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HomeMy WebLinkAboutSUP 07-03; REVISION OF FLOOD INSURANCE RATE MAP; 2011-05-18VPRTt 0. NATIONAL FLOOD INSURANCE PROGRAM FEMA PRODUCTION AND TECHNICAL SERVICES CONTRACTOR May 18, 2011 Mr. Wayne W. Chang, M.S., P.E. Chang Consultants Post Office Box 9496 Rancho Santa Fe, CA 92067 Dear Mr. Chang: IN REPLY REFER TO: Case No.: 1 1-09-2580R Communities: Cities of Carlsbad and Oceanside, CA Community Nos.: 060285 and 060294 316-AD This responds to your request dated May 3, 2011, that the Department of Homeland Security's Federal Emergency Management Agency (FEMA) issue a conditional revision to the Flood Insurance Rate Map (FIRM) for San Diego County, California and Incorporated Areas. Pertinent information about the request is listed below. Identifier: South Coast Materials Quarry Levee Certification Flooding Source: Buena Vista Creek FIRM Panel Affected: 06073C0766F The data required to complete our review, which must be submitted within 90 days of the date of this letter, are listed on the enclosed summary. If we do not receive the required data within 90 days, we will suspend our processing of your request. Any data submitted after 90 days will be treated as an original submittal and will be subject to all submittal/payment procedures, including the flat review and processing fee for requests of tis type established by the current fee schedule. A copy of the notice summarizing the current fee schedule, which was published in the Federal Register, is enclosed for your information. FEMA receives a very large volume of requests and cannot maintain inactive requests for an indefinite period of time. Therefore, we are unable to grant extensions for the submission of required data for revision requests. If a requester is informed by letter that additional data are required to complete our review of a request, the data must be submitted within 90 days of the date of the letter. Any fees already paid will be forfeited for any request for which the requested data are not received within 90 days. If you have general questions about your request, FEMA policy, or the National Flood Insurance Program, please call the FEMA Map Information eXchange (FMIX), toll free, at 1-877-FEMA MAP (1-877-336-2627). If you have specific questions concerning your request, please contact your case LOMC Clearinghouse, 7390 Coca Cola Drive, Suite 204, Hanover, MD 21076 PH: 1-877-FEMA MAP BakerAEC0M, under contract with the FEDERAL EMERGENCY MANAGEMENT AGENCY, is a Production and Technical Services Contractor for the National Flood Insurance Program QAP 01-03 reviewer, Ms. Sara DeGroot, by e-mail at sdegrootmbakercorp.com or by telephone at (571) 357-6029, or the Revisions Coordinator for your request, Mr. Joshua Huim, CFM, by e-mail at jhunnmbakercorp.com or by telephone at (571) 357-6088. Sincerely, Syed Qayum, CFM LOMR Technical Manager BakerAECOM Enclosures cc: Mr. Glen K. Van Peski City Engineer City of Carlsbad Mr. Don Hadley Interim Director of Public Works City of Oceanside NATIONAL FLOOD INSURANCE PROGRAM. FEMA PRoDucnoN AND TECHNICAL.. SERVICES Com\croR Summary of Additional Data Required to Support a Conditional Letter of Map Revision (CLOMR) Case No.: 11-09-2508R Requester: Mr. Wayne W. Chang, M.S., P.E. Communities: Cities of Carlsbad and Community Nos.: 060285 and 060294 Oceanside, CA The issues listed below must be addressed before we can continue the review of your request. Our review of your request revealed that the City of Oceanside is affected by this revision. Please provide community acknowledgment in the form of a letter stating that the city has reviewed the revision request and understands the effects of the revision on flooding conditions in the community, and that any existing or proposed structures to be removed from the Special Flood Hazard Area (SFHA), the area subject to inundation by the base (1-percent-annual-chance) flood, are reasonably - safe from flooding. Alternatively, please submit Application/Certification Form I, entitled "Overview & Concurrence Form," signed by a city official. This CLOMR request will be processed by the Federal Emergency Management Agency (FEMA) only after FEMA receives documentation from the requestor that demonstrates compliance with the Endangered Species Act (ESA). The requestor must demonstrate ESA compliance by submitting to FEMA either an Incidental Take Permit, an Incidental Take Statement, a "not likely to adversely affect" determination from the National Marine Fisheries Service or the US Fish and Wildlife Service (collectively known as "the Services"), or an official letter from the Services concurring that the project has "No Effect" on listed species or critical habitat. If