280 #T SHORE TO MAX WIND i._.1..1 P111 aCHPUTATIONAL OOE"ICrIIr AnD WATER MMYE (SURGE) ESTIMATES COEjFFICXXNT-S BT FR)ICTION FACTOR 0.0025 WIND STRESS CORRECTION FACTOR 1.10 WATER LSVEL DATA (AT OPEN OCAST S)ORELINE) OCEAN BED PROFILE TRAVERSE WATER DISTANCE DEPTH FROM BELOW SHORE MWI I. 0 0 - 0.2 16 0.5 28 1.0 1.0 1.5 4.6 2.0 514 3.0 614 5.0 72 10.0 92 S15.0 U2 20.0 124 30-0 264 35.2 600 40.0 900 LATITUDE % 3,4o4,fl DEGREE AT TRAVIMSE MID-POINT FO1 SHORE TABLE C.15 SUHIAMY-PERTINENT PROBABLE MAXIMUt! hURRICANE (FMH), STORM SURGE COMPUTATIONAL DATA AND RESULTANT WATER LLVEL LOCATION OCEAN CITY, LkT. 38e 20' LONG. 75 04.9'; TRAVERSE-AZIMUTH 110 I=REEM LENGTH 59 NAUTICAL MILES MARYLAND PROBABLE MAXIMUM HURRICANE INDEX CHARACTUISTICS ZONE 4 AT LOCATION 380 20' DWEE NORITH "SPEE OF TRANSLATION PARAMETER DESIGNATIONS SLOW ,ODERATF HIGH CENTRAL PRESSURE INDEX P0 INCHES 27.05 27.05 27.05 PERIPHERAL PRESSURE P INCHES 30.?7 30.77 30.77 RADIUS TO MAXIMUM WIND LRGE 1ADIUS IAUT. MI. 38 38 38 1IWSIATION SPEED ? (yo AMUSPDEE ) [NOTS 1 10 26 48 IXIElUM WIND SPEED vS m.P.H. 124 1133 1146 INITIAL DISTAKCE--NUT.MI.•Y RM 20 MPH WIND 350 293 251 kT SHORE TO MAX. WIND I_ I Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. 1 Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi matelv double the Initial distance. TRAVERSE WATER DISTANCE DEPTH FROM BELOW SHORX MLW NA& T.MI (FEET 0.2 17 0.5 32 . 1.0 29 - 1.5 35 2. 0 4c - 3.0 38 2 4.0 56 " - 5.0 61 2 6 71 2 ? 56 8 60 9 58 - 10 59 - 11, 65 - 12 64 - 13 70 14 62 214! II 1i 7 LATITUDE 0 3)8014.~ DEGREE AT TRAVLVS& MID-POINT FROM SHORE IR600-FOO az --"-K Ip PMH (THPUTATIONAL CODUICIIVT AND WATER LEVEL (SURGE) ESTIMATES C 0 EFF i C E H NTS IOT'iM,, FRICTION FACTOR 0.0025 WIND SrTRESS CORMION FACTOR 1.10 W AT E L SVBL D ATA (AT OPEN MAST SHORELINE) PKH SPEED OF TRANSLATION COMPONENTS S I NT H T _________ F 9E T1 WIND SETUP 14.30 RESSURE SETUP- 2.83 INITIAL WATER LEV. 1.14 ATNOMICAL 5.00 TIDE LEVEL. TU-&-SURG, SILL WATER LEV. 23.27 Vw~ MLK - - ( Q. LOCATION ATLANTIC LAT. 39° 21' LONG. 74" CITY, NEW JERSEY Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. 1/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. 25': TRAVERSE-AZIMUTH 146 DE•.EEm LENGTH 70 NAUTICAL MILES PROBABLE MAXIMUM HURRICANE INDEX CHARACTER2ISTICS ZONE 4 AT LOCATION 39P 21' DEGREE NORTH TABLE C.16 SUMMARY-PERTINENT PROBABLE MAXIMU,. HURRICANE (PMH), STORM SUHGE COMPUTATIONAL DkTA AND RESULTANT WATER LEVEL K LA '0 0. OCEAN BED PROFILE TRAVERSE WATER DISTANCE DEPTH FROM BEUOW SHORE wLx - 0 0 _ 0.2 10.0 D 0.5 15.0. _ 1.0 22.0 - 2.0 38.0 - 5.0 50.o0 11 0.0 72.0. - 20.0 90.10 - 30.0 120.0. _ 4o.o 138.0 _ 50.0 162.0o _ 60.0 210.0 _ 65.0 258.0. _ 70.0 600.0. -. 0 IATITDE P3 5 DEGREE AT TVERS MID-POINT FROM SHORE 600-OO VE SPEED OF, T_ SLATION PARAMETER DESIGNATIONS SIOW HODERATF HIGH ,(sT) (Hn)) ENTRAL PRESSURE INDEX P0 INCHS 27.12 R'IPImUA PRESSURE P• INCHES 30.70 RADIUS TO MAXIMUM WIND LARCE RADIUS NAUT. MI. 40 r1RASIATION SPEED r! (F•ORWARD spra)KNOTS i 49 D(IUM WIND SPEED V. K.P.H. 142 INIrIAL DISTAMCE-11A .MI.A ROM 20 MPH WIND A~TM SHOTROE . yMAX*WN PMH OCMPUTATIONAL COOEFICIENT AND WATER LEVEL (SURGE) ESTIMATES "C0 E F F I C I E N T 5 BOTTOM FRICTION FACTOR 0.0025 WIND STRESS CORRECTION FACTOR 1.10 WATER Lh VEL DATA (AT OPEN CCAST SHORELINE) PMH SPEED OF TRANSLATION ODMPONENTS ST i MT Hr F 3 E T.T WIND SETUP 15.32 PRESSURE SETUP 2.5? INITIAL WATER LEV* 1.10 1AUMNOMICAL 5.70 r II DL L-V "AL-SURGE 2 STILL WATER L. ET MLW. TABLE C.17 SUI4AYM-P ERTINENT PROBABLE HAXIMUJ. hWHRICANE (PMH), STORM M:RGE COMPUTATIONAL DATA AND RESULTANT WATER LEVEL LOCATION LONG ISLAND.LAT. 410 00' LONG. 7i201.8%' TRAVEiSE-AZIMUTH 166 CONNECTICUT DECREEa LENGTH 68.4 NAUTICAL MILES r' Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius to maximum wind. 1/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. OCEAN BED PROFILE TRAVERSE WATER DISTANCE DEPTH FROM BELOW SHORE HMU (HAUT. mi.) JFEgrE 0 0 _ 0.2 22 0.5 38 _ 1.0 43 _ 1.5 53 2.0 67 - 3.0 82 - 5.0 102 _ 10.0 132 _ 15.0 145 _ 20.0 170 30.0 212 40.0 240 50.0 260 - 60.0 302 68.4 6O0 70.0 870 1ATITUDE . 