FEMA provides a 90-day appeal and comment period for new or revised Base Flood Elevations (BFEs), flood hazard zones, and or floodway boundaries. The University of Connecticut, nor the Department of Marine Sciences, makes no warranty, expressed or implied, as to the accuracy, completeness, or utility of this information, nor does the fact of distribution constitute a warranty.When a preliminary flood map becomes available, some residents, business owners, developers and others may disagree with the flood risk shown in certain areas. Attempts have been made to ensure that this data or documentation is accurate and reliable The University of Connecticut, nor the Department of Marine Sciences, does not assume liability for any damages caused by inaccuracies in this data or documentation, or as a result of the failure of the data or software to function in a particular manner. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user. CIRCA continues to work on developing total water level flood maps that include wave data for the Connecticut coast and will update tools as new information becomes available. Wave-related splash over along the Connecticut shoreline requires smaller-scale resolution modeling. The FVCOM modeled data only displays storm surge while FEMA maps incorporate both surge and waves.The FVCOM model has higher accuracy in predicting storm surge levels. The modeled data is calibrated for Long Island Sound to capture the complexity of Connecticut’s geology and landscapes and improve accuracy for effective flood risk design.It is important to note that the 100 year flood event layer in this tool is different from FEMA’s 100 year flood map boundary for a few reasons: The vertical datum for all the datasets is NAVD88. The anticipated sea level of 20 inches by 2050 is also added to these different flood events using the same data described in the paragraph above (2016 LiDAR topographic data). The return period of the storm events is presented as 10, 30, 100, and 500 year flood events or 10%, 3.33%, 1%, and 0.2% annual exceedance probability storms, respectively. The floodwater elevation for the different return periods is calculated empirically using a Poisson-GPD fit. This model is calibrated for Long Island Sound to capture the complexity of Connecticut’s geology and landscapes and improve accuracy for effective flood risk design. The second set of data, is the modeled storm surge water levels using coupled coastal circulation and wave model (FVCOM-SWAVE, finite-volume coastal ocean model with the version of the Simulating Wave Nearshore) to hindcast the 44 highest storms between 1950-2018. These low-lying areas need further evaluation due to the hydrologic complexity created by flood control structures, bridges, and culverts. High probability areas of inundation are color shaded blue as well as low-lying areas, which are all shaded yellow. The Mean Higher High Water (MHWW) and 1 foot and 20 inches sea level rise layers are the modeled tidal water surface that has been created using VDatum (NOAA) and 2016 LiDAR topographic data. Two different sets of data are presented in the viewer. View Map Full Screen Data Description and Usage Click here to learn more about the FEMA Region 1 Viewer. The LiMWA line in this CIRCA viewer was updated in December 2021 to reflect FEMA’s LiMWA Viewer release for New England states, including Connecticut. Any area seaward of the red LiMWA line is either coastal AE or VE zone and must meet new construction requirements outlined in the updated state building code. The coastal AE Zone is depicted on current effective flood insurance rate maps (FIRMs) with the landward limit of the zone labeled “Limit of Moderate Wave Action”. Different projections of sea-level rise/storm surge scenarios will activate automatically at different scales.įEMA’s Limit of Moderate Wave Action (LIMWA) boundary is also shown on this viewer as a continuous red line. Use the Layers menu widget at the bottom of the map window to select data to display. To view the data, zoom in on the map to your area of interest. 7, which was introduced into the 2018 legislative session and was enacted into law as Public Act 18-82. CIRCA’s report on Connecticut sea level rise provided the basis for projections in Bill S.B. CIRCA research recommends that planning anticipates sea level will be 20 inches higher than the national tidal datum in Long Island Sound by 2050. This dataset shows different flood maps with sea-level rise projections (1 foot and 20 inches), above the North American Vertical Datum of 1988 (NAVD88) along the Connecticut coastline and the adjacent inland.
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