the project is likely to cause jeopardy or adverse modification to species, then FEMA may deny the CLOMR request. Please see the enclosed guidance for additional information about the ESA and compliance requirements and for responses to frequently asked questions. Please submit preliminary design plans or drawings, certified by a registered professional engineer, that represent the proposed levee along Buena Vista Creek. These plans should include, but are not limited to, legible topographic information, levee elevations, location and dimensions of any structures, pipes and utilities crossing the levee, and any other pertinent information relative to how the levee was modeled in the HEC-RAS analysis. Please provide a profile that includes the currently effective Base Flood Elevation and levee crest (top of levee) elevation for the length of the proposed levee. This profile should also include topographic information at the upstream and downstream ends of the proposed levee to show the tie-in to high ground. Please send the required data directly to us at the address shown at the bottom of this page. For identification purposes, please include the case number referenced above on all correspondence. LOMC Clearinghouse, 7390 Coca Cola Drive, Suite 204, Hanover, MD 21076 PH: 1-877-FEMA MAP BakerAECOM, under contract with the FEDERAL EMERGENCY MANAGEMENT AGENCY, is a Production and Technical Services Contractor for the National Flood Insurance Program §65.10 a reissuance or revision of the flood in- surance study or maps and will be de- ferred until such time as a significant change occurs; An additional 90 days is required to evaluate the scientific or technical data submitted; or Additional data are required to support the revision request. The required payment has not been submitted in accordance with 44 CFR part 72, no review will be con- ducted and no determination will be issued until payment is received. (51 FR 30315, Aug. 25, 1986; 61 FR 46331, Aug. 30, 1996, as amended at 62 FR 5736, Feb. 6, 19971 §65.10 Mapping of areas protected by levee systems. General. For purposes of the NFIP, FEMA will only recognize in its flood hazard and risk mapping effort those levee systems that meet, and continue to meet, minimum design, operation, and maintenance standards that are consistent with the level of protection sought through the comprehensive flood plain management criteria estab- lished by §60.3 of this subchapter. Ac- cordingly, this section describes the types of information FEMA needs to recognize, on NFIP maps, that a levee system provides protection from the base flood. This information must be supplied to FEMA by the community or other party seeking recognition of such a levee system at the time a flood risk study or restudy is conducted, when a map revision under the provi- sions of part 65 of this subchapter is sought based on a levee system, and upon request by the Administrator dur- ing the review of previously recognized structures. The FEMA review will be for the sole purpose of establishing ap- propriate risk zone determinations for NFIP maps and shall not constitute a determination by FEMA as to how a structure or system will perform in a flood event. Design criteria. For levees to be recognized by FEMA, evidence that adequate design and operation and maintenance systems are in place to provide reasonable assurance that pro- tection from the base flood exists must be provided. The following require- ments must be met: 44 CFR Ch. I (10-1-02 Edition) (1) Freeboard. (i) Riverine levees must provide a minimum freeboard of three feet above the water-surface level of the base flood. An additional one foot above the minimum is required within 100 feet in either side of structures (such as bridges) riverward of the levee or wherever the flow is constricted. An additional one-half foot above the min- imum at the upstream end of the levee, tapering to not less than the minimum at the downstream end of the levee, is also required. Occasionally, exceptions to the minimum riverine freeboard require- ment described in paragraph (b)(1)(i) of this section, may be approved. Appro- priate engineering analyses dem- onstrating adequate protection with a lesser freeboard must be submitted to support a request for such an excep- tion. The material presented must evaluate the uncertainty in the esti- mated base flood elevation profile and include, but not necessarily be limited to an assessment of statistical con- fidence limits of the 100-year discharge; changes in stage-discharge relation- ships; and the sources, potential, and magnitude of debris, sediment, and ice accumulation. It must be also shown that the levee will remain structurally stable during the base flood when