400 27' DEGREE AT TRAVERSE ID-POINT FHOM SHORE 60o-Foz DFTr' PMH (XMPUTATIONAL COEWFICIENT AND WATER LEVEL (SURGE) ESTIMATES COEFFIC-1ENTS BO1`nf FRICTION FACTOR 0.0025 WIND sbfRESS CORREMION FACTOR 1.10 WATER LEV EL DATA (AT OPEN MAS SWORELINS) PMH SPEED OF TRANSLATION COMPONENTS ST I MT Su _ _E E T WIND SETUP 8.73 PRESSURE SETUP 2.46 INITIAL WATIR LEV. 0.97 &STONONICAL 3.10 TIDE LEVEL WTAL-SURGE STILL WATER LWV. 15.26 E1EET MLW ( PROBABLE MAXIMUM HUHRICkNE INDEX CHARAC'IMtISTICS ZONE 4 AT LOCATION 410 00' DXMEE NORTH SPEED OF TRANSLATION PARAMTER DESIGNATIONS SLOW HODEATF HIGH M2?I1AL PRESSURE INDEX P0 INCHES 27.26 27.26 27.26 PERIPHERAL PRESSURE P INCHES 30.56 30.56 30.56 RADIUS TO MAXIMUM WIND LARERADIS NAUT. MI. .8 48 48 mRANSLATION SPEED ?,v(F ORWARD SPEED) KNOTS 115 34 51 1AXlMUM WIND SPEED vx M.P.H. 115 126 136 INITIAL DISTANCE-NAWTeMIJ/ FROM 20 MPH WIND 346 293 259 kT SHORE TO MAX. WIND r Q SUMMARY-PERTINENT PRtJBA.LE MAXIMUI,. hhIRICANE LOCATION WATCH HILL LAT. 43?18.9w LONG. 71 POINT, RHODE ISLAND PROBABLE MAX IMUM HURRlCANE INDEX CHARACTISTICS ZONE 4 AT LOCATION •41 19' REE NORTH Note: Maximum wind speed is assumed to be on the--raverse that is to right of storm track a distance equal to the radius to maximum wind. 1/Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm -diameter between 20 mph iaovels is approxi mately double the initial distance. K TABLE C.18 (nMH), STORM SUHGE COMPUTATIONAL DATA AND RESULTANT MATER LEVEL 50 : T1RAVERSE-AZIMUTH 166 DE•REE: LENGTH 84 NAUlICAL MILES OCEAN BED PROFILE; TRAVERSE WATER DISTANCE DEPTH FROM BELOW SHORE MWI NAMUI T (FELT) 0 0 0.2 28 _ 0.5 40 1.0 77 _ 1.5 98 2.0 119 _ 3.0 117 4.0 114 _ 5.0 128 6.0 114 - 7.0 113 8.0 117 9.0 118 10.0 93 11.0 70 12.0 65 S 3.0 51 L4.o 56 15.0 77? 20.0 131 - 0 1 0 2~ g0O 245 LATITUiE 0 400 38' DEIREE AT TRAVERSE MID-POINT FROM SHORE IT 600-2 = DEFA K 'r 6, ""SPEED STION F •A PARAMETER I(SIPNATIOE.OS 5 35 1IGH , ,(,s T)_ " N'0 ( r) 10 INCHES 27.29 27.29 27.29 P a INCHES 30.54 30.54 30.54 UaDIS TOMA XIMUM WIND IARG RADIUS NAUT. MI. 49 49 4 XIMUM MIND SPEED VA M.P.H. 113 126 134 INITIAL DISTANCE-NAUT.MI .1 FROM 20 MPH WIND 348 284. 255 AT S HOV EI Q MA, •WXI - PMH OC?1PUTATIONAL COOVFICIMN AND WATER LEVEL (SURGE) ESTIMATES C O F F I EE NT S IX•OT•IVY ICTION FACTOR 0.0025 WIND STRESS CORRECTION FACTOR 1.10 WATER LEVE.L DATA (AT OPEN OCAST SHORELINE) PIH SPEED OF TRANSIATION COMPONENTS STI MT -IH F E E" T _. WIND SETUP 10.01 PRESSURE SETUP 2.42 INITIAL WATER LEV. 0.96 .STRON0MIC.L 4.00 POTAhL-SURGE STILL WATER LLk. 17.39 T•-r-LW TABLE C.19 SUPARY-PERTINENT PROBABLE MAXIMUk HURRICANE (PFH), STORM SUGIO COMPUIATIONAL LATA AND RESULTANT WATER)LEVEL LOCATION HAMPTON LT. 420 57' 1ONG. 70"47.l' 'i TRAVQtSE-AZIML 115 cH NEW H&HPSHIRE Note: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to. the radius to maximum wind. F-Initial distance is distance along traverse from shoreline to maximum wind when leading 20 mph isovel intersects shoreline. Storm diameter between 20 mph isovels is approxi mately double the initial distance. C PROR&BI MAXIMUM HURRICANE INDEX CHARAC.!tISTICS ZONE 4 AT LOCATION 420 57' DEGRE NORTh S' ... |SPEE OF THMANS AION PARAMETER IESIGNATIONS SIOW HODESATF HIGH . : •-(sT) (,.,r) , CElAL PRESSURE INDEX .