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HomeMy WebLinkAbout 5 - Safety ElementCity of Seal Beach Safety Element Safety Element Contents Introduction .................................................................................................................................... ..............................1 Purposeand Background ..................................................................................................... ..............................1 StatutoryRequirements ........................................................................................................ ..............................1 Topic 1: Emergency Planning/ Response .................................................................................. ..............................3 Household Emergency Planning ........................................................................................ ..............................7 Neighborhood Emergency Planning ................................................................................. ..............................8 Community Emergency Planning ...................................................................................... ..............................9 AccessI ssues ........................................................................................................................ .............................13 Underground Conversion of Overhead Utilities ............................................................ .............................18 Poti ci es ................................................................................................................................... .............................18 Topic 2: Hazardous Materials ..................................................................................................... .............................22 Policies................................................................................................................................. ............................... 27 Topic3: Geologic Haeards .......................................................................................................... .............................30 SeismicHazards Mapping Act ........................................................................................... .............................30 Geology................................................................................................................................. .............................30 Faultingand Seismicity ........................................................................................................ .............................33 GeologicHazards ................................................................................................................. .............................45 Landslides............................................................................................................................ ............................... 51 Tsunamisaid Seiches .......................................................................................................... .............................53 Poti ci es ................................................................................................................................. ............................... 54 Topic4: Fire H azards ................................................................................................................... .............................57 OrangeCounty Fire Authority .......................................................................................... .............................57 Fire Hazard Severity Classification Slystem ...................................................................... .............................57 Wildland Fire Hazard Potential ......................................................................................... .............................59 Topography......................................................................................................................... ............................... 59 Vegetation............................................................................................................................. .............................59 Climate................................................................................................................................... .............................60 DevelopmentPatterns ........................................................................................................ .............................61 Access.................................................................................................................................... .............................61 FireFighting Capabilities .................................................................................................... .............................62 Local Programs and Legislation ........................................................................................ .............................63 Building Codesand Landscaping Guidelines .................................................................. .............................63 Planning and M ai ntenance of Outdoor Areas Adj a.,ent to Homes ............................. .............................64 Ranting and Fire -wise Rant Choices ............................................................................... .............................65 WeedAbatement .................................................................................................................. .............................66 Water&Aem ........................................................................................................................ .............................66 Policies................................................................................................................................. ............................... 67 Topic5: Flood Hazards ............................................................................................................... .............................68 LocalSetting ......................................................................................................................... .............................70 Flood Protection Measures ................................................................................................ .............................71 WaterQuality Control ......................................................................................................... .............................75 Policies................................................................................................................................. ............................... 76 Topic6: Shoreline Protection ..................................................................................................... .............................78 TheEffects of Man ............................................................................................................. .............................79 LocalConditions .................................................................................................................. .............................81 Policies................................................................................................................................. ............................... 83 1 mplementation ............................................................................................................................. .............................84 City of Seal Beach General Plan S-i (12/03) Safety Element List of Figures Figure S-1 - Los Alamitos l mpact Zones, Joint Forces Tra ni ng Bas. .............................. ............................... 5 Figure S-2 - AELUP Height Restriction Zone for . FTB ...................................................... ..............................9 Figure S-3 - I mpa red Road Access Map ................................................................................ .............................14 FigureS-4 - Regional Seismic M ap .......................................................................................... .............................33 FigureS-5 - Fault Zone Map .................................................................................................... .............................39 Figure S-6 - Seismic Hazards/ Liquefa:;tion Zones ............................................................... .............................51 FigureS-7 - FEMA Flood Zones ............................................................................................. .............................73 City of Seal Beach General Plan &ii (12/03) Introduction Purpose and Background Statutory Requirements The Seismic Safety - Safety Element was originally adopted on July 14, 1975. As the result of subsequent changes in the re- quirements regarding General Plan Elements, the City decided on August 11, 1997 to renenethis Element (i.e., "Safety Ele- ment` ) and to expand its scopeto cover storm drainage, shore- line protection, and the use, transport, and disposal of hazardous materials. The Safety Element is organized into six topics and an imple- mentation chapter. Following the introduction, Topics 1 through 6 discuss separatesefety issues as they relate to the City of Sad Beach. Following the discussion in each topic arepoli- des to deal with the identified issues. The I mplementetion sec- tion of the Element indicates which City Department has primary responsibility for implementing each policy, how it will be funded, and the scheduled timing for implementation. The major topics discussed in the( afety Element are: Emergency Planning) Response Hazardous Materials Geologi c Hmards Fi re H wards Flood Hazards Sioreline Protection I mplementetion I n 1971, the California State Legislature required that all cities and counties adopt Seismic and Sefety Elements as part of their General Plans. The basic objective of the Sefety Element is to reducelossof life, injury, denageto property, and economic and social dislocation resulting from future natural and man - madehazards. To achieve this objective, the Safety Element is utilized asthemajor tool for identifying hazardsthat should be considered beforemeking land usedecisions. Mapping isre- quired of known seismic and other geologic hazards (such as Iandsiidearees), and issuessuch asemergencyevacuation routes and water supply for firefighting must beaddressed. City of Seal Beach General Plan S-1 (12/03) Safety Element Go,ernrre't Code§65302(g) requires a Safety Element that is de- velopedf or the protection of the community from any unrea- sonable risks associated with the effects of seismically induced surface rupture, ground shaking, ground falure, tsunami, seiche, and dam falure; slope instability leading to mudslides aid land- slides, subsidence, liquefaction, and other seismic hazard flooding and wildland and urban fires. A Safety Element shell also address evacuation routes, peak load water supply require- ments, and minimum road widths and clearances required around structures, asthose items relateto identified fireand geologic hazards. City of Seal Beach General Plan &2 (12/03) Topic 1: Emergency Planning /Response The potential for amajor caianity increases with the continuing urbanization of previously unpopulated areas and with the ad- vent of industrial processesthat utilize hazardous materials. The impactsof earthquake, fire, and flood aremagnified asmoreand more high -risk land is urbanized. Becauseof their unknown or unexpected nature, many emergencies requirequick and decisive action. Because disastersae dynamic and we conti nuelly lean through experience, emergency response and planning should also be dynarni c and continually maintained and updated. Sev- eral disatersin Sed Beach and in other communities in Califor- nia have taught us a great deal about disaster response. The City of Sed Beach adopted an Emergency Operations Plan in June 1996. This Plan details the City-s specif ic responsibilities before, during, and after any emergency. This Plan is consistent with the State Emergency Services Plan, which describes the re- sponseof aiI levels of government and certain pri vate sector or- ganizetionsto natural, man -made, or war - caused emergencies that threaten life, property, and the resources of California Sec- t i on 8568 of the California Emergency Services Act provides a basis for the City-s emergency management prograns by requi r- ing ci tiesto carry out the provisi ons of the State Emergency Services Plan. The City-s Plan is an extension of the state plan. The City-s plan describes how the City will respond in the event of, but not limited to, a state of war or act of terrorism emer- gency, natural emergency situations (earthquakes, fires, floods, storms and tsunamis), and man -made emergency situations (pol- lution spills, civil disturbances, aircraft accidents, industrial acci- dents, explosionsand radiological incidents). Emergenciesthet are preceded by a recognized buildup period allow for advance waning to those impacted areas and population groups. Timely waning and information broadcasts are important to citizens= ability to help themselves, and for their evacuation. Emergencies generally occur without advancewaning, and therefore require prompt mobilization and commitment of the emergency organi- zation after the onset of the emergency. Duringor following local emergencies, the City isthefirst agency involved. If the emergency is so I age that the Ci ty-s re- sources ae i nadequate or exhausted, assi stance wi I I be requested of, and provided by, neabyjurisdictions through mutual aid agreements. Neighborhood groupscan assist to the City by conductingfirst aid and search and rescue operations in timesof City of Seal Beach General Plan S-3 (12/03) Safety Element I age disasters. When mutual aid systems are not suffici ent for the disaster task, the County requestsass stance from the state. The Governor-s Office of EmergencyServices(OES)coordi- nates regi onal emergency response and disaster assi stance. The state may al so request ai d f rom t he f ederal government i n t he form of aPres dent ial Disaster Declaration. The Federal Emer- gency Management Agency (FE MA) then provi des di saster as- si stance, temporary housi ng assistance, and recovery funds after a Presidential Disaster Declaration. The City-s Emergency Services Plan lists three temporary seats of government in theevent City Hall isnot available. Theselo- cationsaretheSe1 Beach PoliceDepalment,theSml Beach Public Works Department, and Fire Station #48 on Beverly Manor Road. Duetotheclose proximity of all of thessalternate locations, none of these fa i l iti es are likely to be avai l abl e i n a major catastrophe such as an earthquake. The locations of alter- nate seats of government and emergency facilities have not been evaluated as to their effectiveness i n terms of location and re- sponse capabi I iti es. Mobility of the community to accomplish evacuation and the deployment of emergency personnel during any disaster is es- sential. A variety of emergency response challenges exist within the City of Sed Beach. The City is located in an area subject to strong earthquake impacts and flooding impacts. I n addition, the Los Alamitos hint Forces Traning Bass is located to the north of the City boundary, and flight operations from the Training Base generally take off over the City of Seal Beach, resulting in a potential for aircraft emergency responses, particularly in the cassof an aircraft accident (refer to FigureS -1). Thelargema- jority of flight operationsat theTraining Baseare helicopter op- erations, which do not result in amajor exposure to the general public in the event of an accident. City of Seal Beach General Plan S-4 (12/03) Safety Element f Cif R ES-S .f 1 VVEST MIIIVi7E ICE ..._._ - f � 7 r HUNTIIIG16N Nate: County Unincorporatec areas are shown in white Los Alamitos Impact Zones Joint Forces Training Base LEGEND CERTIFICATION —64— CNEL CONTOUR P,dclpled by the Purport. Land Use Commission for Change County - -- RUNWAY PROTECTION ZONE. sca4 i� rni - CITY BOUNDARIES - - - - - - Ican GoIdinq, Execut,ve Of ±c" r Ela9F Figure S -1 - Los Alamitos Impact Zones, Joint Forces Training Base City of Seal Beach General Plan S-5 (12/03) Safety Element Structures within the City should not exceed the elevations de- fined in the Federal Aviation Regulations (FAR), Part 77 "Ob- jectsAffecting Na/igebleAir Space,` asepplicebleto the Los Alamitos.bint ForcesTraning Base. These regulationsarethe guiddinesthat describe the ulti mete heights of structuresunder the "imaginary surfaces and would be used for determining if a proposed structure isan "obstruction` (refer to Figure S-2- AELUP Height Restriction Zonefor ,FTB). All developments within the City will be subject to the FAR Part 77 Notice Requirements. The sponsor of any project that re- quires thefiling of notification with the Federal Aviation Ad- ministration shall providecopiesof thecompleted FAA form 7460 -1 or 7480-1 to t he D i rector of Development Services and to the Executive Director of theAirport Land Use Commission. TheCitywill incorporetethefindingsof theAirport Land Use Commission and the FAA into its decision- making process a; it pertainsto individual projects. It is the City-s responsibility to develop evacuation plansthet readily and effectively remove residents from hazardous areas to locations of greater safety. The mandate of the City to protect public health, safety, and welfare requires the City to ensure that disaster planningwithin each neighborhood meetsboth the City -sand neighborhood -sinterpretation of acceptablerisk. In issues of overriding safety concerns, the City-s mandate requires affirmative action to maximize public safety. A discussion of emergency response and evacuation must focus on three levels of preparedness: the household, the neighbor- hood, and the community at large. Specific policy decisions and public actions must betaken at each of these levels to assure an acceptable level of risk for the City-s residents. Household Emergency Planning Household emergency planning refersto actionsthat areteken by private citizens to increacetheir own level of disaster prepar- edness. Emergency response at this level generally requiresthe dispatch of specific vehicles to serve specialized functions. The highest probability of an Evacuation occurs from individual households. Isolated occurrences arise due to structural fires or localized flooding, inexperienced in the 1983 storms and again in January 1995. Evacuation at the household level generally does not require public agency assistance, except to deal with the cause of the evacuation and medical care. Problems assod- City of Seal Beach General Plan S-7 (12/03) Safety Element ated with responseto individual households are generally related to street closuresdueto someimpa t directly related to thedis- aster incident itself. Families need to increasetheir general preparednessfor the most likely natural disastersthat could occur in their particular location. Many specific steps can betaken on the part of a homeowner to gain some autonomy and safety in the case of a natural disaster. Adequate supplies, training, and education about theeffectsof likely disastersand available support systems help in this regard. The City can support these individual house- hold effortswith vaiousservices, such as the periodic distribu- tion of emergency planning packetsthat provide up -to -date emergency planning information and response guidelines. Neighborhood Emergency Planning Neighborhood emergency planning requires the neighborhood and thecommunityto determinean axepteblelevel of risk and the resulting public actions to elevatedisaster preparednessto that level. Evacuation planning refersto the removal of people from aeas of extreme hazards to areas of public safety. Asa result of historic development patterns and constraints im- posed by local topography, the City is divided into geographic neighborhoods. These neighborhoods are an integral compo- nent of emergency response planning. Emergency planning should incorporatethe resources of theindividuaiswithinthese neighborhoodsand recognize the constraintseach neighbor- hood embodies. A citizen response model could be incorporated into the City-S Emergency Operations Plan that utilizes a neighborhood coor- dinatesystem of planning and response. This plan could also in- corporateacommunication component for information coordination and emergency resources allocation. It might be posaibleto designate individual neighborhood communication aitesand establish emergency local radio broadcasts. Neighbor- hood planning could build upon the Neighborhood Watch pro- gram. This program has been avictim of funding priorities, but as a responseto the requirement of the Emergency Plan to promote neighborhood autonomy, it could be re- invigorated and supported by City staff. For instance, aperiodic newsletter could beestablished to help keep the neighborhoods informed of the most recent advances in emergency response and coordi- nation. City of Seal Beach General Plan S-8 (12/03) Safety E lement AELUP Height Restriction Zane for JFTB f r t ` SEAL BEACH -4;F HU NT INGT O N r , BEACH Note: County Unincorporated areas are snowri ir, wt ae. Pj �-JJ4 t-, FAR PART 77 Notification Area for JFTB Los Alamitos: 20,000' Radius at 100.1 S1013e LEGEND CERTIFICATION -- OeN —.. 