such additional loading considerations are imposed. Under no circumstances will freeboard of less than two feet be ac- cepted. For coastal levees, the freeboard must be established at one foot above the height of the one percent wave or the maximum wave runup (whichever is greater) associated with the 100-year stillwater surge elevation at the site. Occasionally, exceptions to the minimum coastal levee freeboard re- quirement described in paragraph (b)(1)(iii) of this section, may be ap- proved. Appropriate engineering anal- yses demonstrating adequate protec- tion with a lesser freeboard must be submitted to support a request for such an exception. The material presented must evaluate the uncertainty in the estimated base flood loading condi- tions. Particular emphasis must be placed on the effects of wave attack and overtopping on the stability of the levee. Under no circumstances, how- ever, will a freeboard of less than two 346 Federal Emergency Management Agency §65.10 feet above the 100-year stiliwater surge elevation be accepted. Closures. All openings must be pro- vided with closure devices that are structural parts of the system during operation and design according to sound engineering practice. Embankment protection. Engineer- ing analyses must be submitted that demonstrate that no appreciable ero- sion of the levee embankment can be expected during the base flood, as a re- sult of either currents or waves, and that anticipated erosion will not result in failure of the levee embankment or foundation directly or indirectly through reduction of the seepage path and subsequent instability. The factors to be addressed in such analyses in- clude, but are not limited to: Expected flow velocities (especially in con- stricted areas): expected wind and wave action; ice loading; impact of debris; slope protection techniques; duration of flooding at various stages and ve- locities; embankment and foundation materials; levee alignment, bends, and transitions; and levee side slopes. Embankment and foundation sta- bility. Engineering analyses that evalu- ate levee embankment stability must be submitted. The analyses provided shall evaluate expected seepage during loading conditions associated with the base flood and shall demonstrate that seepage into or through the levee foun- dation and embankment will not jeop- ardize embankment or foundation sta- bility. An alternative analysis dem- onstrating that the levee is designed and constructed for stability against loading conditons for Case IV as de- fined in the U.S. Army Corps of Engi- neers (COE) manual, "Design and Con- struction of Levees" (EM 1110-2-1913, Chapter 6, Section II), may be used. The factors that shall be addressed in the analyses include: Depth of flooding, duration of flooding, embankment ge- ometry and length of seepage path at critical locations, embankment and foundation materials, embankment compaction, penetrations, other design factors affecting seepage (such as drainage layers), and other design fac- tors affecting embankment and founda- tion stability (such as berms). Settlement. Engineering analyses must be submitted that assess the p0- tential and magnitude of future losses of freeboard as a result of levee settle- ment and demonstrate that freeboard will be maintained within the min- imum standards set forth in paragraph (b)(1) of this section. This analysis must address embankment loads, com- pressibility of embankment soils, com- pressibility of foundation soils, age of the levee system, and construction compaction methods. In addition, de- tailed settlement analysis using prose- dares such as those described in the COE manual, "Soil Mechanics Design— Settlement Analysis" (EM 1100-2-1904) must be submitted. Interior drainage. An analysis must be submitted that identifies the source(s) of such flooding, the extent of the flooded area, and, if the average depth is greater than one foot, the water-surface elevation(s) of the base flood. This analysis must be based on the joint probability of interior and ex- terior flooding and the capacity of fa- cilities (such as drainage lines and pumps) for evacuating interior flood- waters. Other design criteria. In unique sit- uations, such as those where the levee system has relatively high vulner- ability, FEMA may require that other design criteria and analyses be sub- mitted to show that the levees provide adequate protection. In such situa- tions, sound engineering practice will be the standard on which FEMA will base its determinations. FEMA will also provide the rationale for requiring this additional information. (c) Operation plans and criteria. For a levee system to be recognized, the operational criteria must be as de- scribed below. All