- P 0INCHES 27.44 27.44 27.44 PERIPHERAL PRESSURE Pn INCHES 30.42 30.42 30.42 RADIUS T0 NAXIMUM WIND LARG RADIUJS FAUT. KI. 57 57 57 TANSLATIGN SPEED iy (FOWARD SPEED) KNOTS 11? 37 52 MAXINUM WIND SPEED, ..P,v. x 107o n1 18 1 INITIAL DiAmcE.-RWT.mI.ND F!ROM 20MPH WIND ,- 353 290 262 4T SHORE TO WA. WIND 1........ DWRE{E LENG'H 40 NAUTICAL MILS C rU f, OCEAN BED PROFILE TRAVERSE WATER DISTANCE DEPTH FROM BIOW SHORE MLN (k,.TMi.){ (FFE•) - 0 0 - 0.2 8 - 0.5 40 - 1.0 64 - 1.5 82 , 2.0 100 - 3.0 105 - 5.0 156 - 10.0 258 - 15.0 336 - 20.0 266 - 25.0 210 - 30.0 322 - 35.0 433 40,0 6OO IATITUDI 0 42 0 48' DEIREE AT TRAVERSE MID-POINT FHOM SHORE TM 60o-=OOT DEPTm •M OCIPUTTIONAL COiFICIENT AND WATER LEVEL (StkGE) ESrIMATES COEFF I C I ENTS kOnO' FRICTION FA¥ 02 0.0025 WIND STRESS CGURLCTION FACTOR 1.10 WATER L-VEL DATA (AT OPEN GCAST SHORELINE) PMH SPEED CF TRANSLATION COMPONENTS ST I ITT I hi F E E" T WIND SETUP 4.25 PRESSURE S'IMP 2.23 INITIAL WAT1. LEV. 0.83 M NORICAL 10.50 VIDE LEVEL TAL-SURGE •TILL WATER L67,. 17.81 EETr MLW I K LOCATION GREAT LAT. W$O3304' LONG. 67' SPRUCE ISLAND. MAINE otej: Maximum wind speed is assumed to be on the traverse that is to right of storm track a distance equal to the radius-to maximum wind. y/Initial distance is distance along traverse from shoreline to maximu• m ind when leading i 20 mph isovel intersects shoreline. Storm diameter between 20 mph Isovels is approxi mately double the initial distance. 30': TRAvERS OCEAN BE TRAVERSE DISTANCE FROM SHORE (NuT.MI. 0 _ 0.2 - 0.5 - 1.0 _ 1.5 - 2.0 _ 3.0 - 4.0 _ 5.0 1 0.0 _ 15.0 20.0 - 30.0 10.0 50.0 - 60.0 70.0 - 120.0 130.0 1'Ii0 180.0 IATITUDE DFRFZ AT MID-POiNT ,E-AZIMUTH 148 EDP ROFILE PROBABLE MAXIMUM HURRICANE INDEX CHARACTrERISTICS I ZO.E 4 AT LOCATION 440 31 DEGREE NOW'TH INO 600-FOOT DEPT' Dif-REEs LFNGTH 178.6 NAUTICAL MILES K TABLE C.20 SUMMARY-PERTINENT PROBABLE MAXIMUI. hUWRICANE (PMH). STOIRM SURGE COMPUTATIONAL DATA AND RESULTANT WATER L•VEL' K WATER DEMT BELOW MLW FEET 0 50 96 "95 125 125 165 247 188 233 438 570 271 511 NIL 4 1,620 4 o17df TRAVERSE FROM SHORE SPEE OF TRANSLTION PARAMETER DESIGNATIONS SLOW HODERATF HIGH -.EMLPRESSURE INDEX P0 INCHES 27.61 27.61 27.61 PERIPHERAL PRESSURE Pn INCHES 30.25 30.25 30.25 ýRDU TO MXMWIND IARGE RADIUS NAUT. MI. •64 64 64 TRASIATION SPEED V (FORWARD SPEED) KNOTS I 19 39 53 "Vx M.P.H. 102 114 122 TINITIAL DISTANCE-NAUT.MID " 1P %A PMH 001PUTATIONAL COEFFICIE2IT AND WATER LEVEL (SURGE) ESTIMATES C 0 E F F . C I E N T S BTJOh F'HzICT'ON FACTOR 0.0025 WIND STRESS CORHEHTION FACTOR 1.10 w.Tz•, L,'v1L DATA (AT OPEN CCAST SHORELINE) 'PMH SPEED OF TRANSIATION COMPONENTS ST I MT HT F E E T WIND SETUP 9.73 PRESSURE SLTJP 1.82 INITIAL WATEW LEV. 0.56 ASTRONOMICAL 16.00 TIDE LEVEL- - tOTAL-SURGE 28.1 STILL WAT•R LLV. EETLM" LW TABLE C.21 OCEAN BED PROFILES PASS CRYSTAL CHESAPEAKE CI•RISTI" RIVER ST. LUCIE BAY MOUTH HAMPTON BEACH* Nautical Nautical Nautical Nautical Nautical Miles from Depth, Miles from Depth. Miles from Depth, Miles from Depth, Miles from Depth, Shore ft. I4LW Shore ft. HLW Shore ft. MLW Shore - ftj MLW Shore ft, MLW 1 2 5 10 15 20 30 40 50 60 70 77 0.55 2.31 6.25 8.33 31.4 100 113 127 3 9 12 13 35 36 40 52 90 160 335 600 0.1 10 16 18.7 3 10 14 9 50 180 300 600 10 90 390 600 5 10 30 50 55 62 44 56 102 178 240 600 0.5 4 10 25 44 20 120 250 250 600 * As developed for Seabrook r 70 0% G% C t 4.20 Dam Safety Tennessee Valley Authority 4.20-1 Reservoir Operations Study - Final Programmatic EIS 4.20 Dam Safety 4.20.1 Introduction The factors associated with dam safety relative to the proposed changes in system operations include: • Effects on reservoir-triggered seismicity (RTS) due to changes in filling or drawdown rates, or higher than normal reservoir levels; • Effects on dam stability of changes in seismicity, higher reservoir levels, filling or drawdown rates; and, • Leakage from dams in response to higher reservoir levels in areas of carbonate rocks with karst development. Potential impacts on these key elements of dam safety are all indirect effects of the policy alternatives. 