20.000' Radius I Adoptea tar the A ?pgrl larva use GOMM*'SWA for prate a, Cr Y BWNDMES Joan Gofcing, Ezecutfve Officer Da: Figure S -2 - AELUP Height Restriction Zone for JFTB f City of Seal Beach General Plan S-9 (12/03) Safety Element Community Emergency Planning Community level emergency planning indudesthedevelopment of an emergency plan to be initiated in the event of acitywide evacuation. The Emergency Operations Plan anticipates this type of concern, and i nd udes provisi ons for emergency hour ng, transportation, clothing, food, and medical aid. As neighbor- hood evacuation planni ng addresses evacuation routes from various neighborhoods, comprehensive citywide emergency planning i nd udes the development of a supportive i nf rastruc- ture responsive to the emergency needs of the community. As part of acommunity -wide response to evacuation planning, the City-s Emergency Operations Plan identifies the roles and relationshipsof all governmental, quasi- governmental, and pri- vate service agencies existing within the City and could be up- dated to inventory faalitieswithin thecommunity availablefor emergency responseneeds. Thisplan becomesoperational in the event of a local emergency and should be periodically up- dated. I n the event of acommunity -wide disaster, more than one evacuation center could need to be established within the City. Thescaleof such adisaster would preclude individual evacua- tion attempts from the community in favor of the effidency of mass evacuation. It isdoubtful that any roadway could a com- modatevehicular evacuation on acommunity- widescale. Citizens relocated to evacuation centers within the community would need to remain in those locations rather than add to the expected confusion on congested roadways. It is not anticipated that any new roadways serving the community would be needed for evacuation. I n the case of acommunity -wide disaster, the City would need to have coordi nated plans with local military organizationsfor theairlift of suppliesand for evacuation of residents requiring medical carebeyond thecapability of the community-s resources. The City of Beal Beach isfortunateto havethe Seal Beach Naval Weapons Station within its corporate boundaries. The Naval Weapons Station can provide personnel and equipment for emergency response activities, and can also serve asap evacua- tion center in thecaseof amajor earthquakein the City. The LosAla-nitosJoint ForcesTraining Bassislocated immediately adjacent to the College Park East neighborhood, and is desig- nated as a regional disaster relief center by the State of Caiifor- nia During amajor emergency responsein southern California, City of Seal Beach General Plan 5-11 (12/03) Safety Element the.bint ForcesTraning Basewould bea tivated for emer- gency medical purposes and for evacuation center purposes. The City-s Emergency Operations Plan should be updated to re- flect this needed coordination with the Naval Weapons Station and t he .bi nt Forces T rai ni ng Base. An Emergency Operations Center (EOC) has been established at the Sed Beach Pol i ce D epart ment to manage commu ni ty- wi de or neighborhood emergend es. City staff, along with other emergency response providers, would be utilized for staffing the EOCand have, at minimum, annual traning events toade- quetely support its operation. A public information officer is desi gnated in the Emergency Operations Plan, with procedures for obtaning and disseminating accurate i nformat i on set forth in the Plan. I n the event of an emergency, whether a natural disaster or a si tuation involving homeland security, the EOC will coordinate response activities with the County of Orange viathe Loma Ridge Emergency Operations Center located in the foothillsj ust off the Eastern Transportation corridor (SR 241) near I rvine Lake. During non - emergency situations, the EOC will liaison with the Orange County sheriff-s Emergency Management Group for disaster coordination and theTerrorism Early Warn- ing Group for Homeland Security Coordination. Another asset avalebleto the City in theevent of an emergency isthe large number of ham radio operatorswho reside in Sed Beach. These ham operators area part of a larger group of ha-n operators known as Radio Amateur Civil Emergency Services (RACES) who can be relied on for assistance during an emer- gency. As with all emergency planning, there must be ongoing mainte- nance and traning. This involves the allocation on the pat of City government of the necessary funding support for an ongo- i ng emergency management coordi nator. City of Seal Beach General Plan 5-12 (12/03) Safety Element Access Issues In Seal Beach, the College Park West community is accred by only one entry point, which creetespotentially undesirableac- cessin theevent of adisaster. The College Park East, Leisure World, and Surfside communities have only two access points, adjacent respectively to Lampson Avenue, Seal Beach Boule- vard, and Pacific Coast Highway, which could result in access difficultiesin amajor earthquakeor flooding situation (refer to Figure S-3 - Impaired Road Access Map). I n addition to these neighborhoods, many of the City-s major roadways are susceptible to circulation restrictionsand geologic or hydrologic hazards that could result in their closure duri ng critical periods. The number of access routes to any neighbor- hood is less signif icant than their ci rculation capacities (e.g., parking, travel -way width) and their susceptibility to closure by hazards (e.g., bridge damage, flooding). Some of the neighborhoods, such as College Park East, College Park West, and Leisure World, are not subject to major envi- ronmental constraints Iikean identified fault or fIoodway. Roadways that provide access tothessneighborhoods can not always remai n open, because under even mi nor adverse condi- tionssuch asadowned treeor electrical line, theseareasmay become i naccessi bl e. The City could undertake a comprehensive emergency access evaluation and upgrade program in which each public and pri- vate road/ trail is eval uated i n terms of providi ng emergency ve- hide access and identifyi ng access problema The goal of this eval uation and upgrade program would be to upgrade the ac- cess-defident areas by retrofitting the substandard roads/ routes in an appropriate manner, based on the results of this evalua- tion. I n addition, an emergency ci rculation system could bedes- ignated for evacuation and response. T he emergency ci rculation road/ route system could be ma n- tained at high priority levelsof policy and financial considera- tion. For instance, thepublic utility companiescould be consulted and encouraged to prioritizethe undergrounding of their utility I i nes along these routes. Tree maintenance could be emphasized on public right -of way and private property along these routes. City maintenance of these roads or emergency routes could receive f undi ng priority. City of seal Beach General Plan &13 (12/03) Safety Element As discussed above, the most severely access - restricted neighborhoods are College Park West, College Park East, Lei- sure World, and Surf side. These neighborhoods are si ngle -access or dual- access neighborhoods and are subject to environmental constraintsthat could restrict access. College Park West College Park West is recognized as an area subject to mul- tiplehazads. The major hazard that could minimize access is bridge collapse due to an ea-thqueke. Theneighbor- hood -sisolation, proximity to open spaceaeas, topog- raphic conditions, and wind patterns make it susceptible to a wi I dfireduring a Santa Ana wind condition. Asa result of t hess i dent i f i ed hazards, College Park Drive could become impassable. I n that event, emergency vehideswould be un- ableto obtain ingress, and vehicular egress of the residents would not bepossible. Thefirehazard potential exists in College Park West dueto thethreat of structural fire spread during aSantaAnawind condition. Thistypeof firecan trigger an evacuation re- sponse, particularly during aSantaAnawind condition. It is imperativeto residents: safety that alternative routes of evacuation beestablished in the College Park West Tea Any routelocated too doseto the existing roadway could quickly succumb to the sane hazard that forced closure of the existing roadway. The location of College Pak West adjacent to the San Gabriel River and the 1 -405/ 1- 605/ Seventh Street interchange maketheoonstruction of an evacuation routein thisaeaappea to beaesthetically and economically unsound. The City needsto continueto investigateand implement an emergencyaccessroutethat will meet thesafety needsof this neighborhood and will be consistent with community economic and environmental goals. An emergency access connection should beinvestigated utilizingtheSan Gabriel River I evees. City of Seal Beach General Plan S-14 (12/03) anaa� � NagaV9 SlISN HWs�4M -ear eeMEW ■. ■fir e,•,aae� epee ■ ■ree ■e ■ ■ee�eer` ■ ■; ■ ■ 3 Q I p D ■ CL ■ C�7 •_r � ■ r eC ■ R : - N R I ■ + I Z �! i■ ■se• F / t ■ It anm�raa ,.3s t • •■ ■cart "� t `•r .; � rata + & � � *► Syr � �, ..,..,.,. �� + o 6 i17 IP 2 * ±'� • • W LLI 0 z • r •t i s m E vo 0 LLJ LLI (If IT LL L1J 0-0 ° 1,- cn _ ¢I dQ❑ Z tr ZLW8 - m00 N 2 LLJ z W €emu a C]O❑ ti m i W ■ � °v I N W c� Q M N Q V V cv O Q `e 'M^ V! L LL �n U U7 w O cn O •.r N V Safety Element College Park East, Leisure World, and Surfside These communities, although not as restricted by access is- sues, face similar concerns to College Park West. These communities are subject to similar firehazard exposures as exist in College Park West dueto thethreat of structural firespread during a SantaAna wi nd condition, with Surf - side havi ng the greatest Exposure due to the bui Idi ng stan- dards in that community. A wind - driven fire can trigger an evacuation response, particularly during a SantaAnawind condition. I n recognition of the greeter fire hazard poten- tial in Surf side, the City has required for some time that all neN construction in Surfside provide residential fi re spri n- klers approved by the Orange County Fi re Authority. It is imperativeto residents: safety that alternative routes of evacuation beesteblished in these communities. Any route located too dose to the existing roadway could quickly suc- cumb to the same hazard that forced its closure. College Park East is served by Larnpson Avenue, with two access points, one to Sed Beach Boulevard, and the other to Val - ley VieN Street in the City of Garden Grove. Leisure World has two major access points, both from Seal Bead Boule- vard. The southerly access point is located adjacent to Lei - sure World Center, which providesan additional access point to Westminster Avenue. Surfside hastwo access points, both of which ultimately access Pacific Coast Highway. Theprimary eccesspoint isat Phillips Street, with direct accessonlyto Pacific Coast Highway. Thesec- ondary access point, at Anderson Street, provides access to Pacific Coast Highwayat Anderson Street or alternateac cess points to Pacific Coast Highway byway of Pacific Avenue in Sunset Beach. The location of these neighbor- hoods, adjacent to freeways, dranagechannels, the San Gabriel River, and the Pa ific Ocean make the construction of evacuation routes i n these areas appear to be aestheti- cally and economically unsound. The City needsto continueto investigeteand implement an alternate emergency access route system that will meet the safety needsof these neighborhoodsand will beconsistent with community economic and environmental goals. The provision of pedestrian walkwaysfor the Leisure World and Surf side communities could beestablished relatively easily to fa ilitate evacuetions by foot. Vehicular access, however, would involve significant construction dueto ex- istingsiteconditionsat each of these neighborhoods. City of Seal Beach General Plan 5-17 (12/03) Safety Element Underground Conversion of Overhead Utilities Policies Overhead utility I i nes are known hazardsthet can be mitigated by relocating them underground. Downed power lines can re- strict and delay emergency response vehicles and evacuation. Heavy windscan cause t ree branches to knock down power lines, creating asafety hazard, and power polesand utility boxes are hazards in road rights -of way. ,%rfside has recently completed acomprehensive utility under- ground conversion progra-n, and there are no overhead utility servicespresent in Surfsideat thistime. Thisprogra-n wascom- pleted through a resident- approved assessment district. 1A. Periodically revieN and update the Emergency Opera- tions Plan to ensure effective implementation of the Plan during an emergency. I ncorporate i nto the Plan as ap- propriate: (a) acitizen response model using a neighborhood co- ordi nete system, such as a N eighborhood Watch program; (b) a comprehensive communications component that maximizes public emergency coordination, re- sponseand resource allocation; (c) aprogra-n of coordination with county, regional, state, and federal emergency agencies, schools, hospitals, and utility companies and their plans; and (d) aprogra-n of coordination with the police. 1B. Amend the Emergency Operations Plan to indude evacuation plans, and indudeprovisionsfor emergency shelter, transportation, clothing, food and medical ad, identifying the facilities and personswithin thecommu- nity that may be utilized in an emergency and communi- cating this information to neighborhood associations and theAmerican Red Cross. 1C. Conti nueto mantan the Emergency Opereti ons Center (EOC) and providefor its adequate support and staffing, City of seal Beach General Plan S-18 (12/03) Safety Element includingtheaxquiaition and mantenanceof amobile Incident Command rapport vehidefor emergency re- sponse. 1D. Conti nue the f unction of an emergency management co- ordinator within t he Pol ice D epartment. The duties of this position shall include, but not be limited to, ongoing training for and operation of the Emergency Operation Center, neighborhood emergency planning and support, ongoing mantenanceof the Emergency Operations Plan, general publictraningand education, and implementa- tion of the City-s emergency planning and coordination. 1E. Ensure the periodic participation of appropriate City staff members in exercisesdesgned to familiarize them with disaster response procedures and operational sup- port for the Emergency Operations Center. 1 F. Promote publ i c awareness i n emergency response pre- paredness by any effective informational media, such as an Emergency Preparedness Ne sletter, neighborhood posters, and regular presentations at neighborhood asso- ciation/ neighborhood watch meetings. 1G. Ensurethat disaster preparedness exercises by involved agend es are f requent enough to help improvetheeffi- ciency of participating mutual aid agencies. 1H. E nsure t hat any new st reet t hat serves as aocess to resi - dent ial development of 5 o more dwelIing units has a minimum of 2 contiguous 10- foot- widepaved travel Ianesthat will remain unobstructed at all times. 11. U ndertake a comprehendve emergency aocess eval uation and upgrade program that: (a) will evaivateeach public and private road and neighborhood in terms of providing emergency vehicle access and evacuation routes, i nd udi ng pe- dest ri an accessnrays or t rai I s; (b) will establish aprogram to upgrade adefici ent roads by retrofitting them with no- parking fire lanes(established in conjunction with theaffected homeowners), turn - grounds, and/ or secondary ac- cess; and City of Seal Beach General Plan &19 (12/03) Safety Element (c) will develop aprimary and secondary emergency circulation plan for evacuation and emergency re- sponse. 1J. Encourage emergency vehicular accessthat isof asuffi- ci ent width to allow people and emergency equipment into the hazard area and still allow for evacuation, if needed. 1 K. Establ i sh and ma nta n no parki ny tow avay zones i n el I critical areas where f easi ble to keep travel lanes and street turn - around areas unobstructed at all times. 1L. Evaluatethelocation of all public facilities necessary for emergency response i n relation to the City-s current Haz- ard Maps and the level of risk associated with their loca- tions, and move facilities located in high or extreme hazard areas to areas I ess subject to hazards, if feasible. 1M. Ensurethat any new public facilitiesaredesgned and lo- cated in such a manner as to d i mi nate potenti al hazard impactsthat may reduce the utility of the facility follow- ing adisaster. 1N. I nform utility companies of potential conflicts between the location of their facilities and the currently identified high or extreme hazard areas and encouragethem to program for relocation or undergrounding of potentially impacted facilities, especially along designated primary emergency routes. 10. EvaluatetheCity -sabilityto relocate service equipment, facilities, and thereat of government on an emergency basis in the event of the occurrence of a hazard that might impact existing service locations. 1P. I niti ate di scussi on with utility companies to identify, es- tablish, and maintain local emergency service facilities. 1Q. Continue to encourage the underground conversion of overhead utilities in existi ng developed areas of the City and continueto requireany new development to under- ground utilities. 1R Ensure compliancewithin the City of Beal Beach with the N otice Requi rements of Federal Aviation Regulations Part T7," Objects Affecting NavigableAirspace,` and City of Seal Beach General Plan 5-20 (12/03) Safety Element with the referral requirementsof PudicUtilitiEsCcd,- Chapter 4, Artide 3.5, §21676. City of Seal Beach General Plan &21 (12/03) Topic 2: Hazardous Materials There are many definitions and descriptive narnesbeing used for the term hazerdaasmate'ial$ each of which depends on the nature of the material. For the purposes of this topic, the definition in §25501(k) of the H Edth and SENy Codewi I I be uti I ized: Any material that, because of its quantity, concentration, or physical or chemical characteristics, poses a significant pre- sent or potential hazard to human health and safety or to the environment if released into thework placeor theenvi- ronment. Hazardous materials include, but are not limited to hazardous substances, hazardous waste, and any material which ahandler or the administering agency hasa reason- able basisfor believing that it would beinjuriousto the health and safety of personsor harmful to theenvironment if released into the work place or the envi ronment. Hazardous materials are manufact ured, transported, stored, used, and disposed of on a regular basis Although hazardous meteri el s i nd dents can happen almost anywhere, certain areas are et higher risk. Areas near roadways, rai I wags, pipelines, air- ways, and weterwaysthet arefrequently used for transporting hazardousmeterielsand ereasneer industrial facilitiesthat use, store, or disposeof such materials havean increased risk. The primarytransportetion routesof hazardousmeterialsin Orange County near the City of Seal Beach are the I -405 and 1 -605 freeways Some transportation of hazardous materials occurs on Pacific Coast Highway and Set Beach Boulevard within the City. T he City does not have di rest authority to regulate the transport of hazardous materials on state highways The United States Department of Transportation hasesteblished regulatory criteriafor safe handling and transportation of hazardous mate- rials. N umerous petroleum product producers with large storage fa- dlitiesmeintein hundredsof milesof pipeli nes throughout the county. However, no major oil pipelinespassthrough the City of Seel Beach. Westmi nster Avenue has a 12.75 -i nch Southern California Edison fuel line, which provides fud to the generet- i ng stations i n Long Beach and H unti ngton Beach, located within its entire right-of-way withi n the City. A 16 -inch Long Beach Gas I i ne f ol lows the southerly right -of -way of the 1 -405 Freeway through its enti re length in the City. Southern Califor- nia Gas Company ma nta ns a 34-i nch gas I i ne general ly along City of Seal Beach General Plan S-22 (12/03) Safety Element Lampson Avenue, Seal Beach Boulevard, and the 1 -405 Fre6way right -of -way. Statistically, the greatest danger to petroleum products I inesend natural gas lines is an accidental dig-in dueto road maintenance and utility or traffic signal systems repairs, renovations, and new construction. Protection against dig -ins is provided by Dig Alert (Underground Service Alert of Southern California), autility- I oceti ng service pai d for by the subscribers of the service ad made up of counties, cities, and public private utility companies in Southern California A valuabletool now availableto the City is the geographical information system (GI S) computer pro - grarn. I mputing the locations of major petroleum products lines and natural gas lines into the City -s GISdatebasewill provide valuable information for the Emergency Services Plan. I n this manner, the City will beableto isolate graphically thoseareas wherethese facilities would be in danger of failure during a seismic event or other emergency and then develop a planned response to thefai Iure. The ai rspece mound the City of Sed Beach is among the busiest i n the nation. Hazardous materials may be transported by ai r over Seal Beach or to desti nations at John Wayne Ai rport, Long Beach Airport, and Los Alamitos Joi nt Forces T rai ni ng Base. Finally, because Seal Beach isacoastal city, it isexposed to oil tanker trafficaswell asother shipscerrying hazardousmaterials, particularly Navy ships utilizingtheSgel Beach Naval