closure devices or mechanical systems for internal drain- age, whether manual or automatic, must be operated in accordance with an officially adopted operation manual, a copy of which must be provided to FEMA by the operator when levee or drainage system recognition is being sought or when the manual for a pre- viously recognized system is revised in any manner. All operations must be under the jurisdiction of a Federal or State agency, an agency created by Federal or State law, or an agency of a community participating in the NFIP. 347 §65.11 (1) Closures. Operation plans for clo- sures must include the following: Documentation of the flood warn- ing system, under the jurisdiction of Federal, State, or community officials, that will be used to trigger emergency operation activities and demonstration that sufficient flood warning time ex- ists for the completed operation of all closure structures, including necessary sealing, before floodwaters reach the base of the closure. A formal plan of operation in- cluding specific actions and assign- ments of responsibility by individual name or title. (Hi) Provisions for periodic oper- ation, at not less than one-year inter- vals, of the closure structure for test- ing and training purposes. (2) Interior drainage systems. Interior drainage systems associated with levee systems usually include storage areas, gravity outlets, pumping stations, or a combination thereof. These drainage systems will be recognized by FEMA on NFIP maps for flood protection pur- poses only if the following minimum criteria are included in the operation plan: Documentation of the flood warn- ing system, under the jurisdiction of Federal, State, or community officials, that will be used to trigger emergency operation activities and demonstration that sufficient flood warning time ex- ists to permit activation of mechanized portions of the drainage system. A formal plan of operation in- cluding specific actions and assign- ments of responsibility by individual name or title. Provision for manual backup for the activation of automatic systems. Provisions for periodic inspection of interior drainage systems and peri- odic operation of any mechanized por- tions for testing and training purposes. No more than one year shall elapse be- tween either the inspections or the op- erations. (3) Other operation plans and criteria. Other operating plans and criteria may be required by FEMA to ensure that adequate protection is provided in spe- cific situations. In such cases, sound emergency management practice will be the standard upon which FEMA de- terminations will be based. 44 CFR Ch. I (10-1-02 Edition) Maintenance plans and criteria. For levee systems to be recognized as pro- viding protection from the base flood, the maintenance criteria must be as described herein. Levee systems must be maintained in accordance with an officially adopted maintenance plan, and a copy of this plan must be pro- vided to FEMA by the owner of the levee system when recognition is being sought or when the plan for a pre- viously recognized system is revised in any manner. All maintenance activi- ties must be under the jurisdiction of a Federal or State agency, an agency created by Federal or State law, or an agency of a community participating in the NFIP that must assume ulti- mate responsibility for maintenance. This plan must document the formal procedure that ensures that the sta- bility, height, and overall integrity of the levee and its associated structures and systems are maintained. At a min- imum, maintenance plans shall specify the maintenance activities to be per- formed, the frequency of their perform- ance, and the person by name or title responsible for their performance. Certification requirements. Data submitted to support that a given levee system complies with the structural requirements set forth in paragraphs (b)(1) through (7) of this section must be certified by a registered professional engineer. Also, certified as-built plans of the levee must be submitted. Certifi- cations are subject to the definition given at §65.2 of this subchapter. In lieu of these structural requirements, a Federal agency with responsibility for levee design may certify that the levee has been adequately designed and con- structed to provide protection against the base flood. [51 FR 30316, Aug. 25, 1986] §65.11 Evaluation of sand dunes in mapping coastal flood hazard areas. (a) General conditions. For purposes of the NFIP, FEMA will consider storm- induced dune erosion potential in its determination of coastal flood hazards and risk mapping efforts. The criterion to be used in the evaluation of dune erosion will apply to primary frontal dunes as defined in §59.1, but does not 348