4.20.2 Regulatory Programs and TVA Management Activities The Federal Guidelines for Dam Safety require that dams with a direct federal interest, which includes all dams in the TVA’s system, must be designed, inspected, and maintained throughout their operating life to verify and protect the structural integrity of the dam and appurtenant structures to ensure protection of human life and property. The requirements for design floods for dams that are the responsibility of federal agencies are contained in the following documents: • Federal Guidelines for Dam Safety, Federal Emergency Management Agency Publication FEMA 93, November 1998. • Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow Design Floods for Dams, Federal Emergency Management Agency Publication FEMA 94, October 1998. 4.20.3 Seismology Existing Conditions Reservoir-triggered seismicity is the initiation of earthquakes by the impoundment or operation of a reservoir. Reservoir-triggered earthquakes can be identified by a change in the pattern of earthquake activity in the immediate vicinity of a reservoir that usually begins during or shortly Resource Issues .. Reservoir-triggered seismicity .. Dam stability .. Leakage from dams 4.20 Dam Safety 4.20-2 Tennessee Valley Authority Reservoir Operations Study - Final Programmatic EIS after (days to a few years) initial filling of the reservoir. Rapid reservoir elevation changes can also trigger earthquakes. The mechanisms that control RTS—primarily increased pore pressures in fractured rock surrounding or beneath the reservoir and increased load due to water volume—are generally agreed upon. The relative importance of these mechanisms on a site-specific basis and whether individual reservoirs exhibit RTS are not as clear. While at least four reservoirs in the Southeastern United States exhibit RTS, the evidence for RTS at TVA reservoirs is weak at best. Many of the TVA reservoirs are located within the Southern Appalachian Seismic Zone, a zone that was active before the introduction of TVA reservoirs and continues to be active today (Reinbold and Johnston 1987). Earthquakes typically associated with RTS are more shallow than most southern Appalachian earthquakes. There have been a few instances of small, shallow earthquakes near TVA reservoirs (e.g., the February 1990 sequence of earthquakes near Tellico Reservoir); there have also been similar sequences of shallow earthquakes in the Southern Appalachians well removed from reservoirs (e.g., Bristol, Virginia in February 1988 and Greeneville, Tennessee in March 1995). If TVA reservoirs do exhibit RTS, it appears to be rare and would be difficult to confirm. To determine whether RTS is occurring or has occurred at any TVA reservoir, detailed seismic activity records would be required in the vicinity of all reservoirs for a few years before and for several years after the initial filling of the reservoirs. This type of seismic documentation is not available. The question of RTS at TVA reservoirs cannot be answered with confidence. If RTS does occur, however, it is not obvious based on earthquake data collected over the past 20 years (Chapman and Mathena 2001). Future Trends No trends have been identified relative to RTS; therefore, future trends are expected to be the same as existing conditions. 