Weapons Station. Because of the distance of the major hazardous materiaistrens- portation routes to t he resi dent i el areas of Set Beach, thethreat of asignificant hazardous materials emergencyisminimal. Pre- vailing weet her conditions and topography at theinddent scene will largely affect the potential magnitude of haffdous materials incidents. Wind direction and velocity, ambient air and ground temperature, and precipitation and humidity will affect the spread of gases, vapors, mists, and the dusts of hazardous mate- rials. Topography can greatly affect the behavior of gases and liquids. The most likely haffdous materials exposure is use of haza'd- ous materials within the City limits. Household cleaning prod- ucts, pool chlorine, dry deaningchemicels, film processing, jewelry making, hospitals, and automobile servid ng involve haz- ardous materials and wastes. The Orange County Fi re Authority needs to oontinueto identify and monitor commercial and in- dustrial users of hazardous materials. It is not reasonableto City of Seal Beach General Plan &23 (12/03) Safety Element closely monitor the use of household hazardous materials, but the City has committed, through its state-mandated Household Hazardous Waste Ran, to several actions, induding educational campaigns regarding reduced usage and proper disposal; pro- moting the County-s Household Hazardous Waste Collection Centers (the nearest is located in Huntington Beach); and nego- tiati ng for annual County - sponsored collection events in Sed Beach. (Each of these collection events costs between $30,000 and $50,000 for an estimated 300 to 400 users or partici pants.) The City of Sed Beach planned responses to radiological and hazardous chemical release conditions are provided for in the County of Orange Hazardous Materials Area Plan. This is a state- mandated plan with established criteria The primary goal of this plan is to achieve the preservation of life, property and environment with themost effectiveand economical allocation of resources during a hazardous materials emergency. The City of Sed Beach isaparticipant in the Orange County Hazardous Waste Management Plan, which provides options for siting of hazardouswastecollection, treatment, recycling and disposal fa- cilities throughout the County. Together, these plansestablish the City-s responsibilitiesand goalsand policies in deaiingwith a hazardous materials incident and with the identification, storage, and disposal of hazardousmaterialsand wastes. The City currently requi res the partici pation of busi nessesin the Hazardous Materials Disclosure Program. Thisinvolvesthedis- closure, at thetimeof obtaining aCity business license, of whether the busi ness wi I I generate or use any of the hazardous materi al s contai ned on the list of such materials, as well as their quantities. This information isforwarded to the Orange County Fi re Aut hori ty, Hazardous Materials Program Office, which de- termi nes a schedule of onsite i nspections. These i nspections currently occur at one- to two -year intervals. During the inspec- tions, there is a revievr of the busi nesses- hazardous material safe - handling, storage, dispensing, and disposal criteria Any noted disposal violations are appropriately followed up by the Fire Authority. The City currently contracts for services for small hazardous material spills, which primarily entails deaning up spills assod- ated with vehicular accidents. Large spills of hazardous materials would involve a response f rom the Orange County Fire Author- ity, which has four Level A Hazardous Materials Mobile Units. The City hasajoint powersagreement with the County for mu- tual aid and joint cost support of these units I n very largespills of hazardous materials, a responsible party is identified, and pri- City of Seal Beach General Plan 5-24 (12/03) Safety Element vatefirms are cont ra ted for an appropri ate and safe dean -up of the si te at the respond ble pa-ty-s expense. Gasolinein underground storagetanksin service stations is con- sidered to bea hazardousmateriel. State, county, and city Health and Fi re Codes requi re special tanks for underground storage. Seal Beach is i n the process of removi ng the known non- complying tanks. Monitoring of somesitesisstill taking pleceto identify any contaminants requiring dean -up. Marine oil spi I Is are consi dered to be a hazardous material emer- gency and aretypically multi - jurisdictional events. The City of Seel Beach is a participant in the Orange County Operational Area Marine Oil Spill Contingency Plan (OSCP). The OSCP is a component of the Orange County Hazardous Materials Area Plan. TheOfficeof Oil Spill Prevention and Response(OSPR) and the U.S. Coast Guard haveprimary respond bilities for the dean -up and response effort in coordination with the responsi- bleparty. The shoreline is a very significant environmental and recreational resource to the City that could be adversely affected in the event of an oil spill, particularly with the Sad Beach Na- tional Wildlife Refugebeing directly exposed to oceen waves through Anaheim Bay. The City of Seel Beach will continue to oppose offshore oil drillingwhen environmental, aestheticand economic resources are t hreatened and will continueto monitor thefederal government-s offshore leasing program to ensure that the impacts of the program on the coastal environment are known and considered. The Sed Beach Naval Weapons Station and the Los Alamitos Joint ForcesTraning Baseareboth involved in I nstellation Res- toration programs to remediate past practices that have resulted in violationsof appropriate groundwater, surfecewater, and soil contamination standards of the state and federal government. Both of these facilities have established aRestoration Advisory Board (RAB), which comprises appropriate state and federal re- viewing agendesand the general public. The City is represented on the Naval Weapons Station RAB, and ci ty staff provides in- formation to the City CoundI and the Environmental Quality Control Board regarding proposed restoration activities, and will proposecomments regarding those proposed activities. Al- though not amember of the LosAlarnitos Joint Forces Training Base RAB, the City does receive documents relating to restora- tion activities, and does revieN and comment on those activities also. City of Seal Beach General Plan 5-25 (12/03) Safety Element Asa storage facility for naval ordnance, the Sed Beach Naval Weapons Station is a source of hazardous materials. As such, the Navy has developed weapons handling procedures to safe- guard against thepotentiel of an acddent involving hazardous materials. Another possi ble source of a hazardous material is a sewage spill or amixing of sewage, industrial wasteor pollutant discharges with storm dranagewaters. This is naturally not ao✓eptable, but operational maintenanceand system capacities must support the strict performancestandard of proper separation and treatment. I n Seal Beach the San Gabriel River has been particularly prob- lematic in regards to water quality. The State Water Quality Control Board is charged with the responsibility for improving water quality in creeks and the ocean. The Los Angeles Regional Water Quality Control Board hasjurisdiction over the San Gabriel River. Each year, awinter storm "first flush` will ad- versely impact thewater quality in the San Gabriel River, which directly impactswater quality along thebeach areaadjacent to themouth of the San Gabriel River. These adverse water quality ind dents havecaused Orange County health officielsto dose Seal Beach to water recreation activities on many occasions. Ad- versewater conditionscan have serious health consequencesfor swimmers. Human and animal wastes carry bacteria and viruses that can cause hepatitis and typhoid fever, although the most common ailment is diarrhea according to Orange County health officials. TheSed Beach City Council has requested theappro- priatewater quality agenciesto develop prograrnsto protect the water quality of water emptying into the San Gabriel River, and ultimately into the Pacific Ocean. The SantaAna RWQCB, under the authority of the State Water Resources Control Board, has the authority for permitting waste dischargesto land or surface waters through aNational Pollu- tion Discharge Elimination Sjstern (NPDES) permit and also formulates and adopts a Basi n Plan for the Santa Ana Region that defineswater quality objectivesand beneficial uses. The Santa Ana Basi n Plan sets narrative and numerical objectives that must be atta ned (or ma nta ned) and descri bes i mplementa- tion programs to protect all waters in the region. The N PD ES storm water management program also cal Isfor the implemen- tation of Best Management Pract i ces (BM Ps) to the " mad mum extent praticable(MEP) in provi di ng cont rol for non -point sourcepollution and urban runoff. BMPsconsist of activities, practices, and/ or proceduresthat reducenon -point sourcesof pollution such as automotive by- products, trash, food wastes, City of Seal Beach General Plan 5-26 (12/03) Safety Element Policies Iandscapeand agricultural runoff, includingferti I izersand pesti- cides, and runoff from construction sites.` 2A. Coordinatewith federal, state, and county hazardous wastemanagement plansto protect the health and welfare of the public, theenvironment, and theeconomyof the City of Sed Beach through comprehensive programs that ensuresafeand responsiblemanagement of hazardous waste and materials. 2B. Implement themeasuresoutlined in theCity-s Household Hazardous Waste Plan, Orange County-s Hazardous Waste Management Plan and HmardousMaterialsArea Plan, and the County -s Operationel Area MarineOiI Spill Contingency Plan to ensure t he eff ect i ve management, transportation and disposal of hazardous waste on aCity- wide level. 2C. Support enforcement of state "right to know` lairs, which outline the public -s right to information about local toxic producers. 2D. Encourage and support the use of alternatives to toxic materials in the home and yard. 2E. Encourage and support the use of antral drop -off centers and/ or mobile collection vehiclesfor proper disposal of hazardous materials. I nvest i gate the establishment of drop -off centers and/ or mobile collection vehicleswithin the City and the establishment of a user fee to pay for such services. 2F. Facilitate coordinated, effective responseto hazardous materials emergencies in the City to minimize health and environmental risks. 2G. Promote public awareness in hazardous materials emer- gency response preparedness by any effective informa- tional media, such asap Emergency Preparedness Newsletter, neighborhood posters, and at least annual presentationsat neighborhood association meetings. 2H. Support the continuation of the Orange County FireAu- thority-s hazardous materials disclosure program. Ensure City of seal Beach General Plan &27 (12/03) Safety Element annual i nspections of bus nesses that generate or use haz- ardous materials, and identify and monitor any historical hazardous materials sites withi n the City for public health and safety issues. 21. Promote public participation and education in the imple- mentetion of the programs identified in the County-s H azardous M ateri al s M anagement Progre n. 2d Encouragethe FireAuthority to monitor theflow of haz- ardous materials through the City to ensure public safety. 2K. Encourage coordi nation between the Orange County Fi re Authority and the Beal Beach Police Department in the designation of routes and enforcement of hazardous ma- terials, routing ordinances, and lairs, with the 1 -405 Free- way as the pri may dedgneted route. 2L. Oppose offshore oil leasing because potential offshore oil spi I I s are a hazard to people and maxi ne resources. 2M. Monitor thefederei government-s offshore oil leasing progran to ensure that the impacts of the program on the coastal environment are known and considered. 2N. Fad I itete the proper separation of server and storm drain systems through construction upgrades and operation and ma ntenance of sewer and storm drain i of rastructure to eliminetetheflow of sanrageinto the City storm drains. 20. Fad Iitatecoordination and participation by all of theju- risdictions that make up the Los Angeles and SantaAna Regional Water Quality Control Boardsto improveweter quality. Encourage the elimination of server dischergesend non -point sourcepollution into the San Gabriel River. 2P. Monitor the I nstelletion Restoration a tivities of the Set Beach Naval WeeponsStation and the LosAlanitos,bint Forces T ra ni ng Base, and attempt to ensure that any site restoration activities are conducted to residential dean -up standards and comply with all appropriate regulatory agency requirements. 2Q. Minimize the presence of animal fecal wale, which jeop- ardizes the public health. City of Seal Beach General Plan S-28 (12/03) Safety Element 2R Limit disturbanceof natural water bodiesand drainage systems, conserve natural areas, protect slopes and chan- nels, and mi ni mize i mpacts f rom storm water and urban runoff on the biological integrity of natural and dranage systems and water bodies. 2S. Minimizechengesin hydrology and pollutant lowing, re- quireincorporation of control, i nd udi ng structural and non - structural BMPsto mitigate the projected increases in pollutant lows and flows, ensure that post - development runoff rates and velocities f rom a site have no significant adverse impa t on downstreern erosi on and streern habi- tat, minimizethequantity of storm water directed to i m- permeebl e surf aces and theMS4s, and mad mizethe percentageof permeable surfaces to allow morepercola- tion of storm water into the ground. Zr. Preserve wetlands, riparian corridors, and buffer zones and establish reasonable limits on the clearing of vegeta- tion from the project site. 2U. Encourage the use of water quality wetlands, biofiltration swales, watershed -scale retrofits, etc. where such measures are likely to be effective and technically and economically feasible. 2V. Provide for appropriate permanent measures to reduce storm water pol I utant lows in storm water from the de- velopment site. 2W. Establish development guideli nes for areas particularly susceptibleto erosion and sediment loss. City of Seal Beach General Plan 5-29 (12/03) Topic 3: Geologic Hazards Seismic Hazards Mapping Act Geology Regional Setting Prompted by damaging earthquakes in northern and southern California, in 1990 the state legislature passed the SdsmicHaz- ards Mapping Act. The purpose of this Act is to protect public safetyfrom theeffectsof strong ground shaking, Iiquefaction, landsl ides end other ground failures, and other hazards caused by earthquakes. The State Geologist is mandated to prepare "Seismic Hazard Maps` that delineetethefollowing seismic hazard zones: Q Amplified shaking hazard zones, Q Liquefaction hazard zones, and Q Earthquake- induced landslide hazard zones. The seismic haea ds maps are 7' /2 California Geological Survey Quadrangles (Scale 1- 24,000). The seismic hazards maps for the Seal Beach area were rd eased on March 25, 1999. The map shows areas where liquefaction or landslide movement is known to haveoccurred and areas where the potential existsfor lique- faction or landslide movement (refer to Figure S-6 on page 51). Southern California is composed of several tectonic plates that move relative to each other. The primary zone of contact be- tween these plates is the San Andreas Fault zone, lying about 60 miles north/ northeast of the City of Sad Beach. The area west of the San Andreas Fault is known as the Pacific Plate, which is moving north relative to the North American Plate on the east side of the fault. Each large plate is composed of smaller plates, moving relative to each other. The relative movements and col - lislonsof these plates have created structures and geomorphic features with variousorientationa TheCityof Seal Beach isin the LosAngdescoastal plain in the Peninsular Rangesof southern California, madeup of hillsand rangeswith intervening, long, and narrow valleysthat trend northwest. Some of the higher peeks in Southern California, City of Seal Beach General Plan S-30 (12/03) Safety Element Topography Faulting and Seismicity Seismic Measurement such as San Jacinto peak at 10,831 feet above sea I eel , are i n the Perri nsul ar Ranges. M uch of the coastal margi n has si ngl e or multiple wide flat benches upon which the highways and coastal cities are situated. The City is shown on the Regional Seismic Map (Figure S4 - Regional Sesmic Map). The City of Sea Beach is in a zone of deformation extending from the foot of the Santa MonicaMountansnear Beverly Hills, southeasterly asfar as NeNport Beach. It is called the NeNport- Inglewood belt of hills and plans. This belt isactually the surface expression of the NeNport-IngleNood Fault zone. The zone variesin width from one to four miles and includes series of folds that ha/egiven rise to most of the surf acehi I I s, plans, and mesas. The f let areas represent segments of the R ei s- toceneland surfacethat was uplifted, tilted southward, and folded by earth movements. The majority of the City is located within an al luvial plan that extends southward from the convergence of Coyote Creek and the San Gabriel River. The two channelsdran from the north - east and north, respectively, and thecombined flow reachesthe seaet AlarnitosGep. Landing Hill, located within Seal Beach, and Alamitos Heights in Long Beach and Bolsa Chica Mesa in Huntington Beach, consisting of uplifted blockswithin the NeNport -I nglewood Fault zone, arethemajor topographicfea- tureswithin and near the City. Elevations within the City very from approximately sea level along the Padfic Ocean to 60 feet at Landing Hill. The Landing Hill areaispa-t of theNeNport- I ngleNood Fault Sjstem. Earthquakes are measured two different ways -4he Richter scale (magnitude of energy released) and the Modified Mercelli scale (i ntensity of movement or affects of shaki ng). The Richter scale is awdl known, but often misunderstood, sys- tem used primarily by sasmologiststo eveluateand comparethe energy of individual quakes accordi ng to an absolute and objec- tive scale. The magnitude of energy released is calculated from t he i nst rumental record made by the event on acdibrated seis- mograph. Sei smogrephs record a zi gzag t race t hat shows t he vayi ng anpl it ude of ground osd I I at ons beneat h t he i nst rument. City of Seal Beach General Plan 5-31 (12/03) Safety Element Magnitude is expressed in whole numbers and decimal fractions. Because of the logarithmic basis of the scale, each whole num- ber i ncrease i n magnitude corresponds to the release of about 30 times more energy than the amount associated with the preced- ing whole number value. The 1906 San Francisco earthquake with a magnitude 8.3 generated 1 million times more energy than the4.3 magnitudeearthquakethat occurred in Laguna Beach in 1969. Furthermore, the Richter magnitudedoes not giveany indication of theatuel damagecaused bythequake. Other factors must be considered: distance to the epicenter and its focal depth, as well a; geological conditions at the location of damage. Even with these data, the Richter magnitude is more meaningful and useful to the scientist than the layman. The Modified MercalIi scale is subjective and related not to the energy released, but to people-s perception of the quake and the damage done, asdetermined by field surveys. This scale is more significant to the public, si nce its steps are del i neeted by cracked plaster, fallen buildings, ground failure, and citizens+ panic, rather than energy relationships measured by instruments. The Modified Mercalli Scale provides a description of theeffect of the different levels of earthquake intensity with the correspond- ing Richter scale (refer to Table S-1). The Los Angeles Basin in which the alluvial plan is located is one of the most active seismic regionsin the United States. Each year, low and moderate intensity earthquakes occur within or near the region. Southern California is likely to experience, on average, one earthquake of M 7.0 and ten earthquakes of M 6.0 over a period of ten years. There are several active and poten- tially ativefault zonesthet could affect development in the area Maximum credible earthquake (MCE) magnitudes resulting from potential seismic activity on various active faults are dis- cussed in thefollowing section and presented in Table S-2 on page 42. City of Seal Beach General Plan &32 (12/03) Safety E lement SEAL BEACH REGIONAL SEISMIC MAP KIZ-\ .N7A FA UL T. 0, L, L Ar I I - HILL a MALIBLJ COAST FAUL r k I T K4 N I A ri t P P r- rL e ..., 6 v xu-, mpv�t . .......... P��! --------------------- ---- A ...... L-i", �u i E I-C - FSADFNA a F- HE LL, O 0 o H I I I IF f, % SANTA ANA SE a A vi ij F e E AC M Cb Figure 5-4 - Regional seismic map DATE: 1 A12002 OAT A $ OORCE: CITY 0 F SEAL BEACH t City of Seal Beach General Plan &33 (12/03) Safety Element Table S -1 - Modified Mercalli Intensity Scale The first scale to reflect earthquake intensities was developed by de Rossi of Italy and Forel of Switzerland in the 1880s. This scale, with values from I to X, was used for about two decades. A need for a more refined scale increased with the advancement of the science of seismology, and in 1902 the Italian seismologist, M ercal I i , devised a new scale of a I to XI I range. The Mercalli Scale was modified in 1931 by American seismologists Harry O. Wood and Frank Neuman to take into account modern structural features: 1 (2) Not felt except by avery few under especially favorable circumstances 11 (2) Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended objects may swing. 