BOARD02598

• Board Meeting Date: 9/18/1974
• Description: Agenda or Table of Contents, Minutes
• Board Meetings - Doc Type: Meeting

delineation. In addition, when you are delineating the floodplain
itself, the intermediate regional floodplain, I think that it is impor-
tant for the hydrologist and the engineer and a planner to include
debris blockage of bridges. It is a fact of life. I don't know of any
stream that the debris blockage does not occur in. I know that the
Corps of Engineers ignores this at this time because, they feel it is a I
very difficult thing to study. But on the other hand, in their flood-
plain information reports they do say, 'vatch out for debris because
this can plug your bridges." I believe that some selection of a criteria,
such as maybe a fifty percent blockage of bridges would be assumed unless
it was demonstrated that this particular stream did not have a debris
problem, and then under those cases it could be less or no debris
blockage at all.

A third point which I think is very important and which is consistent
with flood insurance agency, floodplain management department, is to
limit the encroachment of the floodplains to no more than about fifteen
percent. Let's go back to the half foot deep, one mile floodplain
business and under this regulation we could have a.substantial amount
of filling, and of course, we all know then that the floodwaters would
rise, flood new lands, plus also flood the buildings that are already
built one foot above the floodwaters. Well, the flood insurance agency
feels that there should be no more encroachment under a floodplain than
is reasonable. They think in terms of reasonable as being perhaps
fifteen percent or the kind of encroachment that would not increase the
floods downstream by more than about five percent, maybe sometimes as
high as ten percent. Remember that when we are filling the flood fringe
area we are filling flood storage area. When you fill flood storage
area the floods do not have the opportunity to spread out and therefore
there is greater water concentration '.in the .center part and this does
increase floods downstream. And I think it is something that we have
to acknowledge.

Another recommendation. And this relates to Mr. Sparks'$280,000 esti-
mate. I feel that there should be some good lobbying work done in the
legislature for more funding than the $280,000. I see the job in front
of you as being a very costly one. I know that I would certainly support
dipping into the state surplus to some extent for this kind of fine work
that benefits people allover the state.

I also reel that you have a good floodplain engineer in the form of
Larry Lang and I would certainly recommend that he gets all the support
he needs to carry this program forward.

And finally, I caution you not to give up too much of the hard fought
and hard won land use control ,over the floodplains by making the low
hazard area too wide, too lenient, and perhaps too many exceptions in
the floodplain regulation.

I

Just a comment on one of the questions that came up during questioning
from the board, its relationship to 'the changing of the floodplain.
Mr. Sparks is absolutely right concerning the fact that the floodplain

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