BOARD01033

• Board Meeting Date: 11/13/1963
• Description: Minutes
• Board Meetings - Doc Type: Meeting

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I

Sediment is not an unmixed blessing. The
farmers of the Arkansas Valley have been fight-
ing the sediment problem since they began
irrigating. The deposition of silt along the
upper reaches of the Fort Lyon and the Amity,
for example, have presented problems requiring
dredging and the construction of waste gates
and sand traps designed to draw the sediment
burden out of the water and return it to the
river. These are all expensive and necessary
operations. Land leveling is necessitated by
silt deposition along the farmer's laterals
and this is an approved conservation practice
in the Arkansas Valley under the Agriculture
Department programs and thousands upon thou-
sands of dollars have been spent for this
activity.

So much for silt. How about the fertil-
ity content of the water effected? It is
submitted that by and large the plant food
contained in silt will be dissolved in the
water and that the water with a reduced silt
content will carry substantially the same
fertilization value as water heavily silt
laden. To the extent that plant food may be
contained in organic or colloidal particles
carried in suspension, it should be pointed
out that this is a variable thing. Much of
the silt burden in the water is sterile sand
and the removal of the sand is a benefit to
the water. Whether or not particles carried
in suspension in the water are part of the
sediment burden carrying fertility depends
upon where the flood originated or where the
water originated, what type of soil it fell
on that produced the erosion that produced
this silt burden.

I

Opponents of a permanent pool argue in
opposition that siltation above the dam will
be increased. This is undoubtedly true but I
think it requires some examination to determine
the magnitude and significance of this objec-
tion. First it should be noted that the silt
that is produced is a product of erosion and