4.20.4 Reservoir Levels Existing Conditions Water levels at TVA reservoirs fluctuate under normal operations (see Section 2.2). In addition to the normal operating levels, the reservoirs are designed to withstand forces associated with a flood condition. All TVA dams classified as either high or significant hazard potential are capable of passing the applicable inflow design flood (IDF) as required by the federal guidelines with the exception of Chickamauga. Dams classified as high hazard potential are those dams where failure or improper operation probably would cause loss of human life. Dams classified as significant hazard potential dams are those dams where failure or improper operation would result in no probable loss of human life but could cause economic loss, environmental damage, disruption of lifeline facilities, or could affect other concerns. Dams that are classified as significant hazard potential are often located in predominantly rural or agricultural areas but 4.20 Dam Safety Tennessee Valley Authority 4.20-3 Reservoir Operations Study - Final Programmatic EIS could be located in areas with higher population and significant infrastructure. The hydrologic design for Chickamauga is under review to determine the applicable IDF and needed modifications, if any. Future Trends Reservoirs levels are variable year to year but fall within the flood guides for each reservoir. Levels would not be allowed to fluctuate such that dam safety was compromised. 4.20.5 Reservoir Drawdown Rates Existing Conditions Water pressure from a reservoir causes water to gradually infiltrate the surrounding reservoir rimrock, soil embankments, or foundations. Over time, internal pressures, called pore pressures, are created within the surrounding area. These pressures increase until the surrounding area reaches equilibrium. If the reservoir is rapidly drawn down after pore pressures are established, they may create unstable conditions in the surrounding rim that can cause slides or sloughing of the rim material. The structures that surround reservoirs that are subject to fill and drawdown cycles are designed to withstand the expected fluctuations of external water pressures and internal pore pressures. The design is based on an upper limit on the allowable rate of drawdown. Table 4.20-01 lists the maximum allowable drawdown rates necessary to ensure the stability of the dams within the scope of the EIS. Future Trends Under the existing operations policy, future drawdown rates would continue to be maintained within present limits. 4.20.6 Leakage Existing Conditions Some leakage, or unintended flow, is expected to occur at all dams either through structural joints, earthen embankments, reservoir rims, or foundation materials. Any leakage is evaluated during periodic dam inspections and a determination is made as to whether the volume, rate of change, and sediment content (if any) of the leak poses structural concerns. When necessary, the leakage is periodically measured and recorded so that trends can be defined. Changes in these trends can indicate that a more detailed evaluation of the seepage is warranted. 4.20 Dam Safety 4.20-4 Tennessee Valley Authority Reservoir Operations Study - Final Programmatic EIS Table 4.20-01 Drawdown Limits for Tributary Reservoirs Project1 Description Drawdown Limits2 Apalachia Concrete 3 feet per day not to exceed 12 feet per week Blue Ridge Hydraulic fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week Chatuge Impervious rolled fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week Cherokee Concrete and impervious rolled fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week Douglas Concrete and impervious rolled fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week Fontana Concrete 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per day