111 (3) Felt quite noticeably indoors, especially on upper floors of buildings, but many people do not recognize it as an earthquake. Vibration like a passing truck. Duration estimated. IV (4) During the day felt indoors by many, outdoors by few. At night some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably. V (4) Felt by nearly everyone, many awakened. Some dishes, windows, etc., broken. A few instances of cracked plaster; unstable objects overturned. Disturbances of trees, poles, and other tall objects sometimes noticed. Pendulum clocks may stop. VI (5) Felt by all, many frightened and run outdoors. Some heavy furniture moved; afew instances of fallen plaster or damaged chimneys. Damage slight. VII (5 -6) Everybody runs outdoors. Damage negligible in building of good design and construction; slight to moderate in well -built ordinary structures; considerable in poorly -built or badly designed structures; some chimneys broken. Noticed by persons driving motor cars. VIII (6) Damage slight in specially designed structures; considerable in ordinary substantial buildings, with partial collapse; great in poorly built structures. Panel walls thrown out of frame structures. Fall of chimneys, factory stacks, columns, monuments, walls. Heavy furniture overturned. Sand and mud ejected in small amounts. Changes in well water. Persons driving motor cars disturbed. IX (7) Damage considerable in specially designed structures; well designed frame structures thrown out of plumb; great in substantial buildings, with partial collapse. Buildings shifted off foundations. Ground cracked conspicuously. Underground pipes broken. X (7 -8 +)Some well -built wooden structures destroyed; most masonry and frame structures destroyed with foundation; ground badly cracked. Rails bent. Landslides considerable from river banks and steep slopes. Shifted sand and mud. Water splashed (slopped) over banks. XI (8 +) Few, if any, (masonry) structures remain standing. Bridges destroyed. Broad fissures in ground. U nderground pi pel i nes comp] etel y out of servi ce. Earth sl umps and I and sl i ps i n soft ground. Rai I s bent greatly. X I I (8 +) Damage total. Practically al I works of construction are damaged greatly or destroyed. Waves seen on ground surface. Lines of sight and level are distorted. Objects are thrown upward into the air. Note: Numbers in parenthesis denote Richter Magnitude Source: "California Geology," September 1984 Active and Potentially Active Faults Active faultsare considered likely to undergo renewed move- ment within aperiod of concern to humans. Thessindude faultsthat are currently slipping, thosethat display earthquake activity, and thosethat ha,/e historical surface rupture. The Cali- fornia D ivision of Mines and Geology defines active faults as City of Seal Beach General Plan 5-35 (12/03) Safety Element those that have had surf aoedisplacEment within Holocene time (about t he I ast 11,000 yea's). Such di spl acement can be recog- nized by t he exi stence of sharp diffsin young alluvium, un- weathered terraces, and offset modern streern courses. Potentially active faultsare those believed to havegenerated earthquakes during the Quaternary period, but prior to Holo- cene ti me Regional Seismic Conditions Southern Californiaislocated in aseismicellyactivearea There have been many eart hquekes t h roughout recorded history; some have been large. The 1933 Long Beach quake was the most powerful and closest shock to hit S9d Beach in living memory, and the 1994 Northridge quake was the most recent powerful shod. Both of thesewerefelt widely across the Los Angeles ba- d n and caused considerabledarnage. I n October, 1969, aquake occurred that was felt predominantly in Laguna Beach and South Laguna By way of comparison, the three quakes Iisted above had the following Richter magnitudes: 1933 Long Beach - 6.3; 1994 Northridge- 6.8; 1969 Laguna Beach - 4.3. The re- spective Mercalli magnitudes as perceived in Seal Beach were VI, V, and Ill. Table S-2 shows that among the 10 a tivefaultsand fault zones identified within 100 km of the City of Sall Beach, 3 faults are expected to generateeerthquakesof significance Thesearethe Newport -I nglewood, the Whittier - Elsi nore and the Palos Verdes Fault zones. DespiteMCE veluesof M7.5and larger, the San Andreas, Raymond, San Fernando -Serra Madre, and San Jacinto systems are of secondary consideration because of their large distances from the City. With expected a celerationsbelow 0.4 g, darnagefrom ground shaking generated along the Whit- tier- Elsinore Fault and the offshore Palos Verdes Fault could be reduced effectively by complying with ordinary California Uni- form Building Code requirements for ScismicZone4. However, the proximity of the northwestern tip of the Newport- I nglewood northern (upper) branch, callsfor extremely detailed site - specific geotechnicel investigations in areas impacted by the Newport -I ngleNood Fault. These earth-engi neeri ng studies would better and more accurately estimate the reaction of the surficial sediment to the design - earthquake for thissegment of the Newport -I nglewood Fault. City of Seal Beach General Plan 5-36 (12/03) Safety Element Newport - Inglewood Fault Zone This zone (see Figure S,5), made up of several faults and frac- tures, extends southeast through the Los Angeles Basin. The north branch of the NeNport -I ngleNood Fault (distinctly differ- ent from thefault zone) is made up of up to 3 segments; thus, the accurate location of individual fault traces is likely to be un- certain. The fault is at least 10 miles long, and its Holocene ac- tivity is revealed by characteristic offset stretigrephy and groundwater cut-offs in young Quaternary alluvium. The activity of this fault was proven by the 1933 Long Beach M6.2 earth- quake. The Sed Beach Fault, asegment of the NeNport- I ngleNood Fault zone, is located within the City and generally parallels the coastline, extending from Long Beach generally through the Hellman Ranch property and the Sed Beach Nasal Weapons Station, southerly through Huntington Beach and along the coast to NeNport Beach. Exploration wells have iden- tified the Seal Beach Fault at adepth of over 4,000 feet. The Sed Beach Fault isconsidered potentiallyativeend is included in the Earthquake Fault Zones established under theAlquist- Priolo Earthquake Fault Zoning Act. TheAlquist- Priolo Earthquake Fault Zoning Act waspassed in 1972to mitigetethehazard of surf ace faulting to structures for human occupancy. The ma n purpose of the Act is to prevent theconstruction of buildingsused for occupancy by humanson the surface trace of ativefaalts. Under theAct, the State Geologist hasesteblished regulatory zoneson thesurfacetracesof ativefaultsand isdistributing maps of these zones to all affected cities, counties, and state agencies. The zones are referred to as" Earthquake Fault Zones` (formerly called "SIDeciel Study Zones` ) and providethe municipality or jurisdiction with atool to plan and control neN or reneged construction within thefault zones. Beforeaproposed project can begin, ageotechnicel investiga- tion must be undertaken in order to ascertain whether the pro- ject is on or near an ativefault. A structurefor human occupancy cannot be pl aid over t he t race of an act i ve f aul t, and must beset back aspecified distancefrom thefault (gener- ally 50 feet). Whittier - Elsinore Fault Zone This zone is located approximately half way between the San Andreas Fault and the Pacific shore. The Elsinore Fault system City of Seal Beach General Plan S-37 (12/03) Safety Element Palos Verdes Fault Potentially Active Faults bounds the northern edge of the Santa Ana Mountains. The Glen Ivy North and Glen Ivy South Faults are the two Elsinore system members that could most likely affect the City, and are 20 to 25 miles array. The north branch, at least 17 miles in length, shows Holocene activity through offset stretigraphy and chara teristic physiographic features. Moreover, this fault is be- Iieved to be t he ori gi netor of the M6 earthquake of 1910 in the area The Whittier Fault, 16 milesanrayfrom the City, offsets H of ocene st rat i graphy near t he Santa Ana Ri ver. I t i s bel i eyed that the 1987 Whittier - Narrows M5.9 earthquakeoccurred along concealed thrust segments of thisfa lt, located 6 to 10 miles be- low the earth surface. For agi ven eart hqueke magni t ude, a thrust fau lting mechanism may generetethe highest peak accel- eration when compared with other mechanisms, and thus may causedarnagein excessof that anticipated. Thi s f ault separates the Palos Verdes hills from the Los Angeles basin. Thefault hasan active offshore component crossingthe San Pedro shelf, and is located 15 miles array from the City. Potentially active faults-4.e., thosethat show evidenceof dis- placement during thelast 2 million yeers, but not duringthelast 11,000 years —are represented in thegenerel areaof the City by theCemariIIo- Smi- SentaSusana, I ndian Hill -San Jose, Eaje Rock -San Rafael, and Mission Hillsfault systems. Becausetheir effect on theoverall seismicity of the City isminimal when compared to the activity of Holocenefaults, they are not con- sidered further. City of Seal Beach General Plan S-38 (12/03) x r JAMD nrauvvz) sustl vcsam • uj Z a r ■ +r 1 / 40 /1a, 1 / @ w O co LPL O Q J � 4 2w � � L1. J F-N a ..1 0 Z °� o� aJ 4 Q LL z< O= -r Z ur m x m a J �U � a ■ o � ..■■ : 2 r r < 'S r n+,e �crw r� ■ a 11« ❑ , rr� a, *ISrr ■r• o « •rr _ rrr * � � ` • ►4 +rr+y+ � � � r w c� cn CL � fC Q C y N LL 1 /y� L L O cn LL lei V r « -: , • uj Z a +r 1 / 40 /1a, 1 / @ w O co LPL O Q J � 4 2w � � L1. J F-N a ..1 0 Z °� o� aJ 4 Q LL z< O= -r Z ur m x m a J �U � W (j) z LU ■ w • O ce w c� cn CL � fC Q C y N LL 1 /y� L L O cn LL lei V Safety Element Seismicity The expected ground motion characteristics of esrthquekesat a given location depend on thedistanceof thesourceof the earthqueketothesite, thecharateristicsof the generating fault (intensityof theearthquakeand duration of shaking), and the site - specific geologic and geotechnical conditions. All other conditions bei ng equal, the severity of groundshaking increases with proximity to the epicenter of the earthquake. Assuming equal distance to the epicenter and equal seismic energy output, the least amount of damage would occur on a site underlain by bedrock at ashellow depth. A site underlai n by thick alluvium would experience considerably more damage because of the soil-s tendency to permanently deform to agreeter degree then the bedrock. The intensity of groundsheking (maximum hori- zontai ground acceleration) is measured relative to the accelera- tion caused by gravity (g). California Uniform Building Code standard engineering designs for SasmicZone4can beepplied to accelerations less than 0.4g. Special designs are necessary for vel ues above 0.4g. Themost likelysourceof strong earthquakesheking within the general area would beam4or earthquake(up to M8.25) on the San Andreas Fault, 58 milesto the north - northeast. This active f ault i s bel i eved to have a recurrence i ntervel of 100 to 200 years. Although the Sr Andreas Fault is expected to generate strong earthquakes, because of the great distance between this fault and the City, the average peak acceleration is expected to be within the 0.4g bound as indicated in Table S,2. The N eN- port-I nglewood fault zone, located within the City and desig- nated the SCI Beach Fault, is likely to generate 0.5g or higher ground accelerations. Thegreatest hazard from ground - shaking istheeffect on the structures and the occupants of the structures. The manner in which structures respond to earth movements is dependent upon the type of construction, the underlying geology, and the magnitudeof and distancefrom theearthquake. City of Seal Beach General Plan S-41 (12/03) Safety Element Table S -2 - Maximum Credible Earthquake Magnitudes for Selected Active Southern California Faults within 62 Miles of the City, Their Distance to the City and Average Peak Rock and Stiff -Soil Acceleration Statewide seismic design standards for new construction were not included in building codes until 1933, after the Long Beach earthquake. Although seismic design standards haveimproved over the years, they aremini mum standardsand will not make buildings completely resistant to da-nagefrom earthquakes. Seismic design standardsareonly meent to increase structural stability, reduceda-nage, and minimizelossof life. Generally, certain types of construction withstand ground movement better than others. Wood frame, si ngle -story resi den- tial structures are the most stable duri ng an earthquake. Struc- tureswith unreinforced masonry wallsare the structures most susceptibleto damage. Unreinforced masonry construction was prevalent during the late 1800sto early 1900sfor commercial structures. Thereareno unreinforced masonry buildings in Seal Beach today. City of Seal Beach General Plan S-42 (12/03) Estimated Average Peak Acceleration in City During Maximum Credible Earthquake (as fraction of acceleration City -to -Fault due to gravity) Active Faults and MCE2 Trace Distance Average of 6 According to Active Fault Zones' (Magnitude) (miles) Studies4 Idriss, 1985 Cabrillo Fault 6.5 16 0.15 0.14 Cucamonga Fault 7.0 36 0.08 0.08 Malibu -Santa Monica - Raymond 7.5 30 0.14 0.13 fault zone (Raymond Active) Newport - Inglewood fault zone 7.0 - 0.52 0.49 Palos Verdes fault zone 7.0 15 0.21 0.20 San Andreas (Central) 8.25 58 0.10 0.12 San Andreas (Southern) 7.75 60 0.07 0.08 San Fernando - Sierra Madre fault 7.5 32 0.135 0.12 zone San Jacinto fault zone 7.5 55 0.07 0.07 Whittier - Elsinore fault zone 7.5 16 0.25 0.23 ' Compiled from Ziony and Yerkes (1985). 2 Following Mualchin and Jones (1992), similar to Greensfelder (1974); Cucamonga fault upgraded from M6.5 to M7.0. Retained Greensfelder's M 8.25 for San Andreas fault (Central) and upgraded MCE for San Andreas (Southern) from M7.5 to M7.75. 3 Approximated graphically from Greensfelder's map (1974). a Studies included in Mualchin and Jones (1992). Statewide seismic design standards for new construction were not included in building codes until 1933, after the Long Beach earthquake. Although seismic design standards haveimproved over the years, they aremini mum standardsand will not make buildings completely resistant to da-nagefrom earthquakes. Seismic design standardsareonly meent to increase structural stability, reduceda-nage, and minimizelossof life. Generally, certain types of construction withstand ground movement better than others. Wood frame, si ngle -story resi den- tial structures are the most stable duri ng an earthquake. Struc- tureswith unreinforced masonry wallsare the structures most susceptibleto damage. Unreinforced masonry construction was prevalent during the late 1800sto early 1900sfor commercial structures. Thereareno unreinforced masonry buildings in Seal Beach today. City of Seal Beach General Plan S-42 (12/03) Safety Element The local geology effects the intensity of earthquake shockwaves as they pass through the area All of Sed Beach is loceted on thick alluvial sediments. Severeda-nageto structurescan result wheretall structures are built over thick, soft, water - saturated soils. Thepresenceof ahigh water tablecan makedarnage worse. Areasof thick surficiel soilson hillsidesmay also besus- c epti ble to increased shaking. Geologic conditions vary so markedlythat each individual sitemust beevaluated to deter- mine the seismic standards necessary for construction. Some facilities warrant special seismic standards because of their occupancy and/ or their function. Schools, hospitals, and facili- ties necessary for emergency operationsfall into this category. Other facilities, such as utility lines, warrant special attention to siting and seismic design standards. The Uniform Building Code addresses these fad Iities under thedassification of "essential fa- cilities.` Publicschoolsin Californiafall under theapprovel au- thority of the StateArchitect, who enforcesthe high standards of earthquake bracing for all new schools. Hospitals, clinics, and nursing homesfall under thejurisdiction of theOfficeof State- wide Health Planning and Development. Seismic standards are enforced on all other structures by the City. A major earthquake of magnitude 7 or greater (Richter) on the Newport -I nglewood Fault could have serious effects on the life- Iines (facilities such as highways, bridges, electrical power lines, gas lines, water and sewage li nes and communication lines) in Seal Beach according to qDecial Publication 99, prepared by the Division of Mines and Geology and the Department of Conser- vation. The hypothetical earthquake is postulated as a possible worst casefor emergency planning. Potentially damaging shak- ing could continuefor about 25 secondswithin 25 miles of the Newport -I nglewood Fault Zone, with surf ace displacements av- eraging 3 feet to 6 feet occurring on discontinuous segments of then tivefa It segments. This planni ng scenario earthquake could have the fol lowi ng ma- jor imps is in the Seal Beach area Q Pad ficCoast Highway through Long Beach is dosed (open to local emergency traffic only) from the Los Angel es River east to 7th Street. Q Pacific Coast Highway south of 7th Street in Long Beach to Corona Del Mar is dosed dueto many pavement breaks and settlements. Short portions are open, but no significant through traff is is able to use the route. Reopeni ng the enti re route i n less than 72 hours is not expected. H owever, short City of Seal Beach General Plan 5-43 (12/03) Safety Element portions maybe a cesd ble to emergency traffic in less than 24 hours. Q Garden Grove (SR 22) Freeway is damaged at the i nter- changewith the405 Freeway. Q Moderate damage at the Garden Grove/ 405 Freeway i nter- changecombined with fill settlements hasblocked traffic flow on the Garden Grove Freeway for 36 hours. Q The405 FreeNay isdosed from the Garden GroveFreEway to San Diego Creek. This routein the Westminster and Fountain Valley area has suffered considerable pavement and liquefaction damage. The405 Freeway is not expected to be reopened to through traffic in lessthan 72 hours. However, short segments north of the SantaAna River may be opened to restricted traffic in 36 hours. Q At the 405/ 605 FreEway i nterchange, minor bridge damage i n t he i nterchange area has rest ri cted treff is to a si ngle lane. Q Los Alemitos bint Forces T rai n i ng Base is dosed for 24 hours dueto runway damage dueto liquefaction. Q Seai Beach Naval Weepons Station railroad faalitiesdosed for morethan 72 hoursdueto major disruption of tracks within the Station. Q Telephone service severely restricted to emergency service providers for at lead 72 hours. Q Harbor, Long Beach, LosAlenitos, Haynes, and Hunting- ton Beach power plants all shut down for more then 72 hours. Able to operate at no more than 50 percent of capac- ity for 30 to 60 days. Q All along and adjacent to azoneof surfacerupture, thereare t housands of damaged and I eeki ng gas I i nes, vel ves, and ser- vice con nections. T here are n umerous f i res i n streets at bro- ken gas I i nes. Q Substantial damage towater distribution systems i s ex- pected. Within thefault zone, thedistribution system will be 95 percent out of order. Q About 25 percent of all electrical service connections within the impact area are expected to bewithout electrical power for the first 24 hours. Restoration of power could vary from 1 to 14 days. Q Orange County Sanitation District Plants# 1 and #2 are ex- pected to be shut down for several weeks, with sewageover- flows being bypassed to the Santa Ana River Channel, contaminating nearby beaches. Q Ground failuresin the Seal Beach area havedanaged oil storage fad Iitiesand related piping with consequent fuel spillage into Alamitos Bay. City of Seal Beach General Plan 5-44 (12/03) Safety Element Geologic Hazards Underground wastewater pi pel i nes coul d be expected to per- form reasonably well I except in liquefact ion areas, where si gnifi- cant damageshould beanticipated. Potential failurelocationsare at connections between servicelinesand transmission lines. I n addition to Iossof sanitary sewer service to thousands of people, the most serious imps t of the projected darnageto the waste water system would be the contarnination problemsof thedis- chargeof untreated sewage into the ground, the streets, and the ocean. The primary impact on natural gasfacilities would be f i res, which could be expected due to broken gas mai ns and ser- viceconnectionsin theareasof high liquefaction potential. Fires can be very difficult to deal with when there are damaged road- ways and broken water lines, combined with disrupted commu- nication lines. Preparedness for seismic disturbance is of very great importance relative to gas service. Geologic hazards affecti ng the City area are di rect, construction - related effects and indirect effects that occur only during earth- quakes. Table S,3 presents five Construction- related effectsand two indirect, earthquake- induced impacts. Other generally rec- ognized impactsaresimply not expected within themajority of the City for various reasons. Tsunarniswould only affect the shordinealongthe Pacific Ocean and at Anaheim Bay. 9milarly, the potential impact on mineral resources exists only on the Hellman Ranch property and the Beal Beach Naval Weapons Station, as those are the only mineral production areas within the City. Landsiiding, Either asadirect impact or as an earth - quake - induced