On January 24th, GZA's Chad W. Cox, P.E. and Daniel C. Stapleton, P.E. presented a Breakfast Seminar at the Harvard Club in Boston on "Flood Hazards in the Urban Environment: Implications for Developers, Designers and Attorneys".
Recent storms such as “Superstorm Sandy” have demonstrated the potential impacts to urban communities due to flooding, and the importance of defining and mitigating flood risk. Climate change, including increases in sea level and the occurrence of intense coastal storms and extreme precipitation events, will result in greater impacts in the future than historically experienced. Boston is ranked nationally among major cities as having the 5th greatest risk of flood impact based on flood risk and effects. Further, recent changes to the National Flood Insurance Program, including proposed changes to the Flood Insurance Rate Maps and increases to the flood insurance rates (Biggert-Waters Act 2012), will increase the cost of flood insurance.
GZA’s presentation provided a summary of the key concepts needed to
understand and assess flood risks. These include the types of riverine
and coastal mechanisms which can initiate flooding, including large storms,
rain-on-snow events, local intense precipitation, coastal storm surge, wave
action, and others. The concepts of return period (i.e., the “100-year
flood”) and risk were discussed. This presentation also included
a discussion of FEMA Flood Insurance Rate Maps (FIRMs) and their application to:
a) site selection, site design and construction per the Building Code; and b)
establishment of flood insurance rates. The use of information generated by
FEMA was summarized, along with the types of information that can be
derived from newer computer models which provide detailed site-specific
information for high value or critical facilities. Finally, the effects
of global climate change on local flood risks was considered.