not to exceed 12 feet per week Great Falls Concrete 2 feet per day not to exceed 12 feet per week Hiwassee Concrete 2 feet per day not to exceed 7 feet per week Norris Concrete and earth fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week Nottely Impervious rolled fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week South Holston Impervious rolled fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week Watauga Impervious rolled fill 2 feet per day not to exceed 7 feet per week for 28 feet, then 3 feet per week 1 For those reservoirs not shown, the drawdown rate would follow the rate shown for Blue Ridge. 2 Restrictions are based on dam safety and slope stability considerations. Source: TVA files - Dam Safety Group 2003. Table 4.20-02 details TVA reservoirs within the scope of the EIS that have been monitored for leakage. This table also indicates whether the amount of leakage would increase as the reservoir headwater elevation increases and, where known, describes the cause of the leakage. The data are reviewed periodically to assess the leakage and ensure the continued safety of the structures. Periodically, an Instrumentation Project Performance Report is issued, which reviews the history of the project, evaluates the appropriateness of the instrumentation and frequency of observation, identifies conditions that might threaten dam safety, and evaluates the structural and geotechnical performance of the dam. 4.20 Dam Safety Tennessee Valley Authority 4.20-5 Reservoir Operations Study - Final Programmatic EIS Table 4.20-02 Leakage Monitored at Non-Power and Power Projects Project Leakage Increases with Increasing Headwater Bedrock Leakage Mechanism Non-Power Projects Bear Creek Yes Limestone and shale Karst Cedar Creek No, seasonal Sandstone Unknown Little Bear Creek No, seasonal Limestone and shale Karst Normandy Yes Limestone Karst Tellico No, seasonal Limestone and shale Karst Upper Bear Creek No, seasonal Sandstone, shale and conglomerate Unknown Power Projects Blue Ridge Yes Schist and metagraywacke Spring along abutment/ embankment interface Chatuge Yes Biotite Gneiss Unknown Douglas (Dandridge Dike) Yes Unknown Foundation of dike Fort Patrick Henry Inconclusive Limestone, dolomite, shale Unknown Great Falls Yes Limestone and chert Karst Guntersville No Limestone Karst Melton Hill Yes Dolomite Karst Norris Yes Dolomite Karst Nottely Yes Schist, metagraywacke, metaconglomerate Unknown Tims Ford Yes Limestone and shale Karst Wheeler Yes Limestone Karst Wilson No, seasonal Limestone Karst Source: TVA files - Dam Safety Group 2003. Future Trends The trends exhibited by the leakage observed at TVA dams are shown in Table 4.20-02. These trends are expected to continue through 2030 due to the continued operation of TVA reservoirs under the existing reservoir operations policy. This page intentionally left blank. Hydrologic Research Needs for Dam Safety Analysis At the Tennessee Valley Authority By ound nnessee Valley Authority (TVA) was created in 1933 to provide for the unified ment of the Tennessee River Valley. The purpose of the Act is stated as follows: hereby created . . . the ‘Tennessee Valley Authority’ “ - Preamble. respect to planning, Section 23 requires the President to recommend to Congress gislation as he deems proper “ . . . for the especial purpose of bringing abo ity with said general purposes (1) the maximum amount of flood control, (2) the um development of said Tennessee River for navigation purposes, (3) the um generation of electric p ly for the purposes of promoting navigation and controlling floods. So far as istent with such purposes, the Board is authorized to provide and operate facilities generation of electric