event, would only occur in dose proximity to Landi ng H i 11, due to the practical ly flat site topography of the rema nder of the Ci ty. Because the most hazardous i mpats are those related to, and triggered by, seismic events, detailed presentations on "Ground - shaking` and "Soil Liquefaction` are induded in the next two sections. City of Seal Beach General Plan 5-45 (12/03) Safety Element Table S -3 — Summary of Geologic Impacts Groundshaking during Moderate to Strong Earthquakes Groundshaking isthemovement of theeerth during an earth- quake. Thistypeof deformation does not necessarily cause permanent ground displacement, but improperly designed strut turescan bedamaged by groundshaking, with considerable property losses and possi bleendangerment of human life. At present thereereseverel waysof estimetingshekingmagni- tude et a particular site. Seismic intensities or peak horizontal acceleration and velocity can be calculated. Such calculations providean estimateof theshaking potential that isessential for design and building codes. Because the Los Angeles Basin is an earthquake- pronearea, it is not possibleto plan and construct buildingsthat arecompletely risk -free in the region. Strong ground movements are unwoid- ebleduring major earthquakes. However, at present, buildings areconstructed in Southern Celiforniawith aquentitative knowledgeof themagnitudeand shaking intensity the buildings can safety accommodate, with knowledgeof thessismic pa- City of Seal Beach General Plan S-46 (12/03) Impact Occurrence Impacts Probability Effect Duration Significance 1. Alteration of natural topography, Certain Direct Long -term Insignificant caused by grading at a project site 2. Wind and water erosion during Possible Direct Short -term Significant project development 3. Sloughing /caving of excavations in Possible Direct Short -term Significant saturated unconsolidated/ noncohesive sediments 4. Secondary soil consolidation; Possible Direct Long -term Significant uneven and /or excessive settlement 5. Prime farm land removed from Certain Direct Long -term Significant agricultural inventory 6. Earthquake hazard; strong Possible Indirect Long -term Significant groundshaking of unconsolidated alluvium, danger to humans and structures 7. Earthquake hazard; Possible Indirect Long -term Significant unconsolidated alluvium liquefaction Groundshaking during Moderate to Strong Earthquakes Groundshaking isthemovement of theeerth during an earth- quake. Thistypeof deformation does not necessarily cause permanent ground displacement, but improperly designed strut turescan bedamaged by groundshaking, with considerable property losses and possi bleendangerment of human life. At present thereereseverel waysof estimetingshekingmagni- tude et a particular site. Seismic intensities or peak horizontal acceleration and velocity can be calculated. Such calculations providean estimateof theshaking potential that isessential for design and building codes. Because the Los Angeles Basin is an earthquake- pronearea, it is not possibleto plan and construct buildingsthat arecompletely risk -free in the region. Strong ground movements are unwoid- ebleduring major earthquakes. However, at present, buildings areconstructed in Southern Celiforniawith aquentitative knowledgeof themagnitudeand shaking intensity the buildings can safety accommodate, with knowledgeof thessismic pa- City of Seal Beach General Plan S-46 (12/03) Safety Element Liquefaction rarneters expected at theste, and with information obtained specifically at the site regarding the ground reaction to seismic events. Thisgenerally red ucesground-movement risk to a less - then- significant level. ,9te- spedfic data rega'ding geologic characteristics and earth- engineering propertiesare determined bygeotechnicel investiga- tion at an early phassof aproject design. Eat engineering con - sultingfirmscen generate a picture, based on site- specificdeta, that quantifies ground motion during any assumed magnitude earthquake. The major geol ogi c data on which theassessment is based i nd ude t he t hi ckness of Holocene and Quaternaydepos- its, the depth to cemented alluvium, and the depth to thecrystel- I i ne basement. I t i s general I accepted t hat t he t hider t he Queternay alluvium and the more deeply buried the crystal Iine base, the stronger the ground response to any given seismic event. The necessary earth - engi neering data are t he text ural chars teris- tics, such as the proportion of silt and day, and the mean sedi- ment void ratio. I t is also accepted that the higher the proportion of fines and the higher the void ratio (strongly corre- lated in unconsolidated Holocene sediments), thestronger the groundsheking. Thesediment wetnesset thetimetheeerth- quake occurs enplifies the potentid for earthquake induced damage. However, such an effect is not unquestionably sup- ported by all specielistsin thefield. I nformetion on sediment wetness is presented in publicetionsasapararneter that ex- presses the depth to perched water or to the regional water ta- ble; the shallower the depth to water, the stronger thesheking. During strong earthquakes, unconsolidated and water - saturated sedimentsmayexperiencebulk densficetion Ieadingto an in- stantaneousrisein sediment pore -water pressure. Duringthis extremely short period, theload within thesoil massiscarried bytheweter, and thesoil aoquires the mechanical consistency of asuspenson; for ashort, but critical period, thesoil becomes fluid. Thisprocessof consistency chengefrom solid to fluid is called liquefaction. When asoil beneath a structure liquefies, the structure loses its integrity with extremely daigerous consequences. Although Iiq- uefa tion is alwaysthe result of an increase in pore -water pres- sure, it manifests in several ways. Lateral spreading occurswhen large, superficid, and otherwise stable earthen blocksfIoat over City of Seal Beach General Plan S-47 (12/03) Safety Element liquefied, unstableground. Such events are associated with slightlytilted surfaces, generating oonslderabledamageto utility lines, pipes, etc. Flow failure occurring on slopes larger than 5 percent (1 to 20 V:H) represents a liquefaction modein which the whole surface soil movesdown slope. Ground oscillation is essentially alaterel spread occurringon Teasof flat topography. Loss of bearing strength under structures is the most potentially damaging liquefaction mode because it leads directly to losses in the strength of the structure-s foundation and thus great danger for people and property. Because liquefaction is a perticuler expression of groundshaking, the potential of which was previously indicated to beafunction of site geology and earth- engineering characteristics, thelique- fation potential is also assessed based on geologic and site - spedficgeotechnical data The geologic datathat determinethe liquefaction opportunity (distinctly different from potential) are manly earthquake related; they are the existence of active faults, their characteristic (average) strain if known, and the recurrence of large earthquakes on such faults. The earthquake magnitude isan al- important geologic parameter when assessing liquefac- tion potential because it is strongly correlated with shaking am- plitudeand duration, both of which havebeen found to trigger liquefaction in susceptible soils. Thiselement of susceptibility, discussed in thened paragraphs, combined with theliquefac- tion opportunity previously mentioned, leads to the estimation of the liquefaction potential at any particular site. Liquefaction susceptibility is based on both geologic and geo- technical data The geologic data refer to theageof thesediment and the depositional process leadingto sediment formation. Thus, river - channelsand flood- plansareoonsidered most sus - ceptibleto liquefaction, whilealuvia fanshavealower suscep- tibility. From thestandpoint of sediment ageit iselso accepted that, in the LosAngdesarea, latest Holocene (deposited in the last 1,000years), Holocene (deposited within thelast 11,000 years), and late - middle Pleistocene (deposits formed in the last 1 million yeers), areassociated with distinctly different suscepti- bilitiesto liquefaction: theyoung Holoceneischaracterized by a very high and the Pleistocene by aminimel susceptibility to liq- uefaction. The sediment deposition period is important because aging leads to at least apartial cementation of the eerth matrix and thus an increase in the geologic consol idation. Generally, the older the sediment, the higher the I ikel i hood that the sedi- ment i s consol i dated, or even over - consolidated, which implies that soilsareof high strength and aretherefore not liquefiable. City of Seal Beach General Plan S-48 (12/03) Safety Element Landslides Another important element that has eppredebleimpa t on the susceptibility to liquefaction is the hydrologic condition of the site, namely the Existence of, and the depth to, a body of groundwater. This is significant because the liquefaction event can tekeplaceonly in water - saturated soil. Thus, it isaxepted that groundwater shallower than 30 feet corresponds to condi- tionsof high and very high susceptibilities, whiledeeper water represents low and very low susceptibilities. Thegeotechnicel charateristicsthat dramatically influenceliq- uefation behavior are thepartide- sizecharacteristics, gradation, confining pressure, and relative densi ty of the deposi t. T he per- t i d e shape, the general fabric, and the princi pal stress ratio in the earth mass are potentially important chara teristica Unlike general geologic characteristics, geotechnical investigation lead- ing to detailed soil engi neering charact erization must be done on asite- specific basis. The liquefaction risk can only be mitigated through designs based on meticulous geotechnicel site i nvestiga- tion. 0 nly f ol lowi ng such an investigation one can state that ". . . the environments that favor theoccurrenceof liquefaction can be delineated with reasonable precision ...` The State Division of Minesand Geology Seismic Haffds Mepsfor theSed Beach area show areeswhere historically liq- uefaction occurred cr where geological, geotechnicel, and groundwater conditions point to apotential for the occurrence of aliquefation event (refer to Figure S,6). T he Federal Emergency M anagement Agency (FE M A) def i nes a I a-cd i dews. "Downward and outward movement of siopeforming ma- teriels composed of natural rode, soils, artificial fills, or combi nations of these materials. The movi ng mass may be preceded by any of t hree pri nd pal types of movement: fel- ling, sliding, or flowing or by their combinations.` Although theterm laxsiideisgenerally assumed to mean any siideof rock or soil down ahill, theterm actually enoompassesa number of different typesof Berth movements. Lateral shiftsof level ground or rotational movement of land triggered by heavy saturation, liquefaction, or eerthquekesereelso dassified as landslides. An ancient landslidecan liedormant for yearswith imperceptible creep and gradual consolidation and settlement. City of seal Beach General Plan 5-49 (12/03) Safety Element Gradually the shear strength of the old slide mass is overcome and reactivation occurs as a slow or rapid movement. Theoccurrenceof landslides isa part of thecontinuous, natural process of the downhill movement of soil, rock, and rock de- bris. The speed at which this earth material moves down slope can rangefrom imperceptible creep of soil to sudden mass movementsof an entire hillside. Theszeof alandslidecan rangefrom several sq uare f eet in area to several square miles. Sidethickness may rangefrom lessthan afoot to several hun- dred feet. It isimportant to remember that thecomplex ar- rangement of earth and rock unitssometimesresultsin one piece of land havingasound and stable geological foundation while another piece immediately adjacent, perhaps on the same lot, may be entirely different and potentially unstable. It is there- fore necessary to study each development proposal individually. Landslide Hazard Reduction Damage due to landslides can be reduced through avoidance, removal, or permanent stabilization. Thefirst step isto recog- nize the existence of an ancient Iandslideortheprobebilityof a futurelandslide. This isaccomplished through detaled geologic mapping, trenching, drilling, and photo interpretation of surface geologic conditions. Ancient landslides located in undisturbed and undeveloped areesaretheeasiest to detect through the use of photo interpretation. Detection in developed areas may be much moredifficult because the characteristic features of land- slides-lobe-like forms and track -like hollowsareoften obscured. Probeblefuture slides can often beanticipated in areeswhere other Iandsliding has el ready taken place. Hillsidescovered with deep soils or that are heavily saturated with groundwater may be potential Iandslideareea Additionally, Iandslidepossbilitiesare greatly increased wherethe bedrock and hill slopedirections tend to bet he same. In order to determine the precise origin of the topographic form, it is necessary to conduct supplementary subsurface ex- plorations. Once the configuration of a potentially active land- slideisknown by subsurf ace investigation, thethreshold values of faiIurecan be calculated. A velueof 1.0 represents equi I i b- rium, wheretheforcesresstingfailureor movement equal those forces that cause fail ure. A valuebelow 1.0 would i ndi cate where a geological falure(i.e., landsl ide) is expected to occur. Thepre- sent minimum accepted level of safety valueis 1. 5, which means that thegeologi cal feet ureis50% stronger than equilibrium or theforces promoting feiIure. City of Seal Beach General Plan 5-50 (12/03) c I nc�axv°� ]TT Fsrnvais3at b i n � • r � f 4A fy• a U) LU V Z Qo LLI N LL 0 _ U) U) �i W W c� W a yr a d� .7 LLJ Xz U ZO >Q > mW z�z z W U-j L7 : W J 0 irr iwr rrrrrrrrr.■ ■raft■ 4w i :. ♦� s o ? $y ti b tv U) Q a 0 N a 0 Q m a J N L N .y L LL �n i..l �I U �Q O cn �o •.r N _V i S • r • ■ ,Qo-� ■ ■ i r ■.r LL a Q b tv U) Q a 0 N a 0 Q m a J N L N .y L LL �n i..l �I U �Q O cn �o •.r N _V Safety Element Tsunamis and Seiches When an area is recognized as a potentially haffdouslandslide area, future development can be designed to take this into con - sideretion and existing development can takemitigeting actions to reduce potential hazards to an acceptable level. Several meth - odsof minimizinglandsl iderisksindude: 1) Leaving hazardous areas undeveloped. 2) Removing unstable slope materiel. 3) Engineering grading prior to construction. 4) Providingfor roof, surface, and subsurfecedreinage. 5) Constructing retaningwallsor other barriersto buttress ancient slides. 6) Reducing the driving forces acting ontheslopebyreduc- ing the slope angle or theweight of objectsplaced on the slope. 7) Planting drought - resistant vegetation with deep, strong root systems. Although these techniques represent effective mitigation to pro- tect development from geologic instability, they cannot ulti- matelyguaranteecontrol overtheforcesof nature. Diligent investigation, analysis and reporting is essential in making in- formed land usedecisions, but should not beviewed asbeing absolutely definitive because extreme Events, such as un usually heavy precipitation or severe seismic events, erenot predictable. Within Sed Beach therearefeN arees where landsiiding would beaconcern. Thesteep slope arees adjacent to Landing Hill would betheprimary areesof concern. The State Division of Minesand Geology Seismic Hazard Mepsfor theSed Beach area show areas where landslide movement previously occurred cr t he topographi c, geological, geotechnicd, and subsurf ace wa- ter conditions point to apotential for earthquake- induced land - si ides to occur (refer to Figure S-6 on page 51). Tsunamis are seismic sea waves generated by large submari ne earthquakes, vol ceni c erupti ons, or large submarinelandsiides. City of Seal Beach General Plan &53 (12/03) Safety Element Policies Sichesarestationaryosallationsof enclosed or pertlyenclosed bodies of water caused by landslides, sudden changes in atmos- pheric and wind pressure or earthquakes. Seismically induced seichesare not considered apotential hazard. Thetsunarni haz- ard is considered to below for the elevations ebovethe princi- pal sea bluff in Sed Beach. Areas on the beach or below the sea bluff are considered to have a moderate tsunarnic hazard, de- pending on tidal conditions and their elevation with respect to sea I evel . The Army Corps of Engineershasesti meted a7- to 8 -foot po- tential run -up for the coastal area Assuming acoincidental highest tide, areas below the 16- to 17 -foot contour level could be inundated by a tsunami. The chance of this occurring appears to be low based on existing data; but if an earthquake happened along the Newport -I nglewood fault, atsunarni of amuch higher inundation level could beexpected. 3A. Require a soi I s and geology report to be prepared and filed for all development projects asspecified in the City-s Mu- nicipel Code. 3B. Require geological surveys to be prepared after onsite bor- ingsor subsurfeceexplorationsat the time subdivisions are submitted to the City for approval. 3C. Require supervision by astate licensed soils engineer for gradi ng operations which requi re a gradi ng permit. 3D. Maintain and enforce protection measureswhich address control of runoff and erosion by vegetation management, control of access, and site planning for new development and major remodels, including directing runoff to the street and compliance with setbacks. 3E. Restrict development projects that will cause hazardous geologic conditions or that will expose existing develop - mentsto an unacceptable of risk until the causative factors are mitigated. 3F. Require independent revieN of thegeologic and soils re- ports as appropriate. City of seal Beach General Plan S- (12J 03) Safety Element 3G. Fileand reference copies of pertinent site- specificgeo- logicinformation and indextheinformetion in theCity-s Geographic I nformetion Sjstem. 3H. Provide ongoing maintenenceend inspection of all public dranagefadlitiesand eliminateor mitigate uncontrolled storm drain flow on hillsidesor bluffs. 31. Requiretheuseof drought - resistant vegetation with deep root systems where appropriate for safety reasons i n new development projects to reduce the potential for over - irrigation. Encouragetheuseof drought - resistant vegeta- tion throughout the City through public education efforts. 3d Maintain thepresent City pra ticeof adopting the latest edition of the Uniform Building Code (aS amended and published by the I nternationel Conferenceof Building Of- fiaalsat epproxi mete three-yeer intervals) becauseit in- corporetestheletest a cepted standardsfor seismicdesign that reflect advances in technology and understanding of hazards. 3K. Prohibit the location of neN essential facilities such a; hospitals, fireend policestetions, emergency centers and water tanks in geologically hazardous areas unless it is de- termined that thereisno feasible alternative and thehaz- ard is adequately mitigated. 3L. Requirethet earthquakesurvival and efficient post - disaster functioning beaprimary concern in thesiting, design and construction stendardsfor neN essential facilities. 3M. Evel uete the long-term risks and their associated costs versus the costs of relocation when major improvements to existing essential facilities are proposed and thefacilities areloceted in known h=clousareea Relocate the facility if the analysis i ndicetes this is more cost effectivein the longterm. 3N. Determine the liquefaction potential of a site prior to de- velopment and require that specif ic measures be taken, as necessay, to reduce damage i n an earthquake. 30. Promote the collection of relevant studieson fault loca- tion and history of fault displacement and liquefaction for future refinement of thegeologicel information within and around the City. City of Seal Beach General Plan 5-55 (12/03) Safety Element 3P. Identify the effects of the most probable seismic Event (Modified Mercdli intendty valueVIII or more) on thein- frastructurewithin the City. 3Q. I noorporete information on the probable seismic event impactson infrastructure into thedevelopment of capital improvement programs so a; to upgrade t he survivability of the infrastructure. 3R Work with governmental agencies (i.e., Caltrens and Water Districts) and the public utility companies to identify and promote effective mitigation of the effects of the most probable seismic event on the i nf rastructure which sup- ports t he City of Sed Beach. 3S. Prepare a G eol ogi cal Hazards Map based on a study of thegeological formationsend hazardsof theentireCity, employing a format compatible with the City-s GI S map- ping system. 