Using Multi-Objective Management to Reduce Flood Losses in Your

Habitat Evaluation Procedure: A method developed by the U.S. Fish and
Wildlife Service that evaluates the suitability of wetlands and other habitat types
for fish and wildlife species.
HEP: Habitat Evaluation Procedure.
HUD: U.S. Department of Housing and Urban Development.
Human intervention: A person must be present at the flood-prone site to close
an opening or install or operate a protection device so that the measure will
prevent flood damage.
Hydraulics: The science dealing with the mechanical properties of liquids; it
describes the pattern and rate of water movement.
Hydrology: The science dealing with the waters of the earth. A flood discharge
is developed by a hydrologic study.
Jetty: A structure built perpendicular to the shoreline at inlets to prevent littoral
drift from filling the inlet and to provide protection for navigation.
Littoral: Of or pertaining to the shore, especially of the sea.
Littoral drift: The movement of sand by littoral (longshore) currents in a
direction generally parallel to the beach along the shore.
Mean high water: The average height of the maximum elevation reached by each
rising tide over a specific 19-year period.
Mean low water: The average height of the minimum elevation reached by each
falling tide over a specific 19-year period. All depth measurements in coastal
waters and all depths shown on navigation charts are referenced to MLW.
Mean sea level: The arithmetic mean of hourly heights observed over a specific
19-year period.
Mitigation: (1) Any action taken to permanently eliminate or reduce the longterm
risk to human life and property and the negative impacts on natural and
cultural resources that can be caused by natural and technological hazards. (2) An
action that compensates for the impact of development on a wetland.
NAVD: North American Vertical Datum (see “datum”).
NFIP: National Flood Insurance Program administered by the Federal Emergency
Management Agency’s Federal Insurance Administration.
NGVD: National Geodetic Vertical Datum of 1929, the national datum used by
the National Flood Insurance Program. NGVD is based on mean sea level. It was
known formerly as the “Mean Sea Level Datum of 1929 (MSL).”
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