BOARD01669

• Board Meeting Date: 1/14/1970
• Description: Agenda or Table of Contents, Minutes, Memos
• Board Meetings - Doc Type: Meeting

MR. TEN EYCR:

MR. SPARKS:

MR. TEN EYCR:

MR. STAPLETON:

hazard area. The Corps in its report reports
on two areas. the intermediate flood hazard
and the so-called standard floods. A standard
flood is one which is likely never to occur.
or perhaps once in a thousand years. We have
had no actual experience with standard floods. I
The one that is likely to occur and has
occurred in the past is the intermediate
flood. Therefore the staff recommends that
those portions of the reports which designate
flood hazard areas in the intermediate flood
zone be approved for zoning. This Board has
no authority to zone. We merely establish
areas in which the local authorities can zone
any or all of the area designated by this
Board at their option."

"Mr. Chairman. I'd like to ask Larry to
tell us what frequency flood does this normally
amount to. the intermediate flood plain?"

"You could say once in a hundred years.
However. mathematical calculations are danger-
ous with reference to floods because once in
a hundred years may happen ten years in a row.
This is the problem. The intermediate flood
is one that we have had experience with.
Therefore we say that it may occur next year
or the year after or at any time.

The standard flood is a flood computed
from rainfall of record at a particular point
and spreading it over the entire drainage
area. That is, we take an eight-inch rainfall
some place in the South Platte drainage and
say that this might occur simultaneously over
the entire drainage basin. This is a most
remote possibility.

I

The intermediate is one that we know has
occurred and is almost certain to occur again."

"Thank you."

"How many requests have we now acted upon?