3T. I ntegrate the latest information about earthquake surviv- ability into the City-s public safety education program. Encourage the retrofitting of every home within Sal Beach for eathquekesurvival, especially in theareaof adequate enchori ng (tie -down) of the homes to their foundations. City of Seal Beach General Plan 5-56 (12/03) Topic 4: Fire Hazards California experiences large, destructive wildland fires el most every year. I n October and early November of 1993, 26 major fires burned more than 200,000 acresin Southern California The potential for a severe wildfire to occur is increased when dense vegetation growth and Iargeaocumulationsof dead plant material are present. Weather conditions and steep terrain also increase the hazardous wi Idfi re potential; however, these condi- tionsdo not causewildfires. Human error, arson, high - voltage lines, vehicles, and lightning arethe primary causes of wildfires. Moreover, an expanding population seeking living spaceand recreation in thefire hazardouswildland contributesto the problem. The City of Sed Beach, typifying the more urban con - ditionsthroughout theS'tate, doesnot face a serious threat of wildland fires. Structural fires, which typically involveonly a singlestructure, are the most common fires that are battled routinely by local fire departments. Someof thecommon causesof structural firesare arson, electrical problems, combustiblestoo closeto heat sources, unattended cooking, and misuse of smoking materials. Thecombination of building materias, density, fireflow, hy- drant location, responsetimeof emergency equipment and natural conditionscan exacer bete potential structural firedisa& ters. Orange County Fire Authority The Orange County Fire Authority contracts with theCityto provide needed fire, emergency medical and rescueservices. The Fire Authority also works with the City-s Planni ng Department and developerson construction projectsthat impact fireprotec- tion servicesfrom the projects inception all thewaythrough to approval. Fire Hazard Severity Classification System Therearethreelevelsof fire hazard zoneswithin wildland of O range County. T hese zones are adapted f rom a f i re hazard se- verity classification system for Caiiforniawildland developed by theStateof California Department of Forestry. Theseclassesare moderate, high and ectremefirehazard. This classification util- City of Seal Beach General Plan S-57 (12/03) Safety Element izesfield investigation and present topographical information to definethefirehazard dassesbased upon threecriteria (1) Fuel Loading; (2) Fire Weather; and (3) ,9ope. Fuel- Loading includes threedasses. Light fuelsrepresent flam- mable grass and annual herbs. The majority of Sed Beach fits in this category. Most of these have been altered by man-s actions: urban development, cettlegrazing, fuel breaks, etc. Medium fu- elsindudebrush and other perennial shrubslessthan six feet in height with acrown density of 20 percent or more. Thiscom- prisesavery small area in Sed Beach, primarily at the Hellman Ranch property. Heavyfuds are theheavier brush sped es, woodland types and timber types over six feet in height with a crown density of 20 percent or more. I n Sed Beach thesearees are predominantly defined by stands of Eucalyptus gl obul us (Blue Gum) located on the Bixby Old Ranch Golf Courseand at Gum Grove Park. FireWeether i nd udes three classes. Each class is related to the frequency of critical fireweether daysoccurring in each of the State-s Fire Danger Rating Areasover an eight to ten year period (Fire Danger Rating Areeserewildlend geographical areas hav- ing similar climate.). The Low Gass (Class 1), indudesell those Fire Danger Rating Areeswhich haveexperienced fireweether in thevery high or extreme ranges on an annual averageof less t han one day; t he H i gh G ass (Cl ass 2), has an an n ual average of 1 to 9.5 days; and the Extreme Class ((Dass 3), has an annual ev- erageof morethen 9.5days. Each United States Geological %r- vey topographi c map in the State is keyed to one of the Fi re Danger RatingAreesend assigned that area critical fireweether frequency classification. Based on the above methodology, Seal Beach has been classified asa Gass 1 Fire Danger Area Sope is divided into four dasses es part of the Fire Hazard Se- verity Gassificetion Scale. Thefollowing dasseserebased on the slope: 0-9.9 percent, 10 to 19.9 percent, 20 to 39.9 percent and over 40 percent. Sope is recognized as having an effect on firebehavior similar to theeffect of wind (i.e., an increesein slope produces an i ncreese i n the rate of fire spread). T he sys- tem therefore assigns values to slope, which modify the various firedanger indices accordingly. Sed Beach fellswithin the0 -9.9 percent classification. Each d ass of fuel loading, fireweether, and sl ope isassigned a severityfactor value. Thevalues are multiplied in a met rixto produce a Fire Hazard Severity Scale. This scale is relative, that is, a f re occurri ng i n an area determi ned to represent a moderate City of Seal Beach General Plan 5-53 (12/03) Safety Element fire hazard wi I I be less severe than afire occurring in an area representing an extremefirehazard. It is important to notethat thisinformation represents a synthesis and necessarygenereliza- tion of moredeteiled information, and thus is not an exhaustive description of the vegetation, slope patterns, etc., that exist. Rather, it representstheinterpretation/ generalization of avail - ebleinformation asit relatestosuitabilityof development based on fire safety. Wildland Fire Hazard Potential Topography Vegetation Several factors effect the hazard potential one can expect from a wiIdland firein any given area Thesef actors indudetopogra- phy, vegetation, climate, development patterns, axess, and fire fighting capebilitiesto thearea All of the factors combined to contributeto the devastating wildfire in Laguna Beach on Octo- ber 27, 1993, which engulfed 16,682 acres, destroyed 366 homes (286 homes within the City limits) and damaged 642 homes. T he topography of Bed Beach can best be descri bed as bei ng flat with a single high elevation point of Landing Hill. This to- pographical condition has not much effect on wiIdland f i re be- havi or and on the ability of f i re f i ghters and their equipment to take action to suppress those fires. This topography also allows for adispersel of ar flow, thereby not creeting extremely erratic wi nds. Along with the local topography, marine influences play a si g- nificant rolein shapingthefirehazard potential for the area T he topography and soi I s encountered within the City of Bed Beach, along with d i mati c conditi ons, predominantly influenced by the Pacific Ocean, and the urbanization of the City, have contributed to the plant environment found in Bad Beach. The urbanization of thearea, with the exception of the Beal Beach Naval WeeponsBtation, haseliminated most nativeplant re- gimeswithin thecommunity. Thegenerel vegetativecharacteris- tic of the City of Bad Beach is of typical urban landscaping, with primary ground cover being devoted to decorativegrassend landscape species. City of Seal Beach General Plan &59 (12/03) Safety Element Climate Gum Grove Park is an urban forest area of approximately 14.9 acres I ocated north of Pacific Coast Highway and west of Sad Beach Boulevard. The pri may vegetative species of the park is eucalyptus trees, which were introduced in the 1920s. Climate is the single most important contributing factor to the f i re problem. T he Santa Ana wi nds are a phenomenon caused by very dry and warm ar originating from high - pressure systems over California, Utah, and Nevada Windscan reach 70+ miles per hour and have a humidity of near zero. Precipitation (its an- nual total, seasonal distribution, and storm intensity) hasfurther effectson the moisture content of dead and living vegetation and hencehasimportant effectson fireignition and behavior potential. Precipitation in Orange County averages between 9 and 15 inchesper year and generally falls during the period from November to April. Most of the I arge f i res occur duri ng t he fal I , fol I owi ng abnormal I y wet winters. The wind is a separate factor once a I arge brushf i re has begun. It drives the f i re before it, i ncreed ng the rate of spread downwind in proportion to its velocity. Passi ng through and beyond the fire, it then becomes asuper-heated current of air that can move downhill rapidly and uphill many times faster, especially when funneled by the shape of gullies and canyons. Where the wind and topography combi ne to di rect such an effect, the heat can be so intensethat temperatures may reach 2,400 to 2,600 de- grees. A strong wind can also carry burning debris, igniting many spot fires, oftentimesfrom one -half mileto amiledown- wind. If enough area isablazesimultaneousiy, theupdraft from rising heat can generate a vortex or tornado that can lift up and propel firebrandsover a wide area outside the origi nel fire, which can then rapidly expand. The updraft can generate an unbalanced condition on uneven terrain, which praRstheflamesagainst any nearby steep slopes, igniting them. Therefore, even in theab- sence of any preva I i ng wi nd, t he f i re can generate f i re whi rl s that may move uphill with greet rapidity. Auto - generation ef- fectscan a'isebecauseof thefireitself, if it issufficiently large. These are usually referred to collectively as afirestorm. City of Seal Beach General Plan 5-60 (12/03) Safety Element Development Patterns Access Development patternscan have considerable effect on fireigni- tion and rate of spread. This is especially true in the open space i nterface arees where the presence of man nea highlyflarnma- ble brush creates a critical situation. Building design and material, small lots, and the resulting prox- imityof adjacent structures compound thepotential imps tsof structural fire. When these combine with thethreetsof brush fires, fire hazards reach critical concerns. The,%rfsideand the Sed Bead Traler Park neighborhoods have been identified as having critical development patternswith respect to fire. The development patterns of thesetwo areas of the City affect the potential for fire hazard; high - intensity development, small set- backs, and narrow roads all work to reduce the effectiveness of firefighting efforts. I n addition, small setbacksand flammable building materials, especially within dose proximity to similar structures, tend to increasethepropensity for fireand accelerate its spread. I n recognition of these issues, the City of Sed Bead has required the provision of automatic sprinkler systems in all neN residential development in Surfsideand in all neN two -story cabanas in the Sed Beach Trailer Park for many years. Themost significant factor determining overall fire risk is hu- man proximity. The human element is often responsible for the ignition of major structural fires, as evidenced by the abundance and frequency of fires in the vidnity of residential neighbor- hoods. Unsupervised children, wood burning fireplaces, in- creased recreational useof thewildlands(off -road vehicles), and arson all contributetothelargest singlesourceof fires -man. Any discussion of mess must si multaneously be concerned with egress, as wel I as ingress. Chapter 21 of the Sed Beach Municipal Code ",Subdivisions` setsforth standardsfor roadway development. As a result of early lifestyles and concomitant de- velopmental patterns, numerous neighborhoodsare currently served by roads that do not meet current design standards. Upgrading these roadsto conformity is not, in certain areas, fea- sibleor desirable. For thepurposesof hazard identification, the FireAuthority hasesteblished aminimum unobstructed road- way width of 20 feet. City of seal Beach General Plan S-61 (12/03) Safety Element Fire Fighting Capabilities For avariety of reasons, streets that fail to meet fire department minimum requi rements f or access can restrict emergency mobil- ity in the nei ghborhoods t hey serve. Among other reasons for road width inadequacy are subdivisions approved in theearly 1900s, when roadways were by net ure much narrower than cur- rent standards, lack of aid labl e off -st reet parking, and insuffi- ci ent f i re depart ment turn - grounds. DuetotheIot dept hsin the Old Town portion of the City, t he Fi re Aut hori ty woul d be able to access a restricted access area from an adj oi n i ng st reet. 9tua7 tions are untenable where personnel and equipment may be trapped or unableto reach thefireor fleefrom itspath. The City Council will direct the FireAuthority to identify thosea'eas with only asingleaccessto and from thecommunity, and to as sist in developing alternative access points. By providing asec- ond access roadway, movement of f ire apparat us can be deployed as evacuation isteking place. Deployment of firefight- ing equipment iscriticel to successful firedefenseof anycom- munity. The Fire Authority provides f ire protection and emergency ser- vicesfor the City. Four of the FireAuthority-s stations serve Sed Beach; two are located within the City and two are located within the Cities of Sunset Beach and Los Alamitos. Stations 44 (718 Central Avenue) and 48 (3131 Beverly Manor Road) are Io- cat ed within the City. Station 2 is located at 3642 Green Avenue in the City of Los Alamitos, and Station 3 is located at 16861 12h St reet in the City of Sunset Beach. The Fire ALA hority has automatic aid agreements with the Cities of Long Beach, Gar- den Grove, and Huntington Beach for additional unitswhen needed or when closer. Average emergency and non - emergency response times are ap- proximately 3 to 5 minutes for Stations44 and 48. The response times for Stations2and 3va'yfrom 5 t 12 minutes, depending on the location of the emergency response to the responding station. Station 44 has one paramedic assessment engine, one paid call firefighter enginewith threepersonnel, and onereservesquad (personnel varies), and Station 48 has one engi newith three per- sonnel and one paramedic van with two personnel. Station 2 has one paramedic assessment enginewith three personnel and one reserve squad (personnel varies), and Station 3 has one reserve engine (personnel varies) and one squad (personnel varies). City of seal Beach General Plan 5-62 (12/03) Safety Element A four -year average(1997 -2001) reveds that the Fire Authority responded to approximately 200 calls per year. Of theses 200 calls, 77wereactuel structure fires and the balance were vehicle and other types of f i res. Local Programs and Legislation As experi enced by the City of Sed Beach in the January 1995 floods, the M utuel Aid system works very well. However, miti- gation measures must be i mpl emented to ensure that thevulner- ebilitytostructurel f i res i s reduced. T he success of increasi ng public safety regarding fire hazards relies on systematically f i ght- i ng t he t h reat of f i re bef ore t he f i re occurs t hrough ahost of programs. T hese programs i nd ude systematic amendments to the bui Idi ng codes and fire codes, developing gui del inesfor t he pl acement and location of f i re hyd rants, developing landscape gui del ines, defensiblespacemanagement on acity- widebasis, and analyzing the water system for firefighting use. Building Codes and Landscaping Guidelines The Fi re-Zone M appi ng Bill (Bates Bill, AB 337) requiresthe identification of f i re zones withi n the 15 most vul nerable coun- ties withi n California based on fuel load, weather, slopes and housi ng density. No portion of the City of Seal Beach is located within aVery High Fire Hazard Severity Zone. Wildland firesand structural firesspread by SantaAnawinds have demonstrated theneed for fire - resistive building construc- tion requirements that are more restrictive than theprovisionsin the Uniform Building Codes (UBC). The City of Seal Beach has adopted special building and fire code provisionsthat exceed the U BC requirements. The City should also develop, implement, and maintain acom- munity and neighborhood hazard identification and abatement program to support defensiblespece management. Defensible space isthe private property, usually landscaped, which is man- aged in such amanner that theornamentelsor native plantsdo not increasethefud loading in relation to structures. City of seal Beach General Plan &63 (12/03) Safety Element Planning and Maintenance of Outdoor Areas Adjacent to Homes Whilefuel modification deslswith thetreatment of the ur- ban/ wildlandsinterface, the concept of defensiblespaceapplies to all areas of the City. Creation of defensible space means the arrangement of aocesson the property for ease of firefighting and mantenanceof propertiesto minimizebuildup of fuel that could ignite and cause fireto spread to the home. Better accessfor firefighting should indudethefollowing: Q providing safewalkwaysaround all sidesof the house; and keeping sideyards unobstructed and freeof flammable stored items. Mantenancefor fire safety should indudethefollowing: Q thi nni ng of planti ng to remove dead wood and to reduce build -up of branches and foliage; Q removal of dried leaves and grasses, dead limbs and twigs; and chipping, composting and mulching planting areas where feasi bl e, Q spacing and pruning of trees and shrubs to avoid continuous canopies and "fuel ladders from ground to canopy; Q removal of plants growing up under eaves; Q pruning of tree branches and shrubswithin ten feet of a chi mney; Q removal of leaves, pi ne needles and debris from roofs and ran gutters; removal of combustible stored material and debrisfrom around and under the house and decks; and stacki ng of f i reNood as f ar away f rom the home as possible. When planning thelandscapeof ahome, accessfor firefighting should beconsidered in thedesign. Maintenance considerations outlined aboveshould beconsidered in thechoiceand place- ment of plantings. When located adjacent to anatural vegetation area, construction of combustible structures —fences, decks, and gazebos--should beminimized. Wood deckswith open areas underneath should be enclosed to reduce potential for ignition f rom f i res bel ow. City of seal Beach General Plan &64 (12/03) Safety Element Planting and Fire -wise Plant Choices While much has been written and suggested regardingfire- resistant or fire - retardant plantings, the 1993 Laguna Beach fires demonstrated that any plant will burn. However, reasonable planting selections combined with sound arrangement and spat i ng and good ma ntenance can i mprove t he chance t hat a st ruc- turewill survive awildlands i fire-storm fire. Listsof suggested and not - recommended pl ants f or t he wi I dl ends i nterf ace zone have been prepared by many public agend es, induding the Or- ange County Tak Foro- , County of Los Angeles Fi re D epart- ment, and the City of Oakland, as well as by the garden publications. The County of O range "Report of theWld- land/ Urban I nterfaceTak Force,` July 1994, also indudesa recommended plant list for fuel modification zones. A oompari- son of thessoften conflicting lists revealscertan criteriafor fire - wise planting as fol lows: Low f uel volume, High moisture content; High salt content; Low aromatic oil content; Low heat value, Minimal production of dry litter; and Suited to theelteand climatic conditions so that plantswill be healthy. Consistently " not recommended` plants i nd ude conifers (pi nes, cypress, cedar, and junipers). Also " not recommended` are aca- cia, bouganvilles, and ornamental grasses. Eucalyptus is" not recommended` on many lists because of the high aromatic oil content and the tendency of some species to produce high amounts of dry litter. The use of" not recommended` plants should be avoided adjacent to natural vegetation areas. Because of eucalyptus-s i mportance i n the landscape of Sed Beach, it is important to look at this genus in more detail. There are over 700 species of eucalyptus, and they vary greatly in their size, fuel volumeand litter production. An unmantained blue gum, for exenple, hasagreat deal more flanmablematerial in itsshedding bark, leaf litter, and branchesthan alemon gum. Many of the lemon gums survived the 1993 Laguna Beach fire with some charred trunks and loss of foliage. The County of Orange "Report of theWildland/ Urban I nterfaceTak Force` did not si ngle out or condemn eucalyptus. It emphasized irriga- tion, thinning and spacing as keys to any fire -safe landscape. The City emphasizes the importance of eucalyptus groves by ordi- City of seal Beach General Plan 5-65 (12/03) Safety Element Weed Abatement Water System nance provisions. Gum Grove Park is a public nature park and comprises the major stand of Eucalyptus trees within the City. The City has been actively involved in establishing aprogram to i mprove the health of the grove and increase the sal' etyof the grove from a f i re protecti on standpoint. I rrigation, thinning and dean -up to keep thearnount of litter and dried materials low, arrangement and spacing to avoid con - tinuouscanopies, and keeping foliageaway from structuresare as i mportant as the type of plants chosen. The City of Sed Beach has had aweed abatement program for over 30 years. Property owners are notified when property they own is determined to beaweed nuisance. They then have the option of either abating this problem themselves or having the City do it and bill them for services rendered. In recent years the City has had this work performed through contract services. This program addresses only weed abatement and generally does not address nativeplant material that maybe growing adjacent to an urbanized area Approximately 75 percent of the water used in the City is local groundwater, with the additional 25 percent provided by the Metropolitan Water District (MWD). The City currently has three wells with atotal pumping cepadty of 11.2 million gallons of water per day (mgd). However, delivery cepadty is limited to 5mgd by thecapadtyof the City -s reservoirs. The sources of MWD -swater includenorthern Californiaand the Colorado River. The City currently has an average daly water demand of 2.5 mgd and a maximum daly demand of 4.1 mgd. Thea-nount of water required for extinguishing a singe struc- turefirecan becdculated by using acomplex formulathat takes into account thebuilding type, building construction materials, building area, material typesstored insidethe building, and the surrounding terrain. Afiresimilar in naturetotheOctober 1993 Laguna Beach firestorm would tax thewater supply and delivery system substantially beyond its design capability. I n order to madmizethefiresefety system within the City, the City should continueto work with the City Water Department, in conjunc- City of Seal Beach General Plan 5-66 (12/03) Safety Element Policies tion with the Fi re Authority, to analyze aspects of the water sys- tem that would requi re i mprovement for firefighting use. 4A. Ensure that adequate facilities and fire service personnel are mai ntai ned based on population, f re hazards i n and around the City, and a performance standard of an aver - agetotal reflex timeof seven minutesor less. 4B. Educate and inform the public on fire safety, especially regarding landscaping installation and maintenance in ur- ban areas, to further protect the community and the envi- ronment from unnecessary f ire haffda 4C. Enhancethe ability of all structures within the City to re- sist wildland and structural firesthrough ongoing, appro- priateand cost- effectivechangesto theCity -sZoning, Building and FireCodesand standards. 