energy . . . and the Board is further authorized, whenever an nity is afforded, to provide and operate facilities for the generation of electric in order to avoid the waste of water power, . . .” structural approach to minimizing flood risk was the construction of dams with s an integrated reservoir system of 49 dams (1 project in the Cumberland Riv in the 41,000-square mile Tennessee River drainage basin covering portions of tates. Since these dams were built, significant flood reduction benefits ha along the Tennessee River and its tributaries, and along the lower Ohio and ippi Rivers. TVA dams also provide addition nomic development. reservoir system has been effective in providing over $5B in flood damage on benefits. TVA also recognized that structural measures could not eliminate g, and that there were about 350 communities in the Tennessee Valley with some of flood risk and damage potential. onse to this situation, TVA initiated a floodplain management assistance program based on the concept of averting local flood damages by careful land use g. This approach of working with state and local governments to deal w s was applied throughout the Tennessee River watershed. During this period, romoted the concept of av ate 1960s, TVA utilized its floodplain management experience to assist the Emergency Management Agency (FEMA) with the development of what ional Flood Insurance Program (NFIP). TVA served as a contractor to FEM s that TVA holds in stewardship, and nimize flood damages, ensure the safety of floodplain residents (by keeping the away from the water), preserve TVA’s reservoir operating flexibility for flood purposes, and ensure consistency with local floodplain regulations. TVA’ irs and the river reaches belo is one factor alone. afety Program Development ure of Teton Dam, President Jimmy Carter issued a 1976 memorandum to all Agencies with responsibilities for dams to develop and implement formal nes for dam safety. After participating in the development safety, and determine ore than $75M modifying these dams, with work underway at the remaining two s to ensure its dams meet these guidelines. Because most of TVA’s dams are high structures with significant potential for loss of life and property damage, TVA o modify its dams to safely pass the Probable Maximum Flood (PMF). ized the need to have an outside authority provide estimates of the P (PMP). Further, TVA recognized the need ervice (NWS) was funded by TVA to study two cate p extreme rainfa H (Reference 4). HMR 45, superseded by HMR 56 in 1986, was used in studies prior to HMR 56. These reports provided estimates of precipitation for large areas such as that a 00 square miles. These reports defined depth-area-duration characteristics and antecedent storm potentials. C One of the most controversial aspects of the TVA reservoir system is the annual operating cycle for the tributary projects. There are 10 tributary projects, which have a summer-to-winter fluctuation of from 35 to as much as 90 feet. The seasonally va allocation of flood storage was designed primarily to provide flood protection for the City o vide over 4 million acre-feet of flood storage space needed during the flood season from mid-December through early April. However, the economic benefits attributable t use of these reservoirs have changed over the years and now include enhanced lake front property value, recreational boating, fishing, swimming, wildlife habitat, minimum flow and dissolved oxygen (DO) enhancements, and related functions. Stakeholders, for many years, have questioned the need f to later in the fall. These reservoirs are typically at their highest level by June 1 of each year depending on rainfall/runoff. During