Flood History

DOE-STD-1022-94

characteristics shall be provided. Only the worst case flood hazard should be summarized in detail. The

summary shall include the proximity of the potential source of flood hazard to the site and include applicable

reasons why certain sources are unlikely or present negligible consequences for the site.

E. For hydrologic events that can pose a hazard, additional data shall be required to perform hazard assessment.

Data sources should include, but not be limited to:

Walkdown of site and vicinity

Topographic maps (site-specific and regional)

Aerial photographs

Hydrologic data (i.e., stream gage data)

Historical flood events reports

Federal Emergency Management Agency's flood insurance studies

Dam break studies

F. The sources of available data include past site-specific hydrological studies by DOE and DOE-sponsored

contractors, studies performed by other government agencies (e.g., U.S. Army Corps of Engineers, U.S.

Bureau of Reclamation, U.S. Geological Survey, Flood Insurance Administration, Department of Water

Resources, Agricultural Department, National Weather Service, etc.,), universities, and private organizations.

G. Sections 5.3.2 to 5.3.11 provide criteria needed to define site specific information for each hydrologic event.

5.3.2 Flood History

A. Local and regional flood history with potential causes of flooding under extreme conditions shall be reported

with date, level, peak discharge, and related information. A flood is defined as an abnormally high water stage

or overflow from a stream, floodway, lake, or coastal area. This includes river floods, surges, seiche, tsunami,

dam failures, ice or debris jams, and floods induced by landslides or similar events. Safety-related structures

should not be built on a floodplain unless this is absolutely necessary.

5.3.3 River Flooding

A. Each river in the regional area of the site that could impact the site shall be identified and characterized with

respect to its location and elevation relative to the site.

B. The boundaries of the region to be investigated for river flooding hazard depends primarily whether the rivers

could cause floods large enough under extreme conditions to contribute to flooding at the site. Regional

investigations shall be conducted for rivers relatively close to the site (in general, rivers with flood plain

boundaries less than a few kilometers from the site).