4D. Work with the Water Department and the Orange County Fire Authority to analyze the supply and delivery aspect of thewater system for firefighting useto help identify and correct deficiencies. 4E. Develop an early warning system of SantaAnawind fire danger to alert the public of possible precautions or safety meesuresthat may betaken during those critical times. 4F. As acondition of new development, require private re- spond bilityfor development and mai ntenance of neces- sary nenr f i re f I ow water I i nes and hydrants i n accordance with t he recommendati ons of t he 0 range County Fi re Au- thority. 4G. Encourage property owners to create defend ble space sur- rounding their homes, including providing axessfor fire- fighters, maintaining plantings and outdoor areas, and minimizing combustible structures. 4H. Encourage property owners to consider "fire -wise planting and the use of fire- resistent building materials, especially in landscaped and developed areas adjacent to Gum Grove Park. City of seal Beach General Plan 5-67 (12/03) Topic 5: Flood Hazards Historically, flooding has been beneficial to agricultural soil, wildlife and the general ecological balance. In the unaltered state, water systems haveconsiderablebuilt -in capacityfor de- taining storm watersthat would otherwise surge too rapidly downstrean and into estuarinebasins. Hydrologistsemphasize that, along natural watercourses, flooding is a routine process. Flooding in an urban setting can also be viewed as a natural haz- ard. Virtually all stages of the natural hydrologic cycle, including flooding, have been significantly altered by human intervention. Changes i n land use have profound effects on runoff and ero- si on on the land surface. As vegetation is removed and soil is exposed during construction, erosi on rates may increasesi gnifi- cantly. Thecreation of impermeable surf aces that accompany urbanization increasesand concentrates runoff, leading to a greater incidenceof flooding. A flood may be defined asatemporary risein strewn flow that results i n water overtoppi ng its banks and i nundati ng arees adja- cent to the channel not normally covered with water. The low - land area adjacent to thestrean that is subject to periodic inundation by floodwater is known asthefIoodplan. The magnitude of aflood is measured in terms of its peak dis- charge, which is the maximum volume of water (in cubic feet per second) passi ng a poi nt along the channel. Floods, however, are usually referred to in terms of their frequency of occurrence. For example, the 100 year flood is aflood magni t ude whi ch has a 1 % chance of bei ng equal ed or exceeded i n any gi ven yea. There isacertan element of risk involved usi ng this type of des- ignation because the prediction of aflood of aparticular magni- tude is based on probability and an element of chance is involved. According to stat istical averages, a25 -year flood should occur on the average once every 25 years. However, two 25 -year floods could conceivably occur in any one yea. For planning purposes the flood magnitude most often used in de- 1 i neat ng fIoodplai n boundaries is the 100 -year fIcod. T his flood is also referred to as the irtErrrnfatereja -d or bagEflocd Thedimateof Sed Beach istypically Mediterranean, character- ized by warm, dry summers and cool, ra ny and foggy wi nters. City of Seal Beach General Plan S-66 (12/03) Safety Element The average annual rai nfall is 13 inches. Over 90% of this rain- fall occurs between late October and early April. Flooding isadirect responseto theamount, distribution, and in- tensity of precipitation. Most flooding damage is brought by sudden deluges of already soaked ground, or in the case of the coastal areasof thecity, thecombination of astorm surgewith a high tide. Stormsthat combinehigh total rainfall, longduration, and high daily maxima, asin the 1995storm, arethemost de- structive. Heavy runoff and accelerated erosion areassociated with thistypeof short period torrential rain, aswell aswith storms of longer duration and greeter totals. Historically, floods causing significant damageoccurred in Sed Beech in 1937, 1938, 1941, 1966, 1969, 1978, 1983 and 1995. Flood pot entiel exists in theform of temporary floods related to winter rains and wave run-up. Most of theflood activity isiso- lated along the various drainage channels within the City or the immediatecoastai area Most flood conditionsin Beal Beach are short lived in nature due to the limited sizeof theavailablewa- tershed and the presence of drai nage i mprovements. Damage resulti ng f rom f I oodi ng i n Sed Beach is more inundativethan erosi vein nature. I n general, three separate and distinct types of inundation are known to exist in Sed Beach. Flood inundation hazardsare those associated with major atmospheric events that result in in- undation of developed areas, due to overflow of nearby stream courses, or inadequacies in local storm drain facilities. Facility inundation hazards are those associated with downstream inun- dation that would occur given amajor structural failure in a nearby impoundment. each failureswould most likely becaused by geologic phenomena including seismic events and slope i n- stability. Thethird inundation hazard isstorm surgerun -up that may occur during a high tide. Secti ons of Sed Beach are subj ect to f I oodi ng due to vaerur�-up This type of flooding i s typi cal I y caused by I arge sNel I s produced by storms at sea occurri ng at high tide. Wave run -up was espe- daily damaging to the residences located on Sed Way between the Sgd Beach Pier and the Navy Jetty, and at Surfside, in 1984. T he wat er and debri s I eft by the waves caused no damage to the commercial area; however, damageto the interior of homes near the beach area was substantial. I n north Orange County, increased urban development is per- haps t he most seri ous change i n d rai nape basi n and f I oodpl ai n City of Seal Beach General Plan &69 (12/03) Safety Element Local Setting charateristicsthat can i nf I uence the magnitude aid frequency of flooding. Urbanization often Ieadsto agreeter percentageof impervious surfaces, which increasesthetotel volumeof storm runoff by decreed ng the arnount of water that infiltratesinto the ground. Development can also result in placing artificial fill and other objects in thefloodplain. To protect development from theimpa tsof flooding, stream channelsareoften channelized (e.g., straightened, lined) to move the water off the land more eff idently. However, when water emerges from the improved section of stream channel, it is of- ten delivered to the unchannelized downstream section at rates and velocitiesthat the natural section of stream is not capable of carrying. Piecemeal channelization effortsoften exacerbatethe flooding potential downstream. Therefore, it isimportant that flood hazard reduction operations be comprehensive, well planned programs. A" Master Plan ofDrainege was preparedfor the City ofSeal Beach in February 1999. This document identified the local network of existingflood control facilitiesand thecondition and capacity of each one. Theexisting datawasthen combined with theestimated contributionsfrom futureanticipated land useto determinethetotel storm runoff for the City. Thedocument then outlined aprioritized list of system improvementsand a basisfor establishing funding mechanisms. To continueto be effective, the Plan should be periodically updated to reflect neN hydrologic modelingtechniques, revised rainfall runoff data, changed land useand development patterns, and current costs. Theeffectsof storm water runoff in the City of Sed Beach are typical of problems in inland areas, where run off from several tributary areas combinesto inundatelow- elevation areas, for the non - coastal areasof the City. River, streern, and drainagechan- nel channelization involves straghtening the natural meanders, deari ng the banks and widening and deepening the channel. It is undertaken to assist in flood control and to i ncrease devel opabl e land. Chan nel i zat i on Iowersthe level of the river or stream and the riparian water table, increases the rate of surface run off, in- creasesthestream flow rate, enhances bank and bottom erosi on, and transports a heavier sediment load than the unchannelized strewn. Channelization also affects the beach replenishment process which is discussed in Topic 6, 9nordine Protect ion. City of Seal Beach General Plan S-70 (12/03) Safety Element The San Gabriel River isamajor watercourse adjacent to west- erly boundary of the City. The headwaters commence in the San Gabriel Mountains, approximately 30 milesfrom theoutlet into the Pacific Ocean, adjacent to the City of Seai Beach. The drai n- agearea of the San Gabriel River and its tributaries is about 679 square miles. Development in thefloodplain of the San Gabriel River ranges from sparse et the headwaters i n the mountai ns to dense along portionsof theriver channel located on thealluviel plains. The floodplain in this area has been completely developed. Residen- tial and light industrial development i s predomi nant in the area between the San Bernardino Freeway and the Pacific Ocean. Flood Protection Measures As part of the N ationel Flood I nsu ran ce Program, a report was prepared which delineated flood -prone areas in Beal Beach. The generation of this report and accompanying maps help illustrate where development has been permitted into thefIood zones, creating apotentielly hazardous condition during 100 -year storms (see Figure S-7). A majority of the City-s storm drai n infrastructure, unless oth- erwise noted, is designed for the 25 -year flood. This design standard reflects the standards in use during thetime of the construction of themajor storm drain systemswithin the City. It would, therefore, be inadequate for the more recent, and gener- ally accepted, standard of a 100 -year flood. The major storm drain facility located within the City is the Los Alamitos Retarding Basi n, owned and operated by the County of Orange. This fad Iity is located south of Westminster Avenue, west of S9I Beach Boulevard and adjacent to the Haynes Cool- ing Channel. The Retarding Basin serves a d rai nape area of ep- proximetely 5,420 acres, generally located east of the Sep Gabriel River and Coyote Creek Channel, south of Carbon Creek Channel, west of Bolsa Chica Channel, and north of Westminster Avenue. The drainage area includes portions of Seal Beach, Los Alamitos, Cypress, and the unincorporated area of Rossmoor. The Retarding Basin was built in 1958 by the Or- ange County Flood Control District. The basin has a storage ca- pacity of about 200 acre feet and four pumps discharge storm waters into the San Gabriel River. Los Alamitos Channel, which drai ns di rectly i nto the basi n, was designed i n 1957 for a dis- chargeof 1,460 cubic feet per second (cfs) and isinadequeteto City of seal Beach General Plan 5-71 (12/03) Safety Element carry the 100 -year discharge of 2,650 cfa The existing pumping station was designed for a discharge of 450 cfs, comparable to a 25 -year storm desi gn, which is inadequate to hold a mad mum water surface in the basi n of + 1.0 elevation necessary to prevent upstream f I oodi ng. T he County of O range recognizes t he def i- ci ency of t h i s d rai nage system, and is currently investigating ways to improve the system to provide for increased storm drainage protection to the dra nage basi n. As future plans are f i- nalized, the City will revieN this discussion as part of its bi- annual revieN of the Safety Element. Of the numerous other drainagefacilities throughout the City of Sad Beach, most drain areesereof insignificant sizeor havethe capacity to pass the 25 -year storm. The concept of 100- year protection remainsdesi rable, but may not be achievable in the foreseeablefuture due to financial fa tors. Therefore, the con- cept of providing reasonable level of dranagecontrol to meet the 10-, 25-, or 50 -year desi gn frequency should be consi dered whilewaiting for the ultimate, 100 -year desi gn to be desi gned and funded. D rai nage st ruct ures t hat do not meet the standards of the25 -year storm and/ or drain areas of sufficient sizewill be noted in drainage studies. I n 1995 the City of Sed Beach revised and updated its" Flood- plain Overlay District' provisions in the Code of the City of Sed Beach to promotesound land useand floodplain develop- ment standards pursuant to the rules and regulation of the Fed- eral I nsuranceAdministration and Federal Emergency Management Agency. Areas of special flood hazard have been identified by the Federal Emergency Management Agency on the Flood I nsurance Rate Map (Fl RM) which has been adopted by the City and are referenced in the Floodplain Overlay District provisi ons of the Code. City of Seal Beach General Plan 5-72 (12/03) �i :r U W c� 3Ao 'dD Naa"D agisrr misam y4 - �-A- -.eM=** .V w m . w S E E 0. ■ ■ m a s s wi & ■ a ■ U a ._. ... .1 J ill ■ ■ _ ■ R R � w.�aiaeae.r� Ri f. r• a Rf �.�� = tz,'•., ��� Uq.," `ire Vty r � r r ■ W *`4, S LL m V1 Z Z4 c F O Q � 0 cn p cn Q W LL o Z LL 3 0 O °¢- J ©� LL C M 0 t3 rLL °_ a < , z } 4 �ooJ � Q U U ULLLL §� a ■ .I® W ■• J ■' N Q c O N O O LL LU LL ti Q L LL cn U U �Q U w O cn O •.r N V Safety Element Water Quality Control In 1990 the City, along with the County of Orange, the Orange County Flood Control District, and the other Cities of Orange County (asCo-Permitees), were issued a National Pollutant Dis- chargeElimination System (NPDES) Stormwater Permit as pal of the implementation of the Federal (Dean Water Act, by the Environmental Protection Agency (EPA) through the State of California and the State Water Resources Cont rol Board. The permit i s reneged, general I speaki ng, Every f i ve years. T he Fi rst Term Permit expired early in 1996 and was replaced by the Sec- ond Term Permit. Thecurrent permit, theThird Term Permit, subsequently replaoed the Second Term Permit in September 2001. The NPDES Permit established two major requirements: 1) an effective prohibition of non- stormwater pollutant discharges into the storm drainage system-, and 2) implementation of water quality Best Management Practices (BM Ps) through the devel- opment and adoption of a Drainage Area Management Plan (DAMP). The BM Ps are i ntended to reduce the amount of ero- don sediment discharging into thestormwater dranagesystem to the "maximum edent pra ticable (MEP). Central to an effective prohibition of non- stormwater discharges is the enactment by local jurisdictions of ordinances preventing such discharges. On April 24, 1995, the City of Seal Beach adopted a" Storm Water Management Program' ordinance. The Storm Water Management Program Ordinance is intended to prevent industrial wastepollution, aswell asother non - stormwater pollutant discharges, and all neg development will be required to complywith thewater quality management tech - niques as outlined by the Best Management Praticesof the DAMP. Furthermore, in an ongoing effort to protect and en- hancecoastal waters, the City developed a "Storm Water Quality Management Plan` in July 2001. On January 18, 2002, the SantaAna RWQCB adopted the Or- ange County Municipal N PD ES Storm Water Permit for the northern portion of Orange County (the San Diego RWQCBju- risdiction coverstheremaining portion of Orange County). The new permit updateswater quality standardsfor new develop- ment, and thesestandards havebeen incorporated and applied to this project. These updated standards include numerical sizing criteriafor water quality treatment and proper monitoring and mantenanceof storm water facilities. Numerical sizing criteria specifically statethat acertan quantity of first flush runoff shall City of Seal Beach General Plan 5-75 (12/03) Safety Element Policies be t reefed to remove t he pol I uta-its of concern (t hose i nt ro- duced by the project) to the M EP. The permit supports the use of bio- sNales, detention ponds, infiltration landscaping, con- structed wetlands, and structural BM P devices as means for meeting the MEP and best avai leble technology (BAT) require- ment. 5A. Periodically inspect and maintain all public dranagestruc- tures and remind property owners to maintain private drainage structures in order to maximize capacity. 5B. Implement a public education program pertaining to flood hazards and ways in which citizens can protect themselves and their property. 5C. Contain and utilize runoff from impervious surfaces on- siteto the greatest extent possible. Transmit excess runoff to the nearest street or facility cepableof conveying the runoff without impacting downstream areas. 5D. Plan capacity for the 100 -year flood and provide short term reasonable protection for Iocetionsthat would bene- fit from 10-, 25- or 50 -year storm drainagefacilities. 5E. Consi der the effects on beach sand replenishment of im- provements to drainage channels. 5F. Pursue a regional approach to watershed management, particularly in regards to the San Gabriel River, and coor- dinate improvement planswith local, state, federal, and community -based organizations and agencies, indudingelI of thejurisdictions located upstream on the San Gabriel River. 5G. RevieN and update t he M aster Plan of Drainageto inte- grate the drai nape systems of the enti re City i nto one plan and indudean implementation scheduleand prioritiesfor improvements. 5H. Continue the practice of preventive maintenance, indud- ing storm trwking and proactive street and storm drain mai ntenance. City of seal Beach General Plan &76 (12/03) Safety Element 5d Monitor the effects of inland development on the City-s watershed and its management and attempt to minimize their impacts. 5K. Monitor the Los Alamitos Retarding Ba§n improvement program proposed by the Orange County Flood Control District. 