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<br />Tuesday, May 19 1:30 - 3 :00 PM Trac:k 7 - NFIP Mapping Issues - Moderator: Carl Walt
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<br />REL\TING HEC COMPUTER PROGRAMS TO FEMA MAPS
<br />Lynn Lovell, P,E
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<br />The purpose of this paper is to provid" an overview of the relationship between the technical data (predominately FlEC programs) that is
<br />generated for flood insurance studies (PIS) and the final Federal Emergency Management Agency (FEMA) FIRM maps that are distributed
<br />to the public, The presentation will be aimed primarily at the city or county floodplain administrator who needs only a cursory knowledge
<br />of these programs, but needs an understanding of the basis of the mapped data. The fundamental contents of this paper was used for a training
<br />session for floodplain administrators at the 1997 Texas Floodplain Managers Association annual Texas Flood Conference, A brief overview
<br />of the various hydrologic and hydraulic models that are being used by FEMA technical contractors will be presented. Examples of the
<br />technical elements (such as profiles, cro"s sections, floodways) that are generated and used to produce the FIRM data will be shown, How
<br />those technical elements become the information shown on a community FIRM, in a conditional or final LOMR, or in a FIS will be
<br />demonstrated with actual examples,
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<br />COJ\lIPARISON OF FEQ AND STEADY-STATE MODELLING
<br />Cleighton D, Smith
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<br />The llIinois Department of Natural Resources, Office of Water Resources (IDNR-OWR), along with their consultant Christopher B, Burke
<br />Engineering Ltd, (CBBEL), recently completed a restudy of the Upper Salt Creek regulatory floodplain, The restudy effort was initiated
<br />in 1988, using FEQ methodology, At the time IDNR-OWR was hopeful that FEQ would soon be accepted by the Federal Emergency
<br />Management Agency (FEMA). This did not happen and in 1995, IDNR-OWR changed to steady-state methodology (HEC-I and HEC-2)
<br />to complete the restudy effort. However, some components of the FEQ analysis were used in the steady-state effort. FEQ was used to route
<br />flows through each of the six major flood control structures in the 52-square-miIe Upper Salt Creek watershed, The basis for this modelling
<br />effort was the remnants of the abandoned, FEQ modeL Six "mini" FEQ models were created representing the storage effects of each structure,
<br />FlEC-l hydrographs were generated at the upstream end of the structure and stored in a HEC-DSS file. The FEQ model of the structure
<br />reads the HEC-DSS file as inflow, performs the routing analysis, and writes the outflow to a separate HEC-DSS file. The HEC-l file of
<br />the area downstream of the structure reads the HEC-DSS file containing the FEQ output as input to the downstream area, The regulatory
<br />flows were generated using this methodology. These regulatory flows were input into HEC-2 to generate the base flood elevations
<br />throughout the floodplain. Therefore, the FEQ results were not used to report base flood elevations, but were used in essence as a routing
<br />toot FEMA has recently accepted FEQ on a conditional basis. FEMA has a few remaining concerns regarding FEQ's handling of certain
<br />types of culvert flow. Therefore, FEQ submittals currently require a steady-state comparison for areas where culvert flow is modelled, This
<br />paper looks at FEQ vs steady-state comparison oflhree culverts which are components offlood control structures in the Village of Palatine.
<br />This comparison was required by FEMA as part of their review of a Letter of Map Revision (LOMR) for Palatine based on the Upper Salt
<br />Creek restudy, FEMA's review of this comparison is currently pending.
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<br />AR FLOOD CONTROL RESTORATION ZONE
<br />Karl Mohr and Marty Youmans
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<br />On July 6, 1998, the inaugural Flood Insurance Rate Maps showing the AR flood control restoration zone will take effect. Zone AR is a
<br />new Special Flood Hazard Area designation that may be used in areas where a Federal flood control system that once provided base flood
<br />protection has been shown to no longer provide that level of protection. The Zone AR rule sets forth the regulatory framework for restoring
<br />flood control projects to a level of base flood protection, The rule reflects an intent to make a partner in local efforts to restore base flood
<br />protection effectively, expeditiously, and in accordance with NFIP regulations, while establishing minimum floodplain management and flood
<br />insurance criteria in Zone AR while project restoration proceeds.
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<br />Communities in the Los Angeles and Sacramento areas will be the initial recipients of the Zone AR designation, and the implications of the
<br />flood zone in these areas are significant. Residents and community officials are resistant to the FIRMs designated floodplains, and
<br />secondarily because they feel it is unfair to impose the new floodplains where flood protection will soon be restored. FEMA is launching
<br />an intensive public information program directed toward community oficials, lenders, insurance agents and residents. The campaign focuses
<br />on the importance of purchasing flood insurance, the flood insurance and development requirements in Zone AR and FEMA' s commitroent
<br />to WOlX with communities throughout dle levee restoration process. This paper will focus on Zone AR's legislative origin, the floodplain
<br />management and flood insurance bene:5ts and requirements in Zone AR, the implications of the Zone AR designation in the Los Angeles
<br />and Sacramento areas and FEMA's inJormation campaign,
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