June and July, they are gradually drawn to support downstream water quality and hydropower generation. After August 1 of eac year, the reservoirs have an unrestricted drawdown to lower them to their January 1 floo storage levels. In 1991, TVA completed the Tennessee River and Reservoir System Operation and Planning Review, an Environmental Impact Statement (EIS) that resulted in changes to its reservoir operating policie re review was on maintaining minimum flow below dams at critical times and location increasing DO below 16 dams by aerating releases, and to delay unrestricted summer drawdown until August 1 on ten tributary reservoirs. While flood control was a consideration in review of these alternatives w TVA established a Regional Resource Stewardship Council in March 2000 under the Federal Advisory Committee Act (FACA). The purpose of the Council was to pro advice to TVA on policies, priorities, and practices for managing its land and water resources and programs as part of its public responsibilities. The Council is made up o 20 representatives from across the Valley. They represent a range of interests in TVA’s stewardship activities, including representatives of the Governors of the seven TVA st educational and community leadership. This summer (2001) the Council recommended that TVA undertake a study of its reservoir operating policy to determine if changes could create greater overall value for TVA customers and stakeholders without reducing gains which had been realized in water quality. The study will include evaluation of costs and benefits. The TVA Board responded to this recommendation in October with a commitment to pe c conducted within the National Environmental P One of the major issues to be addressed will be the evaluation of potential change i flood risk that could result from a change in reservoir operating policy. The evaluati must ensure that the tools and analysis process must be capable of providing a clear understanding of how the flood risks could change. This should include impacts on floo frequency throughout the full range of flood potential from the annual event through th PMF, effect on local floodplain regulations as part of the NFIP, elevation and flow duration, and impact on dam safety. At this time there are severa c River Authority). Many factors are dr fl advances in weather forecast capabilities are viewed by the public as a reliable basis for reservoir operations well in advance of actual events; (3) studies raise questions abou previously completed flood frequency analysis and whether these changes in turn s result in changes to published information used for local floodplain regulations for 10 and 500-year flood boundaries and floodways; (4) the hydrologic period of records are increasing, coupled with more sophisticated computational methods and modeling capabilities; and (5) a growing interest on the part of the stakeholders that live along or use the water resource to change the allocation of benefits based on economics. Conclusion Research is needed to focus on flood risk assessment methodology that can be b References: 1. Ad Hoc Interagency Committee on Dam Safety, Federal Coordinating Council for Science, Engineering and Technology, “Federal Guidelines for Dam Safety,” June 19 2. U.S. Weather Bureau, “Probable Maximum and TVA Precipitation Over the Tennessee River Basin Above Chattanooga,” Hydrometeorological Report No. 41, 1965 3. National Oceanic and Atmospheric Administration, “Meteorological Criteria for Extreme Floods for Four Basins in the Tennessee and Cumberland River Watershe Hydrometeorological Report 4. National Weather Servic w Area,” Hydrometeorological Report No. 56, October 1986.