5L. Continueto participate in the National Flood I nsurance Program and utilize the most recent Flood I nsurance Rate Mapsin theimplementation and enforcement of the City -s"Floodplan Overlay District` requirements. City of Seal Beach General Plan &77 (12/03) Topic 6: Shoreline Protection The Californiacoastline has been eroding for thousands of years. Erosion did not present economic or safety issues as long as the coastal areas were left undeveloped or were used for agri- cultureor low - intensity recreation. Thedesirefor magnificent ocean vieNsand convenient beach accesshasinduced many peopleto build at theoceen -sedge, even in high -risk locations. For such dwellings, each severewinter storm isapotential disas- ter. Coastal erosion islikelyto continueor even to acceleratein thefuture. Damagefrom storms and erosion are episodic in nature. The winter storm of 1982 -83 resulted in substantial lossesto Orange County beaches, including theSed Beach area With continued coastal community growth and development, property values Conti nue to increase. Costs f rom damage due to major storms could be greeter each year as coastal land is i ncreed ngly up- graded and developed. Owners of oceanfront properties be- come more concerned with protecti ng thei r investment from storm erosion and structural damage. During and after severe storms, many oceanfront property ownersattempt to construct protective devices that do not consider thecomplex interrela- tionships of the land and sea Beach retreat is a natural process. When consi dered over a long period of time, the sea diffsand beaches are ret reat i ng. Thisre- treat is episodic, infrequent, si te-sped f i c, directly related to wave dimateand rainfall, and highly impacted by urbanization. The protection, preservation, and restoration of sandy beaches and the des re of private property owners to protect their i nvest- ment s are d osel y interrelated. T he val ue and enjoyment of oceanf ront property depends, to a greet degree, upon the exi s- tence of a sandy beach. As sandy beach widths are reduced, an i ncreese i n the amount of wave attack on beachf ront property and thebaseof the Existing sea cliff occurs. Sand management istheat of controlling the littoral sediment resource, to the extent possible, to benefit the recreational and protective f unctions of a beach. I t requi res that changes i n beach width be anticipated beforethey occur. Only then can enlight- ened decisions be made and cost- effective methods be imple- mented to deal with undesirable shoreline behavior. City of Seal Beach General Plan 5-78 (12/03) Safety Element The Effects of Man S nce the early 1900s, man has permanently altered the natural cycle by developing the coastal I ands and harbors. T he major sources of sediment no longer provide the necessary quantities of sediment to keep the natural cydein balance. Under natural conditions, 1.2 million cubic yards of sand per year would be de- livered to the San Pedro cell by the Los Angeles, San Gabriel, and SantaAnaRivers. Dueto the construction of dams, channel lining, detention basi ns, and the urbanization of the land within thewetershed, relatively little coarse sediment, beach sand, reaches the coast. Most sediment deposited on the beeches oc- curs i n the form of urban silt, the mix of dust, hydrocarbons, and other man -made materials, or when the inland storm facili- tiesfail and spot erosi on occurs. The construction of other man -made devices such asbreekwa- ters, jetties, groins, and revetments has interrupted the littoral transport of sediment. Breakwaters are structures that are con- structed offshoreto dissi pate wave action to permit safe har- bors. 9ncewaveaction isreduced within theprotected harbor, littoral transport is effectively reduced to an insignificant level. Jetties are constructed to permit dear channelsfor river flood control purposes and to keep harbor ent rances d ear of sedi- ment. Sand that istransported by littoral current istrapped up- drift of thejetty. Without an adequate system to bypassthejetty, theoppositedowndrift jetty experiences erosion. Groinsare structures that are usually built perpendicular to the beach. They are constructed to form small cells or compartmentsthet are filled with sand. Thesmall distancebetween the groins limits the erosion and traps the sand. All of these structures alter wave patterns by reflecting and diffracting waves so that the adjacent shorelines will be modified and will seek nenr equilibrium shapes. I n 1933, two parallel jetties were constructed along with achan- nel for the San Gabriel River to prevent flooding and enable the development of the Southern California Edison and Los Ange- les Department of Water & Power electric generating plants which requirecooling intakes and outfells. The easterly jetty was built at 725 -long and the westerly jetty was built at 375 -long and was later extended to the 725 - length. By 1940, an additional 800�etty was built to separate the river from the Alamitos Bay. Over the years the Alamitos Bay jetties were extended to 3,400- to provide for a navigational access to the Long Beach Marina These improvements further impeded thelittorel transport of sand to the south. City of seal Beach General Plan &79 (12/03) Safety Element During that same ti me period, the Navy constructed the Naval Weapon Station (1945 -47).1 ncluded in that project weretwo (3,000-and 3,400 rubble mound arrowhead jettiesto form a safe harbor at Anaheim Bair for the loading of armament for Navy vessels. These structures further interrupted nature-s proc- essof sediment transport. The construction of the Los Angelesand Long Beach Harbors created morethan eight milesof breekwatersby 1949. The breakwater effectively prevents littoral transport of sediments from the northerly cell and the bluffs at San Pedro from reach- ing beaches in Long Beach, Set Beach, and downdrift beaches. The beaches behind the breakwater have mi nor wave a tion and are relatively stable, but the beach and water quality have suf- f Bred. I n the 1950s, concern over thecontinuing erosion problem be- tween the San Gabriel Riverjetty and theAnaheim Bayjetty caused agroin to beconstructed adjacent to theSe1 Beach Pier. Theexisting concretesheet pilegroin wasconstructed in 1959 by the Army Corps of Engineers. The groin was constructed to extend 750 feet into the ocean, and each cell (now named West and East Beaches) wasfilled with sand. Thegroin was proposed as "thesolution` to the shoreline erosion problem that had been caused by the construction of thejetties and breakwaters. It was thought that with the construction of the groin, the beach would remai n relatively stable. However, replenishment and ba kpass (sand transfer) projects are required to maintain both beaches. Thecombined effectsof these various structures produce unique problems along the shoreline in Sya1 Beach. The East Beach haswater quality problems. This hasbeen attributed to three conditions: the absence of alittoral current at its north- western edge due to the breakwater; the trash that flows out of the San Gabriel River and Alanitos Bay (Long Beach Marina); and the position of the groin at the pier, which ref lects the pre- vaili ng westerly waves into a counterclockwise current similar to an eddy. The West Beach experiences severe erosion dueto a northwesterly Iongshorecurrent that isgenerated bywavesthat are reflected by thejetty at the entranceto Anaheim Bair. The Sarfside Beach downdrift of theAnaheim Bayjetty has histori- cally experienced severe erosion adjacent to thejetty, which of- ten jeopardizes the beach front residences. Thefear of loss prompted the Sarfside community to construct a rock revet- ment well asalast lineof defenseto protect theexisting homes along the shore. City of Seal Beach General Plan 5-30 (12/03) Safety Element Local Conditions The non-structural solutionstoshorelineerosion include replen- ishment and backpassing. Replenishment places beach sand on theshorelinefrom inland suppliesor dredged from offshore bars. Sand replenishment can be very successf ul in mitigating shorel i ne erosion. I n general, any solution to acoastal problem that closely imitatesthe natural processwill haveagreater chance of success than sol uti ons t hat attempt to overwhelm or counters t the process. The placement of sand in theappropri- ate quantitiescan mi t i gate a man-made obst ruct i on to littoral sand transport. Backpa sing i s a tech n i que where sand is moved from one area to another adjacent or nearby area in the cell. The net sum gain in the sand budget within the cell iszero si ncethe shorelinewill seek itsdynanic equilibrium. Thetemporary movement of sand can be beneficial in temporary protection during thewinter storm seam. Beach sand replenishment has been the predominant method of ma ntai ni ng the shore) i nes i n Sce1 Beach. S nce 1945, 16,237,000 cubic yards of sand was placed on the beach at Sarfside. This beach nourishment occurred with the understanding that the Sarfside Beach would serve as a feeder beach to the beaches to the south. Recently, neN data has indicated that the sand does not entirely reach thebeachesat thesouthern end of thecell as antiapated.TheCorpsof Engineers has recently designated the West NeNport Beach assn additional feeder beach. Between 1954 and 1988, approximately 2,055,000 cubic yards of sand was replenished on the East and West Beaches. I n addition to the replenishment, approximately 250,000 cubic yards of sand was backpassed to combat shore) i ne erosion. Based on today-s costs to dredge sand at $4 to $6 per cubic yard, for trucking in sand at $10 to $15 per cubic yard and to backpa3s sand at $2 to $3 per yard, one can speculate that several millions have been spent and will continueto bespent to maintain theshorelinewithin the Sce1 Beach and H untington subcells. The Seel Beech coastline is characterized by short, generally nar- row sandy beachesseparated by protruding manmadejettiesfor the San Gabriel River and the Sce1 Beach Naval Weapons Sta- tion. Beaches formed prior to the construction of thesejetties are now modified and maintained in theembayments because therethey are patially protected and contained by thejetties. The natural feeding of these beeches has been substantially modified by the construction of thejettiesend thereduction in sediment discharge material from the San Gabriel River due to City of Seal Beach General Plan S-81 (12/03) Safety Element upstream modifications. The sand is held in the bar or com- partment and the compartment f unctions asadosed sand sys- tem (sand moving parallel to shore) that can be managed separately from other coastal compartments. No residential or commercial structures in the City are exposed directly to oceen waveattack. Periodically, a high storm surge has caused local flooding in beachfront homes along the main beach in Sed Beach and in the Surfside area In an ongoing ef- fort to arrest this process and to mantan the beach front for recreational use, the City has undertaken beach nourishment projects, and will continueto investigate long -term solutionsto the beach erosion issue within the community. Beach replenishment is an active management responseto an imbalance in thesediment budget of acoastel compartment. Beach or sand replenishment could bean aesthetically attractive and economic elternativeto theconstruction of hard shoreline protection devices. Beaches are very effective in dissipating waveenergy. It isimportant to understand that sand replenish- ment cannot be expected to solve el I shoreline problems, espe- ciellyareasthat areexperiencing failures independent of wave attack. N evertheless, the potential benefits of usi ng a natural material such as sand for shore protection should remain the primayfocusof the City. Thedevelopment of adatabase could help to preparefor along- rangeplanning effort. Knowledge of the natural and actual rates of shord i ne erosi on is important for planning purposes. Comprehend ve st udi es of rates of erosi on by oceanographers and mari ne geol ogi sts have not been done during past decades. The City of Sed Beach is part id pet ing in afive -year study of the Orange County Coast. Thecost isshared bythefederel government, Orange County, and fivecoastel cities, including Sed Beach. Thestudy began in 1991 and covers the portion of the Orange County coastline from the mouth of the San Gabriel River to the Dana Point headlands, approximately 32 miles. The product of this report will provide a database of sediment type, movement and loca- tion, wind, currents, and wave height and frequency that will es- tablish a" normal` condition. A primary goal isto provide comprehensive coastal dataand information in aformat that helps coordinate and enhance the efforts of federal, state, and local agendesinvolved in managingand mantaningvalueble coastal resources. Such i nformation can be i nval ueble i n design- ing beach nourishment projects and in preparingoiI spill contin- gency plans, both of which are regional issues. The study will provide an opportunity for commendng a regional benchmark City of Seal Beach General Plan 5-32 (12/03) Safety Element Policies investigation and will enable the City to more effectively con- duct "resourcemonitoring` along the City -s coastline. 6A. Prohibit theconstruction of buildingsand other man- made structures on the sandy portion of the beach, unless necessary for public health and safety. 613. Review any development application for shorelinecon- struction with respect to theeffectsof beach encroach- ment, wave reflection, flood and wave hazards, public access and public recreation, shorelinesand supply, and aesthetics. 6C. Prohibit shoreline protective devices unless there isevi- dencethat existing structure(s) arein imminent danger from erosion and waver flooding hazards, and theshore- line protection device is designed to mitigate adverse im- pacts on local shoreline sand supply, public access, and public recreation, and unless all reasonable alternatives have been explored. 6D. Enforce current building setback standards on local beaches to prevent exposure of structures to large sea waves of sei smic or storm origin. 6E. Prevent shorelinedevelopment that would plecestruc- tures in danger of wave attack or degrade natural means of shoreline protection. 6F. Ensurethat storm water and dreinageareconteined, con- trolled, and discharged in an appropri ate men ner. 6G. Explore possibilities for beach or sand replenishment as the primary alternative to the construction of hard shore - line protection devices. 6H. Consider the impacts of flood control improvements on sand replenishment of the beach. 61. Require the repei r of damaged shore) i ne protection de- vicesto beocnsistent with prevailing zoning regulations and general plan policies. City of seal Beach General Plan &83 (12/03) Implementation The policies of the Safety Element of the General Plan establish the actions and requirements necessary to direct sef ety- related demons in the City. I t is recognized that the implementation of the policies in this document may al ready be underway or may evolve dependent upon City staffing levels, economicoondi- tions, and manmadeor natural physical events. Thetime-frane objectives delineated in thissection aregoalsfor ationsto be accomplished over the next several years. This section also iden- tifies actions that need to be undertaken on an ongoing basis. The time -f rarnes are based on a snapshot of the community val- ues, politics, and conditionsat apa-ticular moment in time. 9nce these factors are continually in flux, the City must con- tinually monitor therelevanceof the Safety Element policiesand their implementation progress, so that themain goal of protect- ing the publics health and safety over time is maintained and improved. The City Council recognizes this chargeand will bi- annually revieN the safety objectives achieved duri ng the preced- ing time period, and will set neN safety objectives for the next bi- annual time period, based upon changingconditions, new in- formation and revised City policiesand priorities. Many of theimplementation ationswill require additional staff- ing and/ or additional funding for their successful and timely completion. Fundingconstraints beyond the City -s control may make it difficult or impossible to allocatefundsfor the necessary staff, equipment, or consulting services necessary to complete some of the items. I t is recognized that the necessary staff, equipment, and consultants are dependent upon an annual ap- propriation by the City Council as part of the annual budget process and review and prioritization of safety objectives. It is also recognized that theimplementation measures identified in this Safety Element will redizesubstantial cost benefitsin the preparation for disastersand their avoidanceor impacts. Someof theimplementation measures require capital improve- ment projects to be constructed. These projects may require a revieN according to the provisions of the California Environ- mental Quality Act, and environmental degradation and grading shall be minimized to the greatest extent possible. However, it is also likelythat someof theseprcjects, such as emergency access improvements, may prevent the literal consistency with all of the pertinent General Plan and environmental protection policies, thereby necessitating acareful belandng of competing objec- City of Seal Beach General Plan S-84 (12/03) Safety Element tivea Public health and safety should be of primary concern when prioritizing these competing objectivea The City -s Safety Element i nd udes actions which range from measures necessary to i nsure consistency between the City-s general plan and federal, state, and local reguletionsto thoseac- tions required to fulfill thepoliciesin theplan. Theseactions havebeen divided into four timefra-neswith thedecignation the primary department(s) responaiblefor their implementation. Within one year of adoption of this Safety Element, these City Departments are pri maxi ly responsible for the following: Q Police Department (in cooperation with Fire Authority) a Updating the Emergency Services Plan, incorporating a citizen response model, evacuation plans, emergency aid, acomprehensive communications component, and acoordinetion program with other local government agencies, schools, hospitals and utility companies. Development Servi ces D epa-t meet/ Engineering Depart- ment a Maintaining and updating, asappropriete, aMaster Plan of Drainagefor theentireCity, providingfor amini- mum protection objective of 25 -year flood through the useof flood water conveyances, retention and holding basin facilities, including aprioritization of projects. a 1 nvestigating the establishment of interim holding or drop -off centersfor hazardousmateriaia a Evaluating the location of all public facilities in relation to hazard areas for possible relocation. a Establishing and maintaining critical no parking/ tow array zones for public safety. a Developing an informational hazardousmateriai and disaster preparedness educational program for individ- ual households and neighborhood associations. a Identifying utility facilities in hazard areasfor relocation or undergroundi ng. a Prepari ng a pamphlet regardingfiresafetyasit relates to landscaping installation and maintenance. a Evaluating the relocation of equipment and servicesfor emergency purposes. Within two years of adoption of this Safety Element, these City Departments are pri maxi ly responsible for the followi ng: City of Seal Beach General Plan &85 (12/03) Safety Element Q Police Department (in cooperation with Fire Authority) a Undertaking a oomprehensi ve emergency access and evacuation evaluation program and implementing its recommendations. a Coordinating local emergency service facilities with util- ity companies. Development Servi ces D epa-t meet/ Engineering Depart- ment a Identifying the effects of themost probeblessismic event on the City-s infrastructure. a Developingan education program promotingemer- gency response preparedness, especially for earthquake survivability, and home retrofitting and adequate an- chori ng. a M ai ntai ni ng and updati ng, as eppropri ate, an i of orma- tion pamphlet on flood hazards and protection meas- ures. Within threeyears of adoption of the Safety Element, these City Departments are primarily responsiblefor thefollowing: Q Police Department (in cooperation with Fire Authority) a Mai ntaning the Emergency Operations Center. Development services Department/ Engineering Depart- ment a Preparing a Geological Hazards Map of theentire City. Finally, thelast part of the implementation section listsa tions to betaken on an ongoing basi s and indudethefolIowing: Q City Council a Bi- Annually review the Safety Element objectives achieved during the preceding year and set thesafety objectivesfor thetime period, based upon changing conditions, neiv information, revised City policiesand prioritiesand budget constraints. a Ensurethat adequate facilities and policeand fireser- vices are mai ntai ned to protect the citizens of Sed Beach. a Oppose offshore oil leasing. Q All City Departments City of Seal Beach General Plan 5-66 (12/03) Safety Element a Partici pate in emergency response exerd ses and opera- tional support for the Emergency Operations Center. Q Police Depatment (in cooperation with the Fire Authority) a Mantan mutual ad arrangementsand hold disaster preparedness exercises. a M a nta ni ng an Emergency Management Coordinator function in the Police Department. Q FireAuthority a Monitor local sources of toxic wastes. a Encourage and support the use ofalternativestotoxic materials. a M a nta n t he perf ormance standard of an average total reflex time of seven minutes or less. a Encourage property owners to create defensi ble space surrounding their homes. a Work with the Water Districts to mantan an adequate supply of water, both for consumptive use and emer- gency f i re-f ighti ng supply. Q Development Servi ces D epa-t meet a Requirethat neN streets have a minimum unobstructed width of 20 feet. a Requirethe undergrounding of utilitiesfor neN devel- opment. a Requiresoilsand geology reportsbased on subsurface explorationsand their independent revieN for neN de- velopment. Maintain these reportson fileand index in the City-s Geographic I nformation System. Restrict de- velopment where there is a geol ogi cal unacceptable level of risk. a Req ui re supervi si on of a soi I s engi neer for grading op- erations. a Enforcebluff and hillside protection measures. a Requireerosion control measuresfor neN development. a Adopt thelatest editionsof the Uniform Building Code, especi a ly i n regards to earthquake standards and fire re- sistive construction. a Prohibit the location of neN essential facilities in geo- logically hazardousareas. a Requi re the latest earthquake standards for neN essential facilities. City of Seal Beach General Plan S-87 (12/03) Safety Element a Encourage property owners to consider "fire -wise planting surrounding thei r homes. a Monitor theeffectsof inland development on the Qty-s watershed and attempt to minimizetheir impacts. a Prohibit theconstruction of structureson thesandy portion of the beach. a Enforcecurrent building setback standardsfrom beaches and bluff tops. Q Engineering Department a Ensurethat new publicfaalitiesor major additionsare designed and located to minimizeor eliminateany po- tential hazard impacts. a Promote and implement safe transport and/ or disposal of hazardous wastes. a Facilitate effective response to haeardousmaterials emergend es. a Facilitatethe proper separation of sewer and storm drai n systems through proper design, i nf rastructure up- grades, and timely maintenance. a Provide for ongoing maintenance and i nspections of ell public drai nage facilities and encou rage property owners to maintain private drainage structures. a Maintain and improve the City-s storm drainageinfra- structure capacity. Ensurethat storm water and drainage arecontained, controlled, and discharged in an appro- priate manner. a Eliminateor mitigate uncontrolled storm drain flow on hillaidesor bluffs. Utilizeonly proven and effectiveero- don control methods after fire disasters. Develop, adopt, and construct flood control plans. Minimizetheir environmental consequences. City of Seal Beach General Plan S- (12J 03)